Distant-water fisheries is a crucial component of Taiwan's economy. However, the industry faces significant safety challenges, as high accident rates worldwide underscore the need for effective regulation. Although Taiwan is not a member of the International Maritime Organization (IMO), its extensive distant-water fleet operates under international scrutiny. The IMO’s 2023 revision of the International Convention on Standards of Training, Certification and Watchkeeping for Fishing Vessel Personnel (STCW-F) sets stringent standards for crew competency. This study examines how Taiwan’s regulations align with these international standards. By standardizing training protocols to reduce accidents and ensuring workforce stability, alignment with the STCW-F directly supports the long-term sustainable development of the fishery sector. Using a multi-stage focus group approach, the study gathered expert insights from fishery authorities, associations, and shipowner representatives. The findings reveal critical gaps in medical fitness standards and training certification, offering a roadmap for policy consensus aimed at enhancing the safety and competitiveness of Taiwan's offshore fisheries.
{"title":"Enhancing safety in Taiwan’s distant-water fishing industry: Integrating STCW-F for sustainable development","authors":"Ker-Wei Yu , Chien-Chang Chou , Kun-Yuan Tsai , Jui-Chung Kao , Tsai-Ling Chang , Meng-Chun Tsai , Yung-Sheng Chen","doi":"10.1016/j.fishres.2026.107669","DOIUrl":"10.1016/j.fishres.2026.107669","url":null,"abstract":"<div><div>Distant-water fisheries is a crucial component of Taiwan's economy. However, the industry faces significant safety challenges, as high accident rates worldwide underscore the need for effective regulation. Although Taiwan is not a member of the International Maritime Organization (IMO), its extensive distant-water fleet operates under international scrutiny. The IMO’s 2023 revision of the International Convention on Standards of Training, Certification and Watchkeeping for Fishing Vessel Personnel (STCW-F) sets stringent standards for crew competency. This study examines how Taiwan’s regulations align with these international standards. By standardizing training protocols to reduce accidents and ensuring workforce stability, alignment with the STCW-F directly supports the long-term sustainable development of the fishery sector. Using a multi-stage focus group approach, the study gathered expert insights from fishery authorities, associations, and shipowner representatives. The findings reveal critical gaps in medical fitness standards and training certification, offering a roadmap for policy consensus aimed at enhancing the safety and competitiveness of Taiwan's offshore fisheries.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"294 ","pages":"Article 107669"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080258","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}
Pub Date : 2026-02-01Epub Date: 2026-02-04DOI: 10.1016/j.fishres.2026.107668
Sophie M. White , Amos Mapleston , Morgan S. Pratchett , Reniel B. Cabral
Species biological and harvest data play a vital role in fisheries monitoring and understanding of the status of fish populations. This includes those dominated by recreational harvest. However, reporting in recreational fisheries is rarely compulsory, limiting the availability of catch or biological data, such as fish age and length, for use in stock assessments. Citizen science programs can be a viable way to collect large and diverse data on harvested fish species. Citizen science programs such as Queensland’s (north-eastern Australian state) Department of Primary Industries’ Keen Angler Program (KAP) may address this critical data gap. KAP has been in operation since 2005, and here, we describe for the first time KAP and the data collected in the program so far. In particular, we describe the number of donations and samples, the composition of samples, and patterns of donations (i.e., co-occurrence of donated species) collected through KAP over the past 20 years. Over the past 20 years, KAP has received over 55,000 fish from more than 9000 donations, with the south of Queensland having higher donation numbers compared to the north. Most of the fish donated were ‘Inshore and Estuarine’ species. However, there have been increasing samples of ‘Coral reef’ species, after their addition to the program in 2017. Recreational fishers also tended to supply multiple species in a single donation, providing insights into the targeting strategy of fishers and their use of marine habitats. The capacity to retain participants and continually contribute data could be a significant factor in the sustainability of the program. The high volume and consistent data of KAP could contribute to supporting fisheries monitoring and management.
