Transboundary Fish Stocks Research Articles

A hundred years of Pacific halibut management in the context of global events and trends in fisheries management

The Convention for the Preservation of the Halibut Fisheries of the Northern Pacific Ocean, signed between Canada and the United States of America on 2 March 1923 and ratified on 21 October 1924, established the International Fisheries Commission, renamed in 1953 to the International Pacific Halibut Commission (IPHC). It was the first international agreement for joint management of a marine fishery resource and a major milestone for development of modern standards for marine conservation. The IPHC’s centennial year is an opportunity to celebrate a remarkable history of the Commission, but also reflect on challenges that shaped its mission. Born from alarms about overfishing during World War I, the Commission gradually gained authority to implement a wide range of conservation measures through established public confidence in its basis for decisions. This paper explores the evolution of management measures applied to Pacific halibut commercial fishing shaped not only by the changing stock conditions and growing demand for seafood, but also global events and trends in fisheries management. It examines the impact of rapid commercialization of fisheries driven by population growth and technological improvements, establishment of exclusive economic zones and altered access to fishing grounds, and adoption of Agenda 21, which highlighted the importance of balancing environmental, economic, and social aspects in fisheries management. It concludes by discussing the lessons learned over the past century and their implications for future fisheries management, emphasizing the importance of international cooperation, adaptive strategies, and science-based policies in sustaining transboundary fish stocks like the Pacific halibut.

Genetic investigation of population structure in Atlantic chub mackerel, Scomber colias Gmelin, 1789 along the West African coast.

Sustainable management of transboundary fish stocks hinges on accurate delineation of population structure. Genetic analysis offers a powerful tool to identify potential subpopulations within a seemingly homogenous stock, facilitating the development of effective, coordinated management strategies across international borders. Along the West African coast, the Atlantic chub mackerel (Scomber colias) is a commercially important and ecologically significant species, yet little is known about its genetic population structure and connectivity. Currently, the stock is managed as a single unit in West African waters despite new research suggesting morphological and adaptive differences. Here, eight microsatellite loci were genotyped on 1,169 individuals distributed across 33 sampling sites from Morocco (27.39°N) to Namibia (22.21°S). Bayesian clustering analysis depicts one homogeneous population across the studied area with null overall differentiation (F ST = 0.0001ns), which suggests panmixia and aligns with the migratory potential of this species. This finding has significant implications for the effective conservation and management of S. colias within a wide scope of its distribution across West African waters from the South of Morocco to the North-Centre of Namibia and underscores the need for increased regional cooperation in fisheries management and conservation.

Timing and magnitude of climate-driven range shifts in transboundary fish stocks challenge their management.

Climate change is shifting the distribution of shared fish stocks between neighboring countries’ Exclusive Economic Zones (EEZs) and the high seas. The timescale of these transboundary shifts determines how climate change will affect international fisheries governance. Here, we explore this timescale by coupling a large ensemble simulation of an Earth system model under a high emission climate change scenario to a dynamic population model. We show that by 2030, 23% of transboundary stocks will have shifted and 78% of the world's EEZs will have experienced at least one shifting stock. By the end of this century, projections show a total of 45% of stocks shifting globally and 81% of EEZs waters with at least one shifting stock. The magnitude of such shifts is reflected in changes in catch proportion between EEZs sharing a transboundary stock. By 2030, global EEZs are projected to experience an average change of 59% in catch proportion of transboundary stocks. Many countries that are highly dependent on fisheries for livelihood and food security emerge as hotspots for transboundary shifts. These hotspots are characterized by early shifts in the distribution of an important number of transboundary stocks. Existing international fisheries agreements need to be assessed for their capacity to address the social–ecological implications of climate‐change‐driven transboundary shifts. Some of these agreements will need to be adjusted to limit potential conflict between the parties of interest. Meanwhile, new agreements will need to be anticipatory and consider these concerns and their associated uncertainties to be resilient to global change.

Disentangling politics in the Indian Ocean Tuna Commission

Regional Fisheries Management Organizations (RFMOs) require countries with diverse objectives, aspirations, and interests to cooperate to sustainably manage transboundary fish stocks. These organizations are often subjected and are held responsible for overfishing, slow management responses and failure to follow scientific evidence. Disappointing performance is often attributed to a ‘black box of politics’ or a ‘lack of political will’ among members. Disentangling the politics and motivations behind RFMO decision-making is crucial in understanding how they function and why they might fail. Here, we analysed eight socio-economic indicators to identify the priorities of 30 members of the Indian Ocean Tuna Commission (IOTC) and conducted 41 interviews with key stakeholders to understand their engagement strategies. This study also focuses on how different actors engage, negotiate, and leverage their political power in the development and adoption of Conservation and Management Measure proposals. Our results demonstrate that socio-economic interests, political and economic influences, and management priorities converge on IOTC members to inform their negotiation positions. Even though individual domestic interests drive the decisions taken by members, we identified 34 unique entities that influence member decisions in the IOTC. Additionally, members with tuna interests influence other members, in particular developing States. Further, the decisions by members are not necessarily based on tuna management but tied to sovereignty, foreign aid, and other development aspects outside the realm of the RFMO decision-making. Our findings also indicate the importance of defining clear ownership of the resource and the critical role of various stakeholders.

