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Comparing “data-limited” situations can sometimes feel like the scar comparison scene from the movie Jaws (Spielberg 1975), with each scar origin story escalating the intensity of the experience, not unlike what can happen when comparing the relative “data-limitedness” among management scenarios. While Dr. Hooper (middle) thought his scars were the worst (i.e., the most data-limited), Captain Quint (left) ultimately makes it very clear his scars are much worse (i.e., more data-limited). Chief Brody (right) is undeniably data-rich in this scene
Source publication
The term “data-limited fisheries” is a catch-all to generally describe situations lacking data to support a fully integrated stock assessment model. Data conditions range from data-void fisheries to those that reliably produce quantitative assessments. However, successful fishery assessment can also be limited by resources (e.g., time, money, capac...
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Recent efforts in ocean mapping of seafloor habitat have made data increasingly available. For bottom-dwelling and/or sessile species, there is often a strong relationship between population productivity and habitat, and stock assessment models are likely to be improved by the inclusion of habitat. Here, we extend a recently developed spatio-tempor...
Citations
... Despite their importance, the status of many global fisheries remains unknown or poorly estimated due to a lack of sufficient data or institutional capacity required to conduct traditional stock assessments (Cope et al. 2023). The majority of global fisheries are lacking formal assessment, and studies have estimated that these unassessed fisheries may be in significantly worse condition than assessed fisheries (Costello et al. 2012;Blasco et al. 2020;Hilborn et al. 2020). ...
... Due to the Crevalle Jack's unregulated status, limited research has been done in the region to assess the species' life history (e.g., stock boundaries and migration patterns) or fishery trends (e.g., trends in length and age composition; McBride and McKown 2000;Gervasi et al. 2022b;Jefferson et al. 2022). Therefore, the Crevalle Jack fishery in Florida can be considered data limited, a term that generally describes situations in which the data required to support a fully integrated stock assessment model (including catch time series, indices of abundance, length and age composition, and life history parameters) are missing (Cope et al. 2023). In the Florida Keys, recreational fishing guides have observed a concerning decline in Crevalle Jack catch rates, which is supported by available fisheriesdependent data (Gervasi et al. 2022b). ...
Objective
Fisheries provide countless benefits to human populations but face many threats ranging from climate change to overfishing. Despite these threats and an increase in fishing pressure globally, most stocks remain unassessed and data limited. An abundance of data‐limited assessment methods exists, but each has different data requirements, caveats, and limitations. Furthermore, developing informative model priors can be difficult when little is known about the stock, and uncertain model parameters could create misleading results about stock status. Our research illustrates an approach for rapidly creating robust initial assessments of unregulated and data‐limited fisheries without the need for additional data collection.
Methods
Our method uses stakeholder knowledge combined with a series of data‐limited tools to identify an appropriate stock assessment method, conduct an assessment, and examine how model uncertainty influences the results. Our approach was applied to the unregulated and data‐limited fishery for Crevalle Jack Caranx hippos in Florida.
Result
Results suggested a steady increase in exploitation and a decline in stock biomass over time, with the stock currently overfished and undergoing overfishing. These findings highlight a need for management action to prevent continued stock depletion.
Conclusion
Our approach can help to streamline the initial assessment and management process for unregulated and data‐limited stocks and serves as an additional tool for combating the many threats facing global fisheries.
... Nevertheless, length-based stock assessment methods have emerged in recent decades as alternatives to estimate stock status of data-limited fisheries (Costello et al., 2012). These methods have been successfully applied in datalimited fisheries worldwide (Cope et al., 2023;Quinn & Deriso, 1999), by providing reliable estimates (Pons et al., 2019;Santos et al., 2023) and enhancing management practices. Use of length-based approaches can enable management of data-limited fisheries (Costello et al., 2012;Dowling et al., 2016), thereby supporting implementation of precautionary measures based on informed decision-making. ...
Motorized trawling was banned off part of the Brazilian coast in 1990 due to environmental impacts, thus artisanal fishermen adopted large beach seines as an alternative. No impact assessments have been conducted on any species; therefore, we exam-ined the life history and stock status of shorthead drum, Larimus breviceps, a primary bycatch in tropical shrimp fisheries. Between 2016 and 2017, 969 shorthead drum were collected and analyzed using ELEFAN-based models. Females were larger, more abundant, and older than males. Capture rates of juvenile were high, and no mega-spawners were found. Integrated stock assessment indicated slight overexploitation and growth overfishing. Increased yield per recruit was indicated by high length at first capture. Shorthead drum segregate ontogenetically by size. Growth, mortality, and longevity may be temperature-influenced. We found that beach seine fisheries may impact shorthead drum by population depletion and potential disruptions to reproductive capacity and recommend further studies and management to improve sustainability.
