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Recourses to article 21.5 of the DSU by the United States – Reports of the Panels

CASES CITED IN THESE REPORTS

Short TitleFull Case Title and Citation
Brazil – Aircraft (Article 21.5 – Canada) Appellate Body Report, Brazil – Export Financing Programme for Aircraft – Recourse by Canada to Article 21.5 of the DSU, WT/DS46/AB/RW, adopted 4 August 2000, DSR 2000:VIII, p. 4067
Canada – Renewable Energy / Canada – Feed-in Tariff Program Panel Reports, Canada – Certain Measures Affecting the Renewable Energy Generation Sector / Canada – Measures Relating to the Feed-in Tariff Program, WT/DS412/R and Add.1 / WT/DS426/R and Add.1, adopted 24 May 2013, as modified by Appellate Body Reports WT/DS412/AB/R / WT/DS426/AB/R, DSR 2013:I, p. 237
Canada – Dairy (Article 21.5 – New Zealand and US) Panel Report, Canada – Measures Affecting the Importation of Milk and the Exportation of Dairy Products – Recourse to Article 21.5 of the DSU by New Zealand and the United States, WT/DS103/RW, WT/DS113/RW, adopted 18 December 2001, as reversed by Appellate Body Report WT/DS103/AB/RW, WT/DS113/AB/RW, DSR 2001:XIII, p. 6865
EU – Biodiesel (Argentina) Appellate Body Report, European Union – Anti-Dumping Measures on Biodiesel from Argentina, WT/DS473/AB/R and Add.1, adopted 26 October 2016
EC – Hormones Appellate Body Report, EC Measures Concerning Meat and Meat Products (Hormones), WT/DS26/AB/R, WT/DS48/AB/R, adopted 13 February 1998, DSR 1998:I, p. 135
EC and certain member States – Large Civil Aircraft Appellate Body Report, European Communities and Certain Member States – Measures Affecting Trade in Large Civil Aircraft, WT/DS316/AB/R, adopted 1 June 2011, DSR 2011:I, p. 7
EC – Seal Products Panel Reports, European Communities – Measures Prohibiting the Importation and Marketing of Seal Products, WT/DS400/R and Add.1 / WT/DS401/R and Add.1, adopted 18 June 2014, as modified by Appellate Body Reports WT/DS400/AB/R / WT/DS401/AB/R, DSR 2014:II, p. 365
Japan – Apples Appellate Body Report, Japan – Measures Affecting the Importation of Apples, WT/DS245/AB/R, adopted 10 December 2003, DSR 2003:IX, p. 4391
Japan – DRAMs (Korea) Appellate Body Report, Japan – Countervailing Duties on Dynamic Random Access Memories from Korea, WT/DS336/AB/R and Corr.1, adopted 17 December 2007, DSR 2007:VII, p. 2703
Mexico – Corn Syrup (Article 21.5 – US) Appellate Body Report, Mexico – Anti-Dumping Investigation of High Fructose Corn Syrup (HFCS) from the United States – Recourse to Article 21.5 of the DSUby the United States, WT/DS132/AB/RW, adopted 21 November 2001, DSR 2001:XIII, p. 6675
US – Clove Cigarettes Appellate Body Report, United States – Measures Affecting the Production and Sale of Clove Cigarettes, WT/DS406/AB/R, adopted 24 April 2012, DSR 2012: XI, p. 5751
US – Continued Suspension Appellate Body Report, United States – Continued Suspension of Obligations in the EC – Hormones Dispute, WT/DS320/AB/R, adopted 14 November 2008, DSR 2008:X, p. 3507
US – Continued Suspension Panel Report, United States – Continued Suspension of Obligations in the EC – Hormones Dispute, WT/DS320/R and Add.1 to Add.7, adopted 14 November 2008, as modified by Appellate Body Report WT/DS320/AB/R, DSR 2008:XI, p. 3891
US – Continued Zeroing Panel Report, United States – Continued Existence and Application of Zeroing Methodology, WT/DS350/R, adopted 19 February 2009, as modified as Appellate Body Report WT/DS350/AB/R, DSR 2009:III, p. 1481
US – COOL (Article 21.5 – Canada and Mexico) Panel Reports, United States – Certain Country of Origin Labelling (COOL) Requirements – Recourse to Article 21.5 of the DSU by Canada and Mexico, WT/DS384/RW and Add.1 / WT/DS386/RW and Add.1, adopted 29 May 2015, as modified by Appellate Body Reports WT/DS384/AB/RW / WT/DS386/AB/RW
US – Gasoline Appellate Body Report, United States – Standards for Reformulated and Conventional Gasoline, WT/DS2/AB/R, adopted 20 May 1996, DSR 1996:I, p. 3
US – Shrimp Appellate Body Report, United States – Import Prohibition of Certain Shrimp and Shrimp Products, WT/DS58/AB/R, adopted 6 November 1998, DSR 1998:VII, p. 2755
US – Softwood Lumber VI (Article 21.5 – Canada), Appellate Body Report, United States – Investigation of the International Trade Commission in Softwood Lumber from Canada – Recourse to Article 21.5 of the DSU by Canada, WT/DS277/AB/RW, adopted 9 May 2006, and Corr.1, DSR 2006:XI, p. 4865
US – Tax Incentives Panel Report, United States – Conditional Tax Incentives for Large Civil Aircraft, WT/DS487/R and Add.1, circulated to WTO Members 28 November 2016 (appealed by the United States 16 December 2016)
US – Tuna II (Mexico) Appellate Body Report, United States – Measures Concerning the Importation, Marketing and Sale of Tuna and Tuna Products, WT/DS381/AB/R, adopted 13 June 2012, DSR 2012:IV, p. 1837
US – Tuna II (Mexico) Panel Report, United States – Measures Concerning the Importation, Marketing and Sale of Tuna and Tuna Products, WT/DS381/R, adopted 13 June 2012, as modified by Appellate Body Report WT/DS381/AB/R, DSR 2012:IV, p. 2013
US – Tuna II (Mexico) (Article 21.5 – Mexico) Appellate Body Report, United States – Measures Concerning the Importation, Marketing and Sale of Tuna and Tuna Products – Recourse to Article 21.5 of the DSU by Mexico, WT/DS381/AB/RW and Add.1, adopted 3 December 2015
US – Tuna II (Mexico) (Article 21.5 – Mexico) Panel Report, United States – Measures Concerning the Importation, Marketing and Sale of Tuna and Tuna Products – Recourse to Article 21.5 of the DSU by Mexico, WT/DS381/RW, Add.1 and Corr.1, adopted 3 December 2015, as modified by Appellate Body Report WT/DS381/AB/RW
US – Tuna II (Mexico) (Article 22.6 – US) Decision by the Arbitrator, United States – Measures Concerning the Importation, Marketing and Sale of Tuna and Tuna Products – Recourse to Article 22.6 of the DSU by the United States, WT/DS381/ARB, 25 April 2017
US – Upland Cotton (Article 21.5 – Brazil) Panel Report, United States – Subsidies on Upland Cotton – Recourse to Article 21.5 of the DSU by Brazil, WT/DS267/RW and Corr.1, adopted 20 June 2008, as modified by Appellate Body Report WT/DS267/AB/RW, DSR 2008:III, p. 997
US – Wool Shirts and Blouses Appellate Body Report, United States – Measure Affecting Imports of Woven Wool Shirts and Blouses from India, WT/DS33/AB/R, adopted 23 May 1997, and Corr.1, DSR 1997:I, p. 323

ABBREVIATIONS

Abbreviation Description
2016 Rule Enhanced Document Requirements and Captain Training Requirements to Support Use of the Dolphin Safe Label on Tuna Products, 81 Fed. Reg. 15,444 (March 23, 2016)
2013 Rule Enhanced Document Requirements to Support Use of the Dolphin Safe Label on Tuna Products, 78 Fed. Reg. 40,997 (July 9, 2013)
AIDCP Agreement on the International Dolphin Conservation Program
BCI Business confidential information
BPUE Bycatch per unit of effort
CFR Code of Federal Regulations
DMLs Dolphin Mortality Limits
DPCIA Dolphin Protection Consumer Information Act
DSB Dispute Settlement Body
DSU Understanding on Rules and Procedures Governing the Settlement of Disputes
EEZs Exclusive Economic Zones
EII Earth Island Institute
EPO Eastern Pacific Ocean
ETAO Eastern Tropical Atlantic Ocean
ETP Eastern Tropical Pacific
FAD Fish Aggregating Device
FAO United Nations Food and Agriculture Organization
Form 370 NOAA Fisheries Certificate of Origin (Form 370)
GAO Government Accountability Office
GATT 1994 General Agreement on Tariffs and Trade 1994
Hogarth ruling Earth Island Institute et al v William T. Hogarth, 494 F.3d 757 (9th Cir. 2007)
ICCAT International Commission for the Conservation of Atlantic Tunas
IATTC Inter-American Tropical Tuna Commission
IO Indian Ocean
IOTC Indian Ocean Tuna Commission
IDCP International Dolphin Conservation Program
IUU Illegal, Unreported and Unregulated Fishing
MMPA Marine Mammal Protection Act
NMFS National Marine Fisheries Service
NOAA National Oceanic and Atmospheric Administration
PBR Potential Biological Removal
RFMOs Regional Fishery Management Organizations
TBT Agreement Agreement on Technical Barriers to Trade
TTF Tuna Tracking Form
TTVP Tuna Tracking and Verification Program
USC United States Code
Vienna Convention Vienna Convention on the Law of Treaties, Done at Vienna, 23 May 1969, 1155 UNTS 331; 8 International Legal Materials 679
WCPFC Western and Central Pacific Fisheries Commission
WCPO Western and Central Pacific Ocean
WIO Western Indian Ocean
WTO World Trade Organization

1 Introduction

1.1 Complaint by the United States

1.1.1 Establishment and composition of the Panel requested by the United States

1.1.
On 11 April 2016, the United States requested the establishment of a panel pursuant to Article 21.5 of the Understanding on Rules and Procedures Governing the Settlement of Disputes (DSU), with standard terms of reference1, with respect to certain measures concerning the importation, marketing, and sale of tuna and tuna products, as further described in Section 2.1. At its meeting on 9 May 2016, the Dispute Settlement Body (DSB) referred this dispute to the original panel, if possible, in accordance with Article 21.5 of the DSU.2
1.2.
The Panel's terms of reference are the following:

To examine, in the light of the relevant provisions of the covered agreements cited by the parties to the dispute, the matter referred to the DSB by the United States in document WT/DS381/32 and to make such findings as will assist the DSB in making the recommendations or in giving the rulings provided for in those agreements.3

1.3.
Due to the unavailability of the chairperson of the original panel, the parties agreed on a replacement. The Panel was composed on 27 May 2016 as follows:

Chairperson: Stefán Haukur Jóhannesson

Members: Mary Elizabeth Chelliah

Franz Perrez

1.4.
Australia, Brazil, Canada, China, Ecuador, the European Union, Guatemala, India, Japan, Korea, New Zealand, and Norway notified their interest in participating in the Panel proceedings as third parties.

1.2 Complaint by Mexico

1.2.1 Request for consultations

1.5.
On 13 May 2016, Mexico requested consultations with the United States pursuant to Articles 4 and 21.5 of the DSU, Article 14 of the Agreement on Technical Barriers to Trade (TBT Agreement), and Article XXII of the General Agreement on Tariffs and Trade 1994 (GATT 1994) with respect to certain measures concerning the importation, marketing, and sale of tuna and tuna products.4
1.6.
Consultations were held on 2 June 2016. However, the parties were unable to resolve their dispute.

1.2.2 Establishment and composition of the Panel requested by Mexico

1.7.
On 9 June 2016, Mexico requested the establishment of a panel pursuant to Articles 6 and 21.5 of the DSU, Article 14 of the TBT Agreement, and Article XXIII of the GATT 1994, with standard terms of reference.5 At its meeting on 22 June 2016, the DSB referred this dispute to the original panel, if possible, in accordance with Article 21.5 of the DSU.6
1.8.
The Panel's terms of reference are the following:

To examine, in the light of the relevant provisions of the covered agreements cited by the parties to the dispute, the matter referred to the DSB by Mexico in document WT/DS381/38 and to make such findings as will assist the DSB in making the recommendations or in giving the rulings provided for in those agreements.7

1.9.
Due to the unavailability of the chairperson of the original panel, the parties agreed on a replacement. The Panel was composed on 11 July 2016 as follows:

Chairperson: Stefán Haukur Jóhannesson

Members: Mary Elizabeth Chelliah

Franz Perrez

1.10.
Australia, Brazil, Canada, China, Ecuador, the European Union, Guatemala, Japan, Korea, New Zealand, and Norway notified their interest in participating in the Panel proceedings as third parties.

1.3 Panel proceedings

1.3.1 General

1.11.
After consulting with the parties, the Panel in the proceedings brought by the United States adopted its Working Procedures and timetable on 4 July 2016. After further consultations with the parties, on 29 July 2016, the Panels in both the proceedings brought by the United States and the proceedings brought by Mexico adopted a harmonized timetable for the proceedings. Following further consultations with the parties, the Panels modified their harmonized timetable on 10 August 2016 to extend the deadline for written submissions from third parties.
1.12.
On 3 August 2016, the Panel in the proceedings brought by Mexico adopted its Working Procedures.8 On the same day, the Panel in the proceedings brought by the United States modified its Working Procedures9 to harmonize them with the Working Procedures adopted by the Panel in the proceedings brought by Mexico.
1.13.
The Panels held a consolidated substantive meeting with the parties on 24 and 25 January 2017. Because different Members reserved their rights as third parties in the proceedings brought by the United States, on the one hand, and Mexico, on the other hand, two third party sessions were held on 25 January 2017. On 27 February 2017, the Panels issued the descriptive part of their Reports to the parties. The Panels issued their Interim Reports to the parties on 9 June 2017, and their Final Reports to the parties on 12 July 2017.

1.3.2 Procedures for a partially open meeting

1.14.
On 10 June 2016, at the organizational meeting of the Panel in the proceedings brought by the United States, the United States proposed a change to the working procedures to allow the Panel's substantive meeting to be publicly observed or, if Mexico did not agree to this, to allow a party to request a partially open meeting, whereby that party's statements during the Panel's meeting with the parties could be viewed by the public, either simultaneously or through a delayed broadcast, whereas statements of a party that wished to maintain the confidentiality of these statements could not be so viewed.
1.15.
On 4 July 2016, the Panel in the proceedings brought by the United States sought the views of the third parties on this procedural issue. Nine third parties provided their views. Six third parties opposed the United States' request, whereas three did not.
1.16.
On 14 July 2016, at the organizational meeting of the Panel in the proceedings brought by Mexico, the United States made the same proposal for a change to the working procedures.
1.17.
On 29 July 2016, through a joint communication with the arbitrator acting under Article 22.6 of the DSU in the same dispute, the Panels informed the parties that they considered themselves to have the authority to authorize the United States to lift the confidentiality of its statements at the substantive meeting with the parties. They further indicated that the partial public observation of the meeting would be through delayed viewing (delayed closed-circuit television broadcasting), to ensure that the confidentiality of Mexico's statements would not be breached. The parties were informed that the reasons supporting this determination would be elaborated by the Panels in their Reports.10
1.18.
On 13 December 2016, pursuant to paragraph 3 of the Panels' Working Procedures, the United States requested that the Panels authorize it to lift the confidentiality of its statements made during the Panels' meeting with the parties. The United States therefore requested the Panels to adopt additional working procedures that would authorize each party and third party to lift the confidentiality of its statements made during the Panels' meeting, including its answers to questions. Mexico objected to the United States' request, arguing that the Panels could only open their substantive meetings with the parties to public viewing with the consent of both parties.
1.19.
On 22 December 2016, after consulting with the parties, the Panels adopted Additional Working Procedures on Partially Open Meetings (Additional Working Procedures).11 On the same day, the Panels sent a copy of the Additional Working Procedures to the parties and the third parties, and indicated, pursuant to paragraphs 3.1 and 4.1 of the Additional Working Procedures, that the deadline for a party or third party to indicate its intention to participate in the Panels' meetings with the parties and third parties as a disclosing party or a disclosing third party would be 9 January 2017. In its request of 13 December 2016, the United States had indicated its intention to participate in the Panels' meetings as a disclosing party. Additionally, on 9 January 2017, Australia, Canada, the European Union, Japan, Korea, Norway, and New Zealand indicated their intention to participate in the Panels' meetings as disclosing third parties.
1.20.
As noted above, the Panels met with the parties and third parties on 24 and 25 January 2017. The statements12 of the United States and disclosing third parties were video-recorded, pursuant to the Additional Working Procedures. Following the meeting, the Panels consulted with the parties and third parties and redacted the video-recording to ensure that the positions of Mexico and non-disclosing third parties were not inadvertently contained in the final version of the video-recording. At Mexico's request, the Panels held a preview screening of the redacted video-recording for the parties on 8 March 2017, which both parties attended. The delayed public broadcast was held at the WTO Headquarters in Geneva on 24 March 2017.
1.21.
Further discussion of the Panels' Additional Working Procedures, including the Panels' reasons for granting the United States' request to adopt such procedures, is provided in Section 7.2 of these Reports.

1.3.3 Additional working procedures on Business Confidential Information (BCI)

1.22.
At the Panels' organizational meeting with the parties, both parties requested that the Panels adopt additional working procedures to protect the confidentiality of BCI submitted in the course of the proceedings. The Panels adopted such additional working procedures on 4 July 2016 (in the proceedings brought by the United States) and 3 August 2016 (in the proceedings brought by Mexico). Both Panels adopted identical additional working procedures.
1.23.
The Additional Working Procedures of the Panels Concerning Business Confidential Information (BCI Working Procedures) are annexed to these Reports.13

2 Factual aspects

2.1 The measure at issue

2.1.
Both the proceedings brought by the United States and those brought by Mexico concern the United States' labelling regime for dolphin-safe tuna products14 (the 2016 Tuna Measure). Both parties consider that the 2016 Tuna Measure comprises the following instruments:

a. Section 1385 (Dolphin Protection Consumer Information Act), as contained in Subchapter II (Conservation and Protection of Marine Mammals) of Chapter 31 (Marine Mammal Protection), in Title 16 of the United States Code (the DPCIA);

b. Code of Federal Regulations, Title 50, Part 216, Subpart H (Dolphin Safe Tuna Labeling), as amended by the Enhanced Document Requirements to Support Use of the Dolphin Safe Label on Tuna Products, 78 Fed. Reg. 40,997 (July 9, 2013) (the 2013 Rule) and the Enhanced Document Requirements and Captain Training Requirements to Support Use of the Dolphin Safe Label on Tuna Products, 81 Fed. Reg. 15,444 (March 23, 2016) (the 2016 Rule) (collectively, the 2016 implementing regulations); and

c. The court ruling in Earth Island Institute v. Hogarth, 494 F.3d 757 (9th Cir. 2007) (the Hogarth ruling).

2.2.
Mexico argues that the Measure also includes the following:

a. Any implementing guidance, directives, policy announcements or any other document issued in relation to instruments (a) through (c) above, including any modifications or amendments in relation to those instruments.

2.3.
The Panels' findings on the scope of the measure at issue are contained in Section 7.4.1 of these Reports.
2.4.
The 2016 Tuna Measure specifies the conditions to be fulfilled in order for tuna products sold in the United States to be labelled "dolphin-safe" or to make similar claims on their labels. Use of the term "dolphin-safe", or any other term that claims or suggests that the tuna contained in a tuna product was harvested using a method of fishing that is not harmful to dolphins, is prohibited if the tuna contained in the product was not harvested and processed in compliance with the applicable labelling conditions.15 A more detailed description of the applicable labelling requirements is contained in the Section 7.4 of these Reports.

3 Parties' requests for findings and recommendations

3.1.
The United States requests the Panels in both Article 21.5 proceedings to find that the United States has brought itself into compliance with the DSB recommendations and rulings and that the 2016 Tuna Measure is consistent with Article 2.1 of the TBT Agreement and justified under Article XX of the GATT 1994.16
3.2.
Mexico requests that the Panels in both proceedings reject the United States' claims in their entirety and find that the 2016 Tuna Measure is inconsistent with Article 2.1 of the TBT Agreement and Articles I:1 and III:4 of the GATT 1994, and cannot be justified under Article XX of the GATT 1994.17

4 Arguments of the parties

4.1.
The arguments of the parties are reflected in their executive summaries, provided to the Panels in accordance with paragraph 18 of the Working Procedures adopted by the Panels (see Annexes B-1 and B-2).

5 Arguments of the thiRd parties

5.1.
The arguments of Australia, Brazil, Canada, the European Union, Japan, New Zealand, and Norway are reflected in their executive summaries, provided in accordance with paragraph 19 of the Working Procedures adopted by the Panels (see Annexes C-1, C-2, C-3, C-4, C-5, C-6, and C 7). Additionally, Ecuador requested that the final written versions of its oral statements at the Panels' third party sessions be treated as constituting its executive summary (see Annex C-8). China, Guatemala, India, and Korea did not submit written or oral arguments to the Panels.

6 Interim review

6.1.
On 15 April 2017, the Panels issued their Interim Reports to the parties. On 20 June 2017, Mexico and the United States each submitted written requests for the Panels to review aspects of the Interim Reports. On 27 June 2017, both parties submitted comments on the other's requests for review. Neither party requested an interim review meeting.
6.2.
In accordance with Article 15.3 of the DSU, this section of the Panels' Reports sets out the Panels' responses to the parties' requests made at the interim review stage. The numbering of some of the paragraphs and footnotes in the Final Reports has changed from the numbering in the Interim Reports. The discussion below refers to the numbering in the Final Reports and, where it differs, includes the corresponding numbering in the Interim Reports (in brackets).
6.3.
The parties' requests for substantive modifications are discussed below. In addition to the requests discussed below, corrections were made for typographical and other non-substantive errors in the Reports, including those identified by the parties. This section of the Panels' Reports constitutes an integral part of the Panels' findings.