{"title":"The 20-year Queensland’s fisheries citizen science program and its potential to support fisheries monitoring - The Keen Angler Program","authors":"Sophie M. White , Amos Mapleston , Morgan S. Pratchett , Reniel B. Cabral","doi":"10.1016/j.fishres.2026.107668","DOIUrl":"10.1016/j.fishres.2026.107668","url":null,"abstract":"<div><div>Species biological and harvest data play a vital role in fisheries monitoring and understanding of the status of fish populations. This includes those dominated by recreational harvest. However, reporting in recreational fisheries is rarely compulsory, limiting the availability of catch or biological data, such as fish age and length, for use in stock assessments. Citizen science programs can be a viable way to collect large and diverse data on harvested fish species. Citizen science programs such as Queensland’s (north-eastern Australian state) Department of Primary Industries’ Keen Angler Program (KAP) may address this critical data gap. KAP has been in operation since 2005, and here, we describe for the first time KAP and the data collected in the program so far. In particular, we describe the number of donations and samples, the composition of samples, and patterns of donations (i.e., co-occurrence of donated species) collected through KAP over the past 20 years. Over the past 20 years, KAP has received over 55,000 fish from more than 9000 donations, with the south of Queensland having higher donation numbers compared to the north. Most of the fish donated were ‘Inshore and Estuarine’ species. However, there have been increasing samples of ‘Coral reef’ species, after their addition to the program in 2017. Recreational fishers also tended to supply multiple species in a single donation, providing insights into the targeting strategy of fishers and their use of marine habitats. The capacity to retain participants and continually contribute data could be a significant factor in the sustainability of the program. The high volume and consistent data of KAP could contribute to supporting fisheries monitoring and management.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"294 ","pages":"Article 107668"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190547","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}
Pub Date : 2026-02-01Epub Date: 2026-01-22DOI: 10.1016/j.fishres.2026.107665
Greg G. Sass , Joseph T. Mrnak , Stephanie L. Shaw , Zachary S. Feiner , Colin J. Dassow , Andrew L. Rypel , Holly S. Embke
A long-held assumption in the management of exploited fisheries is that fish populations will compensate with increased recruit survival to replenish the population when adult stock size is reduced through harvest. Observations of depensatory recruitment (reduced recruit survival at low adult stock size) and critical depensatory thresholds have challenged the compensation assumption. Post et al. (2002) postulated that critical depensatory thresholds were related to fish population productivity. Walleye Sander vitreus are a culturally, economically, and recreationally important sportfish whose persistence is being challenged by natural recruitment declines throughout much of its native range. Depensation, among other abiotic and biotic stressors, has been implicated in walleye natural recruitment declines. If walleye population productivity is related to critical depensatory thresholds, then population productivity benchmarks could be established to reduce the probability of crossing them. We used empirically-derived and model predicted depensation values (q) and empirical estimates of walleye population productivity to test for relationships between these variables in northern Wisconsin lakes. We found little evidence for a relationship between q and walleye population productivity across all lakes examined. Our finding failed to support the theoretical postulation of a relationship between these variables by Post et al. (2002) for walleye. Little evidence for a relationship between q and population productivity suggests that depensatory thresholds may differ among individual walleye populations and that walleye populations may transition abruptly between compensatory and depensatory states. Given our findings, conservation efforts for walleye that solely focus on low productivity populations may miss other trends because population productivity may not be considered a broad predictor of crossing a critical depensatory threshold.
