Fisheries Research最新文献

{"title":"Amending the European fishing fleet segmentation based on machine learning and multivariate statistics","authors":"E. Sulanke ,&nbsp;V. Rubel ,&nbsp;J. Berkenhagen ,&nbsp;M. Bernreuther ,&nbsp;T. Stoeck ,&nbsp;S. Simons","doi":"10.1016/j.fishres.2024.107190","DOIUrl":"10.1016/j.fishres.2024.107190","url":null,"abstract":"<div><div>Considering the critical issue of overexploited stocks due to overfishing, the EU’s Data Collection Framework (DCF) was established. Within the DCF, member states collect and analyze data relevant to sustainable fisheries management. To evaluate the status of fisheries, it is necessary to categorize fishing fleets into fleet segments. However, the current DCF segmentation is primarily based on technical vessel parameters, such as vessel length and predominant fishing gear, which often do not accurately represent the fishing activities of the vessels. To address this, we developed an alternative fleet segmentation approach that provides a more realistic overview of fishing activities. This approach utilizes multivariate statistics and is coupled with machine learning techniques for automatization. Applying this approach to two decades of German fisheries data resulted in a data set with fewer segments compared to the DCF approach, which represented the actual fishing strategies more closely. The comparison of biological stock health indicators calculated for both the current and the novel segmentation schemes revealed that the current scheme often misses signs of segments relying on overexploited stocks. The machine learning technique applied showed high classification accuracy, with misclassifications being rare and only occurring in segments with overlapping catch composition. Since machine learning enables almost perfect allocation to the revised segments, we expect a successful implementation of this protocol for future fleet segmentation. This approach is highly suitable for data collection and analysis procedures and can serve as a standard tool. Therefore, this novel approach can contribute to the improvement of fishing fleet analyses and policy advice for better fisheries management.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"281 ","pages":"Article 107190"},"PeriodicalIF":2.2,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental DNA reveals spatial and temporal variation in fish communities before the 10-year fishing ban in the Poyang Lake Basin","authors":"Chunhua Zhou ,&nbsp;Shaoqing Jian ,&nbsp;Zhizhong Jiang ,&nbsp;Jinping Chen ,&nbsp;Shan Ouyang ,&nbsp;Xiaoping Wu","doi":"10.1016/j.fishres.2024.107192","DOIUrl":"10.1016/j.fishres.2024.107192","url":null,"abstract":"<div><div>Poyang Lake is the largest freshwater lake in China, and its unique ecosystem is an important biodiversity reservoir. Fish play an important role in the aquatic ecosystem of Poyang Lake. Accurate assessment of fish species diversity and community composition is essential for studies of fish ecology and conservation management. In this study, environmental DNA metabarcoding was used to analyze fish diversity and community structure in different habitats and seasons in the Poyang Lake Basin. A total of 52 fish species were identified, and limnicolous fish were the most abundant; most fish were omnivorous and small. The fish diversity index was highest in the spring and in the main lake area of Poyang Lake. Cluster analysis and non-metric multidimensional scaling analysis revealed significant differences in fish community structure among habitats. Water temperature and pH were the main environmental factors affecting fish community structure in the Poyang Lake Basin. Non-invasive environmental DNA monitoring methods could provide an important auxiliary method for monitoring fishery resources during the 10-year fishing ban period. This study provides basic information on the fish resources in the Poyang Lake Basin and has implications for fishery management and the development of ecological protection policies.