Tuna Fisheries Management Research Articles

Evidence from interpretable machine learning to inform spatial management of Palau's tuna fisheries

AbstractStatic and dynamic area‐based management tools hold substantial potential to balance socioeconomic benefits derived from fisheries and costs from bycatch mortality of at‐risk species. Palau longline fisheries have high bycatch of at‐risk species including the olive ridley marine turtle and silky and blue sharks. This study analyzed a two decades‐long time series of observer and electronic monitoring datasets from the Palau distant‐water and locally‐based pelagic longline fisheries. An interpretable or explainable machine learning‐based modeling approach was used to derive spatially resolved species‐specific catch rate predictions. These models were conditioned on a suite of potentially informative environmental, bathymetric, ocean‐climate metric, vessel, monitoring system, and set‐specific operational predictors. Overall, there would be limited ecological tradeoffs from focusing fishing effort within primary catch rate hotspots for target bigeye and yellowfin tunas. Mean field prediction surfaces also defined catch rate hotspots for at‐risk species of silky and blue sharks, olive ridley turtle, and pelagic stingray, which did not overlap the hotspots for target species. The predicted target species hotspots, however, overlap olive ridley and pelagic stingray warmspots. Results also identify opportunities for temporally dynamic spatial management to control catch rates of target and bycatch species. Management of fishery operational predictors of fishing depth and soak duration present additional opportunities to balance catch rates of at‐risk bycatch and target species. A transition to employing fleetwide or vessel‐based output controls that effectively constrain the fishery would alter the spatial management strategy to focus on zones with the lowest ratio of at‐risk bycatch to commercial catch. Our findings support evidence‐informed evaluation of spatial management strategies and complementary measures to meet objectives for balancing socioeconomic benefits derived from target species catch with costs to threatened species.

Daya Saing Ekspor Ikan Tuna Indonesia di Pasar Global

Revealed Comparative Advantage (RCA) analysis is a key tool in assessing a country's competitiveness compared to others. This study uses RCA to measure Indonesia's comparative advantage in the global tuna market. The calculated RCA values show Indonesia's superiority in tuna production and exports, especially with a focus on fresh or chilled yellowfin tuna (Thunnus albacares) with HS Code 030232. The RCA values for Indonesia, Panama, the Philippines and the Netherlands are 200, 150, 50, 350, and 400, respectively. These results confirm that Indonesia has a comparative advantage in the international tuna market, which is supported by abundant natural resources, a large fishing workforce, and a history of successful tuna exports. Despite this, challenges remain, including overfishing, the impacts of climate change, and illegal, unreported, and unregulated (IUU) fishing. The decline in tuna production in Indonesia demands better fisheries management and international cooperation to address unsustainable practices. The Indonesian government's commitment to conservation is visible in the Tuna, Skipjack and Tuna Fisheries Management Plan. Overall, Indonesia's vibrant tuna export industry, supported by extensive marine resources, a large international market and robust infrastructure, shows significant potential. The government's commitment, combined with ongoing efforts to increase competitiveness through increased productivity, product quality, diversification and global promotion, positions Indonesia to strengthen its role as a major player in the global tuna export market.

Biological parameters and spawning potential ratio of Longtail Tuna Thunnus tonggol landed in Kranji fishing port, Lamongan District, Indonesia

Abstract. Harlyan LI, Rahman MA, Rihmi MK, Abdillah SFA. 2023. Biological parameters and spawning potential ratio of Longtail Tuna Thunnus tonggol landed in Kranji fishing port, Lamongan District, Indonesia. Biodiversitas 24: 6527-6535. Longtail Tuna (Thunnus tonggol), one of the small-pelagic tropical fisheries in the Fisheries Management Area (FMA-712), is important in supporting global food security. Therefore, to ensure its sustainability, this fishery is applying for fishery certification to be an ecolabel fishery by the Marine Stewardship Council (MSC). However, limited information about Longtail Tuna's biological parameters and stock status in this management area will lead to failure in certification completion. This study aims to provide biological parameters and stock status of Longtail Tuna landed in the Kranji fishing port, Lamongan, Indonesia. Length, weight, and gonad weight of female Longtail Tuna individuals which landed in the Kranji fishing port were conducted from January to April 2023. Several analyses were carried out to figure out the biological parameters of Longtail Tuna, such as length-weight relationship, length at first maturity ( ) and length at first capture ( ) estimation. Length-Based Spawning Potential Ratio (LB-SPR) analysis was conducted to estimate fish exploitation. Results showed that the Longtail Tuna landing in the Kranji fishing port exhibited a negative allometric growth pattern with the length-weight relationship model W = 0.0433 FL2.7608. A comparison between (43.9+0.11cm) and (43.6+0.04cm) indicated that most female Longtail Tuna landed in the Kranji fishing port are mature (60% of the total samples). The LB-SPR analysis showed moderate exploitation status (SPR = 34%). Fishing activities are still manageable in this situation by focusing on stock sustainability. An overlapping fishing ground occurs in the Kranji water, showing the domination of two species landed in the Kranji fishing port, Longtail Tuna and Eastern Little Tuna (Euthynnus affinis). Therefore, Longtail Tuna fishery management might also consider fishery management of Eastern Little Tuna or other species with overlapped habitats.