在被开发渔业的管理中，一个长期存在的假设是，当成鱼种群数量因捕捞而减少时，鱼类种群将以增加的新生存活来补偿种群数量。依赖性招募（低成虫种群数量时招募存活率降低）和临界依赖性阈值的观察对补偿假设提出了挑战。Post等人（2002）假设临界依赖阈值与鱼类种群生产力有关。在文化上、经济上和娱乐上都是一种重要的运动鱼，其持久性正受到其原生范围内自然捕捞量下降的挑战。在其他非生物和生物压力源中，依赖性已涉及到孔雀鱼自然招募下降。如果鱼眼种群生产力与临界依赖阈值有关，则可以建立种群生产力基准来降低跨越它们的概率。我们使用经验推导和模型预测的依赖值(q)和经验估计的白眼种群生产力来测试威斯康星州北部湖泊这些变量之间的关系。我们发现几乎没有证据表明q与所有湖泊的白眼种群生产力之间存在关系。我们的发现未能支持Post et al.（2002）对这些变量之间的关系的理论假设。很少有证据表明q和种群生产力之间的关系表明，依赖阈值在个体的斜眼鱼种群之间可能是不同的，并且斜眼鱼种群可能在补偿和依赖状态之间突然过渡。鉴于我们的研究结果，仅仅关注低生产力种群的保护工作可能会错过其他趋势，因为种群生产力可能不被认为是跨越关键依赖阈值的广泛预测因素。
{"title":"Strength of depensation not influenced by fish population productivity","authors":"Greg G. Sass , Joseph T. Mrnak , Stephanie L. Shaw , Zachary S. Feiner , Colin J. Dassow , Andrew L. Rypel , Holly S. Embke","doi":"10.1016/j.fishres.2026.107665","DOIUrl":"10.1016/j.fishres.2026.107665","url":null,"abstract":"<div><div>A long-held assumption in the management of exploited fisheries is that fish populations will compensate with increased recruit survival to replenish the population when adult stock size is reduced through harvest. Observations of depensatory recruitment (reduced recruit survival at low adult stock size) and critical depensatory thresholds have challenged the compensation assumption. Post et al. (2002) postulated that critical depensatory thresholds were related to fish population productivity. Walleye <em>Sander vitreus</em> are a culturally, economically, and recreationally important sportfish whose persistence is being challenged by natural recruitment declines throughout much of its native range. Depensation, among other abiotic and biotic stressors, has been implicated in walleye natural recruitment declines. If walleye population productivity is related to critical depensatory thresholds, then population productivity benchmarks could be established to reduce the probability of crossing them. We used empirically-derived and model predicted depensation values (<em>q</em>) and empirical estimates of walleye population productivity to test for relationships between these variables in northern Wisconsin lakes. We found little evidence for a relationship between <em>q</em> and walleye population productivity across all lakes examined. Our finding failed to support the theoretical postulation of a relationship between these variables by Post et al. (2002) for walleye. Little evidence for a relationship between <em>q</em> and population productivity suggests that depensatory thresholds may differ among individual walleye populations and that walleye populations may transition abruptly between compensatory and depensatory states. Given our findings, conservation efforts for walleye that solely focus on low productivity populations may miss other trends because population productivity may not be considered a broad predictor of crossing a critical depensatory threshold.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"294 ","pages":"Article 107665"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039602","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}
Pub Date : 2026-02-01Epub Date: 2026-02-03DOI: 10.1016/j.fishres.2026.107667
Kaitlyn M. Bearden , Mark J. Fincel , Elizabeth A. Renner , Paul E. Bailey , Alison A. Coulter
As fishes move throughout their environment, they have the potential to cross jurisdictional boundaries where they may be exposed to different management regulations (e.g., length limits, bag limits). Understanding and incorporating spatial variation in rates, such as movement or survival, can allow managers from multiple jurisdictions to adjust regulations and collaboratively maintain a fishery. Walleye (Sander vitreus) are an important game species in Lake Oahe (USA) where they are managed by two different jurisdictions, North Dakota and South Dakota. Capture and recapture data from 2013 to 2016 were condensed to create annual, 4-digit capture histories for 34,378 jaw-tagged Walleye, which were analyzed using multistate models to estimate apparent survival and transitions (movements). Apparent survival varied by space and time and was low in 2014, increased in 2015, and then dropped slightly in 2016. This pattern could be due to changes in regulations, spatiotemporal differences in angler effort, or resource availability, but requires further exploration. Movement probabilities varied spatially, and there is an overall net movement of Walleye out of one jurisdiction (North Dakota). No covariates (sex, total length, lake elevation) influenced movement or apparent survival, but habitat preferences coupled with differences in how habitat is distributed within Lake Oahe could be overshadowing these effects. Overall, these results confirm interjurisdictional connections within the Walleye population of Lake Oahe, and both management jurisdictions can consider spatial variation in movement and survival of individuals when planning management actions.