... only two out of 12 small tuna species had their stock recently assessed in the Atlantic Ocean (Juan-Jordá et al., 2015;Pons et al., 2017Pons et al., , 2019aLucena-Frédou et al., 2021). The majority of small tuna stocks are classified as data-limited due to the insufficient data availability to support a fully integrated stock assessment model, therefore remaining unassessed (Juan-Jordá et al., 2015;Kindong et al., 2020;Lucena-Frédou et al., 2021;Cope et al., 2023). Since stock assessments are the basis for taking the most appropriate management measures to ensure a sustainable and healthy population (Punt et al., 2006;Hilborn et al., 2020), the lack of basic knowledge makes these species stocks vulnerable to several stressors like overfishing and climate change effects (Pons et al., 2019b;Lucena-Frédou et al., 2021). ...
This is the first assessment of blackfin tuna Thunnus atlanticus stock status. The aim of the present
study was to estimate the status of its Southwestern stock using length-based models. A total of
1929 individuals was gathered in four years of length data (1998–2019). Two length-based models
were applied, Length-Based Spawning Potential Ratio (LBSPR) and Stock Synthesis Data-limited tool
(SS-DL) and five scenarios combining a set of growth parameters (asymptotic length-L∞, and growth
constant-K) were built to accommodate different life histories available in the literature. The natural
mortality (M) was estimated through four empirical methods. Given that the fishery only selects
mature fish, length at selectivity were larger than the length at first maturity and high relative fishing
mortality were found at most scenarios, even with high spawning potential ratio (SPR) values. The
LBSPR estimated higher values of SPR, it presented a steeper decline than SS-DL between 1998 and
2019. In addition, growth parameters influence the estimation of the virginal stock, and intermediate
M/K values seems to represent better the estimated length composition, given the low historical
catch of the species. A declining pattern in SPR was observed over time with a reduction of 12%
according to LBSPR and 7% decrease based on SS-DL methods. However, the overall evaluation of the
Southwestern Atlantic stock of blackfin tuna in 2019 revealed an SPR range of 0.41 to 0.63, suggesting
sustainable exploitation. Even with the limited data, we could have a proxy of stock status estimation
by using length-based models which highlights the importance of such data. However, due to the
high uncertainty of the results, better collection of catch, effort and length data should be considered.
Additionally, SS-DL seems to estimate better SPR values when variability of growth parameters are
placed for a given species.
... Several papers focused on specific, yet broad reaching issues, including dealing with data-limited fisheries, squid resources on the high seas, shark depredation, and biological fisheries models, management strategy evaluation and scientific advice bridging the science-policy interface. Cope et al. (2023) deconstructed the term data-limited fisheries suggesting data-limited was a continuum involving axes of data and resources. They introduced a new tool, guiding principles and applied the approach to 20 different fisheries. ...
... No presente estudo foi fornecido, pela primeira vez, evidências do estado do estoque do , o valor de M/K = 1.5 é comumente adotado quando não há informações disponíveis para todos os parâmetros . portanto compensando o impacto da pesca e assegurando a sustentabilidade da biomassa desovante (Froese, 2004 Cope, J. M., Dowling, N. A., Hesp, S. A., Omori, K. L., Bessell-Browne, P., Castello, L., ... & Prince, J. (2023). The stock assessment theory of relativity: deconstructing the term "data-limited" fisheries into components and guiding principles to support the science of fisheries management. ...
A maioria dos pequenos tunídeos permanece inacessada devido à falta de dados de esforço e captura, o que dificulta o emprego de vários modelos de avaliação de estoque. A albacorinha Thunnus atlanticus é uma espécie de pequeno tunídeo distribuído no Oeste do Oceano Atlântico que também carece de dados e nunca foi avaliada em relação ao estado dos seus estoques. Algumas evidências demonstram que dois estoques em expansão ocorrem ao longo de sua distribuição: um no Atlântico Noroeste e outro no Atlântico Sudoeste. O objetivo do presente estudo foi estimar o estado do estoque sudoeste usando modelos baseados em comprimentos. Foram reunidos quatro anos de dados de comprimento (1998, 1999, 2013 e 2019) de uma variedade de fontes totalizando 1.929 indivíduos. Dois modelos baseados em comprimento foram aplicados, Length-Based Spawning Potential Ratio (LBSPR) e Stock Synthesis Data-limited tool (SS – DL) e cinco cenários com um conjunto de parâmetros de crescimento (comprimento assintótico, L∞, e coeficiente de crescimento, K) foram construídos para acomodar diferentes histórias de vida disponíveis na literatura. A mortalidade natual (M) foi estimada através de quatro métodos empíricos e três time-blocks foram utilizados para acomodar a seletividade de diferentes artes de pesca ao longo do tempo no modelo SS – DL, e, em geral, os comprimento de seletividade foram maiores que o comprimento de maturidade. Apesar disso, altas mortalidades por pesca relativa (F/M >1) foram encontradas na maioria dos cenários, dado que a pesca apenas seleciona peixes maduros, e altos valores de F/M podem estar presentes mesmo que o estoque mostre valores altos de SPR. O LBSPR estimou valores mais altos de SPR do que o SS – DL, apesar disso, esse modelo apresenta um declínio mais acentuado do que o SS – DL entre o final dos anos 1990 e 2019. Isso pode ter ocorrido devido às diferenças nos parâmetros de seletividade estimados por cada modelo. Além disso, parâmetros de crescimento influenciam na estimação do estoque virginal, e valores altos e intermediários de M/K parecem representar melhor a composição de comprimento estimada, dado a baixa captura histórica da espécie. No geral, o estoque Sudoeste da albacorinha pode ser classificado com uma exploração adequada com um SPR decrescente ao longo do tempo (12% LBSPR e 7% SS – DL). Contudo, devido à incerteza dos resultados, maiores coletas de dados de captura, esforço e comprimento devem ser consideradas. Adicionalmente, SS – DL parece estimar melhor os valores de SPR quando há variabilidade nos parâmetros de crescimento de uma espécie.