Is FAD fishing an economic trap? Effects of seasonal closures and other management measures on a purse‐seine tuna fleet

AbstractThe management of fish aggregating devices (FAD) creates heated debates in tuna fishery management organizations striving to reduce the number of deployed floating objects. Through several econometric models and a machine learning approach, we evaluate the consequences of three management scenarios on the catch and profit of the French purse‐seine fleet operating in the Indian Ocean: (1) a half reduction in the number of authorized buoys per vessel, (2) a 72‐day closure of FAD fishing with and (3) without re‐allocation of effort on free schools. The results show a significant decrease of fleet profits by 7%, 10% and 18% respectively. We hypothesize an “economic trap” of FAD fishing caused by the far greater efficiency of this harvesting technique for larger vessels searching for economies of scale, and by the overfished status and catch limitation of yellowfin (Thunnus albacares) and bigeye (Thunnus obesus) tunas in the Indian Ocean. The results are compared with other studies looking at the impact of FAD management measures in other oceans.

Ecosystem Management Policy Implications Based on Tonga Main Tuna Species Catch Data 2002–2018

Despite the crucial role played by international and regional tuna fisheries in facilitating the successful implementation of the ecosystem approach to fisheries management, there exist disparities in viewpoints among these stakeholders, resulting in gaps between regional fisheries management and local communities. Nevertheless, the Tongan government, under the Ministry of Fisheries, is dedicated to the efficient management of its tuna resources, aiming to establish it as the preferred and optimal approach for ensuring the long-term sustainability of its tuna fisheries and the ecosystem services they provide to the community. Recognizing that an appropriate legal, policy and institutional framework is in place for sustainable management of tuna, the first part of this paper presents a review of current Tonga fisheries laws and policies for its tuna fisheries. This review reflects the implementation of an information-based management framework, namely the Tonga National Tuna Fishery Management and Development Plan. The tuna fisheries in Tonga mainly catch albacore (Thunnus alalunga), bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and yellowfin (Thunnus albacares) tuna. These tuna species are caught within Tonga’s exclusive economic zones and play a crucial role in the country’s economy; hence, it is crucial to examine the spatio-temporal distributions of their catch in relation to their environmental conditions. In pursuit of this goal, the tasks of mapping (i) the spatio-temporal distribution of catch landed at ports and (ii) the spatio-temporal of environmental conditions were performed. The study utilizes longline catch per unit effort data spanning from 2002 to 2018 for albacore, bigeye, skipjack, and yellowfin tuna. It also incorporates data on environmental conditions, including sea surface temperature, sea surface chlorophyll, sea surface current, and sea surface salinity. Additionally, the El Nino Southern Oscillation Index is mapped in relation to catch data to examine the potential effects of climate change on the tuna catch. Results show that bigeye, skipjack, and yellowfin CPUE show a central–northernmost distribution and are primarily caught between latitudes 14° S–22° S, while albacore, shows a central–southern distribution. The highest CPUE for all species are in latitudes 15.5° S–22.5° S and longitudes 172.5° W–176.5° W. The data indicate that sea surface current velocities range from −0.03 to 0.04 ms−1, sea surface salinity ranges from 34.8 to 35.6 PSU, sea surface chlorophyll concentration varies from 0.03 to 0.1 mg m−3, and sea surface temperature fluctuates seasonally, ranging from 18 °C to 30 °C. Mapping also reveals that times of reduced catches in Tonga coincide with periods of moderate to strong El Nino events from 2002 to 2018.

