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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
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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
... Successful management of aquatic resources on a global scale requires accurate, up-to-date information not only on their conservation status, but also on their exploitation and trade (Anderson et al. 2019, Blasco et al. 2020, Cope et al. 2023. Publicly available data on sea cucumbers can be found in the Food and Agriculture Organization of the United Nations (FAO) Global Capture Production (FAO 2024c), Global Aquaculture Production (FAO 2024a), and Global Aquatic Trade Statistics (FAO 2024b) databases. ...
Sea cucumbers paradoxically suffer from being both highly prized and commonly disregarded. As an Asian medicine and delicacy, they command fabulous prices and are thus overfished, poached, and trafficked. As noncharismatic animals, many are understudied and inadequately protected. Despite presenting a rich diversity of life histories, members of this broad taxonomic group (class Holothuroidea) are often managed simply as “sea cucumbers” in fisheries worldwide. One cannot imagine fishes (class Pisces) being given the same universal treatment. Yet this may happen for species of sea cucumber that differ on the same fundamental level as tilapia and tuna. As more sea cucumbers reach an endangered status and wild populations become depleted to the point of collapse, critical questions arise about the relevance of established conservation and governance strategies. This article reviews the main threats faced by exploited sea cucumbers, outlines conservation and governance effectiveness, identifies gaps in knowledge, and explores management and research perspectives in the context of climate change and booming fisheries crime. We stress the perilous state of harvested sea cucumbers globally and the urgent need for action.
... Contemporary best practice in single-species stock assessments, when sufficient data are available, involves use of integrated models (Maunder and Punt, 2013;Punt, 2023). These models can incorporate a wide range of information, including catch and abundance indices, length and/or age compositions, and parameters describing the biology of the stock and how it interacts with fisheries, i.e. 'selectivity', which refers to processes affecting the probability of fish being caught and retained (Cope et al., 2023). Due to data and resource limitations, however, such assessments are not feasible for most global fisheries, with many not assessed at all (Costello et al., 2012;Dowling et al., 2015;Blasco et al., 2020). ...
Released (or discarded) fish from recreational and commercial line fisheries can experience significant levels of post-release mortality (PRM), affecting sustainability. Although PRM effects are often considered in data-rich (integrated model) assessments, this is uncommon in data-limited assessments. This study investigates impacts of PRM when applying data-limited, length-based assessment methods for four reef-dwelling demersal fish species in temperate Western Australia (Glaucosoma hebraicum, Chrysophrys auratus, Choerodon rubescens and Epinephelides armatus). These species differ considerably in their biology and susceptibility to PRM. For each species simulations were undertaken to (1) evaluate the reliability of a length-based catch curve (LBCC) method for estimating fishing mortality (F) and selectivity parameters, and (2) predict the impacts of different PRM levels on values of relative biomass, i.e. ratios of fished to unfished equilibrium spawning biomass (B rel), estimated using a length-based equilibrium analysis (LBEA). LBEA extends length-based per-recruit analysis to incorporate a stock-recruitment relationship as well as allow for PRM. On average, estimates of F and selectivity parameters from LBCC for each species were unbiased when applied to simulated data. Precision decreased, however, when LBCC was fitted to data simulated with recruitment variation. For a given F, increased PRM levels reduced B rel for all species, with the extent of impacts varying depending on species biology. LBCC was then applied to two actual datasets, firstly to lengths for all fish that had either been retained or released during historical recreational fishing trips (to estimate gear selectivity), and secondly to length data for retained fish from recent charter fishing (to estimate F and selectivity of landings). The resultant estimates were then used in LBEA to estimate B rel with and without accounting for PRM. Relative impacts of PRM varied among species depending on their biology and size limits. While PRM was predicted to have limited impact on B rel for C. rubescens (as fish are not fully selected by the gear until they attain a relatively large size), accounting for PRM resulted in estimates of B rel (at their current estimated F levels) being reduced by 31% for G. hebraicum, 36% for C. auratus and 23% for E. armatus. It is recommended that, where evidence of PRM exists for a species, this be accounted for in data-limited assessments.