6.1 Requests from the United States

6.4.
The United States requests, with respect to paragraphs 7.3, 7.48, 7.56, 7,613 (paragraph 7,611 in the Interim Reports) and 7,636 (paragraph 7,634 in the Interim Reports) that we replace the term "CFR" with the term "implementing regulations". According to the United States, this change would increase the clarity and consistency of the Reports, as the term "CFR" could be misunderstood as referring to the entire US Code of Federal Regulations. Mexico makes no comments on this request. We agree with the United States that the term "implementing regulations" is clearer than the term "CFR", and accordingly have made the changes requested.
6.5.
The United States requests that we delete a statement contained in paragraph 7.6 that refers to the possibility, under Article 17 of the DSU, of appealing these Panel Reports. According to the United States, because the provisions of the DSU cited in the statement in question do not address the scope of appeal proceedings, the statement is not necessary to assist the DSB in making the recommendations provided for in the covered agreements, and could itself create an issue for appeal, which would not contribute to finding a positive solution to the dispute. Mexico asks us to reject this request. According to Mexico, the United States' request would edit the reasoning of the Panels and interrupt the logic of the paragraph. In our view, it is important to recall in the context of the statement in question that appeal from panel reports is possible under the DSU. However, to avoid any misunderstanding, we have modified the statement in question to make clear that we take no position on the scope of appeal proceedings.
6.6.
The United States requests that we insert additional footnote references in paragraphs 7.45, 7.63, 7.64, 7.66, 7,208 (paragraph 7,207 in the Interim Reports), and 7,259 (paragraph 7,258 in the Interim Reports). According to the United States, these additional citations would further clarify the basis of the Panels' reasoning. Mexico asks the Panels to reject the United States' request in respect of paragraph 7.45, and states that it objects to all edits proposed by the United States that would modify the Panels' descriptions or characterizations of Mexico's evidence. With respect to paragraph 7.63, Mexico argues that the citation requested by the United States would be superfluous, as the paragraph already contains a footnote reference. Finally, with respect to paragraphs 7.64 and 7.66, Mexico objects to the United States' requests on the basis that these requests constitute an attempt by the United States to instruct the Panels as to the evidence on which they should rely for their findings. We note, however, that Mexico does not argue that the additional footnote references requested by the United States are incorrect. We also note that Mexico did not make any comments concerning the United States' requests in respect of paragraphs 7,208 or 7,259. In our view, the footnote references requested by the United States in respect of paragraphs 7.45, 7.63, 7.64, 7.66, 7,208, and 7,259 are accurate, and their addition clarifies the basis of our reasoning. The addition of the references in no way changes the Panels' reasoning or "instructs" the Panels as to which evidence they should use or how that evidence should be interpreted. We have therefore made the requested additions by inserting footnotes 75, 116, 118, 119, 123, 124, 351, and 422.
6.7.
The United States requests that, in paragraph 7.56 we delete the reference to the "original" Tuna Measure to enhance the accuracy of the text. Mexico does not comment on this request. We accept this request, which increases the accuracy of the paragraph in question.
6.8.
The United States requests that we modify certain language in paragraph 7,137 which concerns the relationship between the DSU Article 21.5 proceedings brought by the United States and those brought by Mexico. According to the United States, the language in the mentioned paragraph is not completely accurate, because it fails to fully reflect certain differences in the positions of the parties in the two proceedings, and overstates the extent of the overlap between the two proceedings. Thus, the United States proposes alternative language to more accurately reflect the relationship between the two proceedings. Mexico makes no comment on this request. In our view, the alternative language proposed by the United States accurately reflects the relationship between the two proceedings and enhances the clarity of the paragraph in question. Accordingly, we have made the requested modification.
6.9.
The United States requests that we modify certain language in paragraph 7,151 which concerns our decision not to have recourse to external experts to assist us in understanding the evidence on the record. According to the United States, the language in the third sentence of this paragraph could be misread to suggest that the role of experts in WTO dispute settlement proceedings could be to provide evidence to support or refute the claims of one or other of the parties, rather than to assist a panel in understanding the evidence that the parties have presented. The United States requests that we delete this sentence and add a new sentence at the end of the paragraph noting our decision not to have recourse to experts. Mexico argues that the requested change would interrupt the logic of the paragraph in question. We are not convinced that the identified language could be misread in the way suggested by the United States. Therefore, in our view, the deletion requested by the United States is not necessary. Nevertheless, in the interest of clarity, we have modified the language of the third sentence of paragraph 7,151 in order to make clear that we could only have had recourse to experts for the purpose of enhancing our understanding of the evidence presented by the parties.
6.10.
With respect to footnote 368 in paragraph 7,222 (footnote 352 in the Interim Reports), the United States requests that the figures relating to dolphin mortalities and serious injuries be corrected because there was a typographical error in the underlying footnote 12 of the United States' comments on Mexico's response to Panels' question 57. Mexico does not comment on this request. We have made the requested modification to ensure the accuracy of our findings.
6.11.
The United States requests the Panels to modify the text of footnote 385 in paragraph 7,230 (footnote 369 in the Interim Reports) in order to ensure that it adequately reflects the United States' arguments. Mexico does not comment on this request. Given that this request relates to the Panels' description of the United States' own arguments, we accept the request and have made the requested modification in order to better reflect the United States' position.
6.12.
The United States requests that, in paragraph 7,271 (paragraph 7,270 in the Interim Reports) we add the words "on average" to qualify the sentence that reads "…every dolphin set, by its nature, poses a risk to several hundred dolphins". According to the United States, the addition of this qualification would increase the accuracy of the sentence, as well as its consistency with other sentences on the same issue in other parts of the Reports. Mexico makes no comment on this request. We agree that the addition of this qualification increases the accuracy and consistency of the sentence, and have therefore inserted the requested words.
6.13.
The United States requests that, with respect to paragraph 7,292 (paragraph 7,291 in the Interim Reports) we modify our description of Exhibit MEX-53 to more accurately reflect its contents. The United States proposes alternative language that, in its view, better captures the finding of that Exhibit. Mexico argues that this request should be rejected, because it attempts to edit and re-word the reasoning of the Panels. We consider that the alternative language proposed by the United States accurately reflects the contents of the relevant Exhibit, and have therefore made the requested modification.
6.14.
The United States requests, with respect to paragraph 7,311 (paragraph 7,310 in the Interim Reports) that we modify our description of the information contained in Exhibit USA-44 to more accurately reflect its contents. The United States proposes alternative language that, in its view, better captures the finding of that Exhibit. Mexico argues that this request should be rejected, since it attempts to modify the Panels' interpretation of the evidence. We consider that the alternative language proposed by the United States accurately reflects the contents of the relevant Exhibit. In our view, the proposed wording does not change the Panels' interpretation of the evidence but rather explains the interpretation in a clearer way. Accordingly, we have made the requested modification.
6.15.
With respect to paragraph 7,321 (paragraph 7,320 in the Interim Reports), the United States requests that the figure "397" in the table in this paragraph be corrected to "144". The United States argues that, as noted in the last sentence of this paragraph, the figure "397", which was submitted in the United States' first written submission, was subsequently corrected to "144" through Exhibit USA-179 Rev. The United States therefore requests this modification to be reflected in the table in paragraph 7,321. Mexico opposes the United States' request, arguing that paragraph 7,321 contains an exact copy of the information in the table contained in paragraph 51 of the United States' first written submission. We note that, as the United States argues, this correction was introduced in Exhibit USA-179 Rev. after the United States' first written submission. Therefore, we accept the United States' request and have made the requested modification in order to ensure the accuracy of our findings. We have also introduced footnote 545 explaining the modification that we have made and the reasons therefor.
6.16.
With respect to paragraph 7,344 (paragraph 7,343 in the Interim Reports), the United States' requests us to make modifications to the final sentence of this paragraph in order to clarify that, except for 2014, the number of dolphins referred to represents the number of dolphins released alive in observed sets, and thus represents the maximum possible number of observed serious injuries, not the number of serious injuries actually documented. Mexico requests that the proposed edits to this paragraph be rejected on the ground that the United States' proposal attempts to modify the Panels' interpretation of the evidence. We note that the tables presented in Exhibit USA-179 Rev., in particular the ones concerning purse seine fishing without setting on dolphins in the WCPO, contain data either on direct dolphin mortality or on events in which dolphins were captured but subsequently released alive. Similarly, we note that the numbers discussed in the last sentence of paragraph 7,344, which relate to dolphins released alive, represent the upper limit of the serious injuries that could have been observed. For these reasons, and in order to further clarify our findings, we accept the United States' request, and have made the requested modification to the text of the last sentence of the paragraph at issue.
6.17.
With respect to paragraph 7,365 (paragraph 7,364 in the Interim Reports), the United States requests that we modify the first sentence of this paragraph in order to clarify that the rates referred to are based on a representative subset of all sets in the fishery. Mexico opposes the United States' request, arguing that the proposed modification attempts to edit and re-word the reasoning of the Panels. The United States' request is to add the phrase "data shows that" to the part of the first sentence of the mentioned paragraph where the Panels discuss the evidence on the record, and, in our view, this is not an attempt to edit or re-word our reasoning. We thus accept the United States' request, and have made the requested modification.
6.18.
With respect to paragraph 7,385 (paragraph 7,384 in the Interim Reports), the United States requests that, for reasons of clarity and consistency, the first sentence of this paragraph be modified. Mexico does not comment on this request. We note that the proposed modification improves the quality of the text as it gives the equivalent, on a per 1,000 sets basis, of the numbers presented in the paragraph. For this reason, we accept this request, and have made the requested modification.
6.19.
With respect to paragraphs 7,386 and 7,399 (paragraphs 7,385 and 7,398 in the Interim Reports), the United States request that a footnote be added at the end of these paragraphs for the purposes of adding clarity to the text. Mexico opposes the United States' request, arguing that the proposed citations to a Mexican submission do not support the sentences to which the United States proposes adding them. Mexico also contends that granting this request would amount to modifying the Panels' characterization of Mexico's arguments. Given that the proposed modification concerns our description of Mexico's arguments, and that Mexico disagrees with it, we decline the United States' request.
6.20.
With respect to paragraphs 7,390 and 7,396 (pargraphs 7,389 and 7,395 in the Interim Reports), the United States requests the Panels to modify the last sentences of these paragraphs to make it clear that the numbers given therein refer to potential serious injuries, and not serious injuries actually documented. Mexico opposes this request, arguing that the proposed modification attempts to edit and re-word the reasoning of the Panels. We disagree with Mexico's argument since the requested modification in no way affects our reasoning. We therefore accept the United States' request, and have modified the last sentences of paragraphs 7,390 and 7,396 in order to clarify the basis of our findings.
6.21.
With respect to paragraph 7,394 (paragraph 7,393 in the Interim Reports), the United States requests that we add a footnote reference at the end of the last sentence of this paragraph, to provide further clarity. Mexico argues that the United States' request should be rejected because the proposed text attempts to edit the reasoning of the Panels by adding the phrase "showing no bycatch of marine mammals", which represents the United States' interpretation of the relevant exhibit. We agree with the United States that the requested footnote adds clarity to the text, and have added footnote 657 to the text of the paragraph at issue. In doing so, however, we did not include the phrase "showing no bycatch of marine mammals" suggested by the United States in parenthesis.
6.22.
With respect to paragraph 7,400 (paragraph 7,399 in the Interim Reports), the United States requests us to revise the last sentence of this paragraph to clarify the relationship between the first and second clauses. Mexico argues that the proposed modification should be rejected because the United States' proposal attempts to edit and re-word the reasoning of the Panels. In our view, the proposed textual modification improves and clarifies the text and does not entail any change in the Panels' reasoning. We thus accept the United States' request and have modified the text of paragraph 7,400.
6.23.
The United States requests that we add a parenthetical to footnote 685 to paragraph 7,408 (footnote 664 to paragraph 7,407 in the Interim Reports), which addresses an argument of the United States concerning the direct dolphin mortalities caused by gillnet fishing. According to the United States, the parenthetical would more clearly spell out one element of its argument which was not expressly included in the mentioned footnote, namely that "gillnet fishing does not, necessarily or as a general matter, cause direct dolphin mortalities at a rate on par with that caused by dolphin sets in the ETP". Mexico has not commented on this request by the United States. We agree with the United States that the addition of this parenthetical provides more clarity as to the argument made by the United States, and have therefore made the requested modification.
6.24.
The United States requests that we substitute the phrase "at the same level of risks to dolphins as in the ETP" in paragraph 7,417 (paragraph 7,416 in the Interim Reports) with the phrase "under the determination provisions" to clarify that the "regular and significant mortality or serious injury" standard does not encompass the overall level of "risks" to dolphins in the ETP. Mexico disagrees with the United States' request. According to Mexico, the United States' request attempts to edit and re-word the reasoning of the Panels. Mexico further points out that the statement, as drafted in the Interim Reports, finds support in the United States' second written submission, paragraph 157, cited in footnote 714 of the Reports. We have made the requested modification to paragraph 7,417 because it serves to clarify our reasoning and avoids potential confusion.
6.25.
The United States requests the Panels to make certain modifications and insert two footnote references to paragraph 7,454 (paragraph 7,453 in the Interim Reports) in order to clarify the basis for our findings regarding the potential stress effects dolphins might suffer as a consequence of entanglement in fishing nets. Mexico argues that the United States’ proposal attempts to modify the Panels' interpretation of the evidence and should therefore be rejected. We disagree with Mexico's view that the United States' request represents an attempt to modify our interpretation of the evidence, because the requested modification would not, in our view, modify our reasoning or add a new argument to the paragraph. We have therefore modified paragraph 7,454 and inserted footnotes 814 and 815 as requested by the United States in order to enhance the clarity of our findings.
6.26.
The United States requests that we add a concluding paragraph at the end of section 7.7.2.3.3 summarizing our findings concerning both the observable and unobservable harms to dolphins caused by gillnet fishing. According to the United States, such a paragraph would ensure consistency with the structure of the sections of the Reports containing our findings regarding other fishing methods. To that end, the United States proposes a detailed concluding paragraph drawing from different parts of section 7.7.2.3.3. Mexico objects to the United States' proposal on the ground that it would amount to the United States being allowed to write the Panels' findings or reasoning. We note that we summarize our findings regarding the observable and unobservable harms caused to dolphins by gillnet fishing in paragraphs 7,444 (paragraph 7,443 in the Interim Reports) and 7,456 (paragraph 7,455 in the Interim Reports) of the Reports, respectively. Nonetheless, we are of the view that adding an overall conclusion paragraph at the end of Section 7.7.2.3.3 concerning gillnet fishing would add clarity to the text of the Reports. We have therefore inserted paragraph 7,457 for this purpose. In drafting that paragraph, however, we have modified the language proposed by the United States, so as to ensure consistency with the analogous sections in the Reports concerning other fishing methods.
6.27.
With respect to the heading of the fifth column in the last table in paragraph 7,469 (paragraph 7,467 in the Interim Reports), as well as the texts of paragraphs 7,470 and 7,523 (paragraphs 7,468 and 7,521 in the Interim Reports), the United States requests the Panels to replace the references to dolphin mortality per set in the Australia Eastern Tuna and Billfish Longline fishery with the words "possible dolphin mortalities" or, alternately, "dolphin captures". This is because, according to the United States, the available per set data for this particular fishery refers to dolphin captures, but not necessarily dolphin mortalities. Mexico requests the Panels to reject the United States' request on the ground that it amounts to revising or adding to the Panels' factual findings by arguing that the "capture" of a dolphin by hooking it and pulling it onboard should not be counted as mortality.
6.28.
We first note that the table heading in the Interim Reports referred to by the United States was reproduced directly from Exhibit USA-179 Rev. We further note that the table contained in Exhibit USA-179 Rev. indicates that the data under the heading "Mortality per 1,000 Sets", as it pertains to the Australia Eastern Tuna and Billfish Longline fishery, is an estimate from the dolphin captures in longline hooks, by including the word "est." after each data point and by explaining what "est." means in footnote 5 of the mentioned Exhibit. We also note that in paragraph 58 of its first written submission, the United States explains that, for this particular fishery, the mortality data provided by the United States in connection with the mentioned submission is based on the total number of dolphins captured. It is therefore clear that the heading of the fifth column in the last table in paragraph 7,469, as well as the texts of paragraphs 7,470 and 7,523 of our Reports, should be modified to reflect this fact. To this end, we have added the word "possible" before "mortality" in the heading of the fifth column in the last table in paragraph 7,469 and before "dolphin mortalities" in paragraphs 7,470 and 7,523.
6.29.
The United States requests the Panels to modify the text of the third sentence in paragraph 7,475 of these Reports (paragraph 7,473 in the Interim Reports) to clarify it, and to insert a footnote to this sentence in order to explain the basis of the statement that some longline fisheries present no known risk of observable harm to dolphins. Mexico contends that the United States should not instruct the Panels regarding the evidence on which they should base their findings. In our view, neither of the two requests from the United States modifies the evidence on which we base our findings or our reasoning set out in paragraph 7,475 We consider that both aspects of the United States' request serve to improve the quality of the text of paragraph 7,475 We have thus made the textual modifications requested by the United States and inserted footnote 857.
6.30.
With respect to paragraph 7,541 (paragraph 7,539 in the Interim Reports), the United States requests that we add certain language to the third sentence of the paragraph in order to clarify and ensure the accuracy of the figures relating to the WCPO purse seine fishery. Mexico does not comment on this request. In our view, the proposed language improves the quality of the text by clarifying that the number mentioned in this paragraph is an annual average on a per 1,000 sets basis. We thus accept the United States' request, and have modified the third sentence of the paragraph at issue.
6.31.
The United States requests that we insert additional footnote references in paragraphs 7,683 (paragraph 7,681 in the Interim Reports) and 7,698 (paragraph 7,696 in the Interim Reports). The references proposed by the United States include citations followed by bracketed descriptions of the exhibits referenced in the citations (for example, "Dolphin Mortalities to ETP Dolphin Sets and in Other Fisheries" (Exhibit USA-111) (showing that the ETP benchmark, i.e. the level of per set mortalities caused by dolphin sets in the ETP between 1997 and 2015 was 0.1265 dolphin mortalities per set)"). According to the United States, the addition of these footnote references would more completely reflect the arguments of the United States. Mexico makes no comment regarding the United States' request in respect of paragraph 7,683. Regarding the United States' request in respect of paragraph 7,698, Mexico argues that this request should be rejected because it is an attempt to instruct the Panels as to the evidence on which they should base their findings. We agree with the United States that clarity and completeness is enhanced by adding the citations indicated by the United States in respect of both paragraphs 7,698 and 7,683. Accordingly, we have inserted additional references in footnotes 1176 and 1177 and added a new footnote 1195. Concerning Mexico's argument regarding paragraph 7,698, we do not consider that the United States' request "instructs" us as to the evidence on which we should rely. Rather, the reference clarifies the basis of our reasoning. However, although we accept the United States' requests in respect of paragraphs 7,698 and 7,683, in the interests of style and consistency, we do not consider it necessary to add the bracketed descriptions of the exhibits referenced in the citations, as requested by the United States. Having said that, it would in our view aid reader comprehension if the numerical value of the benchmark, which the United States proposes to add in brackets in the additional footnote references, were included in the body text of the paragraphs in question. Accordingly, at the end of the last sentence of paragraph 7,683, and at the end of the second sentence of paragraph 7,698, we have inserted the words "which the United States calculates as 0.1265 mortalities per set".