Improving electronic reporting rates in the U.S. recreational fishery for Atlantic Bluefin Tuna

AbstractObjectiveIn recent years, electronic self‐reporting has emerged as a potentially powerful tool for timely collection of catch and effort data from recreational fisheries. Such approaches are particularly critical given that recreational fisheries contribute significantly to fishing mortality for popular marine fish species in North America and elsewhere. However, many self‐reporting programs are voluntary and struggle with angler recruitment and retention, while those that are mandatory have demonstrated mixed success with angler compliance. In this study, we surveyed Massachusetts anglers in the recreational fishery for Atlantic Bluefin Tuna Thunnus thynnus; anglers in this fishery are required to report all landings and dead discards, but compliance has historically been poor.MethodsThe survey assessed respondents' Bluefin Tuna fishing experience and behavior, opinions about self‐reporting, and views on the effectiveness of various strategies to increase self‐reporting rates. Because we had access to past reporting history, we were able to compare responses between those who had previously reported Bluefin Tuna and those who had not.ResultWe achieved a response rate of 21.9%, and by comparing survey responses with past reporting history, we estimated a reporting compliance rate of only about 42%. Surprisingly, responses to survey questions generally did not differ markedly between reporters and nonreporters, although we did find evidence that those who complied with the self‐reporting requirement had less faith in the Bluefin Tuna fishery's management process. Among the top strategies identified by respondents to increase reporting compliance were (1) providing incentives; (2) providing behavioral “nudges,” such as reminders; (3) better educating anglers on the benefits of self‐reporting; (4) increasing the user‐friendliness of the reporting technology; and (5) the reframing of norms through leveraging leaders in the fishery.ConclusionOur findings can help to inform self‐reporting and other citizen science approaches to maximize the quantity and quality of recreational data collected, in turn informing the sustainable management of this sector.

The Small-Scale Tuna Fisheries at Yaholu Village, Central Maluku Regency, Indonesia

The small-scale tuna fisheries in Yaholu Village operated on a Fair Trade USA basis and non-Fair Trade basis. The study of sustainable management of small-scale tuna fisheries was conducted from May to July 2021. This study aimed to assess the sustainability status of tuna fisheries operated based on fair trade and non-fair and recommend a strategy for sustainable management strategy. Rapid appraisal for sustainable status and Drives, Pressure, State, Impact, Response (DPSIR) method was used to assess the tuna fishery’s sustainable status and management strategy. Overall, the sustainability for Fair trade was 73.51%, while for non-Fair Trade was 54.02%, the lowest dimension was institutional from non-Fair with a value of 32.82% from a 1 00% sustainable scale. The most sensitive attribute towards sustainability was the migratory range with a Root Mean Square of 6.46. According to DPSIR analysis, there were 5 strategies proposed for small-scale tuna fisheries sustainability at Yaholu Village.

Management of multispecies resources and multi-gear fisheries: The case of oceanic tuna fisheries in Vietnam

The collapse of many marine fisheries is widely believed to result from mismanagement, which typically focuses on managing a single target species. The objective of this study is to assess the optimal management strategy for multispecies resources and multi-gear fisheries, with a specific application to oceanic tuna fisheries in Vietnam. We utilize the Monte Carlo method (CMSY) and Bayesian State-Space (BSM) approach to evaluate the stock status of skipjack tuna (SKJ) (Katsuwonus pelamis), yellowfin tuna (YFT) (Thunnus albacares), and bigeye tuna (BET) (Thunnus obesus) in Vietnam’s sea waters. Additionally, we establish reference points for tuna fisheries by utilizing bioeconomic models and tuna fishing data from longlines (LL), gillnets (GN), and purse seines (PS) for the period of 2000–2019. The findings reveal that SKJ and YFT stocks are overexploited, while the BET stock is not overfished in Vietnam’s sea waters, even though there have been warnings of overfishing in the Western and Central Pacific Ocean. The tuna fishing effort has exceeded sustainable fishing effort, and the current effort of PS and GN fisheries should be reduced to attain optimal stock and harvest levels. It is also necessary to implement policies that shift fisheries from the current unsustainable situation to a situation where fishing effort corresponds to the reference points. This paper offers a useful foundation for devising a suitable management plan for the sustainable management of tuna fisheries, particularly for non-members of the regional fisheries management organizations.