... Continued efforts to collect data on the age structure of the target stocks and to conduct stock assessments using agestructured models are key tasks necessary for the sustainable use of fishery resources. Nevertheless, when forced to conduct stock assessment and management in situations with limited data or resources (Cope et al. 2023), our approach of SSPM-based OMs in MSE is a suitable alternative, albeit with greater uncertainties. ...
A management procedure (MP) automatically calculates an acceptable biological catch from input data, and its performance is quantitatively evaluated by closed-loop simulations of population dynamics with their uncertainties (operating models). In snow crab in the Sea of Japan, an MP based on survey biomass estimates was adopted by stakeholders, rather than a generic MP recommended for data-moderate Japanese stocks. This was done without quantifying its performance owing to data and resource limitations. This study evaluated the performance of the existing MPs and modified the generic MP through closed-loop simulations with state–space surplus production models (SSPMs) conditioned with actual data. The survey-based MP generally worked well to achieve sustainable catch and biomass but tended to be sensitive to the bias in biomass estimates. The modified MP can be more robust to the bias than the survey-based MP with higher catches than the generic MP. This study demonstrates that, although continuing efforts of collecting composition data are inevitable, SSPM could be used as the conditioned operating models even in data-limited situations to sufficiently represent the stock status and its uncertainty.
... Fisheries are complex social-ecological systems (Arlinghaus et al., 2017;Kittinger et al., 2013) that provide food security, livelihoods, culture, meaning, well-being and recreation to millions across the globe (FAO, 2022). Conserving and restoring the ecosystems that fisheries depend on remains a challenge for the Anthropocene that is hindered by a lack of data and its integration into management and conservation Cooke et al., 2019;Cope et al., 2023). About 80% of global fish stocks lack adequate data for a formal stock assessment and will likely never be assessed formally given data and resource limitations (Cope et al., 2023;Costello et al., 2012). ...
... Conserving and restoring the ecosystems that fisheries depend on remains a challenge for the Anthropocene that is hindered by a lack of data and its integration into management and conservation Cooke et al., 2019;Cope et al., 2023). About 80% of global fish stocks lack adequate data for a formal stock assessment and will likely never be assessed formally given data and resource limitations (Cope et al., 2023;Costello et al., 2012). The inclusion of multiple stakeholders is crucial to confront this challenge, and resource users possess rich knowledge, or different ways of knowing, that are mostly untapped Reid et al., 2021). ...
... Conserving aquatic social-ecological systems is a challenge often hampered by a lack of data and its integration into management. This is the case for fisheries, where over 80% of global fish stocks are classified as data-poor; that is, they lack adequate data for a formal stock assessment, and will not be assessed formally given data and resource limitations (Cope et al., 2023;Costello et al., 2012). ...
Social‐ecological systems like fisheries provide food, livelihoods and recreation. However, lack of data and its integration into governance hinders their conservation and management. Stakeholders possess site‐specific knowledge crucial for confronting these challenges. There is increasing recognition that Indigenous and local knowledge (ILK) is valuable, but structural differences between ILK and quantitative archetypes have stalled the assimilation of ILK into fisheries management, despite acknowledged bias and uncertainty in scientific methods. Conducting a systematic review of fisheries‐associated ILK research ( n = 397 articles), we examined how ILK is accessed, applied, distributed across space and species, and has evolved. We show that ILK has generated qualitative, semi‐quantitative and quantitative information for diverse taxa across 98 countries. Fisheries‐associated ILK research mostly targets small‐scale and artisanal fishers (70% of studies) and typically uses semi‐structured interviews (60%). We revealed large variability in sample size ( n = 4–7638), predicted by the approach employed and the data generated (i.e. qualitative studies target smaller groups). Using thematic categorisation, we show that scientists are still exploring techniques, or ‘validating’ ILK through comparisons with quantitative scientific data (20%), and recording qualitative information of what fishers understand (40%). A few researchers are applying quantitative social science methods to derive trends in abundance, catch and effort. Such approaches facilitate recognition of local insight in fisheries management but fall short of accepting ILK as a valid complementary way of knowing about fisheries systems. This synthesis reveals that development and increased opportunities are needed to bridge ILK and quantitative scientific data.