Electronic monitoring for improved accountability in western Pacific tuna longline fisheries

The collection of accurate fisheries catch data is critical to ensuring sustainable management of tuna fisheries, mitigating their environmental impacts and for managing transboundary fish stocks. These challenges are exemplified by the western Pacific tuna longline fishery, who’s management includes >26 nations, but is informed by critically low coverage of fishing activities by scientific observers. The gap in observer data could be filled by electronic monitoring (EM), but there are few trials that span multiple nations. A large-scale trial of EM systems on tuna longliners based in Palau, Federated States of Micronesia and the Republic of the Marshall Islands, is reported on. Comparisons are made of catch rates of market and bycatch species in corresponding EM, logbook and human observer data. Retained species were under-reported in logbooks by up to three times and discards of many species were not reported in logbooks. Discards identified in the EM data included threatened species such as marine turtles. Catch rate estimates from EM data were comparable to those estimated by human observers. EM data recorded a higher species diversity of catches than logbook data. Analysis of the EM data indicated clusters of bycatch that were associated with specific fishing practices. These results suggest further expansion of EM could inform improved management of both target and bycatch species. Ultimately greater coverage of EM data could contribute to reconciling debates in international stock allocation schemes and support actions to reduce the impacts of the fishery on threatened bycatch species.

Transboundary Fisheries Management

Abstract The United Nations Convention on the Law of the Sea created the exclusive economic zone regime, which makes more than 90 per cent of the world’s commercial fish stocks under the national jurisdiction of coastal States. The biological characteristics of fish demonstrate that the long-term sustainability of fisheries can only be achieved through cooperation and coordination among States, especially for the conservation of transboundary fish stocks. However, the ocean may have more than 1,500 transboundary fish stocks, only a limited number are subjected to effective cooperative management. This article provides an overview of the international legal framework on transboundary fisheries and China’s practice on shared stocks and distant water fisheries, and argues that current bilateral fisheries agreements are not sufficient enough to manage transboundary fish stocks and China still has much to do on regulating distant water fisheries.

Toward transparent governance of transboundary fisheries: The case of Pacific tuna transshipment

Transparency is one of the most influential themes in global environmental governance, however it has received limited treatment in transboundary fisheries. Transparency is essential to ensure officials are held accountable for the use of public resources and the achievement of environmental objectives, such as sustainable harvest. Here, we use a case study approach to assess transparency in transboundary fisheries governance, evaluating transshipment in the Western and Central Pacific Ocean, one of the world's most abundant and lucrative fisheries. Transshipment at sea occurs extensively in these fisheries, but often lacks strong monitoring and oversight, and has been associated with illegal or illicit activities. However, actors that rely heavily on transshipment at sea maintain that it can be a legitimate part of the fish commodity chain, under effective regulation. Here we assess whether at-sea transshipment in one of the most regulated and visible fisheries in the world is traceable, verifiable, and legal. Using AIS data and qualitative information from regional and sub-regional sources, we find that 68% of observed potential transshipments remain unsubstantiated even after triangulating with diverse data. We identify three primary areas for improving traceability and transparency of transshipment at sea in the WCPO, and suggest that transparency is ultimately hindered less by technical or administrative constraints, but by tensions between the actors and objectives within management institutions. Increased transparency, and a focus on the underlying dynamics that inhibit it, is necessary to ensure effective conservation and management of transboundary fish stocks, now and in the future.