{"title":"Walleye (Sander vitreus) movement dynamics in Lake Oahe, USA across two management jurisdictions","authors":"Kaitlyn M. Bearden , Mark J. Fincel , Elizabeth A. Renner , Paul E. Bailey , Alison A. Coulter","doi":"10.1016/j.fishres.2026.107667","DOIUrl":"10.1016/j.fishres.2026.107667","url":null,"abstract":"<div><div>As fishes move throughout their environment, they have the potential to cross jurisdictional boundaries where they may be exposed to different management regulations (e.g., length limits, bag limits). Understanding and incorporating spatial variation in rates, such as movement or survival, can allow managers from multiple jurisdictions to adjust regulations and collaboratively maintain a fishery. Walleye (<em>Sander vitreus</em>) are an important game species in Lake Oahe (USA) where they are managed by two different jurisdictions, North Dakota and South Dakota. Capture and recapture data from 2013 to 2016 were condensed to create annual, 4-digit capture histories for 34,378 jaw-tagged Walleye, which were analyzed using multistate models to estimate apparent survival and transitions (movements). Apparent survival varied by space and time and was low in 2014, increased in 2015, and then dropped slightly in 2016. This pattern could be due to changes in regulations, spatiotemporal differences in angler effort, or resource availability, but requires further exploration. Movement probabilities varied spatially, and there is an overall net movement of Walleye out of one jurisdiction (North Dakota). No covariates (sex, total length, lake elevation) influenced movement or apparent survival, but habitat preferences coupled with differences in how habitat is distributed within Lake Oahe could be overshadowing these effects. Overall, these results confirm interjurisdictional connections within the Walleye population of Lake Oahe, and both management jurisdictions can consider spatial variation in movement and survival of individuals when planning management actions.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"294 ","pages":"Article 107667"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190548","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}
Pub Date : 2026-02-01Epub Date: 2026-01-31DOI: 10.1016/j.fishres.2026.107670
Dunja Jusufovski , Guðjón Már Sigurðsson
Various sound-based devices designed to reduce bycatch of small marine mammals in gillnet fisheries have become widely available, yet still remain insufficiently tested in commercial fisheries settings. Thus far, no such device has been tested in the Icelandic cod (Gadus morhua) gillnet fishery which has a notable marine mammal bycatch. To investigate the potential of reducing marine mammal bycatch problem in the gillnet fishery, we tested three acoustic deterrent devices (ADDs): 1) the Fishtek Banana pingers, 2) Porpoise ALert device (PAL), and 3) wideband PAL (wPAL) with a modified pinger signal. The ADD trials were conducted in three different coastal regions of Iceland, where high bycatch has been observed. The ADDs were tested using 12-panel gillnets with three different mesh sizes commonly used in commercial fisheries. In this study, only harbor porpoises (Phocoena phocoena; N = 48) and white-beaked dolphins (Lagenorhynchus albirostris; N = 5) were captured during trials. Contrary to prior research, Banana pingers and PALs did not demonstrate any reduction of bycatch, while the wPAL-equipped nets had no bycatch during the trial. Fish catch and overall commercial value was significantly reduced in gillnets equipped with Banana pingers and PALs than in wPALs. Additionally, PAL-equipped gillnets captured more male than female harbor porpoises. While these trials present a baseline for understanding the effect of the three ADDs on cetacean bycatch, further research needs to address the conditions leading to poor effectiveness of Banana and PAL devices in gillnet fishing.