6.2 Requests from Mexico

6.32.
With respect to paragraph 7.46 Mexico requests that the Panels delete their statement that Mexico did not respond to the United States' argument that Mexico's allegations concerning pressure allegedly applied by the United States to certain US tuna retailers was outside the Panels' terms of the reference. According to Mexico, Mexico was not afforded an opportunity by the Panels to address this issue. Mexico suggests that the Panels did not include any question about the terms of reference in their post-hearing questions. The United States responds that Mexico's request is based on an incorrect premise, since Mexico did have an opportunity to comment on this issue. We note that, contrary to Mexico's suggestion, the Panels did indeed ask Mexico a question about terms of reference following the Panels' joint meetings with the parties. Question No. 72 to Mexico explicitly ask Mexico whether "such alleged action is within the Panels' terms of reference". In its response to this question, Mexico did not respond to this aspect of the Panels' question. Moreover, Mexico had the opportunity to comment on the United States' response to a question from the Panels on precisely this issue, and chose not to do so.18 Accordingly, we reject Mexico's request and retain the accurate statement that Mexico did not respond to this argument.
6.33.
With respect to paragraph 7.60 which contains a description of the AIDCP Tracking and Verification System, Mexico requests that we delete the sentence "However, it does not provide specific legal requirements as to audits or inter-party co-operation". According to Mexico, this statement is inaccurate, and may be read as suggesting that audits and inter-party cooperation have not been implemented under the AIDCP system. Mexico also points to evidence on the record showing that cooperation does occur in the context or under the auspices of the AIDCP. The United States argues that this request should be rejected, since the statement is accurate as drafted by the Panels. We note that the statement to which Mexico objects concerns the apparent absence in the ADICP Tracking and Verification System of any detailed legal requirements concerning audits and inter-party cooperation. The statement says nothing about whether or not parties to the AIDCP, in their own domestic legislation or through arrangements concluded separately from, although in the context of, the AIDCP, do engage in auditing and cooperation. Nevertheless, to avoid confusion, and because we consider that the sentence in question is not essential to the Panels' description, we accept Mexico's request and have deleted the sentence.
6.34.
With respect to paragraph 7.64 which contains the Panels' description of the NOAA Tracking and Verification Regime, Mexico argues that the text does not reflect a "key point" made by Mexico, namely, that US agencies lack authority to audit non-US fishing vessels, carrier vessels, and processors. Mexico requests that we therefore add a sentence reflecting this argument. The United States argues that this request should be rejected, first because the paragraph in question is a description of the measure at issue, rather than a summary of Mexico's arguments, second because the scope of the United States' authority is clear from the paragraph as drafted by the Panels, and finally because the issue of the scope of the United States' authority is dealt with in detail at paragraphs 7,633 and 7,675 of these Reports (paragraphs 7,631 and 7,673 in the Interim Reports). We note, however, that the United States does not argue that the statement proposed by Mexico is substantively incorrect. Accordingly, we accept this request and have inserted a statement reflecting Mexico's view, which in our view brings into sharper relief a point that is already reflected in the paragraph as drafted by the Panels.
6.35.
With respect to paragraph 7.85 which deals with the Panels' identification of the applicable legal test under Article 2.1 of the TBT Agreement, Mexico argues that the Panels' description omits an important element of the calibration test as described by the Appellate Body, namely, that the calibration analysis must be conducted "taking account of the objectives of the measure". According to Mexico, a reference to this element of the test should be included in the paragraph in question. The United States responds that the sentence as drafted by the Panels is accurate. According to the United States, the sentence as drafted correctly identifies the area of agreement between the parties as to the applicable legal standard, but accepting Mexico's request would lead to this paragraph inaccurately describing the parties as being in agreement on the role that "the objectives of the measure" should play in the calibration analysis when in fact the parties disagree on this point. We note that, as we describe in detail in Section 7.5.2 of our Reports, the Appellate Body used a variety of similar formulations to describe the calibration analysis, only one of which referred to the objectives of the measure. The relevance and meaning of the Appellate Body's reference to the objectives of the measure was a major issue in dispute between the parties. We consider that Mexico's proposed alternative language could mislead the reader into believing that both parties had the same understanding of the relevance and meaning of this formulation, which, as noted above, was not the case. Additionally, we recall that we discuss our view of the meaning and relevance of the Appellate Body's reference to the objectives of the measure, including Mexico's arguments, in detail in paragraphs 7,114 to 7,126 of these Reports. We consider that that discussion is sufficiently detailed, and therefore the addition requested by Mexico is unnecessary, and would not increase either the accuracy or the clarity of the paragraph. Accordingly, we reject Mexico's request.
6.36.
With respect to paragraph 7.87 in which the Panels describe Mexico's arguments concerning the applicable legal test under Article 2.1 of the TBT Agreement, Mexico argues that the text, and in particular the reference to "other factors of the even-handedness standard", does not accurately reflect Mexico's position. Mexico requests that the Panels delete this reference and insert alternative text that more closely tracks Mexico's arguments in its written submissions. The United States argues that the paragraph as drafted accurately reflects Mexico's position, since Mexico did refer in its submissions to different "factors" or "elements" of the applicable legal standard. Bearing in mind that this request relates to the Panels' description of Mexico's own arguments, we accept Mexico's request and have made the requested change in order to better reflect Mexico's position.
6.37.
With respect to paragraph 7,107 Mexico requests that, in order to more accurately reflect its arguments, we delete the word "legal" from the phrase "Mexico argues that the reliability of the applicable legal systems...". Mexico argues that it did not use the term "legal" in its submissions, and that this word unduly narrow the scope of the word "systems" in a way that was not intended by Mexico. The United States makes no comment on this request. Bearing in mind that this request relates to the Panels' description of Mexico's own arguments, we accept Mexico's request and have made the requested change in order to better reflect Mexico's position.
6.38.
With respect to paragraph 7,130 which describes Mexico's arguments concerning the relevance of the preamble to the WTO Agreement in the interpretation of the covered agreements, Mexico objects to the Panels' statement that Mexico's argument entails the conclusion that a measure may be found to be inconsistent with a particular provision of the covered agreements "because it does not further one of the goals referenced in the preamble". According to Mexico, this statement does not accurately reflect Mexico's argument, which was that "[m]easures that discriminate in a manner that goes against the objective of sustainable development … can be found to be inconsistent".19 Mexico therefore requests that this statement be deleted and replaced with alternative language that more accurately reflects Mexico's arguments. The United States makes no comment on this request. We accept Mexico's request in order to better reflect Mexico's argument.
6.39.
With regard to paragraph 7,183 (paragraph 7,182 in the Interim Reports), Mexico contends that the paragraph omits key elements of Mexico's argument regarding the US regulations adopted under the Marine Mammal Protection Act, and requests the Panels to make the necessary modifications in order to fully reflect such arguments. Among others, Mexico requests that the Panels use the word "explains", instead of "contends", in characterizing Mexico's description of the regulations, because the United States does not contest the accuracy of Mexico's description. The United States does not object to certain proposed changes to the last sentence of the paragraph at issue but requests the Panels to deny other aspects of Mexico's request. With respect to the proposed changes to the first sentence, the United States requests that the Panels deny Mexico's request, as the text Mexico suggests is inaccurate in that it gives the wrong impression that Mexico's argument was made in response to an argument by the United States. With respect to the proposed changes to the last sentence, the United States contends that Mexico did not argue that "the regulations require the United States to ban seafood imports entirely" from countries that do not "create assessments that estimate population abundance for marine mammal stocks that are killed or seriously injured in their territorial waters". To the contrary, in the view of the United States, the Marine Mammal Protection Act is a fishery-specific, as opposed to country-specific, measure. We note that Mexico's request is composed of two parts, one asking us to include a contextual description of the argument contained in the first sentence of the paragraph at issue, and another requesting further expansion of one of Mexico's arguments in the last sentence of that paragraph. Regarding the first part, we agree with the United States that characterising Mexico's argument as being a response to the United States' argument on the impracticability of collecting information in the context of the PBR methodology is not entirely accurate. Further, we note that, as it stands, the first sentence correctly reflects Mexico's argument. We therefore reject the first part of Mexico's request. Regarding the second part, we agree with Mexico and therefore have modified the last sentence of the paragraph at issue. Finally, we have replaced the word "contends" with "submits".
6.40.
Mexico also requests that the Panels introduce a new paragraph following the existing paragraph 7,183 (paragraph 7,182 in the Interim Reports) of the Reports because the Interim Reports omit to mention two of Mexico's arguments regarding the use of PBR, namely, that (i) the United States used the PBR methodology to evaluate the impact of the dolphin encirclement fishing methods on dolphins in the ETP in implementing the Measure, and that (ii) the use of PBR protects smaller dolphin stocks from total extinction in circumstances where a relatively low number of mortalities can erode the ability of members of the stock to reproduce. The United States argues that the addition of these details is unnecessary because the explanation at paragraph 7,175 is sufficient to accurately describe Mexico's arguments concerning PBR. If, however, the Panels decide to include the details requested by Mexico, the United States points out that the place where Mexico requests that this new paragraph be introduced is not appropriate, and that the appropriate place would be in the context of paragraph 7,175 which sets out Mexico's arguments. We agree with Mexico's request and, have included the details of Mexico's arguments in the new paragraph 7,176. We have, however, modified the language proposed by Mexico in drafting this paragraph. In choosing the place of this paragraph, we have taken the United States' comment into account.
6.41.
Regarding paragraph 7,217 (paragraph 7,216 in the Interim Reports), Mexico argues that this paragraph sets forth the United States' argument regarding the probity of Exhibit USA-179 Rev. but not that of Mexico. Mexico therefore requests that a sentence be added at the end of the paragraph in order to properly describe Mexico's position in this regard. The United States opposes Mexico's request, arguing that this paragraph does not set forth the arguments of either party but rather the Panels' description of Exhibit USA-179 Rev. If Mexico meant to refer to paragraph 7,216 (paragraph 7,215 in the Interim Reports) of the Reports, the United States maintains that that paragraph already addresses, in its second and third sentences, the arguments that Mexico requests the Panels to add. We note that, as the United States argues, paragraph 7,217 contains our description of Exhibits USA-179 and USA-179 Rev., rather than the parties' arguments on those Exhibits. We also note that the comments that Mexico requests us to add to paragraph 7,217 convey Mexico's views on Exhibit USA-179, and not Exhibit USA-179 Rev. We have nevertheless revised the text of paragraph 7,216, where we note the parties' arguments on Exhibits USA-179 and USA-179 Rev., to provide a more thorough description of Mexico's arguments on Exhibit USA-179.
6.42.
Mexico requests that the Panels include a new paragraph, before or after paragraph 7,238 (pargraph 7,237 in the Interim Reports), to reflect Mexico's arguments on whether observer coverage of less than 10% provides scientifically valid data. The United States argues that Mexico's proposed new paragraph is unnecessary and inappropriate, as the Interim Reports already fully summarize Mexico's arguments on this issue. We note that the new paragraph requested by Mexico contains arguments whose thrust has already been described in these Reports, such as in paragraph 7,236 (paragraph 7,235 in the Interim Reports). In fact, the proposed new text makes reference to Mexico's interpretation of some exhibits on the record submitted in support of Mexico's main argument that observer coverage of less than 10% does not provide scientifically valid data. We thus reject Mexico's request.
6.43.
Regarding paragraph 7,250 (paragraph 7,249 in the Interim Reports), Mexico requests that the Panels modify this paragraph which indicates that Mexico did not submit any arguments regarding the meaning of the terms "observed," "unobserved," "observable," "unobservable," "direct" and "indirect"harms. Mexico argues that it did address this issue, and suggests specific language to reflect this in the paragraph at issue. The United States requests that the Panels deny Mexico's request. The United States recalls that at the hearing, Mexico, in response to this question, stated that it would respond to the question fully in writing, but that subsequently Mexico provided no specific arguments on the matter at issue, nor any reference to statements made at the hearing. We note that although Mexico addressed some of the issues regarding the meaning of the terms mentioned in the paragraph at issue, it also stated that it would "submit more detailed information in [its] written reply". However, in response to Panels' question No. 116, sent to the parties after the Panels' substantive meeting with the parties, asking them to explain their understanding of the terms "direct", "indirect", "observed", "observable", "unobserved" and "unobservable" harms or risks, Mexico did not provide any further elaboration on the conceptual differences between these terms. For these reasons, we have modified the text of paragraph 7,250 to reflect Mexico's statements during the meeting as well as its response to Panels' question no. 116.
6.44.
With respect to paragraph 7,276 (paragraph 7,275 in the Interim Reports) which describes Mexico's arguments concerning the ETP large purse seine fishery, Mexico requests that we add certain language to more accurately reflect Mexico's position. In particular, Mexico requests, first, that we clarify that Mexico does not dispute the recent data on dolphin mortalities caused by setting on dolphins in the ETP, and second, that we reflect Mexico's argument concerning the impact of the La Jolla Agreement on the mortality levels in that fishery. The United States does not oppose Mexico's request entirely, but does oppose the addition of the word "recent" in the first sentence. According to the United States, this addition would not accurately reflect Mexico's arguments. In our view, the addition of the word "recent" as requested by Mexico is unnecessary, since the sentence already indicates that Mexico does not contest evidence "collected and published by the AIDCP". This reference to the AIDCP makes clear the extent of the evidence that Mexico does not contest, as the AIDCP only came into existence (in its earliest form) following the entry into force of the La Jolla Agreement in 1992. Thus, we do not accept Mexico's request to add the word "recent". However, we accept the remainder of Mexico's request, which accurately describes Mexico's position, except that we have not accepted the word "emphasizes", which Mexico proposes and which could be read as an endorsement by the Panels of Mexico's argument. Such an endorsement would be inappropriate in the context of the paragraph in question, which is simply a description of Mexico's arguments. We have therefore changed this word to "argues", but have accepted Mexico's request in all other respects.
6.45.
With respect to paragraph 7,277 (paragraph 7,276 in the Interim Reports), Mexico requests that we modify the text to more accurately reflect Mexico's arguments concerning the extent of unobservable harms caused by setting on dolphins in the ETP. The United States does not object to this request, but argues that some of the alternative language proposed by Mexico does not accurately reflect Mexico's written submissions. Bearing in mind that this request relates to the Panels' description of Mexico's own arguments, we accept Mexico's request and have made the requested change, which in our view reflects Mexico's position during the proceedings.
6.46.
With respect to paragraph 7,284 (paragraph 7,283 in the Interim Reports) in which the Panels note that the World Wildlife Fund (WWF), inter alia, has expressed concerns that mortalities in the ETP large purse seine fishery may be understated, Mexico requests the Panels to explicitly recall Mexico's position that the WWF document to which the Panels refer in this paragraph "provides no evidence of mortalities, but simply makes an allegation without support". The United States argues that this request should be rejected for two reasons: first, because the paragraph in question describes the Panels' assessment of the evidence rather than the parties' arguments; and second, because the argument that Mexico requests to be inserted was made by Mexico not in respect of the Exhibit discussed in this paragraph, but in respect of a different WWF document discussed in a subsequent paragraph. Like the United States, we note that the argument that Mexico requests us to include was not made in respect of the Exhibit at issue in this paragraph, but rather in respect of a different WWF document. Additionally, we note that the paragraph in question describes the Panels' own assessment of the evidence having taken into account both parties' arguments, and therefore does not summarize the arguments of either of the parties. We therefore consider that it would be inappropriate to insert a summary of Mexico's argument into this paragraph. In this connection, we recall that panels are not required to explicitly address every argument advanced by the parties to a dispute.20 Moreover, we recall that a panel does not commit error simply because it declines to accord to the evidence the weight that one of the parties believes should be accorded to it.21
6.47.
With respect to paragraph 7,289 (paragraph 7,288 in the Interim Reports) Mexico requests that the Panels delete the statement indicating that Mexico did not dispute the existence of unobservable harms in either of the preceding stages of this dispute (i.e. the original proceedings or the first Article 21.5 proceedings). According to Mexico, this statement is incorrect, as Mexico's position has been consistent throughout the different proceedings in this dispute. The United States requests that the Panels retain the language as drafted because, in the United States' view, the language as drafted correctly reflects that Mexico has changed its position over the course of this dispute with regard to the existence of unobservable harms. In our view, the sentence in question is not essential to the Panels' reasoning in the current Article 21.5 proceedings, as the Panels' findings about the existence of unobservable harms are based on the previous panel and Appellate Body reports in this dispute and the evidence submitted by the parties in the present proceedings, and not on whether either of the parties has changed its position regarding such harms during the course of this dispute. Accordingly, we accept this request and have deleted the sentence in question.
6.48.
With respect to paragraph 7,295 (paragraph 7,294 in the Interim Reports) Mexico argues that the Panels "decided to agree with the US position" on Exhibit USA-43, but omitted to mention arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be added to the end of the paragraph in question recalling Mexico's argument. The United States does not oppose this request, but suggests that the appropriate place to note Mexico's argument would be in the paragraphs describing the parties' arguments, rather than the paragraphs where the Panels explain their reasoning. The United States also requests that, if the Panels accept Mexico's request, they adopt verbs that convey that the sentences reflect Mexico's arguments and not uncontested facts or findings by the Panels. We begin by observing that, in the paragraph in question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that paragraph, the Panels record their own assessment of the Exhibit in question, based on their own reading of it and informed by the arguments of both parties. This is entirely in keeping with the Panels' obligation under Article 11 of the DSU to carry out an "objective" assessment of the matter. As this paragraph contains the Panels' own assessment, it does not repeat the arguments of either of the parties. We therefore consider that it would be inappropriate to insert a summary of Mexico's argument into this paragraph. Nevertheless, to try to accommodate Mexico's concern, we have added new text to footnote 503 in the paragraph in question, in which we describe Mexico's argument using Mexico's proposed text. We have also provided in the same footnote an explanation as to why we do not accept Mexico's argument concerning the meaning and evidentiary value of Exhibit USA-43.
6.49.
With respect to paragraph 7,296 (paragraph 7,295 in the Interim Reports) Mexico argues that the Panels "decided to agree with the US position" on Exhibit USA-45, but omitted to mention arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be added to the end of the paragraph in question recalling Mexico's argument. The United States22 does not oppose this request, but suggests that the appropriate place to note Mexico's argument would be in the paragraphs describing the parties' arguments, rather than the paragraphs where the Panels explain their reasoning. The United States also requests that, if the Panels accept Mexico's request, they adopt verbs that convey that the sentences reflect Mexico's arguments and not uncontested facts or findings by the Panels. We begin by observing that, in the paragraph in question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that paragraph, the Panels record their own assessment of the Exhibit in question, based on their own reading of it and informed by the arguments of both parties. This is entirely in keeping with the Panels' obligation under Article 11 of the DSU to carry out an "objective" assessment of the matter. As this paragraph contains the Panels' own assessment, it does not repeat the arguments of either of the parties. We therefore consider that it would be inappropriate to insert a summary of Mexico's argument into this paragraph. Nevertheless, to try to accommodate Mexico's concern, we have added new text to footnote 506 in the paragraph in question, in which we describe Mexico's argument using Mexico's proposed text. We have also provided in the same footnote an explanation as to why we do not accept Mexico's argument concerning the meaning and evidentiary value of Exhibit USA-45.
6.50.
With respect to paragraph 7,300 (paragraph 7,299 in the Interim Reports) Mexico argues that the Panels "decided to agree with the US position" on Exhibit MEX-14, but omitted to mention arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be added to the end of the paragraph in question recalling Mexico's argument. The United States does not oppose this request, but suggests that the appropriate place to note Mexico's argument would be in the paragraphs describing the parties' arguments, rather than the paragraphs where the Panels explain their reasoning. The United States also requests that, if the Panels accept Mexico's request, they modify the alternative language proposed by Mexico in order to more accurately convey the limited nature of Mexico's argument on this Exhibit. We begin by observing that, in the paragraph in question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that paragraph, the Panels record their own assessment of the Exhibit in question, based on their own reading of it and informed by the arguments of both parties. This is entirely in keeping with the Panels' obligation under Article 11 of the DSU to carry out an "objective" assessment of the matter. As this paragraph contains the Panels' own assessment, it does not repeat the arguments of either of the parties. We therefore consider that it would be inappropriate to insert a summary of Mexico's argument into this paragraph. Nevertheless, to try to accommodate Mexico's concern, we have added new text to footnote 515 in the paragraph in question, in which we describe Mexico's argument using Mexico's proposed text, including the modification suggested by the United States, which seems to us to increase the accuracy of the text. We have also provided in the same footnote an explanation as to why we do not accept Mexico's argument concerning the meaning and evidentiary value of Exhibit MEX-14.
6.51.
With respect to paragraph 7,301 (paragraph 7,300 in the Interim Reports) Mexico argues that the Panels "decided to agree with the US position" on Exhibit USA-47, but omitted to mention arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be added to the end of the paragraph in question recalling Mexico's argument. The United States does not oppose this request, but suggests that the appropriate place to note Mexico's argument would be in the paragraphs describing the parties' arguments, rather than the paragraphs where the Panels explain their reasoning. The United States also requests that, if the Panels accept Mexico's request, they adopt verbs that convey that the sentences reflect Mexico's arguments and not uncontested facts or findings by the Panels. We begin by observing that, in the paragraph in question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that paragraph, the Panels record their own assessment of the Exhibit in question, based on their own reading of it and informed by the arguments of both parties. This is entirely in keeping with the Panels' obligation under Article 11 of the DSU to carry out an "objective" assessment of the matter. As this paragraph contains the Panels' own assessment, it does not repeat the arguments of either of the parties. We therefore consider that it would be inappropriate to insert a summary of Mexico's argument into this paragraph. Nevertheless, to try to accommodate Mexico's concern, we have added a new footnote 517 to the paragraph in question in which we describe Mexico's argument using Mexico's proposed text. We have also provided in the same footnote an explanation as to why we do not accept Mexico's argument concerning the meaning and evidentiary value of Exhibit USA-47. We have also added the full title of the Exhibit into the text of the paragraph in question in the interests of consistency.
6.52.
With respect to paragraph 7,305 (paragraph 7,304 in the Interim Reports) Mexico argues that the Panels "decided to agree with the US position" on Exhibit USA-140, but omitted to mention arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be added to the end of the paragraph in question recalling Mexico's argument. The United States does not make any comment on this request. We begin by observing that, in the paragraph in question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that paragraph, the Panels record their own assessment of the Exhibit in question, based on their own reading of it and informed by the arguments of both parties. This is entirely in keeping with the Panels' obligation under Article 11 of the DSU to carry out an "objective" assessment of the matter. As this paragraph contains the Panels' own assessment, it does not repeat the arguments of either of the parties. We therefore consider that it would be inappropriate to insert a summary of Mexico's argument into this paragraph. Nevertheless, to try to accommodate Mexico's concern, we have added a new footnote 522 to the paragraph in question in which we describe Mexico's argument using Mexico's proposed text. We have also provided in the same footnote an explanation as to why we do not accept Mexico's argument concerning the meaning and evidentiary value of Exhibit USA-140.
6.53.
With respect to paragraph 7,307 (paragraph 7,306 in the Interim Reports) Mexico argues that the Panels "decided to agree with the US position" on Exhibit USA-142, but omitted to mention arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be added to the end of the paragraph in question recalling Mexico's argument. The United States does not object to the idea of the Panels adding a summary of Mexico's argument concerning this Exhibit. However, the United States argues that the Panels should not use the words "Mexico observed", which could be read as suggesting that Mexico's argument was uncontested by the United States. Moreover, the United States argues that the Panels should not accept Mexico's request to include language to the effect that Mexico argued that Exhibit USA-142 "is not probative evidence", since, in the United States' view, this would not be an accurate reflection of Mexico's argument in its submissions. We begin by observing that, in the paragraph in question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that paragraph, the Panels record their own assessment of the Exhibit in question, based on their own reading of it and informed by the arguments of both parties. This is entirely in keeping with the Panels' obligation under Article 11 of the DSU to carry out an "objective" assessment of the matter. As this paragraph contains the Panels' own assessment, it does not repeat the arguments of either of the parties. We therefore consider that it would be inappropriate to insert a summary of Mexico's argument into this paragraph. Nevertheless, to try to accommodate Mexico's concern, we have added new text to footnote 524 in the paragraph in question, in which we describe Mexico's argument using Mexico's proposed text. We accept the wording proposed by the United States, since although it is true that Mexico did not use the words "is not probative evidence" in its submissions, the phrase nevertheless accurately reflects Mexico's position. In the same footnote, we have also inserted an explanation as to why we do not accept Mexico's argument concerning the meaning and evidentiary value of Exhibit USA-142.
6.54.
Regarding paragraph 7,323 (paragraph 7,322 in the Interim Reports), Mexico requests that some modifications are introduced to reflect further Mexico's arguments. The United States argues that if the Panels were to accept Mexico's request concerning this paragraph, the verbs Mexico proposes should be replaced to accurately convey that the sentences summarize Mexico's arguments and are not factual findings by the Panels. We have accepted Mexico's request but made some textual modifications to the language Mexico proposed.
6.55.
Regarding paragraph 7,347 (paragraph 7,346 in the Interim Reports), Mexico requests that we change the figure 6% to 65%. The United States supports Mexico's request. We have made the requested modification.
6.56.
With respect to paragraph 7,584 (paragraph 7,582 in the Interim Reports) which concerns the parties' arguments regarding the new captain training course introduced by the 2016 Tuna Measure, Mexico argues that the description is incomplete because it does not include Mexico's response to the United States' argument. Mexico therefore requests that we insert language summarizing this response. The United States does not object to this request, but argues that the description of Mexico's argument would be better placed in an earlier paragraph where the Panels describe Mexico's argument. The United States also suggests that the Panels should use the words "Mexico also argues" rather than the words "Mexico responds", to more accurately describe the context on which Mexico's argument was made. We accept this request and have inserted Mexico's proposed language, with the change suggested by the United States, which adds to the completeness and accuracy of the description of the parties' arguments. We have also accepted the United States' suggestion to put this language in paragraph 7,583 (paragraph 7,581 in the Interim Reports) rather than paragraph 7,584, since it is the former rather than the latter that describes Mexico's arguments.
6.57.
Regarding paragraph 7,634 (paragraph 7,632 in the Interim Reports), Mexico requests that a sentence be added at the end of this paragraph to better describe Mexico's argument regarding the complex supply chain for tuna by referring to evidence submitted by Mexico on this point, namely, a recent report of the International Seafood Sustainability Foundation. The United States argues that the exhibit that Mexico requests the Panels to cite in the paragraph at issue was submitted in Mexico's comments on the United States response to the Panels' questions and that, therefore, the United States did not have the opportunity to comment on it. The United States also contends that the mentioned exhibit is not relevant to the measure at issue in these proceedings, and that therefore its meaning is not uncontested. Therefore, the United States asks the Panels to make clear that the language proposed by Mexico represents what Mexico argues in this regard, and not an uncontested fact. Finally, should the Panels accept Mexico's request, the United States also requests that another paragraph be inserted in order to provide a summary of the United States' arguments on the same issue. We note that the argument that Mexico requests the Panels to reflect in paragraph 7,634 pertains to the issue of whether tuna companies are able to track a particular catch to the individual vessel that caught it and to other points in the supply chain. The present proceedings, however, concern whether the 2016 Tuna Measure is calibrated to different levels of risks posed to dolphins by different fishing methods in different parts of the ocean, among others, in terms of its tracking and verification requirements. Therefore, the argument that Mexico requests us to reflect in the paragraph at issue is not directly relevant to our inquiry. We therefore deny Mexico's request.
6.58.
Regarding paragraph 7,635 (paragraphs 7,633 in the Interim Reports), Mexico requests that a sentence be added at the end of the paragraph in order to reflect Mexico's argument regarding the unreliability of tracking systems in Thailand, the Philippines and Chinese Taipei at the same level of detail as that at which the arguments of the United States are explained in the same paragraph. The United States argues that the Interim Reports provide a complete summary of Mexico's arguments concerning the tracking and verification regimes of certain Asian countries, and that the summaries of both the United States' and Mexico's arguments are otherwise comparable in terms of the level of detail. If the Panels decide to accept Mexico's request, the United States requests that some modifications be introduced to the language proposed by Mexico to underline that what is said represents Mexico's arguments. Bearing in mind that this request relates to the Panels' description of Mexico's own arguments, we accept Mexico's request and have made the requested change in order to better reflect Mexico's position. In doing so, however, we have modified the language proposed by Mexico in certain regards, to underline that the added text represents Mexico's arguments.

