Strengthening the implementation of International Maritime Organization regulatory frameworks and the responsibilities of a landlocked state as the flag state: A case study of Mongolia

In response to Russia's invasion of Ukraine in 2022, the Western world, including the G7 and EU, implemented an oil price cap on Russian oil as part of economic sanctions. Consequently, oil tankers transporting Russian oil without complying with the price cap faced strong maritime blockades, including port entry bans, restricted access to waters, and prohibitions on ship-to-ship transfers. However, Russia responded by organizing a shadow fleet of tankers. In fact, several countries like North Korea, Iran, and Venezuela have also operated dark ships to evade sanctions. The shadow fleet evolved from dark ships but differs significantly in scale. At one point, shadow fleets constituted approximately 20% of the world's oil tankers. The International Maritime Organization (IMO) has defined shadow fleets as vessels operating illegally to evade sanctions, safety or environmental regulations, insurance costs, or for illegal activities. Shadow fleets are characterized as aging, substandard vessels with inadequate safety equipment and non-existent or inadequate insurance. They also employ deceptive transportation practices such as AIS manipulation and spoofing, frequent flag changes, vessel identity manipulation, and ship-to-ship transfers. Due to these characteristics, shadow fleets pose a serious threat to maritime environment and safety. On December 6, 2023, in IMO Resolution A.1192(33), the IMO warned that the proliferation of shadow fleets is increasing the risk of oil spills and urged member states to prepare accordingly. Recently, incidents of damage to undersea cables and gas pipelines in the Baltic Sea have occurred frequently, with shadow fleets being identified as the cause. The EU Parliament, in its most vulnerable position to Russian threats, adopted a comprehensive resolution on shadow fleet sanctions in November 2024. This resolution recommended specific sanction measures, including vessel designation, along with enhanced monitoring using satellites or drones. By tracking changes in the scale of shadow fleets, it appears that port entry bans and prohibitions on ship-to-ship transfers had little effect due to Russia's securing of alternative routes, while vessel designation had somewhat more effect. Overall, sanctions against shadow fleets can hardly be considered successful. Ultimately, a response based on the United Nations Convention on the Law of the Sea (UNCLOS) is important. According to UNCLOS, the primary responsibility for ensuring maritime safety lies with the flag state. Article 235 of UNCLOS emphasizes the obligation of states to cooperate for the payment of adequate compensation, such as compulsory insurance or compensation funds. Flag states must comply with the obligation to cooperate for appropriate compensation regarding maritime environmental and safety threats posed by shadow fleets. However, when the flag state is either the party trying to evade sanctions or a flag of convenience country, there is a lack of willingness to faithfully fulfill these obligations. Therefore, while strengthening coastal state jurisdiction would be ideal, this is difficult without amending UNCLOS. Nevertheless, the spread of shadow fleets can be prevented through strengthening coastal state authority, such as establishing permitted zones in exclusive economic zones, restricting ship-to-ship transfers, and identifying and monitoring ship-to-ship transfer operations.

This chapter explains the main features of the interface between the UN Convention on the Law of the Sea (UNCLOS) and International Maritime Organization (IMO) regulations. Since its adoption the UNCLOS, and in particular its jurisdictional principles, has remained a reference point for much of the IMO’s work. The chapter suggests that greater use could be made by flag and coastal administrations of the powers afforded them under UNCLOS and IMO treaties to ensure that the high seas do not become a ‘dustbin’ for the spill of polluting substances from ships. Flag states have the power to investigate incidents on the high seas involving its ships. Likewise, coastal states have the power in certain defined circumstances to intercept foreign vessels in their exclusive economic zones (EEZs) and territorial seas, as well as to undertake physical inspection and to detain such vessels.