... Additionally, this complexity inhibits creating functional policies tied to community needs and acceptance [4,[9][10][11], particularly because each fishery has distinct characteristics and objectives. Most unmanaged fisheries have limited management resources available, so any complexity makes the task seem more infeasible [12,13]. ...
The Ecosystem Approach to Fisheries Management (EAFM) strives to balance multiple objectives of ecological wellbeing, social and economic wellbeing, and good governance. The Provincial Government of West Papua with technical support from the USAID Sustainable Ecosystems Advanced Project (SEA) has developed a fisheries management plan (FMP) for the anchovy fishery in Raja Ampat, West Papua Province of Indonesia. EAFM is the appropriate approach to manage the fishery because EAFM multiple objectives reflect the challenges and needs to ensure the sustainability of the fishery resources and to contribute to local communities. The FMP includes management issues, operational objectives, appropriate management measures, and action plans defined through a participatory process. The issues include overfishing as shown by declining anchovy catches, resource competition between local small-scale fishers and industrial fishers, limited livelihood opportunities, and an absence of a functional fishery governance institution. To address these challenges, the FMP has multiple operational objectives: to empower local livelihoods, strengthen institutional management mechanisms, and ensure anchovy resources sustainability. The integration of the socioeconomic aspect means there must be management decision trade-offs that weigh trade-offs of stock sustainability, local poverty, interests of the private sector, and addressing the horizontal conflict between locals and industrial fishers. Strengthening fisheries institutions is critical to ensure integration in resource investments and in detailing activities to implement the FMP because of the complementary roles, and lack of synergy of the multiple agencies. This holistic approach is expected to support the long-term use of the anchovy resources while partially alleviating local poverty.
The peled Coregonus peled is common in the water bodies of the Arctic. Peled reaches high numbers and biomass in the Ob-Irtysh basin coast of Eurasia. It lives in all major rivers of Siberia and it is a typical semi-anadromous species. It is assumed that in the Ob basin there are at least two subpopulations of peled, one of which reproduces in the Ural tributaries of the Ob (Lower Ob), the other in its middle reaches (Middle Ob). Peled in the Middle Ob within the boundaries of the Tomsk region is the main commercial target among whitefish species. Within the Tomsk region, fishing for the Middle Ob population of peled is carried out during its spawning migration, in September-October, on the approach to places of natural reproduction. In this study presents information about the stock, official catch and total allowable catches (TAC) of peled in the Middle Ob in the Tomsk region. In the last decade, the biomass of commercial peled stocks in the Middle Ob varies from 532.1 to 1349.7 tons, averaging 746.1 tons. According to official statistics, the catch of peled in the period from 2013 to 2022 ranged from 39.1 t to 89.7 t, which is below the TAC. According to calculated data, the actual volume of peled removal ranges from 19.9 tons to 86.7 tons or 27–118% of the legal catch of this species, which significantly exceeds the TAC. Thus, excessive fishing pressure on the spawning stock of peled will likely lead to a decrease in the reproductive capacity of the population and will have a negative impact on the state of peled stocks in the Ob basin as a whole.