7 Findings

7.1 Introduction

7.1.1 Procedural overview

7.1.
The current proceedings are the latest in the long-running dispute between Mexico and the United States over the WTO-consistency of the United States' labelling regime for "dolphin-safe" tuna products.23 The procedural history of the dispute is summarized in the Appellate Body's report in the first compliance proceedings24 and in the Decision by the Arbitrator in this dispute25, and need not be repeated in detail here.
7.2.
On 20 November 2015, the Appellate Body circulated its report in the first compliance proceedings brought by Mexico against the measure taken by the United States to comply with the DSB recommendations and rulings in the original proceedings. In these Reports, the Panels refer to that measure as the "2013 Tuna Measure".26 The Appellate Body found that the 2013 Tuna Measure modified the conditions of competition to the detriment of Mexican tuna products in the US market; that such detrimental impact did not stem exclusively from a legitimate regulatory distinction, and, thus, that the 2013 Tuna Measure accorded less favourable treatment to Mexican tuna products as compared to like tuna products from the United States and other countries and was therefore inconsistent with Article 2.1 of the TBT Agreement. The Appellate Body also found that the 2013 Tuna Measure was inconsistent with Articles I:1 and III:4 of the GATT 1994, and that the United States had not demonstrated that it was applied in a manner that did not constitute arbitrary or unjustifiable discrimination as required by the chapeau of Article XX of the GATT 1994.27 The findings of the Appellate Body are described in more detail later in these Reports.
7.3.
On 3 December 2015, the DSB adopted the panel and Appellate Body reports in the first compliance proceedings. In response, on 22 March 2016, the United States National Oceanic and Atmospheric Administration (NOAA) issued an interim final rule with the aim of bringing the labelling regime for dolphin-safe tuna products into compliance with the United States' obligations under the WTO Agreement. As discussed in further detail below, this interim rule (the 2016 Rule) made certain changes to the implementing regulations, but did not affect either the DPCIA or the Hogarth ruling. In these Reports, the DPCIA, the implementing regulations as amended by the 2016 Rule, and the Hogarth ruling are collectively referred to as the "2016 Tuna Measure".

7.1.2 Format of these Reports

7.4.
As described above, these proceedings are somewhat unusual in that two compliance panels have been established – one at the request of the original complaining party and the other at the request of the original responding party – to determine the WTO-consistency of the same measure.28 The unusual nature of the proceedings gives rise to certain complications, the most important of which, concerning the burden of proof, is discussed below.29 It also raises the question of how the two Panels should present their findings, given that both are charged with assessing the WTO-consistency of the same measure. After consulting with the parties, the Panels have decided to issue their findings in a single document, with separate conclusions for each of the two proceedings. This is justified by the close interrelation of the two proceedings. Indeed, insofar as the same questions are raised about the same measure in both proceedings, it would be inefficient and unnecessarily duplicative to deal with each of the proceedings separately.

7.2 Preliminary Issue: United States' request to lift the confidentiality of its statements at the Panels' substantive meetings with the parties and third parties

7.2.1 Procedural background

7.5.
As reflected in Section 1.3.2, following an initial request by the United States and subsequent requests by certain third parties, the Panels in these proceedings authorized the United States and the relevant third parties to lift the confidentiality of their statements at the Panels' consolidated substantive meeting with the parties and at the third party session. The Panels permitted the partial public observation of their meeting through delayed viewing, to ensure that the confidentiality of Mexico's statements or the statements of non-disclosing third parties was not breached. The parties were informed that the reasons supporting the Panels' decision on the United States' request would be elaborated by the Panels in their Reports.

7.2.2 Merits of the United States' request for a partially open meeting

7.6.
The Panels note that US – Tuna II (Mexico) is the first dispute in which a WTO adjudicator at the request of a party organized a partially open meeting with the parties. An identical request was made by the United States in the arbitration conducted under Article 22.6 in this dispute.30 The arbitrator granted that request in the light of the particular circumstances of that proceeding.31 The arbitrator who granted the United States' request in this dispute was composed of the same individuals as these Panels. Unlike the arbitrator, however, the Panels also benefited from, and took into account, the views expressed by the third parties participating in these compliance panel proceedings. Moreover, we recall that panel reports are subject to appeal. In the light of this, and bearing in mind our responsibility under Article 12.7 of the DSU to explain the basic rationale behind our findings, it is appropriate to set out in these Reports the Panels' full legal analysis even if the arbitrator has already provided a full legal analysis of essentially the same issue in its decision.32
7.7.
Accordingly, we set out below the detailed reasons supporting our decision to grant the United States' request in the light of the specific circumstances of these proceedings. We begin by summarizing the parties' and third parties' arguments.
7.8.
The United States submits that it is not asking the Panels to mandate the opening of the meeting over Mexico's objection. Instead, the United States seeks to exercise its right to disclose to the public its own statements at the Panels' consolidated substantive meeting, and to that end requests that the Panels facilitate this disclosure by adopting appropriate procedures. The United States argues that it is possible for the Panels to authorize the United States to disclose its own statements and at the same time to maintain the confidentiality of Mexico's statements. In the United States' view, meetings opened for public observation enhance understanding of the dispute settlement system and promote confidence in its objectivity and professionalism.
7.9.
The United States submits that its request is supported by the Appellate Body report in US – Continued Suspension. According to the United States, the Appellate Body in that dispute agreed that each party has the right to maintain the confidentiality of its own statements and therefore provided each party and third party a possibility to lift the confidentiality of their statements at the Appellate Body's hearing. The United States notes that it is possible to protect Mexico's right to maintain the confidentiality of its statements while also protecting the United States' right to disclose its own statements to the public.
7.10.
Mexico observes at the outset that it is not in a position to accept open meetings in this dispute. Mexico recalls that even in those disputes where it did not object to open meetings, it had indicated that this was without prejudice to its systemic position on public observation of meetings in dispute settlement proceedings. Mexico also notes that the meetings in the original and first compliance proceedings in this dispute were not open for public observation.
7.11.
In Mexico's view, the Panels should reject the United States' request. For Mexico, it is clear from the DSU that panel meetings are confidential, except if all parties agree otherwise. Mexico considers that Appendix 3 of the DSU indicates that deliberations must be kept confidential. Mexico recalls in this connection that it was a third party in US – Continued Suspension, and that it was among the Members that criticized the approach taken in that dispute at the DSB meeting at which the panel and Appellate Body reports were adopted. Mexico notes that unlike in that dispute, in this dispute there has been no agreement by the parties on holding a public meeting. In Mexico's view, there is in the present dispute a relationship of confidentiality between the parties and the Panels, not between each party and the Panels. According to Mexico, the Appellate Body in EU – Biodiesel (Argentina) declined the European Union's request to allow public observation of the oral hearing, noting that the other party expressed a preference against doing so.
7.12.
In Mexico's view, proceeding as the United States requests would affect the rights of Mexico and those of other Members that have systemic concerns about open meetings. Mexico submits in this regard that acceding to the United States' request could force other Members to accept open meetings because otherwise only one party's views are ventilated. Mexico suggests that the DSU already gives the United States the possibility to make its statements available on the website of the United States Trade Representative, as is its practice. Mexico considers that the United States' right to disclose its own positions and statements to the public does not have to be exercised through an open meeting.
7.13.
Mexico is therefore of the view that the Panels should deny the United States' request for a partially open meeting. Mexico also clarifies that it is not prepared to waive its right to confidentiality and that it therefore designates all information submitted by it in this dispute as confidential. Mexico considers that all statements and documents submitted by the parties and third parties are confidential until the Panels' Reports are circulated.
7.14.
Brazil, China, Ecuador, Guatemala, Korea, and India are opposed to the United States' request. Brazil, China, Ecuador, Guatemala, and Korea consider that panels may not hold open meetings, except with the agreement of all parties. Brazil, Ecuador, and Korea are of the view that this is clear from, inter alia, Article 14 of the DSU on panel deliberations.33 China, Ecuador, Guatemala, and India submit that the United States is free to increase transparency by releasing its statements to the public without the assistance of the Panels pursuant to Article 18.2 of the DSU. Moreover, Brazil, China, and Guatemala question whether a partially open panel meeting would meaningfully improve transparency. Brazil and India also observe that the issue of open hearings is a systemic and sensitive one on which Members have not reached consensus.
7.15.
Australia notes that it supports transparency and that it therefore, in principle, also supports the United States' request in this dispute, noting that panel meetings have been opened in the past with necessary safeguards to protect confidentiality. Norway considers that the DSU does not prevent panels from holding a partially open meeting as the United States suggests and notes that Article 12.1 of the DSU permits panels to depart from the working procedures in Appendix 3 after consulting with the parties. Japan is of the view that a partially open meeting would require additional work of the Panels and parties, but that the Panels can properly conduct a partially open meeting through delayed broadcasting without disclosing statements of WTO Members that do not wish to make them in public. In Japan's view, the only novelty in the United States' request is that it is one party, rather than all parties, that wishes to disclose its statements to the public.
7.16.
The Panels begin their analysis by noting that numerous WTO adjudicators, including the Appellate Body, panels and Article 22.6 arbitrators, have on request opened meetings with parties for public observation in their entirety, except for any parts of meetings during which BCI was addressed.34 If a WTO adjudicator has the power to accede to a request to fully open a hearing or meeting with the parties, then a fortiori it must in principle also have the power to go less far, including by opening only parts of a meeting with the parties.
7.17.
The meetings with parties in previous WTO dispute settlement proceedings that have been opened for public observation in their entirety have been opened with the agreement of all parties. At those fully open meetings, the parties were authorized to disclose not only statements of their own positions, but also statements of the positions of the other party or parties. The situation in the present proceedings is different, however. The United States is seeking authorization to disclose statements of its own positions only.
7.18.
We observe in this regard that, according to Article 18.2 of the DSU, nothing in the DSU precludes a party "from disclosing statements of its own positions to the public".35 According to the Appellate Body, this provision allows a party to forego confidentiality protection in respect of statements of its own positions.36 The Appellate Body has further confirmed that Article 18.2 covers not just statements in written form, but also oral statements and responses to questions at Appellate Body hearings.37 The same holds true, in our view, for oral statements and responses given at meetings of panels. We further observe that Article 18.2 does not stipulate that a party may disclose its statements only once, or only after any meetings of a WTO adjudicator with the parties.38
7.19.
Mexico, supported by several third parties, nevertheless considers that we cannot authorize the United States to forego confidentiality protection in respect of its statements of its own positions, except with Mexico's agreement. Mexico bases this contention on the Appellate Body's procedural ruling in EU – Biodiesel (Argentina).39 In our view, Mexico's reliance on this procedural ruling is misplaced. In EU – Biodiesel (Argentina), the Appellate Body rejected a unilateral request by the European Union that the Appellate Body conduct a fully open hearing even though the other party, Argentina, was not supportive of that request.40 This is not the situation we are facing, since the United States in this dispute requests authorization to disclose statements of its own positions, not those of Mexico.41
7.20.
Mexico further seems to consider that in respect of meetings or hearings, the DSU protects the confidentiality of the relationship between the parties taken as a group and a WTO adjudicator, rather than between each of the parties and a WTO adjudicator. We note, however, that Article 18.2 gives each party individually the right to disclose statements of its own positions. Where a fully open meeting is to be held, it is clear that all parties need to request authorization to disclose the statements of their own positions that they wish to make at the meeting. This does not imply, however, that one party can simply veto another party's request that it be authorized to disclose statements of its own positions. Indeed, this is also the approach taken by the Appellate Body in respect of third parties participating in its hearings (which the Appellate Body refers to as "third participants"). Although the Appellate Body has referred to a relationship of confidentiality between "the third participants"42 and itself, it has authorized those third participants that so wished to lift the confidentiality of their statements at the hearing, despite objections by other third participants.43 Thus, the Appellate Body did not impose an inflexible "all-or-none" rule for the lifting of confidentiality. In our view, this approach is equally appropriate in respect of the relationship between the parties and any WTO adjudicator. Indeed, it would be incongruous to permit individual third parties to forego confidentiality protection in respect of their statements (in those disputes where the parties have requested the same) even as other third parties wish to hold on to that protection, but to withhold that same opportunity from a party merely because another party objects to the granting of such an opportunity. Put another way, when it comes to authorizing the lifting of confidentiality protection for their statements, we consider that we should treat parties no less favourably than third parties.
7.21.
Mexico has also referred to Article 14.1 of the DSU and Paragraph 3 of Appendix 3 of the DSU, which provide that panel "deliberations" are to be confidential. We do not agree that these provisions imply that we cannot authorize the United States to lift the confidentiality of its statements. These provisions relate to a panel's internal work, not the meetings with the parties and third parties.44 Moreover, just like the Appellate Body, panels have authorized third parties that so wished to lift the confidentiality of their statements even as some third parties objected.45 This approach necessarily assumes that Article 14.1 does not prescribe closed panel meetings with parties or third parties.
7.22.
In our view, the confidentiality of panel meetings is covered by Paragraph 2 of Appendix 3 of the DSU, which says that panels shall meet in closed session. However, this paragraph forms part of those provisions from which panels may depart pursuant to Article 12.1 of the DSU, after consulting the parties and provided that such departure is not contrary to another provision of the DSU.46 In any event, Paragraph 2 in our view does not preclude a party or third party from foregoing confidentiality protection for its statements at a panel meeting, provided that another party (hereafter a "non-disclosing party") or other third parties (hereafter "non-disclosing third parties") can maintain confidentiality protection for their statements. Indeed, as already explained, this is the approach followed by those panels that held partially open third party sessions. We consider that Paragraph 2 permits the same approach in the present proceedings with regard to the parties.
7.23.
In the light of the foregoing, we consider that in principle we have the power to authorize the United States to disclose statements of its own positions (but not those of Mexico or a non-disclosing third party) to the public through a partially open panel meeting, even if Mexico opposes the United States' request. However, it does not follow that we must automatically grant the United States' request. We thus proceed to provide the main considerations that underpin our decision to grant the United States' request in the particular circumstances of these proceedings.
7.24.
Although the United States has an autonomous right to disclose statements of its own positions to the public, that right is not absolute. In the context of this dispute, it notably finds its limitation in Mexico's right not to have statements of its own positions disclosed by the United States during any public parts of the Panels' consolidated meeting.47 Mexico indicated in this regard that it wished to maintain the confidentiality of its own positions and information submitted to the Panels. It is therefore necessary to provide for a review process prior to any public viewing of a partially open meeting, to allow the Panels and the parties to ensure that any statements disclosed by the United States do not inadvertently disclose, directly or indirectly, statements of Mexico's positions. It follows that we may authorize the United States to disclose in a partially open meeting only those parts of its statements that do not disclose statements of Mexico's positions, and that we must therefore reserve the right to appropriately redact the statements that the United States wishes to be open for public observation.48
7.25.
For the same reason, we consider that we may authorize the United States to disclose in a partially open meeting only those parts of its statements that do not disclose statements of non-disclosing third parties. Likewise, we consider that we may authorize disclosing third parties to disclose in a partially open third party session only those parts of their statements that do not disclose statements of Mexico or non-disclosing third parties. Consequently, we must also reserve the right to redact (i) the statements of the United States to ensure that they do not disclose, directly or indirectly, statements of non-disclosing third parties' positions, and (ii) the statements of disclosing third parties to ensure that they do not disclose, directly or indirectly, statements of Mexico's or non-disclosing third parties' positions.
7.26.
A further limitation arises from the requirements of due process. These requirements mean, inter alia, that all parties must be given the opportunity to lift the confidentiality of statements of their own positions at partially open meetings. In these proceedings, Mexico chose not to avail itself of that opportunity. Further, these requirements mean that the implementation of any additional working procedures for partially open meetings, including the associated redaction process, must not impair the ability of any party that opposes partially open meetings to present its case or defence effectively.
7.27.
We note, in addition, Mexico's argument that if a partially open meeting is conducted, viewers will by definition be exposed to only one party's statements. In our view, however, this does not compromise due process. First, a party that does not wish its statements at a WTO adjudicator's meeting to be open for public observation is not thereby deprived of the possibility to otherwise disclose statements of its positions to the public. More importantly, Article 18.2 already allows each party to disclose statements of its own positions to the public independently of whether another party does the same. A partially open meeting thus does not create a new situation. The media, for instance, can (and does) already report to the public based on statements of only one party's positions where only that party has made available its statements on its government's website. Finally, we recall that in disputes where the meetings with the parties were opened for public observation, both the Appellate Body and panels have authorized third parties that so wished to lift the confidentiality of their statements at the relevant hearing or third-party session. Under this practice, it is accepted that viewers of those meetings are exposed to the views of only some third parties, even though the Appellate Body and panels are required to take all third parties' views into account.49
7.28.
Another factor that in our view should be taken into account when assessing a request for a partially open meeting is the importance, articulated in Article 3.3 of the DSU, of the prompt settlement of disputes. This suggests to us that the conduct of a partially open meeting should not significantly delay a WTO adjudicator's proceedings. In our view, one way to fulfil this objective is to devise additional working procedures governing partially open meetings that put appropriate emphasis on workability and efficiency.
7.29.
In addition, we must bear in mind our primary duty, which is to carefully assess the matter before us and resolve the dispute between the parties. Partially open meetings impose a greater burden on a WTO adjudicator than fully open meetings, owing to the need to make sure that there is no disclosure of statements of any party that wishes to maintain the confidentiality of its statements. In deciding whether to authorize a request for a partially open meeting, it therefore appears appropriate that a WTO adjudicator assess at the outset whether it has access to the requisite resources, in technical, logistical and human terms, to conduct a partially open meeting and any associated redaction process. Otherwise, the conduct of a partially open meeting could potentially have an adverse impact on the proper discharge of the adjudicative function and could thus also be detrimental to due process or the prompt settlement of disputes.
7.30.
We note, finally, the Appellate Body's view that any authorization to forego the confidentiality protection for statements of a party's or third party's positions must not undermine the integrity of the adjudicative function. The Appellate Body has already clarified in this regard that the mere fact of permitting public observation of a meeting does not have an adverse impact on the integrity of the adjudicative function.50
7.31.
In sum, it is in our view permissible for a WTO adjudicator to authorize a request for a partially open meeting if the conduct of such a meeting does not impair or interfere with (a) a non-disclosing party's or non-disclosing third party's right to confidentiality protection of statements of its own position, (b) due process, (c) the prompt settlement of disputes, or (d) the careful and efficient discharge, or the integrity, of the adjudicative function. Beyond that, we consider that it falls within the sound discretion of each WTO adjudicator considering a request for a partially open meeting to decide whether it is appropriate in the particular circumstances of its case to accede to that request.51 We observe in this respect that the rejection of such a request by a WTO adjudicator would not in and of itself deprive the requesting party of its right to disclose statements of its own positions to the public, since it would still have available to it other ways of exercising that right.
7.32.
Guided by the foregoing considerations, in the present proceedings we devised additional working procedures in consultation with the parties that we think fully protect Mexico's and non-disclosing third parties' right to confidentiality protection, satisfy the requirements of due process, and are sufficiently workable and efficient to safeguard the promptness of dispute settlement and the proper discharge and integrity of our adjudicative function.52
7.33.
In granting the United States' request we notably also take into account the following four circumstances. First, the present dispute concerns the protection of dolphins and thus a conservation-related measure. In this kind of dispute, even a partially open meeting is apt to enhance understanding of, and confidence in, the WTO dispute settlement process.53 Second, there was in these proceedings only one relatively short and consolidated substantive meeting with the Panels that was requested to be partially opened for public observation. Third, the parallel conduct of an arbitration under Article 22.6 of the DSU in this dispute required the assembly of a substantial Secretariat support team. We were thus in a position where we could conduct a partially open meeting and carry out the associated redaction process without this compromising our substantive work. Finally, in granting the United States' request, we also seek to ensure consistency, since the arbitrator in this dispute has already authorized an identical request by the United States.
7.34.
On the basis of these considerations, we therefore conclude that in the particular circumstances of these compliance panel proceedings it is, on balance, appropriate for us to accept the United States' request that it be permitted to disclose through public viewing the statements of its own positions made during the Panels' meeting. We likewise permit any third parties that so request to disclose through public viewing the statements of their own positions made during the Panels' third party session.54 Our authorizations are subject to the dual condition that the public viewing take the form of delayed (rather than simultaneous) viewing, and that any parts of the meeting, including the third party session, opened for partial public observation not disclose statements of Mexico's positions, or positions of non-disclosing third parties, and hence be subject to redaction prior to the public viewing as necessary.