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"281 ","pages":"Article 107192"},"PeriodicalIF":2.2,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Survey of the invasive alien pink salmon (Oncorhynchus gorbuscha) for infective agents in the Fennoscandian Rivers Tana and Neiden","authors":"Riikka Holopainen ,&nbsp;Tuija Kantala ,&nbsp;Tiina Korkea-aho ,&nbsp;Petra Heikkinen ,&nbsp;Antti Oksanen ,&nbsp;Panu Orell ,&nbsp;Satu Viljamaa-Dirks","doi":"10.1016/j.fishres.2024.107187","DOIUrl":"10.1016/j.fishres.2024.107187","url":null,"abstract":"<div><div>Pink salmon (<em>Oncorhynchus gorbuscha</em>, Walbaum 1792) is an invasive alien species in the Fennoscandian rivers, and its growing populations cause concern for their impact on the native salmonids and river ecosystems. One of the major concerns is fish diseases and the potential ability of pink salmon to transmit pathogens to the native salmonid species. In this study, pink salmon were sampled during their spawning migration in the Rivers Tana and Neiden in northern Norway and Finland in 2021. The fish were surveyed for viral hemorrhagic septicemia virus (VHSV), infectious pancreatic necrosis virus (IPNV), infectious salmon anemia virus (ISAV), salmonid alphavirus (SAV), piscine orthoreovirus (PRV), <em>Renibacterium salmoninarum</em>, and <em>Gyrodactylus salaris</em>. No viral diseases or infections with <em>R. salmoninarum</em> or <em>G. salaris</em> were detected. However, 23 % of the fish were found infected with a parasitic roundworm, <em>Hysterothylacium aduncum</em>. Additionally, external anomalies, such as hemorrhages or lesions in the skin, were observed in 35 % of the fish studied, and some of the fish exhibited degenerative myopathy. Based on this study, pink salmon appears not to pose a high infection risk to the native salmonid fish populations in the Rivers Tana and Neiden. Nevertheless, the results demonstrate that pink salmon have the potential to carry salmonid pathogens. More information on the susceptibility of pink salmon to different pathogens and on the overall effect this invasive species has on native fish species is needed. As the number of migrating pink salmon in the Fennoscandian rivers appears to increase, the potential risk of parasites and other pathogens spreading between fish species will also rise.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"281 ","pages":"Article 107187"},"PeriodicalIF":2.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0165783624002510/pdfft?md5=78e6d72bf4bd924c0a89f47622085c0b&pid=1-s2.0-S0165783624002510-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142310987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental drivers of non-commercial reef fisheries in Guam","authors":"Leilani Sablan ,&nbsp;Brett Taylor ,&nbsp;Peter Houk","doi":"10.1016/j.fishres.2024.107180","DOIUrl":"10.1016/j.fishres.2024.107180","url":null,"abstract":"<div><div>Small-scale artisanal reef fisheries in the Pacific islands are prevalent and essential for society and culture, yet they remain poorly understood compared to commercial fisheries. General catch-and-effort trends have been characterized, but few studies have coupled landings data with fisher interviews to determine how both catch and effort may be related to environmental factors. This study examined several metrics of catch and effort with respect to fishing locations, fishing methods, moon phases, and seasonal cycles that accounted for differences in windspeed and rainfall in Guam. Creel surveys were conducted over a one-year period from 2021 to 2022, sampling 1836 kg of landed fish. Hierarchical regression trees for environmental factors showed season was the most important predictor of average daily landings, whereby six times more landings were predicted during the calm season compared to the windy season due to higher catch success on exposed windward reefs that became accessible during calm months. Moon phase was a secondary predictor of average daily landings whereby four times more landings were predicted during full moon for spearfishing, while double the landings were predicted during new and mid-moons for bottom fishing. Catch composition also differed across seasons and geography, with a greater presence of large parrotfishes and surgeonfishes, caught on the exposed windward reefs as their habitats became more accessible during calm months. While most target species were abundant on both leeward and windward reefs, several species appeared to have habitat preferences and were better represented on either windward or leeward reefs regardless of season. Moon phase was the top predictor of size within the spearfishing sector, whereas season best predicted size for bottom fishing. Thus, both phenology and fishing access appeared to drive fish sizes. The smaller sizes and lower catch biomasses on the accessible leeward reefs are a concern for Guam fishers that are subjected to trade wind seasons limiting access to productive fishing grounds for half of the year. Cumulatively, the results provide the first predictive framework of landings, composition, and size for Guam’s coral reef fisheries across all seasons to guide and improve ongoing fisheries management planning.