... Fisheries are complex social-ecological systems (Arlinghaus et al., 2017;Kittinger et al., 2013) that provide food security, livelihoods, culture, meaning, well-being and recreation to millions across the globe (FAO, 2022). Conserving and restoring the ecosystems that fisheries depend on remains a challenge for the Anthropocene that is hindered by a lack of data and its integration into management and conservation Cooke et al., 2019;Cope et al., 2023). About 80% of global fish stocks lack adequate data for a formal stock assessment and will likely never be assessed formally given data and resource limitations (Cope et al., 2023;Costello et al., 2012). ...
... Conserving and restoring the ecosystems that fisheries depend on remains a challenge for the Anthropocene that is hindered by a lack of data and its integration into management and conservation Cooke et al., 2019;Cope et al., 2023). About 80% of global fish stocks lack adequate data for a formal stock assessment and will likely never be assessed formally given data and resource limitations (Cope et al., 2023;Costello et al., 2012). The inclusion of multiple stakeholders is crucial to confront this challenge, and resource users possess rich knowledge, or different ways of knowing, that are mostly untapped Reid et al., 2021). ...
... Conserving aquatic social-ecological systems is a challenge often hampered by a lack of data and its integration into management. This is the case for fisheries, where over 80% of global fish stocks are classified as data-poor; that is, they lack adequate data for a formal stock assessment, and will not be assessed formally given data and resource limitations (Cope et al., 2023;Costello et al., 2012). ...
Social-ecological systems like fisheries provide food, livelihoods, and recreation. However, lack of data and its integration into governance hinders their conservation and management. Stakeholders possess site-specific knowledge crucial for confronting these challenges. There is increasing recognition that Indigenous and local knowledge (ILK) is valuable, but structural differences between ILK and quantitative archetypes have stalled the assimilation of ILK into fisheries management, despite acknowledged bias and uncertainty in scientific methods. Conducting a systematic review of fisheries-associated ILK research (n = 397 articles), we examined how ILK is accessed, is applied, is distributed across space and species, and has evolved. We show that ILK has generated qualitative, semi-quantitative, and quantitative information for diverse taxa across 98 countries. Fisheries-associated ILK research mostly targets small-scale and artisanal fishers (70% of studies), and typically uses semi-structured interviews (60%). We revealed large variability in sample size (n = 4 – 7638), predicted by the approach employed, and the data generated (i.e., qualitative studies target smaller groups). Using thematic categorisation, we show that scientists are still exploring techniques, or ‘validating’ ILK through comparisons with quantitative scientific data (20%), and recording qualitative information of what fishers understand (40%). A few researchers are applying quantitative social science methods to derive trends in abundance, catch, and effort. Such approaches facilitate recognition of local insight in fisheries management, but fall short of accepting ILK as a valid complementary way of knowing about fisheries systems. This synthesis reveals that development and increased opportunities are needed to bridge ILK and quantitative scientific data.
... indices, length and/or age compositions, and parameters describing stock biology and how it 61 interacts with fisheries, i.e. 'selectivity', which refers to processes affecting probability of fish 62 being caught and retained or discarded (Cope et al., 2023). Due to data and resource 63 limitations, however, such assessments are not feasible for the majority of global fisheries, 64 with many not assessed at all (Blasco et . ...
Released (or discarded) fish from recreational and commercial line fisheries can experience significant levels of post-release mortality (PRM), which can affect the sustainability of fish stocks. Although effects of PRM are often considered in relatively data-rich (integrated model) assessments, this is uncommon with data-limited assessments. This study investigates the impacts of PRM when applying data-limited length-based methods to data for four reef-dwelling demersal fish species in temperate Western Australia (Glaucosoma hebraicum, Chrysophrys auratus, Choerodon rubescens and Epinephelides armatus).
... 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.
... catch curve and per recruit analysis), and dynamic integrated modelling approaches, applied to all available data considered applicable and sufficiently reliable for assessment (Fletcher and Santoro 2015). The level of assessment varies depending on data availability and resourcing for assessment (e.g., Cope et al., 2023), with the level of resourcing directed towards assessment determined, at least in part, by the level of ecological risk, the biology and population dynamics of the relevant species, the characteristics of the fisheries exploiting the species. ...
... 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.