Direct engagement of the fishing industry in the provision and co-creation of knowledge and data for research and management is increasingly prevalent. In both the North Atlantic and North Pacific, enhanced and targeted engagement is evident. More is needed. Science-Industry collaborative approaches to developing questions, collecting data, interpreting data, and sharing knowledge create opportunities for information transfer and improved understanding of ecosystem interactions, stock dynamics, economic incentives, and response to management. These collaborations require clear communication and awareness of objectives and outcomes. These initiatives also require careful attention to conditions and interactions that foster respect, trust, and communication. Respect is critical and entails acknowledging the respective skills and expertise of both scientists and fishers. Trust is needed to build confidence in the information developed and its use. Communication is essential to maintain relationships and leverage shared insights. To assess current trends and future opportunities related to this type of engagement, we convened a networking session of research scientists, industry scientists, industry leaders, and fishers at the Annual Science Meeting of the International Council for the Exploration of the Sea (ICES) to address the following questions: (1) What are scientific needs that could be addressed with industry-collected data or knowledge? And (2) How can science-industry collaboration be made sustainable? Here we identify opportunities and acknowledge challenges, outline necessary conditions for respectful and sustainable collaborative research, and highlight ways to promote stakeholder involvement in developing science. We address industry concerns and solicit industry advice. We also address challenges to scientists in ensuring standards for scientific data, conflict of interest, and applying information to advise management. The discussions in this session and subsequent correspondence have led to a set of guidelines and best practices that provide a framework to advance further collaboration between industry and research science. We identify opportunities for directed engagement. We also detail potential approaches to clarify expectations and develop avenues for iterative communication and Frontiers in Marine Science These authors share first authorship ‡ Convenor, ICES Network Session-a new era for science-industry collaboration § Industry participant (e.g., fisher, fleet manager, industry leader, industry scientist) engagement to sustain collaborative efforts over time. The intent is to improve and expand data streams and contextual understanding of ecosystem processes, stock assessment, and socioeconomic dynamics to the benefits of science and industry alike.
This report summarizes and synthesizes results from the Swedish Agency of Marine and Water
Management (SwAM, or HaV) funded project “Förvaltningsmål för nationella arter (Management
goals for nationally managed species)”. The objectives of the project have been to promote the
development of management goals and associated status assessment methods and indicators, as well
as reference points, for some nationally managed fish stocks both in coastal as well as freshwater
areas. The report focusses largely on species and stocks that can be defined as data-poor. Such stocks
are characterised by marked limitations in data availability and/or resources allocated to detailed
analytical stock projections. Data-poor stocks also often lack carefully formulated management
goals and associated methods and indicators for assessing stock status. In this report, we provide an
overview of potential assessment methods and indicators and try to synthesise how they work and
what the strengths and weaknesses are by applying them to selected data poor stocks such as
pikeperch, pike, whitefish, and vendace. We also discuss how they relate to different potential
management goals and provide recommendations for their application. We grouped the indicators
and assessment methods by the three categories that are now used in the yearly status assessment
framework provided by SLU Aqua (Resursöversikten/Fiskbarometern) – i) mortality, ii)
abundance/biomass and iii) size/age structure. The results are also described for these three main
categories of assessment indicators. Included is also a status report from a size- and age-based
population dynamics model (Stock Synthesis 3) that is being developed for pikeperch in Lake
Hjälmaren.
An important experience from the project is that to improve the assessment methods for Swedish
national fish stocks, it is important that managers develop both general as well as more detailed
quantitative goals for the individual stocks. This should ideally be conducted in various forms of
collaboration with the main stakeholders and scientists involved with assessment as participatory
processes foster legitimacy. Carefully articulated management goals, which are possible to translate
into quantitative targets, will facilitate the development of various approaches and methods to
monitor stock statuses. Given the strong and complex interactions of fish and their environments it
is also important to consider other pressures than fisheries when developing indicators and
assessment methods.
Successful fisheries management systems tend to be underpinned by harvest strategies, specifying formally agreed data collection systems, assessment approaches and management measures used to regulate fishing pressure. While harvest strategies can be effective even in data‐ and capacity‐limited (DCL) situations, their development remains challenging in such contexts. We present a process and decision‐support tool, FishPath, to guide the identification of suitable harvest strategy component options given often debilitating conditions: (i) resource limitations and lack of technical management capacity; (ii) ‘uniqueness’ of DCL fisheries; (iii) the concept of harvest strategies is unfamiliar to managers and scientists, and the universe of options is hard to navigate; and (iv) the lack of an effective participatory process to identify solutions tailored to local contexts. These conditions can lead to either management paralysis or generic solutions that may be poor fits to specific conditions. The FishPath Tool uses a diagnostic questionnaire that elicits the key characteristics and specific circumstances of a fishery. It compares these with the requirements of alternative options from an inventory of possible harvest strategy components, identifies where these requirements are met and provides customised, transparent guidance on the appropriateness of component options of a harvest strategy, specific to the fishery of interest and its governance context. The FishPath Process is a facilitated multi‐stakeholder, participatory engagement process aimed to set fisheries on the path to develop a harvest strategy. The FishPath Process and Tool combine to ensure a bottom‐up, documented, transparent, replicable and efficient process.