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"281 ","pages":"Article 107180"},"PeriodicalIF":2.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0165783624002443/pdfft?md5=1f5942bd1e41bd1b5a8017898ee28dcc&pid=1-s2.0-S0165783624002443-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Center for the Advancement of Population Assessment Methodology (CAPAM): A perspective on the first 10 years","authors":"Mark N. Maunder ,&nbsp;Paul R. Crone ,&nbsp;Brice X. Semmens ,&nbsp;Juan L. Valero ,&nbsp;Lynn Waterhouse ,&nbsp;Richard D. Methot ,&nbsp;André E. Punt","doi":"10.1016/j.fishres.2024.107162","DOIUrl":"10.1016/j.fishres.2024.107162","url":null,"abstract":"<div><p>The Center for the Advancement of Population Assessment Methodology (CAPAM) was established in 2013, envisioned as an institute that could conduct, organize, and communicate stock assessment research with the aim of benefiting fisheries assessment efforts internationally. CAPAM’s activities have focused on its workshop series and consequent special issues in <em>Fisheries Research</em>. The information generated through CAPAM and its permanent recording as journal articles has greatly benefited the stock assessment community and can potentially contribute to modelling in general. We discuss what has made CAPAM successful, its future, and what could be done to reach the ultimate goal of producing a good practices guide for fisheries stock assessment.</p></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"281 ","pages":"Article 107162"},"PeriodicalIF":2.2,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0165783624002261/pdfft?md5=119d4bfe63927512ab5d5bcd04fcdd03&pid=1-s2.0-S0165783624002261-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating fisheries independent surveys to account for the spatiotemporal dynamics of spiny dogfish (Squalus acanthias) in US waters of the northwest Atlantic","authors":"Alexander C. Hansell ,&nbsp;M. Conor McManus","doi":"10.1016/j.fishres.2024.107173","DOIUrl":"10.1016/j.fishres.2024.107173","url":null,"abstract":"<div><p>Spiny dogfish (<em>Squalus acanthias</em>) are a ubiquitous shark species found throughout the northwest Atlantic. Understanding their abundance and distribution patterns are paramount for determining stock status and guiding harvest. Previous work describing their abundance and distribution has relied on a single fisheries independent trawl survey and focused on course size groupings, ultimately capturing only a part of their geographic distribution and making such tools unavailable for use as stock assessment inputs, respectively. Here, we develop spatiotemporal models that integrate multiple surveys’ data to provide a more holistic understanding of the species distribution over time. Models were developed to produce predictions in abundance by season (spring and fall), sex (male and female) and size (6 cm length bins) to assess differences across these dimensions. Models also incorporated environmental covariates to assess whether oceanographic conditions allow for explaining distribution patterns or addressing survey catchability concerns. Model results suggest that spiny dogfish spatiotemporal dynamics were influenced by bottom water temperature. Distributional metrics (northings, eastings, effective area occupied) were largely similar between males and females over time, but highlighted seasonal patterns that reflect their seasonal migrations. For both sexes and season, relative abundance estimates have been stable over time; however, male abundance has increased in recent years in both spring and fall. Integrating the surveys into a single index has not changed perception on spiny dogfish abundance trends for this region, but better accounts for the species’ range. Through the development of these models, we provide more holistic, model-based relative abundance indices for future use in stock assessments of northwest Atlantic spiny dogfish.