{"title":"First trials of commercially available pingers for cetacean bycatch reduction in Icelandic bottom set gillnet fishery","authors":"Dunja Jusufovski , Guðjón Már Sigurðsson","doi":"10.1016/j.fishres.2026.107670","DOIUrl":"10.1016/j.fishres.2026.107670","url":null,"abstract":"<div><div>Various sound-based devices designed to reduce bycatch of small marine mammals in gillnet fisheries have become widely available, yet still remain insufficiently tested in commercial fisheries settings. Thus far, no such device has been tested in the Icelandic cod (<em>Gadus morhua</em>) gillnet fishery which has a notable marine mammal bycatch. To investigate the potential of reducing marine mammal bycatch problem in the gillnet fishery, we tested three acoustic deterrent devices (ADDs): 1) the Fishtek Banana pingers, 2) Porpoise ALert device (PAL), and 3) wideband PAL (wPAL) with a modified pinger signal. The ADD trials were conducted in three different coastal regions of Iceland, where high bycatch has been observed. The ADDs were tested using 12-panel gillnets with three different mesh sizes commonly used in commercial fisheries. In this study, only harbor porpoises (<em>Phocoena phocoena</em>; N = 48) and white-beaked dolphins (<em>Lagenorhynchus albirostris</em>; N = 5) were captured during trials. Contrary to prior research, Banana pingers and PALs did not demonstrate any reduction of bycatch, while the wPAL-equipped nets had no bycatch during the trial. Fish catch and overall commercial value was significantly reduced in gillnets equipped with Banana pingers and PALs than in wPALs. Additionally, PAL-equipped gillnets captured more male than female harbor porpoises. While these trials present a baseline for understanding the effect of the three ADDs on cetacean bycatch, further research needs to address the conditions leading to poor effectiveness of Banana and PAL devices in gillnet fishing.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"294 ","pages":"Article 107670"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080253","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}
Pub Date : 2026-02-01Epub Date: 2026-01-20DOI: 10.1016/j.fishres.2026.107656
Corey B. Wakefield , Luke Loudon , Euan S. Harvey , Simon J. Nicol , Ashley J. Williams , Stephen J. Newman
Estimates of age are required to derive life history information that is critically important for stock assessments. Determining fish ages from sectioned otoliths is typically costly and time consuming with many species, particularly those from tropical environments, requiring higher levels of expertise in the interpretation of annual growth zones. This study achieved a high and generally accepted level of precision in predicting fish ages (i.e., < 5.5 % IAPE) using otolith biometry for a deepwater snapper, Pristipomoides zonatus over a remarkable age range (i.e., 3–60 years, n = 664). The results provided important insights into the relatively greater influence of otolith thickness for predicting fish age, with Gradient Boosting Machine models achieving higher precision than two other multivariate ensemble approaches (i.e., Bagging and Random Forest). Slight improvements in the precision of age predictions were achieved with the inclusion of sex (i.e., female or male), and with the removal of age cohorts with relatively lower sample sizes (i.e., subset age range 4–25 years, n = 519, IAPE 4.7 %, 93 % of predicted ages within ±2 years). The relatively linear increase in otolith thickness and weight with age, and their strong influence on age predictions, emphasises the decoupling between asymptotic somatic growth and the continual accretion of otolith material with age. Hence, further advances in predicting ages of fish using otolith biometry should focus on quantifying accretion on the medial surface in the proximal aspect (i.e., deepening of the sulcus). This study provides a method for deriving robust ages of fish without sectioning otoliths, which is fast and relatively inexpensive, and thus has a broad application toward the monitoring, assessment, and sustainability of fish stocks globally.
