KIMS Periscope

KIMS Periscope No. 293

Maritime Delineation & Delimitation Transparency Through the IUU Fishing Lens: Low-Hanging Fruit in the Fight Against IUU Fishing

The Max Planck Foundation
Arron N. Honniball


Two broad and complex maritime security issues in Southeast Asia –as with most regions– includes: (1) necessities for maritime claims being advanced in a manner substantively and procedurally consistent with UNCLOS, and (2) eliminating illegal, unreported and unregulated (IUU) fishing (Viet Nam Note Verbale 22/HC-2020; Joint Communiqué of 55th AMM; A/RES/70/1, Target 14.4). Both challenges are primarily addressed independently, requiring regional cooperation and substantive measures and assistance among like-minded states. However, fisheries law inherits and presupposes all coastal states are faithfully applying the zonal approach of UNCLOS. A focus on the overlapping areas between both fields can reap mutual benefits, including while negotiating and addressing more substantive or politically sensitive control measures to combat IUU fishing activities, or IUU fishing related activities (e.g., recommendations in Hutniczak and Delpeuch (2018)).

One example where all coastal states can provide a mutual and meaningful contribution, founded in the universality of UNCLOS (Joint Communiqué of 55th AMM), is to fully implement the obligations of providing due publicity to, and deposition of, the outer limits of their maritime zones claimed, or maritime boundaries delimited (UNCLOS, Articles 16(2), 47(9), 75 and 84). Its significance lays in clearly defining particular cases of IUU fishing as a matter of legal certainty, while its relevance lays in the fact that progress on this oft overlooked procedural obligation would be low-cost as compared to the equally important substantive obligations upon states to combat IUU fishing, and avoid disputes debated in efforts to expand the IUU fishing fight into related, but possibly distinct, maritime concerns (contrast: Barnes and Rosello (2020); Jesperson and Henriksen (2022)). This commentary explores the nexus between zonal transparency and IUU fishing, including policy consequences thereof. Southeast Asia provides an illustrative example, but other regions may require similar analysis and approaches.

The Due Publicity/Deposition–IUU Fishing Nexus

Coastal states party to UNCLOS are obliged to provide due publicity to the outer limits of their archipelagic waters (UNCLOS, Article 47), territorial sea (UNCLOS, Article 16), continental shelf (UNCLOS, Article 84) and exclusive economic zone (EEZ) (UNCLOS, Article 75). This also includes due publicity of relevant EEZ or continental shelf delimitation agreements, as well as depositing a copy of all of the above with the UN Secretary-General (plus the ISA Secretary-General concerning the continental shelf outer limits). Pending delimitation, provisional arrangements between valid claimant states may govern fisheries activities therein (UNCLOS, Articles 74(3) and 83(3)).

The purposes of these provisions transcends maritime delimitation: “the international community and the users of the seas and oceans need to know the limits of the maritime zones in which a coastal State exercises its sovereignty or sovereign rights and jurisdiction, in view of the different legal regimes applicable” (SPLOS/30/12, Paragraph 3). Beyond legal principle, transparency in maritime claims has assisted in crystalizing possible disputes and the exchange of views, as evident in the publicly circulated communications that react to a maritime frontier, or delimitation practice, brough to light by said transparency (SPLOS/30/12, Paragraph 14).

However, by 31 March 2020 –despite annual calls from the UNGA (e.g., A/RES/76/72, Paragraph 5), technical assistance from DOALOS and UNSG (Deposit Guidelines (2021); SPLOS/30/12, Paragraph 24; LOSICs)– only 81 Contracting Parties to UNCLOS and 1 Non-Contracting Party have made at least one relevant deposit with UNSG so as to discharge their obligations (SPLOS/30/12, Paragraph 12). Concerning deposits with the ISASG, only 10 states have made relevant deposits, including the Philippines in respect of Philippine  Rise (Philippines Note Verbale 00137). Of those 82 states, the states fully implementing all transparency requirements for all outer limits and delimitation agreements will be considerably lower, thereby obscuring an authoritative distribution of jurisdiction and clarity on the laws applicable to private actors, including fishers. Taking Southeast Asia as an example, one finds mixed state practice, ranging from full implementation (Philippines archipelagic waters: M.Z.N.69.2009.LOS), to partial implementation (Thailand delimitation lines: significant continental shelf transparency, but EEZ agreements lack due publicity, e.g., 1993 India/Thailand Agreement), to those awaiting any implementation (Malaysia/Brunei EEZ and continental shelf delimitation lines: 2009 Exchange of Letters on Maritime Boundary Delimitation; Forbes (2020), p. 80).