</p></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"281 ","pages":"Article 107173"},"PeriodicalIF":2.2,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0165783624002376/pdfft?md5=816009e65609fdb1e26eba43d0af9e58&pid=1-s2.0-S0165783624002376-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the potential of bait reuse in a large-scale SMART drumline program","authors":"Craig Bell ,&nbsp;Paul A. Butcher ,&nbsp;Keith Cox ,&nbsp;Stephen Morris ,&nbsp;Curtis Champion ,&nbsp;Brendan Kelaher","doi":"10.1016/j.fishres.2024.107176","DOIUrl":"10.1016/j.fishres.2024.107176","url":null,"abstract":"<div><p>Bait quality is an important characteristic that can influence the catchability of target species and contribute to sustainable fishing practices. We used bioelectrical impedance analysis (BIA) to assess the impact of various handling treatments on the quality of sea mullet (<em>Mugil cephalus</em>); a commonly used bait on SMART (shark-management-alert-in-real-time) drumlines in the New South Wales (NSW, Australia) shark management program. Specifically, we focused on the consequences of reusing sea mullet as drumline bait to improve the cost-effectiveness of a program incorporating 305 drumlines and spanning ∼1200 km of the east coast of Australia. After being deployed in seawater for 10 hours at 15°C, 20°C and 25°C temperatures in a flow-through mesocosm aquarium, sea mullet underwent brining, freezing, and ice storage treatments. Electrical impedance (comprised of resistance and reactance) was used as a bait quality indicator. Brining improved bait quality by reducing impedance, ice storage indicated potential quality declines while frozen baits remained stable. Resistance and reactance values of iced fish significantly increased with increasing temperature. Freezing baits showed considerable variation among resistance and reactance values. The results indicate that sea mullet could possibly be reused as bait. However, these reuse procedures now need to be tested in field trials to assess for any changes in the catchability of target sharks relative to fresh bait. We also demonstrate the utility of BIA for rapid, non-destructive assessment of bait quality.</p></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"281 ","pages":"Article 107176"},"PeriodicalIF":2.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0165783624002406/pdfft?md5=b89007140fafe934bc1009241d55ef61&pid=1-s2.0-S0165783624002406-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large pelagic fish exploitation by longliners in the Atlantic Ocean and Mediterranean Sea: A contribution to spatial planning and sustainable fisheries","authors":"Marcelo Francisco Nóbrega ,&nbsp;Luis Henrique França ,&nbsp;Alexandre Ricardo dos Santos Junior ,&nbsp;Jorge Eduardo Lins Oliveira","doi":"10.1016/j.fishres.2024.107178","DOIUrl":"10.1016/j.fishres.2024.107178","url":null,"abstract":"<div><p>Understanding longline fisheries dynamics is crucial for sustainable resource management. This study aims to provide a panorama of the fishing effort of the principal nations that have exploited tuna and associated species in the Atlantic Ocean for the past decade, integrating vessel data from Global Fishing Watch (GFW) and catch data from the International Commission for the Conservation of Atlantic Tunas (ICAAT), with specific information on the production of these different fleets and resources. Twelve nations represented 94.6 % of all Apparent fishing hours (AFH) of the total effort in the Atlantic Ocean and 99.9 % of all catches in the last years. Our study revealed that regions proximate to the continental shelf break and oceanic islands exhibit notably higher fishing effort than other areas within the Atlantic Ocean. We also highlight a declining trend in fishing efforts in the last ten years, likely due to regulation and overfishing. The blue shark (<em>Prionace glauca</em>) was the most caught species in biomass, representing 38.1 %; bigeye tuna (<em>Thunnus obesus</em>) represented 20.5 %; swordfish (<em>Xiphias gladius</em>) 15.1 %; albacore tuna (<em>Thunnus alalunga</em>) 11.3 %, and yellowfin tuna (<em>Thunnus albacares</em>) 6.1 %. The alarming trends in pelagic shark catch emphasise the need for immediate conservation actions. Management strategies should target critical nations, addressing their significant contributions to shark catch. The lack of information on several species and periods highlights the need for comprehensive research and management initiatives.