DNA metabarcoding to assess prey overlap between tuna and seabirds in the Eastern tropical Atlantic: Implications for an ecosystem-based management

Overfishing has been drastically changing food webs in marine ecosystems, and it is pivotal to quantify these changes at the ecosystem level. This is especially important for ecosystems with a high diversity of top predators such as the Eastern Atlantic marine region. In this work we used high-throughput sequencing methods to describe the diet of the two most abundant tuna species, the Skipjack tuna (Katsuwonus pelamis) and the Yellowfin tuna (Thunnus albacares), highly targeted by fisheries off west Africa. We also explored prey diversity overlap between these tuna species and the seabird species breeding in Cabo Verde that are most likely to share prey preferences and suffer from bycatch, the Brown booby (Sula leucogaster) and Cape Verde shearwater (Calonectris edwardsii). Overall, the diet of both tuna species was more diverse than that of seabirds. Skipjack tuna diet was dominated by prey from lower trophic levels, such as krill, anchovies, and siphonophores, while the Yellowfin tuna diet was mainly based on epipelagic fish such as flying and halfbeak fishes. Some of the most abundant prey families detected in the Yellowfin tuna diet were shared with both seabird species, resulting in a high prey diversity overlap between this tuna species and seabirds These results have implications for the management of tuna fisheries in the Eastern Tropical Atlantic, because a large decrease of both tuna species might have cascading effects on both primary and secondary consumer levels, and the decrease of these underwater predators may have implications on the viability of tropical seabird populations.

DNA sequencing shows that tropical tuna species misidentification can be an underestimated issue in fish landings

Taxonomic identification of food is a key component to the correct implementation of traceability pipelines during fish processing. Genetic methods have increased exponentially our discrimination power at the species level. In this context, sustainable management of tuna fisheries can clearly profit from the implementation of this kind of quality control procedures, although they are more difficult to implement at the earlier stages of tuna processing, from harvest to the arrival of fish landings at a processing plant. Here we provide a case study using tuna landings to a processing plant in Cabo Verde, an important small island developing State, which supplies mainly the European Union region. Using DNA sequencing based species identification of tissue samples, we found a taxonomic miss-assignment of species identity in 33% of the individuals in the three target tuna species, Bigeye ( Thunus obesus ), Yellowfin ( Thunus albacares ), and Skipjack ( Katsuwonus pelamis ). More than half of Yellowfin samples were wrongly assigned as bigeyes or skipjacks. We also found that many bigeyes were wrongly assigned as yellowfins or skipjacks. None of the skipjacks were incorrectly assigned. The proportion of Yellowfin samples incorrectly assigned as bigeye was significantly higher than the samples of bigeye incorrectly assigned as yellowfins. These results clearly prove the need for improved traceability processes, which should encompass the whole processing pipeline, from harvesting to the consumer. • DNA sequencing found issues of species traceability on tuna landings in Cabo Verde. • Miss-assignment of species identity occurred in 33% of the tuna individuals. • Miss-assignment did not occur in Skipjack tunas, only in Yellowfin and Bigeye tunas.

Increasing industry involvement in international tuna fishery negotiations

<h2>Summary</h2> The private sector can play a prominent role in global ocean governance. Yet, industry stakeholders are diverse, and how specific companies engage with policymakers remains poorly understood. Here, we focus on Western and Central Pacific tuna fisheries, which provide ∼60% of global tuna catch and a critical source of income for developing island states. We identified relationships between companies and governments in international fishery negotiations from 2005 to 2018. Relative industry attendance nearly doubled during this time, and 15 of 158 companies have dominated corporate representation since 2014. Further, industry members outnumbered government policymakers on half of the ten largest delegations, and 70% of island state delegations included foreign companies. Meeting attendees corroborated the influence of industry stakeholders, but this differed across countries. During our study period, management of tuna fisheries improved overall, suggesting that company involvement does not hinder sustainability outcomes and could play a supportive role when agendas are aligned.

Leadership as the Main Driving Factor of Regional Sustainable Development Cooperation: A Case Study of ASEAN Tuna Ecolabelling (ATEL)

ASEAN Tuna Ecolabelling (ATEL) has agreed on a scheme of tuna ecolabelling after the approval at the Ministerial of ASEAN Ministry of Agriculture and Forestry (AMAF) meeting in 2018. It makes ATEL the first regional seafood eco-label scheme in the world. It becomes an achievement of ASEAN in supporting Sustainable Development Goals (SDGs), especially for tuna fisheries management. Unfortunately, after four years, its scheme has not yet been completed and takes no support from ASEAN countries, including Indonesia as the initiator. Lack of leadership in ASEAN is the leading cause of the delay in the implementation of ATEL in its region. Leadership is the primary key to encouraging sustainable development, especially during the Covid-19 pandemic. The study aims to analyze the lack of leadership as the main factor in the low effectiveness of regional cooperation in ASEAN. This research is expected to be a solution for completing the ATEL implementation process in that region.