While not directly linked to the IUU fishing concept in fisheries law, all states are expected to give full effect to relevant norms of international law, including UNCLOS, to eliminate IUU fishing (IPOA-IUU, Paragraph 10). A closer look at the widely accepted and applied (e.g., PSMA, Article 1(e); 2015 USA/Russia IUU Cooperation Agreement, Article 1(1)(a)) descriptive definition of IUU fishing found in the IPOA-IUU highlights the relevance of these obligations in defining IUU fishing in two key cases:

“3.1.1 [Illegal fishing refers to activities] conducted by national or foreign vessels in waters under the jurisdiction of a State, without the permission of that State, or in contravention of its laws and regulations;


3.3.2 [Unregulated fishing refers to fishing activities] in areas or for fish stocks in relation to which there are no applicable conservation or management measures and where such fishing activities are conducted in a manner inconsistent with State responsibilities for the conservation of living marine resources under international law” (IPOA-IUU, Paragraph 3).

Paragraph 3.1.1. on illegal fishing clearly presupposes that the boundaries of all coastal states’ waters are clearly defined and given due publicity to other states and fishers. Likewise, then is it clear to fishers as to which state permission must be sought, or which coastal state’s laws and regulations are applicable and must be complied with (UNCLOS, Article 62(4)). Defining unregulated “fish stocks in relation to which there are no applicable conservation or management measures” may also turn on questions of which maritime zone they are located within: a regulating coastal state, a nonregulating coastal state, a regulated/unregulated high seas stock, or whether the stock is transboundary or discrete. Objective answers, accessible to all states and actors, require transparent maritime boundaries.

Thus, the descriptive definition of IUU fishing presupposes that clear and consistent maritime claims by coastal states are made and duly known, which globally is not yet the case. By and large, this assumption continues into other fisheries instruments concerning IUU fishing. An FAO Checklist to Combat IUU Fishing (2021) is an excellent resource on states duties and implementation but focuses on fisheries law and the due publicity of conservation and management measures, not maritime boundaries. Interestingly, due publicity on the delineation of maritime zones was a coastal state measure in a 2000 Preliminary Draft of the IPOA-IUU (Paragraph 27) but does not feature in the final IPOA-IUU. It has been relegated to two passing sentences in the 2002 FAO Technical Guidelines to Implement the IPOA-IUU, whereby a “coastal State should ensure that waters under its jurisdiction are clearly delineated and marked on charts” (pp. 34, 75).

Nonetheless, some states are taking note of the importance of identifying and addressing this nexus. The Maldives includes an awareness of the needs of maritime delimitation in their NPOA-IUU (2019), as well as noting the FAO Technical Guidelines’ recommendations on delineation transparency (p. 32). Meanwhile, suspected illegal activities may have gone unproven and unaddressed by flag states because of evidentiary hurdles arising from a lack of due publicity on area-based management tool boundaries, a danger equally applicable to maritime delineation generally (Okafor-Yarwood (2022)). The lack of full transparency in zonal boundaries, as required by UNCLOS, therefore frustrates the application of the generally accepted definition of IUU fishing. This has a number of practical and policy implications in international law and national responses to IUU fishing, three of which can be highlighted here.

First, the distribution of concurrent state responsibilities to combat IUU fishing is undermined. Coastal states have primary responsibility to combat IUU fishing in their maritime zones (Schatz (2016); SRFC Advisory Opinion, Paragraph 106). Due publicity and deposition are clearly essential elements not only in defining illegal or unregulated fishing, but also in defining the geographic scope of their legal responsibilities to the international community. Likewise, for example, flag states have concurrent responsibilities to combat illegal fishing or related activities by their vessels in foreign maritime zones (SRFC Advisory Opinion, Paragraphs 123-124; South China Sea Arbitration Award, Paragraphs 741-744; PSMA, Articles 3 and 20) and port states have concurrent responsibilities to combat illegal fishing or related activities in foreign maritime zones by visiting foreign vessels (PSMA, Articles 3, 9, 11-12, 18). Coastal states which have not provided transparency on the limits of their maritime zones may find cooperation from flag states and port states less forthcoming when zonal ambiguities arise. Flag and port states may be hindered in taking enforcement action against vessels which utilise the lack of transparency in maritime boundaries to dispute whether illegal fishing has occurred on the grounds of foreseeability of the law and legal certainty. This will complicate the ability of distant water fishing nations, such as South Korea, to discharge their due diligence obligations under UNCLOS because this includes not only the prescription of adequate laws, but a certain level of vigilance in their enforcement (SRFC Advisory Opinion, Paragraph 131).

Second, interstate mechanisms designed to analyse the enforcement of international fisheries law by foreign states and then promote the discharge of their respective obligations will be frustrated by a lack of transparency in maritime boundaries. For example, the EU and USA may adopt trade measures concerning a flag or coastal state they perceive as failing to discharge their IUU fishing-related duties in international law (Honniball (2020)). NOAA has recently proposed to amend the USA’s identification and certification procedure to address states facilitating illegal fishing in foreign EEZs (87 FR 40763), which, as above, would benefit from legal certainty on the outer limits or delimitation lines of the EEZ for both identification and constructive dialogues.