</p></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"281 ","pages":"Article 107178"},"PeriodicalIF":2.2,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S016578362400242X/pdfft?md5=60359d60393ae2a247b0c6a6303f1919&pid=1-s2.0-S016578362400242X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of philopatry in white mullet Mugil curema (Pisces: Mugilidae)","authors":"Angélica Colín ,&nbsp;Susette Castañeda-Rico ,&nbsp;Luis M. Guevara-Chumacero ,&nbsp;Eloisa Pacheco-Almanzar ,&nbsp;Ana L. Ibáñez","doi":"10.1016/j.fishres.2024.107175","DOIUrl":"10.1016/j.fishres.2024.107175","url":null,"abstract":"<div><p><em>Mugil curema</em> is a common species in America and some African coastal areas. It is thought to perform reproductive migrations to the open sea and possibly spawn in estuarine waters. Previous studies described it as a species complex composed of cryptic species, which could be explained by reproductive isolation and/or philopatric behavior. In order to assess genetic diversity, genetic structure and philopatry in <em>M. curema</em>, we sequenced and analyzed two mitochondrial genes (control region and Cytochrome Oxidase Subunit I [COI]) and 10 microsatellite loci from adult individuals from 10 locations in the Gulf of Mexico, one in the Atlantic Ocean, and three in the Mexican Pacific. The mitochondrial results showed two genetic groups: Gulf of Mexico (GOM) and Mexican Pacific (MP). There was relatively high genetic distance between the groups (4.5 % for COI and 11.7 % for the control region), but they did share haplotypes. In addition, two genetic groups were found within the MP group, which could constitute cryptic lineages. The microsatellite results showed genetic connection between GOM and MP, probably as a consequence of recent contact. The results also showed genetic structure within GOM and MP; genetic subgroups differed between the sexes in the GOM (F_ST=0.348 ♂ and 0.275 ♀), but not the MP (F_ST=0.233 ♂ and 0.166 ♀). The results of genetic structure and gene flow support the hypothesis of regional philopatry in males in the GOM and both sexes in the MP. The difference between regions could be explained by the fact that these are located geographically on different oceanic slopes. We recommend that areas where there is strong mixing of males and females and high genetic diversity be considered conservation priorities.</p></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"280 ","pages":"Article 107175"},"PeriodicalIF":2.2,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time varying M with starvation mortality in a state-space stock assessment model: Part 2: Atlantic cod (Gadus morhua) on the southern Grand Bank of Newfoundland","authors":"Noel G. Cadigan ,&nbsp;S.J.W.W.M.M.P. Weerasekera ,&nbsp;Paul M. Regular ,&nbsp;Rick M. Rideout","doi":"10.1016/j.fishres.2024.107174","DOIUrl":"10.1016/j.fishres.2024.107174","url":null,"abstract":"<div><p>State-space models are now a common tool for modeling time-varying ecological phenomena. This extends to state-space stock assessment models (SSAMs), recognized as pivotal components within the evolving landscape of next-generation stock assessment methodologies. Though methods are rapidly evolving, the estimation of time-varying rates of natural mortality (<em>M</em>) remains a challenge, and the sensitivity of stock assessments and management advice to assumed <em>M</em> values underscores the pressing need for improved estimation methods. Using southern Grand Bank (SGB) Atlantic cod as a case study, we introduce a novel approach to estimate time-varying <em>M</em>. We first convert a length-based starvation M index into an age-based index, which we then include in an age-based SSAM to estimate two components of M: starvation M and a remainder component. This produces a new SGB cod SSAM with time-varying total stock <em>M</em>. This model produces a large decrease (68 %) in the size of the model process errors (i.e., their standard deviation) and better fit compared to a model that did not account for time-varying <em>M</em>, indicating that the starvation <em>M</em> index improves our model of stock productivity. By leveraging readily available information on fish body condition and the proportion of fish in really poor condition, the proposed methods offer a valuable solution to the challenges associated with estimating time-varying M. The proposed methods offer a tractable solution to the common struggles associated with quantifying changes in fish productivity, which is crucial for the management of dynamic systems.</p></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"280 ","pages":"Article 107174"},"PeriodicalIF":2.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0165783624002388/pdfft?md5=6461e70f529bba8384f716fa04f160d8&pid=1-s2.0-S0165783624002388-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}