{"title":"High precision in age predictions derived from multivariate ensemble analyses of otolith biometry for a long-lived deepwater snapper","authors":"Corey B. Wakefield , Luke Loudon , Euan S. Harvey , Simon J. Nicol , Ashley J. Williams , Stephen J. Newman","doi":"10.1016/j.fishres.2026.107656","DOIUrl":"10.1016/j.fishres.2026.107656","url":null,"abstract":"<div><div>Estimates of age are required to derive life history information that is critically important for stock assessments. Determining fish ages from sectioned otoliths is typically costly and time consuming with many species, particularly those from tropical environments, requiring higher levels of expertise in the interpretation of annual growth zones. This study achieved a high and generally accepted level of precision in predicting fish ages (i.e., < 5.5 % IAPE) using otolith biometry for a deepwater snapper, <em>Pristipomoides zonatus</em> over a remarkable age range (i.e., 3–60 years, n = 664). The results provided important insights into the relatively greater influence of otolith thickness for predicting fish age, with Gradient Boosting Machine models achieving higher precision than two other multivariate ensemble approaches (i.e., Bagging and Random Forest). Slight improvements in the precision of age predictions were achieved with the inclusion of sex (i.e., female or male), and with the removal of age cohorts with relatively lower sample sizes (i.e., subset age range 4–25 years, n = 519, IAPE 4.7 %, 93 % of predicted ages within ±2 years). The relatively linear increase in otolith thickness and weight with age, and their strong influence on age predictions, emphasises the decoupling between asymptotic somatic growth and the continual accretion of otolith material with age. Hence, further advances in predicting ages of fish using otolith biometry should focus on quantifying accretion on the medial surface in the proximal aspect (i.e., deepening of the sulcus). This study provides a method for deriving robust ages of fish without sectioning otoliths, which is fast and relatively inexpensive, and thus has a broad application toward the monitoring, assessment, and sustainability of fish stocks globally.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"294 ","pages":"Article 107656"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001839","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}
Accurate age determination of commercially important fish species is essential for sustainable fisheries management and stock assessment. However, traditional methods relying on the manual counting of otolith annuli are labour-intensive, time-consuming, and subject to significant inter-reader variability. This study introduces SwinGPC-AgeRecognitioNet, a hybrid deep learning framework designed for efficient automated age estimation in the Mediterranean horse mackerel (Carangidae: Trachurus mediterraneus), to address these challenges. The proposed architecture synergises Swin Transformer-based feature extraction with a Gaussian Process Classifier (GPC) to capture global structural patterns while providing robust probabilistic predictions. The methodological workflow integrates three critical stages: (1) high-level feature extraction via Swin Transformer; (2) discriminative feature selection using Recursive Feature Elimination; and (3) hyperparameter-optimised classification via GPC. Experimental evaluations on a dataset of 1231 otolith images reveal that the proposed model consistently outperforms Convolutional Neural Networks architectures (e.g., VGG, ResNet), achieving accuracies of 88.66 % in multi-class classification and up to 94.33 % in binary tasks. These findings highlight the potential of SwinGPC-AgeRecognitioNet as a scalable, high-precision tool for fisheries science, offering a reliable alternative for data-driven resource management.
{"title":"Age recognition of a semi-pelagic fish (Carangiformes: Carangidae) using a Swin Transformer and Gaussian Process Classifier with otolith images","authors":"Muammer Türkoğlu , Ömerhan Dürrani , Onur Polat , Habib Bal , Tuncay Ateşşahin , Seda İşgüzar , Syeda Zahra Dürrani , Kadir Seyhan","doi":"10.1016/j.fishres.2026.107658","DOIUrl":"10.1016/j.fishres.2026.107658","url":null,"abstract":"<div><div>Accurate age determination of commercially important fish species is essential for sustainable fisheries management and stock assessment. However, traditional methods relying on the manual counting of otolith annuli are labour-intensive, time-consuming, and subject to significant inter-reader variability. This study introduces SwinGPC-AgeRecognitioNet, a hybrid deep learning framework designed for efficient automated age estimation in the Mediterranean horse mackerel (Carangidae: <em>Trachurus mediterraneus</em>), to address these challenges. The proposed architecture synergises Swin Transformer-based feature extraction with a Gaussian Process Classifier (GPC) to capture global structural patterns while providing robust probabilistic predictions. The methodological workflow integrates three critical stages: (1) high-level feature extraction via Swin Transformer; (2) discriminative feature selection using Recursive Feature Elimination; and (3) hyperparameter-optimised classification via GPC. Experimental evaluations on a dataset of 1231 otolith images reveal that the proposed model consistently outperforms Convolutional Neural Networks architectures (e.g., VGG, ResNet), achieving accuracies of 88.66 % in multi-class classification and up to 94.33 % in binary tasks. These findings highlight the potential of SwinGPC-AgeRecognitioNet as a scalable, high-precision tool for fisheries science, offering a reliable alternative for data-driven resource management.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"294 ","pages":"Article 107658"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039674","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}