Collapse of cooperation? The North-Atlantic mackerel dispute and lessons for international cooperation on transboundary fish stocks

A changing climate will challenge the effectiveness and functioning of existing international resource management structures or international regimes. This is already evident in regimes that manage transboundary fish stocks, where rapid changes in the abundance and distribution of fishery resources threaten international cooperation. This article examines the breakdown in resource cooperation for the northeast Atlantic mackerel fishery where, for over a decade, Coastal States have failed to reach an agreement on the management of the stock after a climate-induced shift in the stock’s distribution. Why did the management regime fail? And what are lessons learnt for such regimes more generally? This article sheds light on the interplay between a relatively weak international regime, domestic interests related to the importance of the national fishing industry and a breakdown in the common principles – fisheries science – that international cooperation is based on. The limited flexibility in the negotiating position of the various states – and thus, the regime at large – can be ascribed to a combination of strong domestic industry influence on negotiating positions, and a disagreement over the appropriate methods to measure stock biomass in tandem with unclear allocation principles. Strengthening existing mechanisms to cooperatively manage shared stocks between Coastal States will be important to avoid such disputes in the future. However, states are weary of relinquishing decision-making powers. Therefore, starting with an agreement on the fundamentals, namely the science that underpins diverging claims, could be a first step towards a long-term solution for the northeast Atlantic mackerel.

Fish distributions reveal discrepancies between zonal attachment and quota allocations

AbstractThe oceans’ fisheries contribute to human wellbeing by providing essential nutrients, employment, and income. Changes in fish distribution, due to climate change or stock expansion, jeopardize conservation objectives because fishers catch more than is allocated as quota. Quotas, or catch shares, should, therefore, correspond to the share of the fish stock biomass present within a country's Exclusive Economic Zone, a concept known as Zonal Attachment. Here, we assess the Zonal Attachment of transboundary fish stocks present in northern Europe, in the waters of the United Kingdom, the European Union (without the United Kingdom), and Norway. In 12 of 14 important fish stocks, estimates of Zonal Attachment to the United Kingdom were significantly higher than current quota allocations, explaining the country's substantial discard problem. With environmental change, and stock recovery under improved fisheries conservation, scientific evidence should be used not only to set catch limits, but also to re‐examine catch shares.

Climate change, shifting threat points, and the management of transboundary fish stocks

Climate change, shifting threat points, and the management of transboundary fish stocks

Ecosystem-based management can contribute to cooperation in transboundary fisheries: The case of pacific sardine

Transboundary fish stocks complicate sustainable fishing strategies, particularly when stakeholders have diverse objectives and regulatory and governance frameworks. Pacific sardine (Sardinops sagax) in the California Current is shared by up to three fishing nations— Canada, the United States, and Mexico—and climate-driven abundance and distribution dynamics can complicate cooperative fisheries, leading to overfishing. This study builds on previous analyses by integrating ecosystem linkages into a game theory model of transboundary sardine fisheries under various climate scenarios. Cooperative fishing strategies that account for the ecosystem-wide value of sardine as forage for other species result in increased economic benefits compared to strategies that only account for the single-species value of sardine fisheries to a given fishing country. Total ecosystem landed value is maximized at a sardine fishing rate only somewhat lower than sardine FMSY, which is more precautionary but still allows the fishery to operate. Incorporating ecosystem dynamics into management-applicable models can highlight ways in which ecosystem-based fisheries management can improve both sustainability and profitability and help managers prioritize wider ecological research. Ecosystem-based management will be increasingly required to understand and adapt to the observed rapid shifts in species distributions due to climate change, and to design strategies to achieve sustainable and profitable fisheries amidst changing ecosystems.

Competition or cooperation in transboundary fish stocks management: Insight from a dynamical model

An idealized system of a shared fish stock associated with different exclusive economic zones (EEZ) is modelled. Parameters were estimated for the case of the small pelagic fisheries shared between Southern Morocco, Mauritania and the Senegambia. Two models of fishing effort distribution were explored. The first one considers independent national fisheries in each EEZ, with a cost per unit of fishing effort that depends on local fishery policy. The second one considers the case of a fully cooperative fishery performed by an international fleet freely moving across the borders. Both models are based on a set of six ordinary differential equations describing the time evolution of the fish biomass and the fishing effort. We take advantage of the two time scales to obtain a reduced model governing the total fish biomass of the system and fishing efforts in each zone. At the fast equilibrium, the fish distribution follows the ideal free distribution according to the carrying capacity in each area. Different equilibria can be reached according to management choices. When fishing fleets are independent and national fishery policies are not harmonized, in the general case, competition leads after a few decades to a scenario where only one fishery remains sustainable. In the case of sub-regional agreement acting on the adjustment of cost per unit of fishing effort in each EEZ, we found that a large number of equilibria exists. In this last case the initial distribution of fishing effort strongly impact the optimal equilibrium that can be reached. Lastly, the country with the highest carrying capacity density may get less landings when collaborating with other countries than if it minimises its fishing costs. The second fully cooperative model shows that a single international fishing fleet moving freely in the fishing areas leads to a sustainable equilibrium. Such findings should foster regional fisheries organizations to get potential new ways for neighbouring fish stock management.