Illegal, unreported, and unregulated (IUU) fishing poses a significant threat to marine ecosystems, coastal livelihoods, and regional security, particularly in the strategically important Natuna Sea. This paper examines how the United Nations Convention on the Law of the Sea (UNCLOS) 1982 provides the legal framework for addressing illegal fishing activities and shaping law enforcement strategies between Vietnam and Indonesia. The study analyzes the obligations of coastal and flag states under UNCLOS, focusing on exclusive economic zones (EEZs), sovereign rights over marine resources, and the responsibilities to prevent, deter, and penalize IUU fishing. Through a case study approach, the article explores specific incidents involving Vietnamese fishing vessels operating in Indonesia’s EEZ around the Natuna Sea. It assesses how Indonesia has leveraged UNCLOS provisions, alongside domestic maritime law, to assert sovereignty, enforce regulations, and protect marine resources. The study also highlights challenges in enforcement, including jurisdictional ambiguities, resource constraints, and diplomatic tensions that complicate bilateral and regional responses. The analysis demonstrates that while UNCLOS 1982 establishes clear legal standards for maritime governance, its effectiveness depends on coordinated law enforcement, regional cooperation, and the integration of domestic and international legal mechanisms. The paper argues that addressing illegal fishing in the Natuna Sea requires not only adherence to UNCLOS but also proactive diplomatic engagement, capacity-building, and multilateral cooperation within Southeast Asia. Ultimately, the study concludes that UNCLOS serves as both a legal foundation and a practical tool for promoting sustainable fisheries management, strengthening maritime security, and mitigating conflict between Vietnam and Indonesia in the Natuna Sea.

The global issue of Sustainable marine fisheries is considered as common concern to humankind. The emergence and persistence of noncompliant fisheries practices conveniently labelled ‘Illegal, Unreported and Unregulated fishing’ (IUU fishing), is of particular concern for the international community, regional fisheries management organizations and coastal states. The International Tribunal for Law of the Sea (ITLOS) in its first full-bench Advisory Opinion in 2015 found that Arts. 62(4), 58(3), 192 of the United Nations Convention on the Law of the Sea (UNCLOS) contain obligations for a flag state to ensure that vessels flying their flags do not engage in illegal fishing in the exclusive economic zones of coastal states. By this explanation, the Advisory Opinion initially has clarified the inadequate international fisheries law regime through ITLOS interpretive approach, which this paper attempts to examine by applying an exact legal scrutiny. The framework set by the Tribunal may allow States affected by IUU fishing, to exert greater pressure on flag states, particularly flag states of convenience, that do not comply with their responsibilities under UNCLOS. This paper suggests that the regulations on IUU fishing under international law should be enhanced and revised in order to draw an appropriate solution suitable for sustainable fisheries management.

The International Maritime Organization (IMO) has the authority to impose conditions on ships exercising the right of transit passage through straits used for international navigation or the right of archipelagic sea lanes passage through archipelagic States. This chapter discusses whether measures by coastal States or international organizations taken together are likely to spoil the balance between freedom of navigation and environmental and security interests of coastal States as well as the international community. The United Nations Convention on the Law of the Sea (UNCLOS) makes ample reference to the freedom of navigation, for example in Article 36 (freedom of navigation in straits used for international navigation), Article 58 (freedom of navigation in the Exclusive Economic Zone), Article 78 and Article 87 (high seas). The freedoms in these Articles mean the same - freedom of movement of ships. Keywords: archipelagic sea lanes; coastal States; exclusive economic zone; freedom of navigation; international maritime organization (IMO); international straits; UNCLOS

Illegal, unreported, and unregulated ( IUU ) fishing continues despite global condemnation and the adoption of the International Plan of Action to Prevent, Deter, and Eliminate Illegal, Unreported, and Unregulated Fishing in 1999. Although fisheries and the marine environment are not the primary emphasis of the World Trade Organization, 20 years of negotiations culminated in the Agreement on Fisheries Subsidies ( AFS ) in June 2022. The interpretation and application of the AFS will inevitably influence State parties’ rights and obligations under the United Nations Convention on the Law of the Sea ( UNCLOS ), which establishes the legal framework for all marine space activities. Indeed, UNCLOS tribunals are already incorporating external rules of international law when interpreting and applying treaty provisions, as highlighted in the International Tribunal for the Law of the Sea’s Climate Change Advisory Opinion in 2024. Accordingly, this study investigates the influence of the AFS , particularly provisions concerning IUU fishing, on UNCLOS rights and obligations. It argues that the AFS will have an impact on, inter alia, sovereign rights of exclusive economic zone coastal States; due regard obligations; flag States’ duties over administrative, technical, and social matters; the obligation to comply with other rules of international law; and obligations to protect and preserve the marine environment.