Pub Date : 2026-01-01Epub Date: 2026-01-10DOI: 10.1016/j.fishres.2026.107650
Joel Anderson, Isabelle Cummings, Zachary Olsen, Mark Fisher
The Atlantic Croaker Micropogonias undulatus is a key estuarine-dependent species in Texas and the greater Gulf of Mexico, particularly as the target for a commercial bait fishery but also as one of the most common bycatch species encountered in commercial shrimp trawls. Declining effort in the inshore (estuarine) shrimp trawl fishery in Texas since the 1990s has resulted in increasing abundance of Atlantic Croaker, although a concurrent change in mean body size has not been explored. Here, the observed abundance of Atlantic Croaker in fishery-independent trawls was related to observed mean total body length in trawls, fishery-independent gill nets, and observed recreational angler harvest from boat ramp intercepts centered on the eight major bay areas of Texas. Annual abundance estimates correlated negatively and significantly with mean size in trawls in 7/8 bays, in gill nets in 4/8 bays, and in angler harvest data in 1/8 bays. Annual growth rate parameters (k) for young-of-the-year specimens were developed using size-filtered monthly bag seine and trawl length-frequency data, and the magnitude of k was tightly and negatively correlated with annual abundance coast-wide. Body size of Atlantic Croaker in Texas is driven by annual abundance, and growth of Atlantic Croaker is relatively slow in years when abundance is relatively high. Observed increases in abundance driven by reduced bycatch mortality are driving long-term declines in body size in Texas, which may ultimately drive changes to mean body size in the recreational harvest and commercial bait fisheries.
{"title":"Body size of Atlantic Croaker Micropogonias undulatus in Texas is density dependent","authors":"Joel Anderson, Isabelle Cummings, Zachary Olsen, Mark Fisher","doi":"10.1016/j.fishres.2026.107650","DOIUrl":"10.1016/j.fishres.2026.107650","url":null,"abstract":"<div><div>The Atlantic Croaker <em>Micropogonias undulatus</em> is a key estuarine-dependent species in Texas and the greater Gulf of Mexico, particularly as the target for a commercial bait fishery but also as one of the most common bycatch species encountered in commercial shrimp trawls. Declining effort in the inshore (estuarine) shrimp trawl fishery in Texas since the 1990s has resulted in increasing abundance of Atlantic Croaker, although a concurrent change in mean body size has not been explored. Here, the observed abundance of Atlantic Croaker in fishery-independent trawls was related to observed mean total body length in trawls, fishery-independent gill nets, and observed recreational angler harvest from boat ramp intercepts centered on the eight major bay areas of Texas. Annual abundance estimates correlated negatively and significantly with mean size in trawls in 7/8 bays, in gill nets in 4/8 bays, and in angler harvest data in 1/8 bays. Annual growth rate parameters (<em>k</em>) for young-of-the-year specimens were developed using size-filtered monthly bag seine and trawl length-frequency data, and the magnitude of <em>k</em> was tightly and negatively correlated with annual abundance coast-wide. Body size of Atlantic Croaker in Texas is driven by annual abundance, and growth of Atlantic Croaker is relatively slow in years when abundance is relatively high. Observed increases in abundance driven by reduced bycatch mortality are driving long-term declines in body size in Texas, which may ultimately drive changes to mean body size in the recreational harvest and commercial bait fisheries.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"293 ","pages":"Article 107650"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925288","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}
Coastal waters are important habitats for the endangered European eel. In a large-scale experiment marked glass eels were released in two geographically distinct coastal areas in the southern Baltic Sea. Generalized linear mixed models were used to test for effects of restocking on yellow eel density as well as eel condition and growth following a before-after-control-impact analysis design. Alongside of increased natural immigration, restocking distinctly increased the yellow eel density by around 1.5–3 times in both restocked areas compared with densities recorded before the release. Increased densities by restocking did not generally lead to slower growth, altered body condition, or a change in the sex ratio of naturally immigrated eels. Restocked eels had comparable condition and grew somewhat faster than naturally immigrated eels in both restocked areas within the first three years after restocking. These results suggest, that the habitat capacity for eels in the restocked areas was not reached by the current natural settlement in combination with the released eels. Therefore, eel restocking in coastal waters seems to be a useful management option to locally increase the escapement rate of mature silver eels.