7.3 Preliminary Issue: United States' failure to request consultations

7.35.
In its first written submission, Mexico argues that the United States did not request to hold consultations with Mexico in relation to the Article 21.5 proceedings it initiated, and thereby violated its obligations under Articles 4, 6, and 21.5 of the DSU. According to Mexico, as a legal matter, consultations must be held in Article 21.5 proceedings unless explicitly agreed otherwise in a sequencing agreement between the disputing parties. In Mexico's view, in normal circumstances, the United States' failure to request consultations prior to requesting the establishment of a panel under Article 21.5 would undermine the jurisdiction of the panel established pursuant to that request. However, given the specific circumstances of these proceedings, wherein the subject matters of the two proceedings substantially overlap and consultations were held in the proceedings brought by Mexico55, Mexico does not challenge the jurisdiction of the Panel established pursuant to the request of the United States. Mexico does, however, request that the Panels set forth guidance for future cases, especially as to whether, in the absence of an agreement with the other party, a Member may initiate Article 21.5 proceedings without first requesting consultations. In Mexico's view, there is nothing in the DSU or in the jurisprudence that prevents the Panels from providing the requested guidance on this important systemic issue.56
7.36.
In response to Mexico's request for guidance, the United States submits that the Panels should not issue the guidance requested by Mexico given that there is no live controversy behind Mexico's request. In the view of the United States, the guidance requested by Mexico would amount to an advisory opinion that would not contribute to resolving the dispute and would therefore be outside the mandate of the Panels. Moreover, the United States argues that there is in fact no requirement to request consultations under Article 4 of the DSU as a condition for requesting the establishment of a compliance panel pursuant to Article 21.5 of the DSU. According to the United States, the Appellate Body has already confirmed this point. Further, in the view of the United States, Article 4 of the DSU is, according to its own terms, inapplicable in situations where the original responding party initiates Article 21.5 proceedings.57
7.37.
The Panels begin by observing that, as Mexico acknowledges, consultations were held between the parties in the context of the compliance proceedings brought by Mexico. As we have already noted, those proceedings are closely connected to the proceedings brought by the United States, in the context of which Mexico alleges that the United States failed to request to hold consultations. The consultations held in the context of the proceedings brought by Mexico would certainly have enabled the parties to "exchange information, assess the strengths and weaknesses of their respective cases, [and] narrow the scope of the differences between them"58 with respect to both the proceedings brought by Mexico and those brought by the United States. Indeed, Mexico also acknowledges that "in the circumstances of this dispute the holding of consultations in the parallel proceeding mitigates the failure of the United States to consult[.]"59 We do not see, therefore, that the United States' failure to consult could, in the specific circumstances of these proceedings, have had any practical effect on the parties' ability to understand, prepare for, or even narrow their dispute.
7.38.
Moreover, we note that in Mexico – Corn Syrup, the Appellate Body declined to decide whether the general obligations in the DSU regarding prior consultations were applicable in proceedings under Article 21.5 of the DSU. The Appellate Body nevertheless held that, even if those obligations were applicable, non-compliance therewith – that is, failure to engage in consultations - would not deprive a panel of its authority to deal with and dispose of a dispute before it.60 Accordingly, we do not agree with Mexico that in normal circumstances, failure to request consultations would vitiate the jurisdiction of a panel established pursuant to Article 21.5 of the DSU. Consequently, in the specific context of these proceedings, even if the United States were required to have requested consultations prior to requesting the establishment of a panel under Article 21.5 of the DSU, its failure to do so would not negate our jurisdiction. Therefore, we do not consider that the "guidance" Mexico requests would have any legal implications in the present circumstances (even if Mexico were challenging the jurisdiction of the Panel established at the request of the United States, which, as we noted above, it is not). In our view, therefore, the United States' characterization of Mexico's request for guidance as a request for an "advisory opinion" appears to be accurate.
7.39.
In this respect, we are mindful that no provision of the DSU explicitly gives panels the power to issue advisory opinions or, indeed, to make any findings other than those required to resolve the dispute before them. Indeed, a number of provisions of the DSU suggest that panels should not make findings in respect of issues that are not in dispute.61 For example, Article 3.7 of the DSU provides that the "aim of the dispute settlement mechanism is to secure a positive solution to a dispute". Similarly, Article 3.4 of the DSU stipulates that "[r]ecommendations or rulings made by the DSB shall be aimed at achieving a satisfactory settlement of the matter in accordance with the rights and obligations under this Understanding and under the covered agreements". Additionally, Article 7.1 of the DSU charges panels with making "such findings as will assist the DSB in making the recommendations or in giving the rulings provided for in that/those agreement(s)". In our view, these provisions make clear that the purpose of the dispute settlement system is to resolve disputes between Members.
7.40.
This understanding of the scope of WTO dispute settlement has been confirmed by the Appellate Body. In US – Wool Shirts and Blouses, after noting that Article 3.2 of the DSU indicates that one of the functions of dispute settlement is to "clarify the existing provisions of [the covered] agreements in accordance with customary rules of interpretation of public international law", the Appellate Body explained that this provision is not meant "to encourage either panels or the Appellate Body to 'make law' by clarifying existing provisions of the WTO Agreement outside thecontext of resolving a particular dispute. A panel need only address those claims which must be addressed in order to resolve the matter in issue in the dispute".62 This statement indicates that panels are generally not required or, indeed, empowered to engage with issues that are not in dispute between the parties and whose resolution would accordingly not contribute to the "prompt settlement"63 of disputes.
7.41.
In our view, given that Mexico has indicated that it is not challenging the jurisdiction of the Panel established pursuant to the United States' request, and given the Appellate Body's clarification that failure to consult would not in any event deprive a panel established pursuant to Article 21.5 of the DSU of its authority, the question on which Mexico seeks "guidance", that is, whether in the absence of agreement with the other party a Member is allowed to initiate an Article 21.5 compliance proceeding without requesting consultations, is not one which must be addressed in order to resolve the matter before us. Accordingly, we decline to set forth the guidance requested by Mexico.

7.4 The measure at issue

7.4.1 Elements of the measure at issue

7.42.
The Panels now turn to describe in more detail the measure at issue in these proceedings. In this context, we will first identify the elements that constitute the measure at issue, and then proceed to describe them as relevant for the purposes of these proceedings.
7.43.
We recall that in the original and the first compliance proceedings, the Tuna Measure was described as consisting of three elements, namely, (a) the DPCIA; (b) the relevant implementing regulations; and (c) the Hogarth ruling.64 In the present proceedings, the United States' description of the 2016 Tuna Measure refers to the same three elements.65 The only difference between the Tuna Measure as described in the original and first compliance proceedings and as described by the United States in the present proceedings is that in these proceedings the United States' reference to the implementing regulations includes the amendments made by the 2016 Rule.66 Mexico's description of the components of the Measure, however, is less clear. Although in certain parts of its submissions, Mexico, like the United States, refers to the 2016 Tuna Measure as comprising the same three elements mentioned above67, in other parts of its submissions, Mexico refers, in addition to those three elements, to two additional elements. First, in its panel request in these proceedings, Mexico refers, to "[a]ny implementing guidance, directives, policy announcements or any other document issued in relation to instruments [(a)] through [(c)] above, including any modifications or amendments in relation to those instruments".68 Second, in certain parts of its submissions, Mexico refers to the alleged action of the United States in pressuring US retailers not to distribute Mexican tuna products.69
7.44.
With respect to the first additional element cited in Mexico's panel request, that is, "[a]ny implementing guidance, directives, policy announcements or any other document issued in relation to instruments [(a)] through [(c)] above, including any modifications or amendments in relation to those instruments", we note that Mexico does not argue that, as a measure taken to comply with DSB recommendations and rulings within the meaning of Article 21.5 of the DSU, the 2016 Tuna Measure includes, in addition to the three elements cited above, "[a]ny implementing guidance, directives, policy announcements or any other document issued in relation to instruments [(a)] through [(c)] above, including any modifications or amendments in relation to those instruments" that the Panels would need to take into account in their analysis in these proceedings. Neither has Mexico presented any evidence of such directives, announcements, modifications or amendments to the Panels. As such, Mexico's description refers to this additional element in the abstract, without arguing that in fact there exists such an element which is subsumed within the definition of the measure taken to comply subject to these proceedings. Further, the claims and arguments that Mexico has presented in these proceedings do not in any way pertain to this alleged additional element of the 2016 Tuna Measure.
7.45.
With regard to the second additional element, namely, the alleged action of the United States in pressuring US retailers not to distribute Mexican tuna products, we note, first, that, unlike the fourth element discussed above, this element is not included in the description of the measure at issue in Mexico's panel request. We also note that it is not clear whether Mexico is arguing that this element is, in the jurisdictional sense, part of the measure taken to comply in these proceedings. In response to a question from the Panels concerning whether Mexico was seeking separate findings from the Panels in respect of this alleged element of the Measure, Mexico stated that it was not.70 Rather, Mexico explains that "[t]he action of the United States in pressuring retailers not to distribute Mexican tuna products is itself a measure implemented under and in relation to the 2016 tuna measure with the specific intent to impede the marketing of Mexican tuna products in the US market".71 Although this argument suggests that Mexico sees this element as a measure, or as a part of the 2016 Tuna Measure, in the same response, Mexico also argues that these letters constitute additional evidence of the detrimental effect of the 2016 Tuna Measure. However, Mexico also states that since the United States acknowledges that the 2016 Tuna Measure has a detrimental effect on Mexican tuna products, "it is not necessary for the Panels to consider this evidence to rule on the issues before them".72 For its part, at the Panels' joint substantive meeting with the parties, the United States argued that this alleged additional element falls outside the Panels' terms of reference. Moreover, the United States disagrees with Mexico's allegation that the US government has pressured US retailers not to sell Mexican products. The United States indicates that it invited US retailers to submit statements to be used in the context of the arbitration proceedings under Article 22.6 of the DSU in this dispute.73 We note that the statements cited by Mexico were submitted to, and taken into account by, the Arbitrator in the mentioned arbitration proceedings.74 As Mexico also acknowledges, none of the claims or arguments presented by Mexico in these compliance proceedings in any way pertain to this alleged additional element of the 2016 Tuna Measure.75 Mexico has not explained how this alleged additional element interacts with the other elements of the 2016 Tuna Measure, and neither has it advanced any arguments concerning whether the alleged additional element stems exclusively from a legitimate regulatory distinction.
7.46.
We recall that this second additional element of the 2016 Tuna Measure is not included in Mexico's panel request. We also note that Mexico did not respond to the United States' argument that this alleged additional element is not within the Panels' terms of reference. In the light of Mexico's own statement that the Panels need not consider this aspect of Mexico's claim in the light of the United States' concession that the 2016 Tuna Measure has a detrimental impact on Mexican tuna products, it would, in our view, at any rate be unnecessary to deal with this alleged additional element of the Measure in order to fulfil our functions under the DSU.
7.47.
On the basis of the foregoing, we will assess parties' claims and arguments in relation to the 2016 Tuna Measure defined as consisting of (a) the DPCIA, (b) the relevant implementing regulations; and (c) the Hogarth ruling, which are the three elements of the Measure on which both parties agree, and to which both parties' claims and arguments pertain. We now turn to a detailed description of each of these three elements.

7.4.2 Description of the measure at issue

7.48.
As noted above, the 2016 Tuna Measure consists of (a) the DPCIA, (b) the implementing regulations as amended by the 2016 Rule, and (c) the Hogarth ruling. The panels and the Appellate Body in previous stages of this dispute have described the original and the 2013 Tuna Measure in detail.76 In this section, the Panels describe the 2016 Tuna Measure only insofar as relevant for the purposes of resolving the claims raised in the present proceedings.
7.49.
The 2016 Tuna Measure, like the previous versions of the Tuna Measure, pursues two objectives: first, to ensure that consumers are not misled or deceived about whether tuna products contain tuna that was caught in a manner that adversely affects dolphins; and, second, to contribute to the protection of dolphins, by ensuring that the US market is not used to encourage fishing fleets to catch tuna in a manner that adversely affects dolphins.77 To this end, it conditions the use on a tuna product78 of a dolphin-safe label upon certain requirements that vary depending on the fishing method by which tuna contained in the tuna product was harvested, the ocean area where it was caught, and the type of vessel used. The Measure also prohibits any reference to dolphins, porpoises, or marine mammals on the label of a tuna product if the tuna contained in that product does not comply with the labelling conditions provided for in the measure.79
7.50.
The 2016 Tuna Measure sets out several substantive conditions for access to a dolphin-safe label. First, it disqualifies from being labelled all tuna products containing tuna harvested by two methods of fishing: (i) large-scale driftnet fishing on the high seas80; and (ii) vessels using purse seine nets to encircle or "set on" dolphins anywhere in the world81. Although the DPCIA's disqualification of tuna products derived from tuna caught by setting on dolphins was suspended in 2002 by virtue of administrative action82, the Hogarth ruling overturned that action shortly thereafter83, thereby restoring this condition of access to the US dolphin-safe labelling regime. The disqualification of tuna products containing tuna caught by setting on dolphins thus formed part of, and is unchanged as compared to, both the original and the 2013 Tuna Measure. Second, all other tuna products, that is, those containing tuna harvested by all other fishing methods, are potentially eligible for the dolphin-safe label, but become ineligible if they contain tuna caught in a set or other gear deployment during which a dolphin was killed or seriously injured.84 The 2016 Tuna Measure also prescribes a number of certification and tracking and verification requirements relating to the substantive conditions.
7.51.
With respect to certification, the 2016 Tuna Measure provides that, for a tuna product to be labelled dolphin-safe, it must be accompanied by certain certifications that the eligibility requirements were met. Under 50 CFR Section 216.91(a)(3), for fishing trips that began on or after 21 May 2016, captains85 of all vessels in all fisheries other than the large purse seine86 fishery in the Eastern Tropical Pacific Ocean (ETP)87 and a large-scale driftnet fishery88 must certify, that:

No purse seine net or other fishing gear was intentionally deployed on or used to encircle dolphins during the fishing trip in which the tuna were caught, and that no dolphins were killed or seriously injured in the sets or other gear deployments in which the tuna were caught.89

7.52.
In these fisheries, certification by an independent observer may also be required, under certain circumstances described below.90
7.53.
Additionally, under the 2016 Tuna Measure, captains of vessels operating outside the ETP large purse seine fishery (and high seas driftnet fisheries) must certify, in addition to the above, that they have completed the National Marine Fisheries Service (NMFS) Tuna Tracking and Verification Program (TTVP) dolphin-safe training course (the Captain Training Course).91 The course, which can be accessed on the Internet in English, Mandarin Chinese, Indonesian, Japanese, Korean, Spanish, Tagalog, Thai, and Vietnamese, covers four main topics: identifying dolphins of the taxonomic family Delphinidae; identifying intentional gear deployment on or encirclement of dolphins; identifying dolphin mortality and serious injury; and physically separating dolphin-safe tuna from non-dolphin-safe tuna from the time of capture through unloading.92 The contents of the Captain Training Course are discussed further below.93
7.54.
For large purse seine vessels in the ETP, certification is required from both the vessel captain and an International Dolphin Conservation Program (IDCP)-approved observer94 that (a) no dolphins were killed or seriously injured during the sets in which the tuna was caught, and (b) none of the tuna was caught on a trip using a purse seine net intentionally on or to encircle dolphins.95
7.55.
With respect to tracking and verification, tuna products are eligible to receive a dolphin-safe label only if they meet the tracking and verification requirements provided for in the 2016 Tuna Measure.
7.56.
The 2016 Tuna Measure, like the 2013 Tuna Measure, requires that dolphin-safe and non-dolphin-safe tuna, wherever and however caught, be segregated from the moment of catch through the entire processing chain.96 However, the requirements pursuant to which tuna must be segregated, tracked, and verified differ as between tuna caught in the ETP large purse seine fishery, on the one hand, and other fisheries, on the other hand. This is because the tracking and verification of tuna caught in the ETP large purse seine fishery must be conducted consistently with the Agreement on the International Dolphin Conservation Program (AIDCP) Resolution to Adopt the Modified System for Tracking and Verification of Tuna (AIDCP Tracking and Verification System).97 However, the tracking and verification of tuna caught in other fisheries must be conducted according to different regulations established principally in the implementing regulations.
7.57.
The AIDCP Tracking and Verification System is based on the use of Tuna Tracking Forms (TTFs). Every TTF has a unique number. On every fishing trip, ETP large purse seine vessels must maintain two forms, one to record tuna harvested in dolphin-safe sets, and one to record tuna harvested in non-dolphin-safe sets.98 Under the AIDCP, the determination of the dolphin-safe status of tuna is made at the end of each set.99 The IDCP-approved observer and the vessel engineer are required to initial each entry following each set.100 Once the tuna harvested in a particular set is on board the fishing vessel, it is loaded into wells designated as either dolphin-safe or non-dolphin-safe, and recorded on the trip TTF.101 Tuna from one set can be loaded into a well containing tuna from another set and tuna from one set can be loaded into multiple wells, provided that the designations are correct (that is, that tuna harvested in dolphin-safe sets is stored only in wells designated as dolphin-safe, and tuna harvested in non-dolphin-safe sets is stored only in wells designated as non-dolphin-safe).102 At the end of each fishing trip, the IDCP-observer and the captain of the fishing vessel sign both TTFs to certify that the information on the forms is accurate.103 Trans-shipments of tuna (i.e. transfer of tuna at sea before completion of the fishing trip) are permitted, but must be documented on the TTFs of both the transferring and the receiving vessels.104
7.58.
When tuna is unloaded at port, dolphin-safe and non-dolphin safe tuna must be unloaded into separate bins, and each bin must be identified with the corresponding TTF number. The AIDCP Tracking and Verification System does not prohibit tuna stored in different wells on-board the vessel from being comingled in individual bins, or tuna stored in the same well on-board the vessel from being separated into different bins. The only requirement is that dolphin-safe and non-dolphin-safe tuna be stored in separate bins.105
7.59.
At the time of unloading, the relevant TTF must be transmitted to the competent authority of an AIDCP party.106 The relevant TTF number must then accompany the tuna through sales of portions of the catch, and through every step of processing of those portions.107 The relevant national authority must report any subsequent transfer of ownership to the AIDCP Secretariat, specifying, inter alia, the TTF number(s).108 During storage and processing, dolphin-safe and non-dolphin-safe tuna cannot be processed on the same lines at the same time, and processors must maintain records complete enough to allow the lot numbers of processed tuna to be traced back to the corresponding TTF number.109 Tuna exported as AIDCP dolphin-safe must be accompanied by a certificate of its dolphin-safe status issued by a competent authority, which must also include a reference to the relevant TTF number.110
7.60.
The AIDCP Tracking and Verification System also provides that the national programs established by the parties to the AIDCP should include periodic audits and spot checks for tuna products, as well as mechanisms for cooperation among national authorities.111
7.61.
The AIDCP Tracking and Verification System is directly applicable to US-flagged large purse seine vessels in the ETP by virtue of 50 CFR Section 216.93. Foreign-flagged large purse seine vessels catching tuna in the ETP are also required to comply with the System. Under the 2016 Tuna Measure, tuna products containing tuna harvested in the ETP by non-US-flagged large purse seine vessels may be labelled dolphin-safe only if the vessel belongs to a nation that is a party to the AIDCP and is therefore subject to the AIDCP Tracking and Verification System.112 Additionally, the NOAA Form 370 requires that imports of tuna harvested by non‑US-flagged ETP large purse seine vessels, or of tuna products derived from the same, be accompanied by documentation from the appropriate AIDCP member country certifying that there was an IDCP‑approved observer on board the vessel at all times, and listing the numbers of the associated TTFs. Thus, under the Measure, tuna products containing tuna caught by both US‑flagged and non-US-flagged large purse seine vessels in the ETP have access to the dolphin-safe label only if the handling of the TTFs and the tracking and verification of tuna are conducted consistent with the AIDCP Tracking and Verification System.113
7.62.
Under the 2016 Tuna Measure, tuna caught in a fishery other than the ETP large purse seine fishery is not required to comply with the requirements of the AIDCP Tracking and Verification System. Rather, it is subject to what the United States refers to as the "NOAA regime".114 To be eligible for a dolphin-safe label under the NOAA regime, tuna caught outside the ETP large purse seine fishery must be kept physically separate from non-dolphin-safe tuna from the time of catch, through offloading and processing.115
7.63.
Under the NOAA regime, all tuna product imported into the United States, regardless of where the tuna was caught and whether the dolphin-safe label is used, must be accompanied by a NOAA Form 370 (Form 370), which designates, inter alia, whether the tuna is dolphin-safe.116 Dolphin-safe and non-dolphin-safe tuna products must have separate Form 370s. For tuna product designated dolphin-safe, Form 370 contains the necessary certifications, and requires identification of the harvesting vessel, the fishing gear used, and the trip on which the tuna was caught.117
7.64.
The NOAA regime requires US tuna processors to submit monthly reports to the US Tuna Tracking and Verification Program for all tuna received at their processing facilities.118 These reports contain the same information as is contained in the Form 370, as well as certain additional information, such as unloading dates and the condition of the tuna products.119 Additionally, NMFS is empowered to undertake verification activities, including dockside inspections of vessels, monitoring of Form 370s, monitoring of cannery reports, audits of US canneries, and retail market spot checks.120 Other US agencies may conduct on-board inspections on the high seas and in US waters. In its submissions on this aspect of the Measure, Mexico noted that US agencies lack authority to audit non-US fishing vessels, carrier vessels, and processors (i.e. canneries).121
7.65.
Additionally, the 2016 Tuna Measure establishes new chain of custody requirements for tuna products produced from tuna caught outside the ETP large purse seine fishery, and which are to be marketed as dolphin-safe. Specifically, US processors and importers of such tuna products must collect and retain for two years information on each point in the chain of custody of the tuna or tuna product, including information on all storage facilities, trans-shippers, processors, and wholesalers/distributors.122 The retained information must be provided to NMFS upon request, and must be sufficient for NMFS to conduct a trace-back of any tuna product marketed as dolphin-safe to verify that the tuna product in fact meets the dolphin-safe labelling requirements. The information must also be sufficient to enable NMFS to trace back any non-dolphin-safe tuna loaded onto the harvesting vessel back to one or more storage wells or other storage locations for a particular fishing trip to prove that such non-dolphin-safe tuna was kept physically separate from dolphin-safe tuna through unloading. These new requirements apply to all tuna products labelled dolphin-safe if those products contain tuna harvested on a fishing trip beginning on or after 21 May 2016.
7.66.
Breach of these requirements may lead to the imposition of sanctions. In particular, sanctions for offering for sale or export tuna products falsely labelled dolphin-safe may be assessed against any producer, importer, exporter, distributor, or seller who is subject to the jurisdiction of the United States.123 Violators may be prosecuted under the DPCIA provisions directly, under federal provisions prohibiting false statements and smuggling, or under federal labelling standards.124
7.67.
Additional certification and tracking and verification requirements may be imposed on tuna and tuna products made from tuna caught outside the ETP large purse seine fishery pursuant to the so-called "determination provisions". In the 2016 Tuna Measure, there are two relevant determination provisions: one concerning certification125, and one concerning tracking and verification.126
7.68.
With respect to certification, under 50 CFR Section 216.91(a)(3)(v) provisions, NOAA may require an observer certification in addition to the captain certification where the Assistant Administrator has determined that a fishery other than the ETP large purse seine fishery has either a regular and significant association between dolphins and tuna (similar to the association between dolphins and tuna in the ETP) or a regular and significant mortality or serious injury of dolphins is occurring. The observer must be a participant in a national or international program acceptable to the Assistant Administrator. The Assistant Administrator retains the discretion to determine that an observer certification is unnecessary.
7.69.
With respect to tracking and verification, the determination provisions state that, where the Assistant Administrator has made a certification of regular and significant association or regular and significant mortality or serious injury under 50 CFR Section 216.91(a)(3)(v), any imported tuna or tuna product made from tuna caught on a trip beginning on or more than 60 days after the publication of a notice of the determination in the Federal Register, and which is intended to be labelled as dolphin-safe, must be accompanied by valid documentation signed by a representative of the vessel flag nation or the processing nation (if processed in another nation) certifying that (a) the catch documentation recorded on the Form 370 is correct; (b) the tuna or tuna products meet the US dolphin-safe labelling standards; and (c) the chain of custody information is correct.127 The Panels examine these additional requirements in more detail later in these Reports.128
7.70.
In summary, there are four central elements or aspects of the 2016 Tuna Measure:129

a. The "eligibility criteria", pursuant to which tuna products made from tuna caught by (a) setting on dolphins and (b) driftnets in the high seas are disqualified from accessing a dolphin-safe label, while tuna products made from tuna caught by other fishing methods are provisionally eligible;

b. The "certification requirements", which require certain documentation to accompany tuna intended to be labelled as dolphin-safe;

c. The "tracking and verification requirements", which impose certain conditions concerning the segregation of dolphin-safe and non-dolphin-safe tuna from the time of catch through off-loading, processing, and sale;

d. The "determination provisions", which allow for additional certification and tracking and verification requirements to be imposed in respect of tuna caught outside the ETP large purse seine fishery under certain circumstances.