Defining a disproportionate burden in transboundary fisheries: Lessons from international law

The international legal framework for fisheries governance requires that conservation and management measures for transboundary fish stocks do not place a disproportionate burden on developing States. Yet this framework does not define “disproportionate” nor does it make clear the criteria against which the balance of a conservation burden might be judged to be disproportionate. This gap in the legal framework exacerbates conflicts over transboundary fisheries resources, and undermines the ability of small island developing states, such as those in the Western and Central Pacific, to enjoy fully the benefits of the resources in their exclusive economic zones. It also constrains the ability of regional fisheries management organisations (RFMOs) to ensure the long term sustainability of stocks. This paper considers how the question of proportionality has been addressed in other areas of international law, including use of force, maritime boundary delimitation, climate change, international watercourses and trade. It finds that while approaches to proportionality are influenced by the context of the regime in which it is applied, they can nevertheless provide useful lessons for RFMOs and their Members in designing equitable conservation and management measures that do not place a disproportionate conservation burden on developing countries.

COMPARING PROACTIVE AND REACTIVE MANAGEMENT: MANAGING A TRANSBOUNDARY FISH STOCK UNDER CHANGING ENVIRONMENT

AbstractEnvironmental change in general, and climate change in particular, can lead to changes in distribution of fish stocks. When such changes involve transboundary fish stocks, the countries sharing the stock need to reconsider their harvesting policies. We investigate the effects of changing stock distribution on the optimal fishing policies in a two players’ noncooperative game. We compare reactive management, under which the manager ignores future distributional shifts (knowingly or unknowingly), with proactive management where the manager considers such shifts in his decisions. A dynamic programming model is developed to identify closed‐loop Nash strategies. We show that the role of two players is symmetric under reactive management but asymmetric under proactive management where managers anticipate future changes in stock ownership. The player losing the stock tends to harvest more aggressively compared to the player gaining the stock who acts more conservatively. Strategic interactions show tendency for complementary actions that can change abruptly during the ownership transition. The differences between management regimes vary from quantitative to qualitative; differences are minimal for stocks with little or no schooling, whereas highly schooling stocks may avoid collapse only under proactive management.

Moving Beyond Rights-Based Management: A Transparent Approach to Distributing the Conservation Burden and Benefit in Tuna Fisheries

Abstract Determining the distribution of the conservation burden and benefit is a critical challenge to the conservation and management of trans-boundary fish stocks. Given current levels of overfishing and overcapacity in many trans-boundary fisheries, some or all participating States must necessarily reach a compromise with regard to their interests and carry some share of the conservation burden. This article proposes a new approach to distributing the conservation burden and benefit in trans-boundary fisheries, and explores this approach in the world’s largest tuna fishery: the tropical tuna fisheries of the western and central Pacific. Such an approach would enable Regional Fisheries Management Organizations (RFMOs) to transparently ensure that conservation burden and benefit distributions are consistent with international obligations. The article recommends that RFMOs consider developing decision-making frameworks that would enable existing scientific processes to determine the necessary extent of conservation measures, while a new conservation burden methodology would then determine the implementation of the measure and its impact on each member.

Conservation and management of transboundary fish stocks: Comments in light of the adoption of the 1995 agreement for the conservation and management of straddling fish stocks and highly migratory fish stocks

The 1982 United Nations Convention on the Law of the Sea has not properly settled the question of conservation and management of straddling fish stocks and highly migratory fish stocks in areas beyond zones under national jurisdiction, despite the recognition of the interdependence of these stocks with those located within exclusive economic zones. As a consequence, unregulated fishing under the open access regime of the high seas has caused overfishing of these living resources and has led, in recent years, to tensions between coastal states and high seas fishing states. In 1992, the United Nations Conference on Environment and Development requested that the United Nations convene a conference aimed at implementing the relevant provisions of the Convention and with a view to establishing a conservation and management regime for the two types of stocks concerned. In August 1995, the conference adopted an agreement for the conservation and management of straddling fish stocks and highly migratory fish stocks. Although the agreement is generally considered to be in accordance with the relevant provisions of the Convention, it nevertheless contains innovative provisions that might be considered as marking a departure from the latter. This article attempts to analyze the agreement in relation to the Convention, other relevant instruments, and state practices, and identifies where the agreement has contributed to an effective implementation of the relevant provisions of the Convention and where it has gone beyond its regime in order to deal with recent fisheries management issues not foreseen in 1982.

The Management of Transboundary Fish Stocks under the LOS Convention

The Management of Transboundary Fish Stocks under the LOS Convention