Multi‐species hotspots detection using self‐organizing maps: Simulation and application to purse seine tuna fisheries management

Abstract To fulfil fisheries management objectives that often include implementing the precautionary and ecosystem‐based approaches, multispecies fisheries data need to be analysed. Amongst the different methods dealing with these multidimensional data, self‐organizing maps (SOMs) remain rarely used, although they are highly flexible in data input and offer visualization possibilities particularly suited to summarize complex datasets. Here, we propose to combine SOMs with a clustering approach to break down data complexity and produce simple geographic maps showing catch hotspots, which can indicate sensitive zones in terms of fishery management. To promote this approach, we tested it first on simulated datasets and then on the open‐access ICCAT commercial catch database of the tropical tuna fisheries of the Atlantic Ocean. We aimed to detect drifting fish aggregating devices (dFADs) catch hotspots of juveniles of two tuna species, bigeye and yellowfin tunas and of the silky shark, a commonly bycaught vulnerable shark species, in tropical tuna purse seine fisheries. Simulations on datasets increasing in complexity (in number, geographic and duration extent of the hotspots and number of species in the analysis) informed us about the method's sensitivity and limits. Our findings showed that, in the context of multi‐specific fisheries, the detection of the hotspot is dependent on a certain level of catch within the hotspot and that adding species to the analysis tended to mask small and short‐duration hotspots. Applied to tropical tuna fisheries' data, the method confirmed the empirical knowledge on which first time‐area closures were based and provided scientifical support. All in all, the visual support provided by the method, its interpretability and its potential transferability to other fisheries' systems constitute its main strengths and imply a possible implementation in management decisions; specifically, as a tool to reach agreement between stakeholders in the definition of regulated areas for protecting juveniles of tunas and vulnerable associated species to dFAD practices.

Multi-species hotspots detection using self-organizing maps: simulation and application to purse seine tuna fisheries management

Multi-species hotspots detection using self-organizing maps: simulation and application to purse seine tuna fisheries management

Preliminary information for the small-scale yellowfin tuna fishery management in Nayarit, Mexico

The small-scale tuna longline fishery operating on the coast of Nayarit started recently in 2013. We provide the first detailed report on some biological parameters for the yellowfin tuna (YFT) in Nayarit (Mexico). We sampled 584 YFT, representing a catch of 25.5 t. We fit the length–weight relationship, used the t-test to determine the type of growth, and estimated the selectivity curve. The total length data varied from 73.0 to 228.0 cm, with a mean of 153.0 ± 23.5 cm (mean ± SD). Weight ranged from 5.8 to 128.0 kg, with a mean of 43.7 ± 19.4 kg. Length–weight fitting results and the t-test suggested negative allometric growth. Selectivity fitting results suggested that selectivity follows an asymptotic pattern. Our results represent the first step into gathering information to establish research and monitoring programs for the YFT on the Pacific coast of Mexico. The information provided in this study could help develop proper regulations to assure a well-managed fishery and the sustainable exploitation of YFT in Nayarit.

Modelling the impacts of climate change on skipjack tuna (Katsuwonus pelamis) in the Mozambique Channel

AbstractSkipjack tuna play a significant role in global marine fisheries and are of particular interest for socio‐economy in the tropical waters of the Mozambique Channel. However, human‐induced climate change has been leading to a reduction and reallocation of biomass, along with other ecological changes, thereby creating a feedback loop with negative socio‐economic consequences for fisheries‐reliant coastal communities. The objective of this study was to predict the potential skipjack tuna fishing grounds by 2050 and 2100. To that end, skipjack tuna catch data were collected from Spanish purse seine fleets, and subsequently, generalized additive models were used to model these data against a combination of environmental variables and future pathway projections from BIO‐ORACLE models under optimistic (RCP2.6) and pessimistic (RCP8.5) scenarios. Both optimistic and pessimistic scenarios by 2050 predicted that the potential fishing grounds will relocate southward from tropical to more temperate waters, with moderate shifts in the potential fishing grounds of purse seines to the latitude &gt;16°S, whereas the pessimistic scenario predicted higher displacement catches of purse seines in the southernmost part (&gt;24°S) and moderate to high catches in northern (&gt;20°S) of the Mozambique Channel by the end of the century. Despite the degree of uncertainty surrounding the climate change impacts on skipjack tuna, we argue that fisheries stakeholders, administrators and regional tuna fisheries management organizations should work towards building resilience and ensuring sustainability while reducing or mitigating vulnerability and climate change impacts on local and regional communities and their livelihoods.