7.71.
Of course, these elements form part of a single measure and thus work together towards the same objectives.130 They are highly interconnected and interrelated. For example, as the Appellate Body emphasized in the first compliance proceedings, the two substantive conditions for access to the dolphin‑safe label – namely, the conditions of "no setting on dolphins" and "no dolphins killed or seriously injured" – are both defined by, and verified through, the associated certification and tracking and verification requirements.131 Accordingly, in conducting our assessment of the WTO-consistency of the 2016 Tuna Measure, we will carefully consider both the individual elements of the 2016 Tuna Measure and the way in which these elements work together and mutually reinforce one another.132 We will examine the Measure as a whole, in an integrated manner133, taking account of the overall architecture of the dolphin-safe labelling regime.134

7.5 Claim under Article 2.1 of the TBT Agreement

7.5.1 Introduction: "technical regulation", "like products", and "detrimental impact"

7.72.
As noted above, the United States asks the Panels to find that the 2016 Tuna Measure brings the United States into compliance with its WTO obligations, including Article 2.1 of the TBT Agreement. Mexico, however, asks the Panels to find that the 2016 Tuna Measure is WTO-inconsistent, including under Article 2.1 of the TBT Agreement.
7.73.
In its report in the first compliance proceedings in this dispute, the Appellate Body confirmed that in order to establish a violation of Article 2.1 of the TBT Agreement, a complainant must establish that (a) the measure at issue is a technical regulation within the meaning of Annex 1.1 to the TBT Agreement; (b) the relevant products are "like" products; and (c) the measure at issue accords less favourable treatment to imported products than to the relevant group of like products.135 Moreover, the Appellate Body stated that the "treatment no less favourable" element of the analysis must be addressed in two distinct steps. First, a panel must determine whether the challenged measure modifies the conditions of competition to the detriment of the relevant imported products vis-à-vis like products of domestic origin and/or like products originating in any other country.136 If the panel makes such a finding, then it must proceed to determine whether the detrimental impact on imports stems exclusively from a legitimate regulatory distinction rather than reflecting discrimination against the group of imported products.137
7.74.
The parties agree that the 2016 Tuna Measure, like the previous versions of the Tuna Measure, is a technical regulation within the meaning of Annex 1.1 to the TBT Agreement. They also agree that the relevant products, i.e. Mexican tuna products on the one hand and tuna products produced by the United States and other countries on the other hand, are "like".138 We do not see that the facts, including the overall architecture and structure of either the original or the 2013 Tuna Measure, or the nature of the products at issue have changed in any way that would call these conclusions into doubt. The parties have not suggested that this would be the case. Accordingly, we agree with the parties that the 2016 Tuna Measure is a technical regulation, and that the relevant products are "like".
7.75.
The parties also agree that the 2016 Tuna Measure modifies the conditions of competition to the detriment of Mexican tuna products in the US market.139 Specifically, the parties agree that the key elements of the original and 2013 Tuna Measures – in particular the disqualification of all tuna caught by setting on dolphins from using a dolphin-safe label, and the provisional qualification of tuna caught by other fishing methods to use such a label – and the relevant features of the US market for tuna remain unchanged, so that most Mexican tuna products are still being excluded from access to the dolphin-safe label, whereas most like products from the United States and other Members are still eligible for such label.140
7.76.
In this connection, we recall that in the first compliance proceedings, the Appellate Body explained that:

[A]ccess to the dolphin-safe label constitutes an advantage on the US market for tuna products by virtue of that label's significant commercial value. We further recall that, in the original proceedings, the Appellate Body relied on the following factual findings by the original panel: (i) the Mexican tuna cannery industry is vertically integrated, and the major Mexican tuna products producers and canneries own their vessels, which operate in the ETP; (ii) at least two thirds of Mexico's purse seine tuna fleet fishes in the ETP by setting on dolphins and is therefore fishing for tuna that would not be eligible to be contained in a dolphin‑safe tuna product under the US dolphin-safe labelling provisions; (iii) the US fleet currently does not practice setting on dolphins in the ETP; and (iv) as the practices of the US and Mexican tuna fleets currently stand, most tuna caught by Mexican vessels, being caught in the ETP by setting on dolphins, would not be eligible for inclusion in a dolphin-safe product under the US dolphin-safe labelling provisions, while most tuna caught by US vessels is potentially eligible for the label. These various factual elements thus supplied the foundation for the Appellate Body's finding of detrimental impact.141

7.77.
Like the parties, we do not see that there has been any relevant change in these factual circumstances. Indeed, we agree with the parties that the 2016 Tuna Measure maintains the overall architecture and structure of the original and 2013 Tuna Measures – in particular, it maintains the regulatory distinction between tuna products derived from tuna caught by setting on dolphins and tuna products derived from tuna caught by other fishing methods. Thus, although the 2016 Tuna Measure has introduced new requirements in respect of tuna products made from tuna caught outside the ETP, the distinction between tuna caught by setting on dolphins, which (together with tuna caught by high seas driftnet fishing) is ineligible to receive a dolphin-safe label, and tuna caught by other fishing methods, which is provisionally eligible for a dolphin-safe label, remains in effect.142
7.78.
In the light of this, and given the parties' agreement that the relevant factual situation has not changed from the original or the first compliance proceedings, we find that, by excluding most Mexican tuna products from access to the dolphin-safe label, while granting conditional access to such label to like products from the United States and other countries, the 2016 Tuna Measure, similar to the original and the 2013 Tuna Measure, modifies the conditions of competition to the detriment of Mexican tuna products in the US market.143
7.79.
The parties' disagreement as to the WTO-consistency of the 2016 Tuna Measure centres on the question of whether the detrimental impact caused by the 2016 Tuna Measure nevertheless does not accord treatment less favourable to Mexico within the meaning of Article 2.1 of the TBT Agreement, because such detrimental impact stems exclusively from a legitimate regulatory distinction. This question is at the heart of these proceedings. The parties, however, have very different understandings of the legal standard to be applied in this part of the analysis under Article 2.1 of the TBT Agreement. Accordingly, we now turn to consider the proper meaning of the "legitimate regulatory distinction" test on the basis of the text of Article 2.1 and the Appellate Body's guidance in the previous stages of this dispute.

7.5.2 "Legitimate regulatory distinction": the applicable legal standard

7.80.
As noted above, the Appellate Body has clarified that the existence of detrimental impact is not sufficient to establish a violation of Article 2.1 of the TBT Agreement. Rather, if a panel determines that a measure has modified the conditions of competition to the detriment of imported products vis-à-vis like products of domestic origin and/or like products originating in any other country, then the panel must proceed to determine whether the detrimental impact on imports stems exclusively from a legitimate regulatory distinction rather than reflecting discrimination against the group of imported products.144
7.81.
In this connection, the Appellate Body has repeatedly emphasized that the specific context provided by other provisions of the TBT Agreement is instructive in understanding the expression "treatment no less favourable" in Article 2.1. According to the Appellate Body, the specific context provided by, in particular, Annex 1.1, Article 2.2, and the second, fifth, and sixth recitals of the preamble, supports the view that Article 2.1 does not operate to prohibit a prioriany and every restriction on international trade. Moreover, in the Appellate Body's view, the sixth recital sheds light on the meaning and ambit of the "treatment no less favourable" requirement in Article 2.1 by making clear that technical regulations may pursue legitimate objectives but must not be applied in a manner that would constitute a means of arbitrary or unjustifiable discrimination. On the basis of these considerations, the Appellate Body has clarified that Article 2.1 should not be read to mean that all regulatory distinctions would per se constitute less favourable treatment within the meaning of Article 2.1.145 Rather, some distinctions that entail detrimental impact may not give rise to less favourable treatment under Article 2.1. This would be the case, in particular, where the detrimental impact on imports stems exclusively from a legitimate regulatory distinction.146
7.82.
The Appellate Body has stated that in determining whether the detrimental impact on imports stems exclusively from a legitimate regulatory distinction, a panel must carefully scrutinize whether the technical regulation at issue is even‑handed in its design, architecture, revealing structure, operation, and application in the light of the particular circumstances of the case. The Appellate Body has pointed out that where a regulatory distinction is not designed and applied in an even‑handed manner – because, for example, it is designed or applied in a manner that constitutes a means of arbitrary or unjustifiable discrimination – that distinction cannot be considered "legitimate", and thus the detrimental impact will reflect discrimination proscribed under Article 2.1. Therefore, a measure that involves "arbitrary or unjustifiable discrimination" would not be designed and applied in an "even-handed manner". At the same time, according to the Appellate Body, the fact that a measure is designed in a manner that constitutes a means of arbitrary or unjustifiable discrimination is not the only way in which a measure may lack even-handedness, such that the detrimental impact cannot be said to stem exclusively from legitimate regulatory distinctions.147 Rather, it is one of the ways to determine whether the measure is even‑handed and therefore its detrimental impact stems exclusively from a legitimate regulatory distinction.148
7.83.
The Panels note that, in the first compliance proceedings in this dispute, the Appellate Body explained that, in interpreting and applying the "treatment no less favourable" element of Article 2.1 of the TBT Agreement, and in particular in assessing whether the identified detrimental impact stems exclusively from a legitimate regulatory distinction, a panel does not err by assessing whether the detrimental impact can be reconciled with, or is rationally related to, the policy objective pursued by the measure at issue, so long as, in doing so, it does not preclude consideration of other factors that may also be relevant to the analysis.149 Similarly, the Appellate Body stated that "depending on the nature of the measure at issue and the circumstances of the case at hand, additional factors – beyond the question of whether the discrimination can be reconciled with the policy objective – could also be relevant to the analysis of whether the discrimination is arbitrary or unjustifiable".150 We understand the Appellate Body as meaning that, in assessing whether a measure is "even-handed", a panel may consider whether the measure/regulatory distinction causing the detrimental impact is designed or applied in a manner that constitutes a means of "arbitrary or unjustifiable discrimination". One way of assessing this is by considering whether there is a rational relationship between the discrimination and the objectives pursued by the measure. However, this is not the only way in which "arbitrary or unjustifiable discrimination" may be assessed.
7.84.
Having made these observations, the Appellate Body in the first compliance proceedings went on to recall that in the original proceedings in this dispute, the United States sought to explain that the original Tuna Measure was even‑handed, and that the detrimental impact did stem exclusively from a legitimate regulatory distinction by introducing the notion of "calibration". In particular, the United States contended that the original Tuna Measure was even‑handed because the distinctions that it drew between different tuna fishing methods and different areas of the ocean could be explained or justified by differences in the risks to dolphins associated with such fishing methods and areas of the ocean. This, in turn, led the Appellate Body in the original proceedings to examine the legitimacy of the original Tuna Measure's regulatory distinctions through the lens of the concept of "calibration".151 While emphasizing that "calibration" does not constitute a separate legal test, the Appellate Body in the first compliance proceedings nevertheless held that there was a special relevance in those Article 21.5 proceedings in conducting an assessment of whether, under the 2013 Tuna Measure, the differences in labelling conditions for tuna products containing tuna caught by large purse-seine vessels in the ETP, on the one hand, and for tuna products containing tuna caught by other fishing methods in other fisheries, on the other hand, are "calibrated" to the differences in the likelihood that dolphins will be adversely affected in the course of tuna fishing operations by different vessels, using different fishing methods, in different areas of the ocean.152 The Appellate Body then repeatedly emphasized that, in its view, the appropriate way, in the context of this dispute, for a panel to assess whether the detrimental impact caused by the Tuna Measure stems exclusively from a legitimate regulatory distinction is to assess whether the Measure is properly "calibrated" to the risks to dolphins arising from different fishing methods in different areas of the ocean.153 To this end, the Appellate Body explained that a panel should conduct an analysis involving: first, an identification of whether different tuna fishing methods in different areas of the oceans pose different risks to dolphins; and, second, an examination of whether, in the light of these risks, the different treatment created by the relevant regulatory distinctions show that, as between different groups of tuna products, the treatment accorded to each group is commensurate with the relevant risks, taking account of the objectives of the Measure.154
7.85.
In the light of these statements of the Appellate Body, both parties have argued, and we agree, that the question whether the 2016 Tuna Measure is "calibrated" to the risks to dolphins arising from different fishing methods in different areas of the ocean is central to our analysis in these proceedings.155 However, the parties have very different views about how the calibration analysis should be understood and applied. Indeed, as the United States has noted, the parties appear to read the Appellate Body's report in the first compliance proceedings, and the legal test set out therein, "very differently".156 In particular, although the parties agree that "calibrated" means "appropriately tailored to" or "commensurate with" the relevant risks157, they fundamentally disagree about how that test should be applied, and in particular as towhat the 2016 Tuna Measure must be calibrated to.
7.86.
In the United States' view, the calibration analysis essentially requires the Panels to assess whether, under the 2016 Tuna Measure, the differences in labelling conditions for tuna products containing tuna caught by large purse-seine vessels in the ETP, on the one hand, and for tuna products containing tuna caught by other fishing methods in other areas of the ocean, on the other hand, are calibrated to the differences in the likelihood that dolphins will be adversely affected in the course of tuna fishing operations by different vessels, using different fishing methods, in different areas of the ocean.158 According to the United States, the Appellate Body has explicitly recognized that the United States' tuna labelling regime will not violate Article 2.1 of the TBT Agreement if it is properly calibrated to the risks to dolphins arising from different fishing methods in different areas of the ocean.159 The United States contends that under the applicable legal standard, the Panels must analyse the relative harms in respect of observed mortality or serious injury, as well as a comparative assessment of unobserved harms, caused by different fishing methods in different areas of the world's oceans.160 The Panels must then evaluate the relevant regulatory distinctions in light of the risks of overall harm to dolphins, and determine whether those distinctions are explained by, and appropriately tailored to, the relevant risks.161 In other words, the Panels, having analysed the different risks to dolphins caused by different fishing methods in different areas of the ocean, should assess whether the relevant regulatory distinctions address these risks in a way that is commensurate with the respective risk profiles of the different fisheries.162 In this regard, the United States submits that if the risks to dolphins across fisheries were the same, but the requirements imposed by the 2016 Tuna Measure were different, then the Panels could conclude that the relevant regulatory distinctions are not calibrated.163
7.87.
Mexico has a different understanding of the applicable legal standard. According to Mexico, even-handedness is the central concept for determining whether detrimental treatment caused by a measure stems exclusively from a legitimate regulatory distinction.164 In Mexico's view, the "even-handedness" standard should be applied through a "multi-factor legal test".165 For Mexico, calibration, while important, is not a synonym for even-handedness, but rather only one "factor" of the applicable legal test.166 Thus, according to Mexico, the calibration test complements, but does not replace the assessment of whether the regulatory distinctions are applied in a manner that constitutes a means of arbitrary or unjustifiable discrimination, for example, on the basis of whether or not they can be reconciled with, or are rationally related to, the policy objectives of the measure.167
7.88.
Mexico therefore urges the Panels to take into account a number of factors in applying the legal test for even-handedness.168 Certainly, one of these factors is whether or not the discriminatory effects of the Tuna Measure's regulatory distinctions can be justified on the basis that they are calibrated to different relevant circumstances.169 However, another question is whether or not the discriminatory effects constitute arbitrary or unjustifiable discrimination on the basis that the regulatory distinctions cannot be reconciled with, or rationally connected to, the measure's policy objectives (what we, for brevity, call the "rational connection" test).170 In Mexico's view, these questions do not create independent or discrete legal tests; rather, they are elements within the overall analysis of whether or not the Tuna Measure is even-handed, and they must be assessed cumulatively, in relation to one another, on a common record of facts and circumstances.171 In response to a question from the Panels, Mexico contends that the calibration analysis "can and must" occur within the "constraints" of the rational connection test for arbitrary and unjustifiable discrimination.172
7.89.
In this respect, Mexico considers that the United States is incorrect to the extent that it attempts to narrow the legal analysis to a single-factor test, i.e., the question of whether or not the 2016 Tuna Measure is calibrated to the relative risks to dolphins in different fisheries.173 Mexico also considers that the United States is incorrect insofar as its proposed legal test would preclude the Panels from assessing the relationship between the detrimental impact caused by the relevant regulatory distinctions and the objectives pursued by the measure.174 In this connection, Mexico observes that it is only if consumers are able to accurately distinguish between tuna caught in conditions that are harmful to dolphins from tuna caught in conditions that are not harmful to dolphins that the use of harmful fishing techniques could be discouraged in the US market through the use of the dolphin-safe label.175 For Mexico, it follows from this that the accuracy of the dolphin-safe label, as a consumer information measure, is essential to the objective of protecting dolphins from adverse effects arising in different fisheries.176 Therefore, in Mexico's view, the accuracy of the dolphin-safe information provided to consumers on the US label is a central factor in the assessment of whether the regulatory distinctions drawn by the measure are calibrated to the relative risks of overall harms to dolphins posed by different fishing methods in different ocean regions.177 Indeed, according to Mexico, the reliability of different certification and tracking and verification systems is an integral element of the risk profiles of different fisheries.178 In practical terms, this means that while the calibration analysis should analyse the different risk profiles of different fishing methods in different areas of the ocean, it must also take into account the reliability of the record-keeping and reporting — that is, the accuracy of the information provided — by the tuna suppliers in different countries, including the level and effectiveness of governmental oversight over the fishers and trans-shippers of the tuna and the producers of the product, and the existence of illegal, unreported and unregulated fishing (IUU).179 Such considerations would, in Mexico's view, be especially relevant to the Panels' assessment of any differences in the certification and tracking and verification requirements.180
7.90.
Finally, Mexico argues that, in the context of these proceedings, the Panels' assessment of even-handedness should encompass consideration of whether the 2016 Tuna Measure gives rise to "unjustifiable discrimination" for reasons other than the relationship (or lack thereof) between the detrimental impact and the objectives pursued by the 2016 Tuna Measure. Specifically, Mexico argues that the Panels should determine whether the 2016 Tuna Measure gives rise to "unjustifiable discrimination" because the differences in labelling conditions "discriminate against an environmentally sustainable fishing method … in favour of an environmentally unsustainable fishing practice".181 In Mexico's view, while WTO Members are free to choose their own objectives, they cannot employ means that are inconsistent with the objective of sustainable development. According to Mexico, because the 2016 Tuna Measure discriminates against an environmentally sustainable fishing method in favour of one that is unsustainable, the Measure is inconsistent with the principle of sustainable development and can be found to be inconsistent with the WTO Agreement on this ground.182
7.91.
The United States disagrees with Mexico's understanding of the applicable legal standard. First, the United States argues that Mexico's proposed test for arbitrary or unjustifiable discrimination, and its contention that the even-handedness analysis is a multi-factor test, is incompatible with the approach adopted by the Appellate Body in the first compliance proceedings. According to the United States, Mexico's argument seeks to divert the Panels from conducting the required risk-based analysis, and would lead the Panels to consider factors other than the risks to dolphins – factors not relied on by the Appellate Body in either its original or first compliance reports – thus improperly minimizing the importance in the analysis of the relative overall risks to dolphins resulting from the use of different fishing methods in different fisheries.183 In the United States' view, the fact that there may, in theory, be different ways to test for even-handedness does not detract from the fact that, in this dispute, the Appellate Body has clarified that the appropriate analysis is whether the Measure is properly calibrated to the risks to dolphins arising from different fishing methods in different areas of the ocean.184
7.92.
The United States further contends that Mexico is incorrect in arguing that the Panels should assess whether the relevant regulatory distinctions in the 2016 Tuna Measure are calibrated to the relative risks of inaccurate dolphin-safe certification, reporting, and/or record-keeping.185 In the United States' view, this is not the test that was articulated by the Appellate Body186, and the United States finds no support in either of the Appellate Body's previous reports in this dispute.187 Rather, according to the United States, the Appellate Body has made clear that the relevant test is whether the relevant regulatory distinctions are calibrated to the risks to dolphins arising from different fishing methods in different areas of the ocean.
7.93.
Moreover, the United States argues that Mexico's approach would require the Panels to apply one calibration test to the eligibility criteria (that is, calibration to the risks to dolphins caused by different fishing methods in different areas of the ocean), and an entirely different calibration test to assess the certification and tracking and verification requirements (that is, calibration to the risks of inaccurate dolphin-safe certification, reporting, and/or record-keeping). According to the United States, in the first compliance proceedings, the Appellate Body faulted the compliance panel for applying one test to the eligibility criteria and a different test to the certification requirements and tracking and verification requirements, emphasizing that the same test must be applied to each of these cumulative and highly interrelated regulatory distinctions. In the view of the United States, applying different tests to different regulatory distinctions would lead to the type of segmented analysis that the Appellate Body criticized in the previous proceedings. Thus, adopting Mexico's proposed legal test would amount to "reversible error".188
7.94.
In sum, we understand the United States' position to be that the applicable legal standard under Article 2.1 of the TBT Agreement is whether the relevant regulatory distinctions in the 2016 Tuna Measure are calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean. On the other hand, Mexico's view is that the Panels must assess whether the 2016 Tuna Measure is "even-handed" by applying a "multi-factor" legal test that asks a number of questions, including whether the Measure is calibrated to both the risks to dolphins arising from the use of different fishing methods in different areas of the ocean and the risks of inaccurate labelling, as well as whether there is a rational relationship between the relevant regulatory distinctions and the objectives pursued by the 2016 Tuna Measure.
7.95.
We note that the present proceedings form part of a continuum that includes the original and first compliance proceedings in this dispute. We must therefore accord due cognizance to the recommendations and rulings made by the DSB in the original and first compliance proceedings, based on the findings of the Appellate Body and original and first compliance panels.189 In our view, the Appellate Body's report in the first compliance proceedings is particularly instructive on the question of the applicable legal standard. We note, however, that the parties have very different understandings of the parts of this report that set out the applicable legal standard. Accordingly, we will summarize our understanding of the key legal findings in that report before explaining their implications for our task in the present proceedings.
7.96.
In our view, the Appellate Body's report in the first compliance proceedings contains a number of passages that clarify the legal test that we should apply in these proceedings.
7.97.
We first observe that, the Appellate Body in the first compliance proceedings did indeed state, in the section of its report containing "Preliminary Observations" on "Whether the Panel erred in its interpretation of Article 2.1 and its articulation of the legal standard for determining whether the detrimental impact on imported products stems exclusively from a legitimate regulatory distinction", that "a panel does not err by assessing whether the detrimental impact can be reconciled with, or is rationally related to, the policy pursued by the measure at issue, so long as, in doing so, it does not preclude consideration of other factors that may also be relevant to the analysis".190 In stating this, the Appellate Body was reiterating its view that factors other than the question of whether discrimination can be reconciled with the policy objective of the measure at issue may be relevant to an analysis of whether discrimination is arbitrary or unjustifiable.191
7.98.
However, immediately after making these general observations, the Appellate Body recalled that in the original proceedings in this dispute, the United States sought to explain that its measure was even-handed by introducing the notion of "calibration". The Appellate Body explained that in those proceedings, the United States contended that its measure was even-handed because the distinctions that it drew between different tuna fishing methods and different areas of the ocean could be explained or justified by differences in the risks associated with such fishing methods and areas of the ocean.192 The Appellate Body observed that this line of argument led the Appellate Body in those proceedings to examine the legitimacy of the original Tuna Measure's regulatory distinctions through the lens of the concept of calibration.193
7.99.
In the light of this background, and bearing in mind that in the first compliance proceedings the United States had again made arguments concerning the calibration of its tuna labelling regime, the Appellate Body in the first compliance proceedings found that:

[T]here is a special relevance in these Article 21.5 proceedings in conducting an assessment of whether, under the amended tuna measure, the differences in labelling conditions for tuna products containing tuna caught by large purse-seine vessels in the ETP, on the one hand, and for tuna products containing tuna caught in other fisheries, on the other hand, are "calibrated" to the differences in the likelihood that dolphins will be adversely affected in the course of tuna fishing operations by different vessels, using different fishing methods, in different areas of the oceans.194

7.100.
The Appellate Body then proceeded to consider the first compliance panel's application of the legal standard it had articulated. In this context, the Appellate Body found that the panel had erred because, in the light of the circumstances of the dispute and the nature of the distinctions drawn under the 2013 Tuna Measure, the panel was required to assess whether the certification and tracking and verification requirements were calibrated to the risks to dolphins arising from different fishing methods in different areas of the ocean.195 In this respect, as we have noted above, the Appellate Body noted that "the Appellate Body's assessment of even‑handedness in the original proceedings was focused on the question of whether the original tuna measure was calibrated to the risks to dolphins arising from different fishing methods in different areas of the oceans", and emphasized that the Appellate Body had accepted the premise that the United States' tuna labelling regime "will not violate Article 2.1 if it is properly calibrated to the risks to dolphins arising from different fishing methods in different areas of the oceans".196 Thus, in concluding its review of the first compliance panel's analysis under Article 2.1 of the TBT Agreement, the Appellate Body stated:

[W]e have not found error in the Panel's articulation of the legal standard. However … We have further found that, in the light of the circumstances of this dispute and the nature of the distinctions drawn under the amended tuna measure, the Panel erred by failing to consider whether differences in the relative risks of harm to dolphins from different fishing techniques in different areas of the oceans explain or justify the differences in the certification requirements and the tracking and verification requirements applied inside and outside the ETP large purse-seine fishery.197

7.101.
The Appellate Body thus found that while the first compliance panel did not err in its articulationof the applicable legal standard (which focused on the existence of a rational connection between detrimental treatment and the objectives pursued by a challenged measure, but also recognized that the existence of such rational relationship was not the only element that could be taken into account), it nevertheless erred in its application of that standard in this particular dispute by failing to assess whether the measure was "calibrated" to the risks posed to dolphins by different fishing methods in different areas of the ocean. As noted above, the Appellate Body emphasized that in the original proceedings, the Appellate Body had found that the United States' labelling regime would not be inconsistent with Article 2.1 of the TBT Agreement if it were calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean.198
7.102.
In our view, these statements make clear that, while there may in theory be a number of ways in which a panel could assess the "even-handedness" of a measure challenged under Article 2.1 of the TBT Agreement, in the specific context of these proceedings, the appropriate legal standard for the Panels to apply is one that focuses on the relationship between the risks posed to dolphins by different fishing methods in different areas of the ocean, on the one hand, and the relevant regulatory distinctions, on the other hand. In this connection, we note that, as in both the original and first compliance proceedings, the United States has once again based its arguments on the notion that the 2016 Tuna Measure is calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean. Mexico has also engaged in extensive argumentation on the question of whether the Measure is properly calibrated. In our view, the parties' continued reliance on an analysis of calibration supports our view that, in these proceedings, it is appropriate for us to assess the even-handedness of the 2016 Tuna Measure by analysing it through the "lens" of calibration.199
7.103.
As we understand it, the Appellate Body's reasoning indicates that, in the context of this dispute, and without prejudice to the ways in which the "even-handedness" could be applied in other cases, the "even-handedness" of the Tuna Measure can be determined by assessing whether its relevant regulatory distinctions are calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean. Accordingly, we read these passages as indicating that our task in these proceedings is to ascertain whether the relevant regulatory distinctions are appropriately "calibrated" and "tailored" to, and commensurate with200, the different risks to dolphins arising in different fisheries. If the relevant regulatory distinctions are so calibrated, this will indicate that the 2016 Tuna Measure is not inconsistent with Article 2.1 of the TBT Agreement.201
7.104.
In this connection, we note Mexico's argument that "the Panels need not undertake such a comparison [i.e. the calibration analysis]. Rather, it is the United States that must demonstrate that such a comparison was undertaken".202 Insofar as Mexico is arguing that the calibration analysis imposes a process obligation on the United States, and that what the United States must prove is not (or not only) that the 2016 Tuna Measure is calibrated, but also that the United States actually undertook a calibration analysis prior to establishing the Measure, we disagree. We find no support for this notion in either the text of Article 2.1 of the TBT Agreement or in the panel or Appellate Body reports in the prior proceedings of this dispute. As we understand it, Article 2.1 of the TBT Agreement does not impose a particular process or set of procedures that should be applied by WTO Members before adopting technical regulations. Rather, it requires Members to ensure that technical regulations accord treatment no less favourable to the products of a Member than to like products of national origin or originating in any other country. In other words, it is a particular treatment to be accorded to imported products (i.e. one that is no less favourable than that accorded to domestic or foreign like products), rather than a specific process of adoption that is imposed by Article 2.1 of the TBT Agreement. Moreover, we understand the Appellate Body's report in the first compliance proceedings as indicating that the panels themselves must undertake an assessment of whether the Tuna Measure is calibrated.203
7.105.
In thus finding, we must emphasize that we do not mean to imply that the process through which a technical regulation is adopted has no place in, or bears no consequence to, our analysis under Article 2.1 of the TBT Agreement. Indeed, the process of adoption can be relevant for a panel to determine whether a technical regulation is even-handed in light of the "particular circumstances of the case, that is, the design, architecture, revealing structure, operation, and application of the technical regulation at issue".204 In this sense, insofar as the process of adoption of the 2016 Tuna Measure could help demonstrate its (lack of) even-handedness, it will form part of our analysis.205 However, as we noted above, Article 2.1 is explicitly concerned with the nature of treatment accorded by technical regulations, and accordingly we do not understand Article 2.1 to establish a separate or distinct obligation relating to the process by which the 2016 Tuna Measure was adopted.
7.106.
Two issues related to the legal standard outlined above (i.e. calibration to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean) must now be clarified further. First, we must determine if we should focus our calibration analysis on the question of whether the 2016 Tuna Measure is calibrated only to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean, as the United States argues, or if our calibration analysis should also consider whether the relevant regulatory distinctions are calibrated to risks relating to inaccurate certification and tracking and verification, as Mexico argues. Second, we must further consider the relationship between the calibration analysis and the question of whether there is a rational connection between the regulatory distinctions and the objectives of the 2016 Tuna Measure.
7.107.
The first issue concerns the scope of the calibration analysis. As we have explained above, Mexico argues that the reliability of the applicable systems in different fisheries for certification, tracking and verification are integral elements of the 'risk profile' of different fisheries.206 In Mexico's view, this means that, in addition to analysing whether the relevant regulatory distinctions are calibrated to the risks to dolphins, we must conduct an "additional examination"207 of whether the relevant regulatory distinctions are calibrated to the different relative risks (i.e. likelihood) of inaccurate dolphin-safe certification, reporting, and/or record-keeping with respect to the tuna caught in different fisheries and different areas of the ocean.208 As we noted above, the United States rejects Mexico's view, arguing that the standard articulated by Mexico is "not the test applied by the Appellate Body"209, and that applying the standard articulated by Mexico would result in the Panels applying different legal tests in respect of different regulatory distinctions, contrary to the Appellate Body's guidance in the first compliance proceedings.210
7.108.
In determining the proper scope of the calibration analysis, we look to the guidance provided by the Appellate Body in previous stages of this dispute. Of particular importance, in our view, is that the Appellate Body, in both its original and first compliance reports, repeatedly referred to the importance of assessing whether the measure is calibrated to "the different risks to dolphins arising from different fishing methods in different areas of the oceans"211, "the risk that dolphins may be killed or seriously injured when tuna was caught"212, "the likelihood that dolphins would be adversely affected in the course of tuna fishing operations in the different fisheries"213, the "differences in the likelihood that dolphins will be adversely affected in the course of tuna fishing operations by different vessels, using different fishing methods, in different areas of the oceans"214, "the relative adverse effects on dolphins arising outside the ETP large purse-seine fishery as compared to those inside that fishery"215,"the differing risk profiles of the different fisheries"216, "the differences in risks in different fisheries"217, and "the different risk profiles in different fisheries".218 We have not found any reference in either of the Appellate Body reports in this dispute suggesting that the proper analysis is whether the 2016 Tuna Measure is calibrated to anything other than the risks posed to dolphins by the use of different fishing methods in different areas of the ocean.
7.109.
With respect to Mexico's specific argument that risks relating to inaccurate certification, reporting, and/or record-keeping form an "integral part" of the risk profiles of different fisheries, in our view, the Appellate Body's reasoning in the preceding reports in this dispute does not support this view. As noted above, the Appellate Body has repeatedly stated that the applicable legal standard is calibration to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean. To us, this suggests that the relevant inquiry is one that focuses on the risks that dolphins face as a result of the use, in different areas of the ocean, of different fishing methods. In particular, the inquiry is one that centres on the risks that dolphins will be killed or injured by the use of different fishing techniques in different fishing grounds.219 Indeed, this is how the Appellate Body appears to have understood the expression "risk profile". For example, at paragraph 7,165 of its report in the first compliance proceedings, the Appellate Body notes that the compliance panel "gave some consideration to the respective risk profiles associated with different fishing methods in different areas of the ocean" by noting that "setting on dolphins is inherently dangerous to dolphins even where no dolphin is seen to be killed or seriously injured".220
7.110.
As we see it, the risks of inaccurate certification, reporting, and/or record-keeping are not risks that affect dolphins themselves, though they may, as Mexico alleges221, have an indirect influence on the extent to which different fishing methods are used to catch tuna intended for the US market.222 Nor are they risks that arise from the use of different fishing methods in different areas of the ocean, even though fish caught in different areas of the ocean through the use of different fishing methods may be associated with a greater or smaller risk of inaccurate labelling depending on a range of interconnected factors, including the persons involved in the catch, available technology, and applicable domestic and international regulatory requirements.223 Accordingly, we do not think the Appellate Body in either the original or the first compliance proceedings intended subsequent compliance panels to include risks relating to inaccurate certification, reporting, and/or record-keeping within the "risk profiles" that it instructed those panels to assess and compare. Rather, the Appellate Body's focus was clearly on the risks of observable and unobservable mortality and injury caused to dolphins as a result of the use of different fishing methods in different areas of the ocean.
7.111.
In order to explore this issue further with the parties, we asked Mexico to clarify whether there is support in either of the Appellate Body's reports for its view that the reliability of different systems for certification and tracking and verification are integral elements of the risk profile in different fisheries.224 Mexico responded that the Appellate Body's reports in the original and first compliance proceedings "do not directly address" whether the Tuna Measure must be calibrated to the relative risks of inaccurate dolphin-safe information being passed on to US consumers, or whether the reliability of the applicable systems for certification, tracking and verification are integral elements of the risk profile of different fisheries. In Mexico's view, however, "the maintenance of label accuracy is part of the Appellate Body's reasoning".225
7.112.
As we discuss in more detail later in these Reports, we agree with Mexico that the question of the accuracy of certification, and tracking and verification was relevant to the Appellate Body's analysis in the original and the first compliance proceedings. That, however, is different from saying that the applicable legal standard, as clarified by the Appellate Body, requires the Panels to determine whether the 2016 Tuna Measure is calibrated, inter alia, to the risk of inaccurate dolphin-safe information being passed to consumers, or that risks relating to inaccurate labelling are an integral part of the risk profiles of different fisheries. In our view, Mexico's acknowledgement that the Appellate Body reports "do not directly address" this point also confirms our reading of those reports. Given the importance placed by the Appellate Body on the calibration test, and the detail with which it described that test, we believe that, if the Appellate Body had considered risks of inaccurate labelling to be part of the "risk profile" of a fishery, such that a subsequent compliance panel would need to assess whether the relevant regulatory distinctions were calibrated to the risks of inaccurate labelling, it would have said so explicitly. However, as Mexico acknowledges, it did not. Rather, it repeatedly referred to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean.
7.113.
Therefore, those risks are not part of the risk profiles of different fisheries, and accordingly the applicable legal standard does not require us to assess whether the different regulatory distinctions are calibrated to the different risks of inaccurate certification or tracking and verification that may exist in different fisheries. That said, such risks are relevant to the application of the legal test to the facts, as we explain in detail below.226
7.114.
We now turn to consider the second issue requiring further clarification with regard to the legal test, namely the relationship between the calibration analysis and the question of whether there is a rational connection between the regulatory distinctions and the objectives of the 2016 Tuna Measure. As noted above, Mexico argues that the calibration analysis "can and must" occur within the constraints of the rational connection test for arbitrary and unjustifiable discrimination.227 In particular, Mexico argues that "the accuracy of the dolphin-safe label, as a consumer information measure, is essential to the objective of protecting dolphins from adverse effects arising in different fisheries"228, and that the calibration analysis must take into account the nexus between the regulatory distinctions and this objective.229 Mexico argues that this position is confirmed by the Appellate Body's statement in the first compliance proceedings that the calibration analysis must be undertaken "taking account of the objectives of the measure".230
7.115.
Insofar as Mexico's argument suggests that we should assess the existence of a rational relationship between the detrimental impact and the objectives of the 2016 Tuna Measure as a separate or distinct step in our analysis, we are not convinced that Mexico's approach is supported by the Appellate Body's reports in the original or the first compliance proceedings. In the first place, we note that although the Appellate Body in the first compliance proceedings found that the first compliance panel had not erred in its articulation of the applicable legal standard, including in its emphasis of the importance of assessing whether the detrimental impact could be reconciled with, or was rationally related to, the policy pursued by the measure at issue231, it nevertheless held that there was a "special relevance" in this dispute in conducting a proper calibration analysis. In the light of this holding, the Appellate Body proceeded to find that the first compliance panel had erred by failing to conduct such an analysis.232 As we have explained above, in our view, these findings of the Appellate Body establish that in this dispute, the question of whether the 2016 Tuna Measure is consistent with Article 2.1 of the TBT Agreement can be answered by assessing whether that Measure is calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean.233 We do not read the Appellate Body as requiring any additional, separate analysis of, for example, the abstract relationship between the objectives of the Measure and the detrimental impact.
7.116.
Additionally, we do not agree with Mexico that the Appellate Body's statement that the calibration analysis must be conducted taking account of the objectives of the Measure indicates that the calibration analysis should be "constrained" by an analysis of whether the detrimental impact is rationally related to the objectives of the measure, insofar as "constraint" in this context suggests an external benchmark against which the calibration analysis described above must be checked and with which it must be reconciled. Rather, we understand this statement to mean that (a) the form and content of the calibration test must be appropriately informed by the objectives pursued by the measure, and (b) the calibration test should itself be applied taking account of the measure's objectives.
7.117.
With respect to (a), we understand the Appellate Body's reference to the objectives of the Measure to mean that those objectives inform the criteria in respect of which calibration is to be assessed. For example, it is conceivable that the Panels could assess whether the relevant regulatory distinctions of the 2016 Tuna Measure were calibrated to the different depth of the ocean floor in different regions. Such an analysis, however, would have no connection to the objectives pursued by the Measure based on the evidence on the record, and accordingly would fall foul of the Appellate Body's guidance. On the other hand, calibration to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean would take account of the objectives of the 2016 Tuna Measure, which, as noted above, are "contributing to the protection of dolphins, by ensuring that the US market is not used to encourage fishing fleets to catch tuna in a manner that adversely affects dolphins" and "ensuring that consumers are not misled or deceived about whether tuna products contain tuna that was caught in a manner that adversely affects dolphins".234 Accordingly, because the form and content of the legal standard articulated by the Appellate Body are informed and shaped by the Measure's objectives, we take those objectives into account in applying the legal standard articulated by the Appellate Body.
7.118.
With respect to (b), we also understand the Appellate Body's reference to mean that, in applying the calibration test to the facts, and in particular in developing an appropriate methodology for assessing calibration and in assessing whether the relevant regulatory distinctions are in fact calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean, we should bear in mind the objectives of the 2016 Tuna Measure. In this regard, we consider that although, as we have explained above, the calibration test does not require us to consider whether the 2016 Tuna Measure is calibrated to the risks of inaccurate certification, reporting, and/or record-keeping, those risks are nevertheless central to our application of the calibration test, precisely because in applying the calibration test we must take the objectives of the Measure into account.
7.119.
In this connection, we note that by the expression "risk of inaccuracy", we understand the first compliance panel, the Appellate Body, and the parties to mean the risk that, as a result of an error in the certification, and tracking and verification processes, the information recorded and reported at any stage of the tuna catch and processing chain could misrepresent the actual dolphin-safe status of a batch of tuna. In other words, we understand it to mean the risk that an error in the recording and reporting of information somewhere in the catch and processing chain could result in a batch of tuna being designated as dolphin-safe while in fact containing tuna that should have been designated as non-dolphin-safe.
7.120.
In this regard, we find it important to note that, as we understand it, the existence of a margin of error in certification, and tracking and verification requirements does not necessarily equate or give rise to a risk that the information ultimately conveyed to a consumer by a dolphin-safe label will itself be incorrect. In our view, the risk of inaccurate information being passed to consumers by the label will depend not only on the referred margin of error, but also, and importantly, on the extent of events that require recording whether a dolphin mortality or serious injury was observed in a given fishery.
7.121.
To give an example, it is possible to think of a situation where the margin of error is high but where, due to a low occurrence of events that require recording whether a dolphin mortality or serious injury was observed, the risk of incorrect information ultimately conveyed to a consumer by a dolphin-safe label would be low. Conversely, there might be a situation where the margin of error is low but the extent of events that require recording whether a dolphin mortality or serious injury was observed is so high that there is a higher risk of incorrect information ultimately conveyed to a consumer by a dolphin-safe label. In our view, the risk profile is a good proxy to measure the extent of events that require recording235 whether a dolphin mortality or serious injury was observed.
7.122.
Thus, in applying the calibration test and taking into account the objectives of the 2016 Tuna Measure, we cannot assume that the mere existence of margins of error in certification, and tracking and verification requirements is necessarily inconsistent with the objectives of the Measure. Rather, in our view, the central question is whether any margins of error in certification, tracking and verification, and any differences in the margins of error tolerated by different certification, and tracking and verification requirements, are calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean.
7.123.
To put this another way, we consider that, in applying the calibration test, it is appropriate for us to consider whether the certification, and tracking and verification requirements applied in different fisheries are commensurate with, and tailored to, the particular risk profiles of those fisheries. In our view, in a fishery where the risks to dolphins are low, it may be calibrated to apply certification, and tracking and verification requirements that tolerate a higher margin of error than the certification, reporting, and/or record-keeping requirements that apply in respect of fisheries with a high risk profile. This is because the risk that the dolphin-safe label will communicate inaccurate information is a function of numerous factors, including not only the regulations in place, but also the different levels of dolphin interaction, mortality, and serious injury in different fisheries. Thus, in fisheries with high dolphin interactions and harms, more sensitive certification, and tracking and verification requirements may be needed to ensure the ultimate accuracy of the dolphin-safe label, whereas in fisheries with low dolphin interactions and harms, less sensitive requirements may be sufficient. Thus, the extent to which margins of error in certification, and tracking and verification requirements, or any differences in the margins of error in different certification, and tracking and verification requirements, are consistent with the objectives of the 2016 Tuna Measure cannot be answered by looking at the regulations in isolation. Rather, it is necessary to examine them in the light of the relevant risk profiles in different fisheries, in particular by assessing whether any margins of error in certification, and tracking and verification requirements are themselves calibrated to, tailored to, and commensurate with the different risk profiles in different fisheries.
7.124.
Thus, we consider that the objectives of the 2016 Tuna Measure can and should be taken into account in the application of the calibration test to the facts, in particular in assessing whether any margins of error in certification, and tracking and verification requirements, or any differences in the margins of error in different certification, and tracking and verification requirements, are calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean. This, however, is not the same as requiring that the relevant regulatory distinctions themselves be calibrated to the different risks of inaccurate certification and tracking and verification, nor is it the same as "constraining" the calibration analysis by reference to a separate analysis of the relationship between the Measure's objectives and the detrimental treatment.
7.125.
We further note that, as we understand it, Mexico's argument that the calibration analysis should be constrained by the rational relationship test appears to create an artificial distinction between the consumer information and the dolphin protection objectives of the Measure. As we understand it, the 2016 Tuna Measure does not pursue two distinct objectives. Rather, the two objectives are mutually complementary and reinforcing, and work together to "address [the effects of] adverse of fishing techniques on dolphins".236 In this connection, while it is certainly true that the 2016 Tuna Measure "is a labelling measure which, by its nature and design, is primarily focused on conveying accurate information to consumers"237, we agree with the United States that "that information is not provided simply for the sake of informing consumers".238 Rather, the Measure aims to convey accurate information to consumers in order to ensure that the US tuna market is not used to encourage fishing fleets to catch tuna in a manner that adversely affects dolphins.239 The objective of providing information to consumers is therefore a part of, rather than separate from, the objective of protecting dolphins.240
7.126.
Finally on this point, we note Mexico's argument that conducting a calibration analysis that is constrained by an examination of the existence of a rational connection between the detrimental impact and the objectives of the Measure is necessary in order to "ensure[] symmetry between Article 2.1 of the TBT Agreement and the chapeau of Article XX of the GATT 1994".241 In the context of this dispute, it is unnecessary for us to opine on the existence of a systemic "symmetry" between the two provisions. We would simply note that the calibration analysis we have described is fully consistent with the legal standard applicable under the chapeau of Article XX of the GATT 1994, as clarified by the Appellate Body. The calibration test looks precisely at whether the relevant regulatory distinctions are "tailored to", "commensurate with", or "explained" by differences in the underlying situation to which the 2016 Tuna Measure seeks to respond.242 As we see it, this is similar to the inquiry under Article XX of the chapeau, which considers, inter alia, whether the measure is "applied in a manner which would constitute a means of arbitrary or unjustifiable discrimination".
7.127.
In sum, we find that in these proceedings, there is a "special relevance" to an analysis of whether the 2016 Tuna Measure is calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean. In particular, we recall the Appellate Body's statement in the first compliance proceedings that the Measure will not be inconsistent with Article 2.1 of the TBT Agreement if it is properly calibrated to those risks. For the reasons given above, we conclude that the risk of inaccurate labelling does not form part of the "risk profiles" of different fisheries. Additionally, we disagree with Mexico's argument that the calibration analysis must be "constrained by" a distinct analysis of the relationship between the detrimental impact and the objectives of the Measure. Having said that, in our view the calibration analysis "takes account of the objectives of the Measure" insofar as those objectives inform the shape and content of the calibration test. Moreover, as we explain in more detail below, the objectives of the Measure will also be taken into account in the applicationof the legal standard to the facts at issue.
7.128.
Before concluding our discussion of the applicable legal test, we briefly note Mexico's argument that WTO "Members are of course free to choose their own objectives. But if the means they use to achieve those ends are inconsistent with the objectives of sustainable development, then they are likewise inconsistent with their WTO obligations".243 In response to a question from the Panels concerning the legal basis for this argument, Mexico argues that while the reference to sustainable development in the preamble of the WTO Agreement does not itself create any obligations, nevertheless the text of all WTO obligations that in any way relate to the objective of sustainable development or environmental protection must be interpreted and clarified within this textual context.244 Moreover, Mexico contends that the principle of sustainable development has risen to the status of a principle of international law applicable to all countries245, and accordingly should be taken into account by the Panels when interpreting Article 2.1 of the TBT Agreement in accordance with customary rules of interpretation of public international law246, including the rule codified at Article 31(3)(c) of the Vienna Convention on the Law of Treaties. Finally, Mexico refers to the "17 global goals and the 169 global targets of the Sustainable Development Goals approved by the United Nations in September of 2015 – with the support of both Mexico and the United States" and posits that, although not binding, they should "provide helpful guidance as context from broader public international law in this dispute for the purposes of interpreting and clarifying the relevant obligations in the WTO covered agreements in a manner that is consistent with the objective of sustainable development".247 In particular, Mexico argues that the Sustainable Development Goal 14, and its targets 14.2 and 14.4, on sustainable management of marine ecosystems and effective regulation of fishing practices, respectively, provide "useful context" for this dispute.248
7.129.
As we understand it, Mexico's argument is that the Panels should, at the least, interpret Article 2.1 of the TBT Agreement in the light of the principle of sustainable development. This is so because (a) the preamble of the WTO Agreement refers to sustainable development, and (b) sustainable development has risen to the status of a principle of international law applicable in the relations between all countries.
7.130.
It is not entirely clear to us what, in Mexico's view, would be the result of interpreting Article 2.1 in the light of the principle of sustainable development. In its response to the Panels' question, Mexico suggests that "[m]easures that discriminate in a manner that goes against the objective of sustainable development are inconsistent with this important context [i.e. the context provided by the preamble of the WTO Agreement] and, therefore, can be found to be inconsistent with the obligations and requirements in Article 2.1 and the chapeau to Article XX".249 This argument, however, does appear to elevate the preambular language to the level of substantive obligation, despite Mexico's assertion to the contrary. As Mexico itself acknowledges, however, the preamble to the WTO Agreement does not of itself create substantive obligations. We of course recognize that the preamble of the WTO Agreement "add[s] colour, texture and shading to [the] interpretation of the agreements annexed to the WTO Agreement".250 In our view, however, to accept, as Mexico proposes, that a measure may be found to be inconsistent with a particular provision of one of the covered agreements because it discriminates in a manner that goes against one of the goals referenced in the preamble to the WTO Agreement would go far beyond recognizing that the preamble informs the interpretation of the covered agreements.251 Rather, it would elevate the language of the preamble to the level of a norm, and accord it more weight than the language used by the Members in framing the obligations contained in the covered agreements.
7.131.
In our view, Article 2.1 is essentially concerned with ensuring that technical regulations are designed and applied in a manner that affords national treatment and most favoured nation treatment to all WTO Members.252 That Article 2.1 may apply in respect of technical regulations that themselves pursue the objective of sustainable development is beside the point, since it may just as well apply in respect of technical regulations that have nothing whatsoever to do with sustainable development. At any rate, we note that, we do not consider that the 2016 Tuna Measure is concerned with sustainable development. Rather, it is concerned with the protection and well-being of dolphins.253 While the protection of dolphins of course has an impact on the conservation and therefore the sustainability of dolphin populations, that does not render the 2016 Tuna Measure a "sustainability" measure, nor does it turn a dolphin-safe label into a "sustainability" label. The WTO Agreement does not obligate the United States or any other Member to regulate only for the objective of "sustainable development", and in our view a measure is not inconsistent with Article 2.1 of the TBT Agreement merely because it pursues some other objective.