Navigation of ships carrying radioactive materials is directly envisaged by the United Nations Convention on the Law of the Sea (UNCLOS) in only two provisions. The first is Article 22 and second is Article 23. These provisions confirm that ships carrying radioactive materials enjoy the right of innocent passage, with a possible requirement of using sea lanes and the need to carry documents prescribed by international agreements. according to UNCLOS, a ship carrying radioactive materials enjoys the right of innocent passage in the territorial sea and freedom of navigation in the exclusive economic zone (EEZ). In light of the difference between the two zones that makes the position of the coastal State in the territorial sea stronger than it is in the EEZ, the restrictions may be more severe, and in any case no less severe, for passage through the territorial sea than for navigation in the EEZ. Keywords: exclusive economic zone (EEZ); international agreements; Navigation of ships; radioactive materials; UNCLOS

‘Strait’ is not a term of art, and it is not defined in any of the conventions produced by the United Nations Conferences on the Law of the Sea. It bears its ordinary meaning, being ‘geographically, a narrow passage between two land masses or islands or groups of islands connecting two sea areas.’ It is the legal status of the waters constituting the strait and the fact of their use by international shipping, rather than any definition of ‘strait’ as such, that determines the rights of coastal and flag States in the waters of the strait. This chapter first considers the rules governing straits prior to the UN Convention on the Law of the Sea (UNCLOS), before turning to a detailed analysis of the UNCLOS regime, notably the transit passage through straits used for international navigation, established by Part III of the Convention. It addresses a coastal State’s legislative jurisdiction and the (less clear) scope of a coastal State’s enforcement jurisdiction. It considers the issue of whether there is a right similar to transit passage through international straits as a matter of customary international law. The chapter concludes by noting special regimes which regulate passage through particular straits.

The jurisdiction of a state principally extends to its own territory, territorial sea, and airspace. At sea, states generally have jurisdiction only over vessels within their territorial waters. The high seas are areas where the freedom of navigation is guaranteed and fall under the jurisdiction of no specific state. Under the principle of flag state jurisdiction, a vessel on the high seas is subject to the jurisdiction of the state whose flag it flies. One significant exception to this flag state principle is the right of hot pursuit, as stipulated in Article 111(1) of the United Nations Convention on the Law of the Sea (UNCLOS). The right of hot pursuit allows a coastal state to pursue and seize a vessel suspected of violating its laws and regulations while in its territorial sea, contiguous zone, or exclusive economic zone (EEZ), even if the pursuit extends onto the high seas. This right effectively extends the coastal state's jurisdiction to the high seas and constitutes a significant exception to the principles of freedom of navigation and flag state jurisdiction. However, the requirements for exercising the right of hot pursuit have long been a subject of controversy in international law, and even after being codified in 1982 UNCLOS, issues of interpretation remain contentious. Key areas of disagreement include the maritime zones where pursuit may begin, the entities authorized to conduct the pursuit, the continuity of pursuit, and the use of force during pursuit. For South Korea, where much of the national territory is adjacent to the sea, analyzing the legal principles and cases related to the right of hot pursuit under UNCLOS has considerable significance in enforcing domestic law at sea. This paper first briefly examines the extraterritorial application of criminal law in connection with passive personality jurisdiction when exercising the right of hot pursuit. It then explores the requirements for the right of hot pursuit under UNCLOS, with a particular focus on the maritime zones where pursuit may commence and the requirement of continuity. The domestic case of the M/V Tyumen is analyzed in this context. Additionally, this paper addresses considerations for interpreting and applying the provisions on the right of hot pursuit under UNCLOS, as well as key factors to be considered by domestic law enforcement agencies, such as the Korea Coast Guard, when exercising this right.