Third, looking further afield, due publicity in maritime delineation and delimitation is clearly a procedural rule of significant substantive importance, primarily in the exercise of the rights and responsibilities of coastal states, flag states and states of registry (aircraft). Other thematic fields are also built upon the faithful application of the zonal approach and therefore any use of the IUU fishing momentum to stimulate further due publicity and deposits of maritime boundaries will have knock on effects for improved ocean governance and the avoidance of disputes in functional jurisdiction. For example, greater transparency will assist in implementing the different rights of navigation or marine scientific research, which depend on the zones in question, as well as cooperative responsibilities of e.g., transboundary living resources (UNCLOS, Articles 63-67), maritime security (UNCLOS, Articles 58(2), 100, 108-109 and 113), transboundary harm (UNCLOS, Article 194(2)) or unjustifiable transboundary interferences (UNCLOS, Article 78(2)).

Likewise, developments in the pipeline are building on the assumptions that the outer limit of maritime boundaries, or at least maritime claims, are (going to be) public and circulated as required by UNCLOS. This includes both the ongoing BBNJ Agreement process (A/CONF.232/2022/5, Article 3(1)) and ISA Mining Code process (ISBA/25/C/WP.1, Regulation 4). Using the political momentum of the fight against IUU fishing to address resource-light –but fundamental– procedural obligations such as due publicity and deposition of maritime boundaries will not only better equip coastal, flag, market, port and nationality states to combat IUU fishing, or the non-fulfilment of state responsibilities, but will also put in place the legal landscape the Area regime or BBNJ exploitation will utilise, before any uncertainties over the jurisdiction of extraction occur.

Finally, UNCLOS is silent on the consequences of not fulfilling the transparency requirements concerning maritime limits. Lack of implementation clearly will not affect the inherent right to a maritime zone, nor the declaratory effect of any lawful exercise of the right to establish an EEZ. One can however note that a failure to implement would, after a reasonable period of time, respectively violate Article 16(2), 47(9), 75 or 84 of UNCLOS. As an obligation erga omnes, any UNCLOS Contracting Party could bring this before compulsory dispute settlement. The optional exclusion of maritime delimitation disputes from Part XV, Section 2 of UNCLOS does not extend to the due publicity obligations (UNCLOS, Article 298(1)(a)).


In short, calls for transparency in the fisheries supply chain (Virdin et al. (2022)), or transparency in fishing vessels ownership and practices (the EU IUU Coalition (2019)), should be matched by transparency in the zonal framework – who’s jurisdiction ends where. At relatively low cost, a focus on implementing the longstanding, but unfulfilled, delineation and delimitation transparency requirements of UNCLOS holds significant potential to contribute to both combatting IUU and wider good governance based on the rule of law and UNCLOS. However, beyond the UN such procedural duties gain comparatively little international attention or pressure, with fisheries lawyers focusing on fisheries law and delimitation experts focusing on the impacts of maritime features, or evolving jurisprudence. This commentary has sought to raise awareness on the importance of implementation by viewing delineation and delimitation transparency through the IUU fishing lens. Most, if not all states are publishing ocean policies that include combatting IUU fishing (e.g., Korea NPOA-IUU (2014); RPOA-IUU (2007)). This global momentum could be utilised to ensure universal implementation of the transparency requirements in Articles 16(2), 47(9), 75 and 84 of UNCLOS, thereby further transforming political statements into practical implementation – to the benefit of all states and a rules-based order. Fully implementing the zonal transparency requirements of UNCLOS would also set a good example, raising hope that the deeper transparency requirements permeating all pillars of the current Further Revised Draft BBNJ Agreement will be fully implemented.

The views expressed in this article are those of the authors, and do not necessarily reflect the views of the Foundation, any other staff, or that of any other institution.

Arron N. Honniball 박사는 국제평화와 법치를 위한 막스 플랑크 재단 (The Max Planck Foundation for International Peace and the Rule of Law) (독일)의 선임연구원이다. 이전에는 국제법센터 (Centre for International Law) (싱가포르국립대학교, 싱가포르)에서 연구원 (2019-2021년)으로, 네덜란드 해양법연구소 (Netherlands Institute for the Law of the Sea) (위트레흐트대학교, 네덜란드)에서 박사 과정생 (2014-2018년)으로 재직한 바 있다.

  • The author’s opinions expressed in this article are the author’s own and does not reflect the view of KIMS.

KIMS regularly sends out Kakao messages with the latest research output on maritime security. We offer latest insights into what the current issues are and what ought to be done in this ever-changing world. Anybody interested in reading these findings are encouraged to subscribe to our channel.

카톡친구 버튼

친구추가 버튼

코드스캔 버튼

QR코드 스캔

채널 버튼

Leave a Comment

Your email address will not be published. Required fields are marked *