A Bayesian Multilevel Ordinal Regression Model for Fish Maturity Data: Difference in Maturity Ogives of Skipjack Tuna (Katsuwonus pelamis) Between Schools in the Western and Central Pacific Ocean

The maturity ogive is vital to defining the fraction of a population capable of reproduction. In this study, we proposed a novel approach, a Bayesian multilevel ordinal regression (i.e., Bayesian continuation ratio model), to model the maturity ogive. The model assumes that the observed maturity stage originates from the categorization of latent continuous variables. We demonstrated this approach by testing whether there are differences in the maturity ogive of skipjack tuna (Katsuonus pelamis) in the western and central Pacific Ocean between two school types, i.e., free-swimming and floating-object-associated schools. The model results show that K. pelamis, given the same fork length, are more likely to have a higher maturity stage in a free-swimming school than those associated with floating objects. The gonadosomatic index revealed the same conclusion. Our results indicate that fish aggregation devices (FADs) could negatively affect the maturity of K. pelamis and consequently reduce the population reproductive potential. This study provides (1) an alternative approach to analyze fisheries ordinal data; (2) important quantitative evidence to evaluate the existing ecological hypotheses; and (3) implications for tuna fisheries management.

Small scale tuna fisheries profiles in the Indonesia archipelagic waters

Indonesia is one of the largest tuna producers in the world, which contributes 16% to world tuna production. The dominant tuna species catched in Indonesia are Albacore Tuna (Thunnus alalunga), Madidihang/Yellowfin Tuna (T. albacares), Big Eye Tuna (T. obesus) dan Southern Bluefin Tuna (T. maccoyii). The tuna fisheries have contributed significant jobs or livelihood to the coastal communities. Profit and revenue sharing is a common remuneration system found on tuna fisheries though out Indonesia. However, these fishers are vulnerable given their economic and welfare conditions and of usually limited options of others livelihood. Small fishers have limited access to livelihoods, access to finance and access to skills or fishing technology. Therefore, the inclusion of socio-economic performance or indicators into the tuna fisheries management is crucial in Indonesia.

Tuna Fisheries Conservation and Management in the Pacific Islands Region

Abstract The Korean tuna fishing fleet has a long history of participation in the tuna fisheries of the Western and Central Pacific Ocean (wcpo), the largest tuna fisheries in the world. As one of the largest distant water fishing fleets operating in the wcpo, Korea has a strong interest in maintaining access to both eez s and the high seas, and ensuring sustainability of the region’s tuna stocks. The regulatory environment for tuna fisheries in the wcpo is complex and multi-layered, with regional, sub-regional and national legislation, regulation and policies all affecting tuna fishing vessels and operations. Management of tuna fisheries within Pacific Island eez s is increasingly being tightened, including through the introduction of zone-based management approaches, and Pacific Island countries are also advocating for improved management of tuna fishing in the high seas. While all four primary tuna species in the wcpo are currently considered healthy, catch rates and economic conditions in the southern and tropical longline fisheries are in decline and catch reductions will be necessary to improve catch rates and increase economic returns for longline vessels. Within this context, the Korean distant water fishing fleet will need to strengthen engagement and cooperation with Pacific island States in order to maintain their competitiveness.

Common but differentiated rights and responsibilities in tuna fisheries management

AbstractThe UN Law of the Sea Convention (LOSC) and one of the implementing agreements of the Convention—the UN Fish Stocks Agreement (UNFSA)—mandates all states to cooperate in the management of highly migratory and straddling fish stocks. In doing so, the UNFSA specifies that the special requirements of developing states need to be taken into account. To date, except in the Western and Central Pacific Fisheries Commission (WCPFC), there is no formal mechanism to identify these differential responsibilities in tuna regional fisheries management organizations (RFMOs). Although some conservation and management measures exempt small‐scale and artisanal fishing vessels, power imbalances within RFMOs tend to favour the interests of more developed and larger distant water fishing nations over those of small developing coastal states. To facilitate the implementation of differentiated responsibilities as mandated in UNFSA, in this study we develop a three‐step framework that could be applied in the case of new conservation and management measure proposals. The framework has also been tested based on two developing countries and compared with a developed state in the Indian Ocean Tuna Commission and the adopted resolutions in 2019. To facilitate better transparency and equitable decision‐making processes across RFMOs, this framework could be adapted based on member states' fisheries management objectives and target and non‐target species.