7.6 Burden and standard of proof

7.132.
Before proceeding, it is convenient to say something about the burden of proof. The Panels note that the general principles applicable to burden of proof in WTO dispute settlement require that a party claiming a violation of a provision of the WTO Agreement by another Member must prove its claim.254 Further, it is generally for each party asserting a fact, whether complainant or respondent, to provide proof thereof.255 We also note that the fact that proceedings initiated under Article 21.5 of the DSU concern measures taken to comply with DSB recommendations and rulings does not alter the allocation of burden of proof.256 We will be guided by these principles with regard to burden of proof in these proceedings.
7.133.
However, we note that these proceedings are somewhat unusual, in that both the original complaining party and the original responding party have requested the establishment of panels under Article 21.5 of the DSU to determine the consistency with the WTO Agreement of a measure taken to comply by the original responding party. The parties' written and oral submissions have not clearly distinguished between claims and arguments made in respect of the proceedings brought by the United States, on the one hand, and those made in respect of the proceedings brought by Mexico, on the other hand. This is perhaps inevitable given that the parties agree as to what is the measure taken to comply, namely the 2016 Tuna Measure, and both proceedings focus on two issues, namely, whether the 2016 Tuna Measure (a) complies with the requirement to provide "treatment no less favourable" under Article 2.1 of the TBT Agreement and (b) meets the conditions laid down in the chapeau of Article XX of the GATT 1994.
7.134.
Although, technically speaking, these Panels deal with two disputes, in terms of their practical dynamics, these proceedings resemble very much proceedings dealing with a single dispute, except with respect to the issue of burden of proof. The allocation of the burden of proof requires special attention in these proceedings because both the original complainant (Mexico) and the original respondent (United States) are at the same time both complainant and respondent in these proceedings. Further, the claims and arguments of both parties presented in the proceedings brought by Mexico are the mirror image of their claims and arguments presented in the proceedings brought by the United States. Thus, in the proceedings brought by the United States, the United States, as complaining party, argues that the 2016 Tuna Measure brings the United States into compliance with the WTO Agreement because it complies with the requirement to provide "treatment no less favourable" under Article 2.1 of the TBT Agreement and meets the conditions laid down in the chapeau of Article XX of the GATT 1994. Mexico as the responding party argues the opposite. In the proceedings brought by Mexico, Mexico as complaining party argues that the 2016 Tuna Measure fails to bring the United States into compliance with the WTO Agreement, because it neither complies with the requirement to provide "treatment no less favourable" under Article 2.1 of the TBT Agreement nor meets the conditions laid down in the chapeau of Article XX of the GATT 1994. The United States as the responding party argues the opposite. Accordingly, the United States' claim that the 2016 Tuna Measure brings the United States into compliance with the WTO Agreement is a claim that is made both as a complaint and as a response. The same is true of Mexico's claim.
7.135.
Given this situation, it is not entirely clear how in practice we should apply the principles on burden of proof cited above. While the parties appear to agree on these principles, neither has explained how those principles could actually be applied in the light of the consolidated way in which the parties presented their arguments. In this regard, we note that, in its first written submission, Mexico explains that "[t]his submission presents Mexico's prima facie case that the measure violates [Article 2.1 of the TBT Agreement and the chapeau of Article XX of the GATT 1994] in the Article 21.5 – Mexico II proceeding. It also responds to the first written submission of the United States in the Article 21.5 – United States proceeding".257 The submission does not, however, distinguish between those arguments made as part of Mexico's prima facie case, and those made in response to the United States' submission. The United States similarly argues in its second written submission that "[t]he United States agrees that with respect to the matter brought by the United States, the United States has the burden of proof, and with respect to the matter brought by Mexico, Mexico has the burden of proof". The United States does not, however, make any distinction in its submissions between the two matters.258
7.136.
In its third party statement, Norway argues that "the burden of proof does not shift depending on who initiated the Article 21.5 proceedings".259 In Norway's view, the principles outlined by the Appellate Body and quoted above apply regardless of whether the United States or Mexico initiated proceedings under Article 21.5 of the DSU. In order to explore this issue with the parties, we asked them to comment on Norway's argument. In response, Mexico maintains that "[i]n both Article 21.5 proceedings, the burden of proof under the chapeau of Article XX is on the United States. In the case of Article 2.1, the initial burden is on the United States and Mexico respectively".260 The United States responds by arguing that "Mexico carries the burden of proof for its claims that the measure taken to comply is inconsistent with a covered agreement in the matter brought by it, and the United States carries the burden of proof with respect to the existence of a measure taken to comply in the matter brought by it".261 Again, however, neither party explains how, in practice, both parties could bear the burden of proof in respect of their own proceedings, given that neither party distinguished between the arguments it made in the proceedings brought by the United States and those it made in the proceedings brought by Mexico.
7.137.
Given the special nature of these proceedings, while we will follow the basic principles on burden of proof that have emerged from WTO dispute settlement, we will avoid applying those principles in a mechanistic fashion, because doing so would not only cause unnecessary confusion, but would also risk not respecting parties' due process rights. Given that both parties address overlapping legal issues and present the same sets of exhibits, in both proceedings, and given the narrowly-defined nature of the claims before us, we find it appropriate to apply the above-referenced principles on burden of proof in a cumulative or holistic fashion. That is, since both parties are at the same time the complainant and the respondent in these proceedings, in resolving these issues, we will assess both parties' claims and arguments in a holistic fashion.
7.138.
With respect to standard of proof, we recall that the principle in WTO dispute settlement is that the complainant who has the initial burden of proof has to make a prima facie case for the burden to shift to the respondent to rebut that case. In this regard, we recall that a prima facie case is one which, in the absence of effective refutation by the other party, requires a panel, as a matter of law, to rule in favour of the party presenting the prima facie case.262 Since we will evaluate holistically the parties' submissions in these proceedings, with respect to the issues that we will assess, we will find for the party that overall presents a more convincing case in terms of arguments and evidence.
7.139.
Independently of our explanations above regarding the allocation of the burden of proof, and the issue of the standard of proof, in reviewing the parties' arguments in support of their claims, we will be guided by the principle that "the party that asserts a fact is responsible for providing proof thereof".263 In this regard, we recall that "[i]t is important to distinguish, on the one hand, the principle that the complainant must establish a prima facie case of inconsistency with a provision of a covered agreement from, on the other hand, the principle that the party that asserts a fact is responsible for providing proof thereof".264 We note that the parties also agree with this point. In both its second written submission and its response to the Panels' question, the United States argues that "regardless of which party has the general burden of proof, the party that asserts a fact is responsible for providing proof thereof".265 Mexico similarly recognizes that, as the Appellate Body explained in the first compliance proceedings in this dispute, "each party bears the burden of substantiating the assertions that it makes".266
7.140.
We note that the approach we have laid out above is consistent with the statement by the Appellate Body in the first compliance proceedings in this dispute that the burden of proof is not "an entirely binary issue".267 The Appellate Body in those proceedings further explained that both parties in a claim under Article 2.1 have "responsibilities" to substantiate their claims and arguments, and that the burden of proof should not be applied "mechanistically".268 We also find support in the reasoning of the panel in EC and certain member States – Large Civil Aircraft (Article 21.5 – US) that "WTO dispute settlement proceedings do not involve any particular temporal sequence of proof. Both parties will adduce evidence in support of their own arguments or to rebut the arguments made by the other at various stages of a dispute, sometimes simultaneously, throughout the entirety of a proceeding".269
7.141.
Finally, we also consider our approach to be consistent with our obligation under Article 11 of the DSU to conduct an objective assessment of the matter before us, "including an objective assessment of the facts of the case and the applicability of and conformity with the relevant covered agreements".

7.7 Factual findings

7.7.1 Introduction

7.142.
The Panels now turn to assess the evidence on the record relating to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean. This will enable us to identify the risk profiles of different fisheries, on the basis of which we will then determine whether the 2016 Tuna Measure is calibrated to the risks to dolphins arising from the use of different fishing methods in different areas of the ocean.270
7.143.
In this section, we (i) outline the findings made by the Appellate Body and the panels in previous stages of this dispute regarding the appropriate methodology to be used in assessing the evidence on the risk profiles of different fishing methods, as well as their factual findings regarding the nature of the risks posed and harms done to dolphins by such methods; (ii) discuss certain preliminary issues on the methodology that we will use in assessing the evidence on the record; (iii) make findings about the risk profiles of individual fishing methods; and finally (iv) provide a comparative assessment of the results of the method-specific findings.

7.7.1.1 Findings made in previous proceedings

7.144.
We recall that these compliance proceedings are not occurring in a vacuum, but rather form part of a continuum of events, beginning with the original panel proceedings. In this connection, we note that numerous findings on the methodology to assess evidence and on the facts have been made over the course of this dispute. Such findings are relevant to our task of analyzing the evidence and assessing the risks posed to dolphins by the use of different fishing methods in different parts of the ocean. In our view, these factual findings must be taken into account in our analysis of the factual record in order to avoid any doubts as to the objectivity of these compliance proceedings.271 In this Section, we will discuss these existing findings and our interpretation of how they should be applied in the context of the present proceedings.

7.7.1.1.1 Previous findings regarding the appropriate methodology to be used

7.145.
We observe that in previous stages of this dispute, the Appellate Body has provided guidance on the nature of the assessment that should be undertaken in determining if the Tuna Measure is adequately calibrated to the relative risks to dolphins arising from the use of different fishing methods in different parts of the ocean.
7.146.
In the first compliance proceedings and in the context of completing the legal analysis after having reversed some of the legal findings made by the compliance panel regarding Article 2.1 of the TBT Agreement272, the Appellate Body found that the panel had not put itself in a position to conduct an assessment of whether the 2013 Tuna Measure was even-handed in addressing the respective risks of setting on dolphins in the ETP large purse-seine fishery versus other fishing methods outside that fishery.273 The Appellate Body explained that this was because, in the panel's assessment of the relative harms posed to dolphins by setting on dolphins versus other fishing methods, the compliance panel focused almost exclusively on the unobserved harms associated with different fishing methods.274 The Appellate Body explained that although there was considerable evidence on the record concerning the nature and scope of the relative risks associated with different fishing methods in different areas of the ocean275, the compliance panel did not address what that evidence indicated in respect of the overall levels of risks in different fisheries, and how these fisheries compared to each other. The Appellate Body also held that it failed to consider the relative risks posed by different fishing methods in respect of observed mortality or serious injury, while focusing solely on the narrower difference in the respective risks attributable to unobserved harms.276 In other words, the Appellate Body faulted the first compliance panel for conducting a narrow assessment of the relative risks posed by different fishing methods, in particular, because it failed to consider the relative risks arising from observed mortalities and serious injuries to dolphins.
7.147.
As we understand it, the Appellate Body's finding in this connection indicates that, in our factual assessment, we need to undertake an evaluation of the overall levels ofrelativerisks or levels of harms277 attributable to different fisheries, including in respect of both observable and unobservable harms. We note, however, that the nature of the concept of "overall levels of relative risks", and what it entails in practical terms, is not immediately clear.
7.148.
In this regard, we observe that both parties presented arguments on how the Panels should understand the concept of "overall relative levels of harm". Mexico argues they can be understood as the aggregate of direct and observed dolphin mortality and serious injury together with the indirect and unobserved harms to dolphins caused by a particular fishing method.278 For its part, the United States considers that the expression "overall relative levels of harm" conveys two concepts: (i) the use of the words "overall" and "harms" conveys the scope of harms that the Panels should examine, i.e. mortalities and serious injuries, as well as those unobservable harms that are "a result of the chase itself"279, and (ii) the inclusion of the word "relative" conveys that the Panels should compare these harms across fishing methods and fisheries.280
7.149.
In our view, an assessment of the overall levels ofrelativerisks attributable to different fisheries, including in respect of both observable and unobservable harms, entails a comparison of the different risks to dolphins arising from the use of different fishing methods in different parts of the ocean. In particular, it entails an assessment of the risks to dolphins posed by the fishing method predominately used by Mexico (i.e. setting on dolphins in the large purse seine fishery in the ETP), which is ineligible for the dolphin-safe label, in comparison with the risks to dolphins posed by other fishing methods in different parts of the ocean.281 As a basis to conduct this comparison, we observe that we will need to establish the risk profiles of the relevant fishing methods in different areas of the ocean, taking into account data on both observable and unobservable harms.
7.150.
In this regard, we are mindful of the difficulty posed by the scientific and technical nature of the information needed to undertake this task and the inherent difficulties associated with this type of data. Indeed, we note that in the first compliance proceedings, the Appellate Body itself recognized "the difficulty associated with making such an assessment of the respective risks, particularly in the light of the highly contested evidence adduced by the parties", and also stated that "the panel was [not] necessarily in a position to come to a definitive or precise view as to the extent to which the relevant risk profiles differed".282 In this vein, we asked the parties during the course of our substantive meeting whether, in their view, the Panels should consult with external experts to better understand the different risk profiles in different fisheries. Both parties agreed that it was in the Panels' discretion to seek such guidance from independent and qualified experts. The United States submitted that even if the Panels' have this discretion, they could still come to a determination on this issue based on the evidence on the record.
7.151.
In our view, the difficulties that the Appellate Body recognized in the first compliance proceedings are equally present in these proceedings. Indeed, we are not necessarily in a position to come to a definitive or precise view as to the extent of relevant risks and how precisely they may differ across different fisheries in different parts of the ocean. Nevertheless, we decided not to consult with external experts for the purpose of enhancing our understanding of the evidence presented by the parties. This is because our ultimate task in these proceedings is to establish whether the 2016 Tuna Measure is consistent with the United States' obligations under Article 2.1 of the TBT Agreement, and not to conduct a fully-fledged scientific evaluation of the different risks that dolphins face across the globe. While our analysis under Article 2.1 of the TBT Agreement requires a determination of the different risk profiles of different fishing methods in different parts of the ocean, we consider that this can and should be done on the basis of the available scientific information that has already been produced by experts on the matter and that has been submitted as evidence by the parties. In this connection, our task is to conduct a thorough and objective review of the evidence on the record, and not necessarily to come to conclusions aiming to establish scientific or environmental truth. We note that, as the evidentiary record and the arguments of the parties show, the relevant scientific and environmental issues are still highly debated by experts in the field of marine biology and fisheries management. We will therefore conduct our assessment in light of such inherent difficulties and limitations in the evidence on the record, and the divergence in the arguments presented by the parties on the basis of that evidence.
7.152.
With these caveats in mind, and in the light of the Appellate Body's finding on the relevant analysis, we will undertake an evaluation of the overall levels of relative risks attributable to different fisheries, including in respect of both observable and unobservable harms.

7.7.1.1.2 Previous factual findings: observable and unobservable harms to dolphins

7.153.
In the previous stages of these proceedings, both the panels and the Appellate Body made a number of factual findings relevant to our current examination, in particular, regarding the harms caused to dolphins by different fishing methods in different areas of the ocean. In this section, we will briefly discuss those findings.
7.154.
In doing so, we are mindful that the Appellate Body has stated that "doubts could arise about the objective nature of an Article 21.5 panel's assessment" if, on a specific issue, that panel were to "deviate from the reasoning" in the original report "in the absence of any change in the underlying evidence in the record".283In other words, in conducting the factual assessment described above, we consider that we should take due account of the relevant reasoning and findings that led to the original and 2013 Tuna Measures being found to be WTO-inconsistent. We will thus take account of this reasoning, unless we find that there has been a relevant change in the underlying evidence in the record.
7.155.
We now move to discuss those previous relevant factual findings concerning harms to dolphins in the ETP large purse-seine fishery and other fisheries. We note that such harms can be broadly categorized as relating to (i) observable harms, both observed and unobserved, and (ii) unobservable harms.
7.156.
Regarding observable harms, the first compliance panel found that these are "the kind of interactions that can and, under the amended tuna measure, must be certified, and whose occurrence renders ineligible for the dolphin-safe label any tuna caught in the set in which the harmful interaction (i.e. the death or serious injury) occurred".284 The first compliance panel also described observable harms as "perceptible during fishing operations"285, but also found that the concept extended beyond certified serious injuries or mortalities, and could include dolphin mortality or serious injury occurring after the end of the fishing operation. In this vein, the compliance panel stated that "[w]hile it may be that dolphins injured in gillnets die at some later time, injuries such as those leading to gillnet parts 'protruding from the mouth' of dolphins would seem clearly to be the kind of 'serious injury' that is observable".286
7.157.
Regarding unobserved harms, the original panel broadly described these as "negative impacts on dolphins beyond observed deaths and serious injuries".287 It also explained that it understood "the United States' use of the terms 'observed mortalities and injuries' as referring to dolphin killings or serious injuries that are reported during (or immediately after the conclusion of) dolphin-setting operations. Thus, to the extent that setting on dolphins also results in dolphin deaths or injuries that are not observed or taken into account as observed killings or serious injuries, the other adverse effects identified by the United States may be described as unobserved deaths or injuries of dolphins".288 Moreover, in concluding on the issue of unobserved harms caused by setting on dolphins, the original panel found "a degree of uncertainty in relation to the extent to which setting on dolphins may have an adverse impact on dolphins beyond observed mortality".289 Nonetheless, the original panel considered that sufficient evidence had been put forward by the United States to raise a presumption that genuine concerns exist in this respect.290
7.158.
The concept of unobserved harms was also discussed in the first compliance proceedings. In this connection, we note that the first compliance panel recalled the findings made in the original proceedings, including that setting on dolphins causes unobservable harms to dolphins beyond mortality and serious injury, that these harms arise "as a result of the chase itself".291 The first compliance panel described unobservable effects as "negatively impacting the health and well-being of dolphin populations"292 and also clarified that "[n]one of […] fishing methods other than setting on dolphins inflict the same kinds of unobservable harms that are caused by net sets".293 In relation to ETP large purse seine fishing by setting on dolphins, the compliance panel noted that "even if there are tuna fisheries using … gear types that produce the same number of dolphin mortalities and serious injuries allowed or caused in the ETP … it is simply not the case that such fisheries are producing the same level of unobserved harms, such as cow-calf separation, muscular damage, immune and reproductive system failures, which arise as a result of the chase in itself".294
7.159.
We note that in drawing further distinctions between the unobservable harms of setting on dolphins and other fishing methods, the first compliance panel introduced the notion of "direct" and "indirect" harms, clarifying that "indirect and unobservable harms may follow consequentially from observable harms caused by tuna fishing methods other than setting on dolphins"295, thus constituting a broader concept, not necessarily involving the element of chase.
7.160.
Regarding the types of unobservable harms caused by setting on dolphins, the first compliance panel stated that, while the evidence on the record "clearly establishes that tuna fishing methods other than setting on dolphins pose serious threats to dolphins, we have been unable to find any indication in this evidence that fishing methods other than setting on dolphins cause the kinds of unobservable harms that are caused by setting on dolphins".296 Hence, despite the "degree of uncertainty" noted by the original panel "in relation to the extent to which setting on dolphins may have an adverse impact on dolphins beyond the observed mortality"297, the first compliance panel noted the same genuine concerns regarding setting on dolphins. The first compliance panel also stated that "unlike the kinds of unobservable harms caused by setting on dolphins, these types of indirect harms ar