Port states, coastal states and national security: A law of the sea perspective on the 2017 Qatar-Gulf crisis

This article explores the interface of regimes in the law of the sea and international maritime law and discusses to what extent and how area-based management measures adopted by the International Maritime Organization (IMO) may be employed to support the objectives of the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement). In pursuing this quest, the article first explores the interface between the United Nations Convention on the Law of the Sea (UNCLOS), the BBNJ Agreement, and IMO instruments to support the conservation of marine areas beyond national jurisdiction. Second, the article discusses the notion of area-based management on the high seas, as this is expected to be the principal point of convergence between UNCLOS, the BBNJ Agreement, and IMO instruments. Third, the article examines the IMO instruments that will be most useful in supporting area-based management measures adopted under the BBNJ Agreement. Finally, the article concludes with observations on the opportunity the BBNJ Agreement provides IMO to play a larger role in supporting conservation of the ocean commons.

The high seas beyond littoral State jurisdiction Grotius needs to prevail over Selden and the particular interests of littoral States as the Oceans Public Trust becomes the new crucible defining administration of equitable responsibility for the collective community of States in custody of the high seas regime res communis. The International Maritime Organization (IMO) is a reliable example of the pre- United Nations Convention on the Law of the Sea (UNCLOS) development of conventional arrangements as now beginning to organize within the framework of the Oceans Public Trust, especially in consideration of IMO's structure, governance and regulatory responsibility within the high seas regime for protection and preservation of usage of the res communis communal property of the oceans as well as the therein contained living and non-living resources.Keywords: high seas regime res communis; International Maritime Organization (IMO); littoral States; Oceans Public Trust; UNCLOS

The contribution of fisheries access agreements to flag State responsibility

The coastal state obligation not to impede the laying or maintenance of submarine pipelines on the continental shelf according to United Nations convention on the law of the sea

As the global maritime sector advances towards decarbonisation, alternative fuels such as biofuels, hydrogen, and ammonia are increasingly being considered to reduce greenhouse gas (GHG) emissions. However, these fuels pose unique environmental risks, particularly in cases of accidental spills. This study investigates whether the current international legal framework—comprising conventions like MARPOL and the United Nations Convention on the Law of the Sea (UNCLOS)—is sufficient to mitigate and repair environmental damage from spills of these alternative fuels, given that no specific international agreements directly address this issue.The analysis draws on the complex interplay between maritime law and environmental protection, highlighting that MARPOL’s primary focus has been on regulating traditional pollutants, which limits its applicability to newer fuel types whose chemical properties and ecological impacts vary significantly. According to research by Hsieh and Felby, approximately 70% of fuels in maritime operations must transition to low-carbon alternatives to meet International Maritime Organization (IMO) decarbonisation targets, yet safety data on these new fuels is scarce. Thus, an incident involving such fuels could create challenges for damage quantification, risk assessment, and cleanup protocols (Hsieh & Felby, 2017).In terms of liability and enforcement, UNCLOS provides a general framework for pollution control, conferring responsibility primarily to flag and coastal states. However, the unique characteristics of alternative fuels, such as ammonia’s toxicity or hydrogen’s flammability, highlight the limitations of existing port and coastal state powers under Articles 211 and 218, which were developed and construed with conventional pollutants in mind (UNCLOS, 1982). Additionally, the IMO’s non-binding guidelines, while useful, do not hold the weight of enforceable international law, leaving significant enforcement gaps when spills involve non-traditional fuels.This study also considers the “ocean implementation gap” as outlined by Hinds, referring to the lack of inter-agency cooperation among UN organizations tasked with ocean governance, which impedes the development of cohesive regulations for alternative fuel risks. There is a need for fostering UN inter agency cooperation due to their capacity for supporting maritime environmental safety projects (Hinds, 2003). There is also a need for increasing capacity development and ocean research. For instance, only a few initiatives, such as the GreenVoyage2050 project, address the safe use of alternative fuels, leaving major safety concerns unaddressed, as Tandros notes, in terms of fire and explosion risks (Tandros et al., 2023).In conclusion, while MARPOL and UNCLOS provide foundational frameworks for pollution control, they are not fully equipped to handle the emerging risks associated with alternative fuel spills. The paper recommends establishing legally binding international standards and promoting inter-agency cooperation to bridge the implementation gap. Addressing these regulatory gaps is essential to advancing maritime sustainability and ensuring that the transition to low-carbon fuels does not inadvertently heighten environmental risks.