{"title":"Large-scale experiment demonstrates potential benefits of restocking glass eels in coastal waters of the southern Baltic Sea","authors":"Janek Simon , Tyrell DeWeber , Jens Frankowski , Malte Dorow","doi":"10.1016/j.fishres.2026.107651","DOIUrl":"10.1016/j.fishres.2026.107651","url":null,"abstract":"<div><div>Coastal waters are important habitats for the endangered European eel. In a large-scale experiment marked glass eels were released in two geographically distinct coastal areas in the southern Baltic Sea. Generalized linear mixed models were used to test for effects of restocking on yellow eel density as well as eel condition and growth following a before-after-control-impact analysis design. Alongside of increased natural immigration, restocking distinctly increased the yellow eel density by around 1.5–3 times in both restocked areas compared with densities recorded before the release. Increased densities by restocking did not generally lead to slower growth, altered body condition, or a change in the sex ratio of naturally immigrated eels. Restocked eels had comparable condition and grew somewhat faster than naturally immigrated eels in both restocked areas within the first three years after restocking. These results suggest, that the habitat capacity for eels in the restocked areas was not reached by the current natural settlement in combination with the released eels. Therefore, eel restocking in coastal waters seems to be a useful management option to locally increase the escapement rate of mature silver eels.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"293 ","pages":"Article 107651"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925291","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}
Pub Date : 2026-01-01Epub Date: 2025-12-01DOI: 10.1016/j.fishres.2025.107612
Brett Wilson , Joseph Facendola , Amanda Southwood Williard
The commercial blue crab (Callinectes sapidus) harvest represents one of the most valuable fisheries in North Carolina and is a significant economic driver for coastal communities. The diamond-backed terrapin (Malaclemys terrapin), an estuarine Emydid turtle, is listed as a Species of Special Concern in North Carolina, where incidental bycatch in crab pots is a prominent threat. Efforts to reduce bycatch by installing bycatch reduction devices (BRDs) to funnel openings on crab pots have been met with resistance due to perceived negative impacts to blue crab catch. In 2020, the North Carolina Marine Fisheries Commission (NCMFC) designated Diamond-backed Terrapin Management Areas (DTMAs) in two waterbodies in North Carolina, within which North Carolina Division of Marine Fisheries (NCDMF) approved BRDs must be incorporated into all crab pots. While this regulatory measure was taken to mitigate fisheries impacts on diamond-backed terrapins, the NCDMF acknowledged the need to explore alternative gear modifications that exclude diamond-backed terrapins while minimizing impacts to target species catch. The primary goal of our study was to test the efficacy of industry-sourced gear modifications to crab pot funnel entries for diamond-backed terrapin exclusion and assess impacts of these modifications on blue crab catch. Results from fisheries-independent and fisheries-dependent testing show that narrow funnel designs (NFD) effectively exclude diamond-backed terrapins without significant reductions in catch or size of blue crabs. Our results highlight the effectiveness of collaboration between management agencies, researchers, and industry stakeholders to achieve broadly acceptable solutions to reduce diamond-backed terrapin bycatch in the commercial blue crab fishery.
{"title":"Industry-sourced approaches to diamond-backed terrapin bycatch reduction in the North Carolina commercial blue crab fishery","authors":"Brett Wilson , Joseph Facendola , Amanda Southwood Williard","doi":"10.1016/j.fishres.2025.107612","DOIUrl":"10.1016/j.fishres.2025.107612","url":null,"abstract":"<div><div>The commercial blue crab (<em>Callinectes sapidus</em>) harvest represents one of the most valuable fisheries in North Carolina and is a significant economic driver for coastal communities. The diamond-backed terrapin (<em>Malaclemys terrapin</em>), an estuarine Emydid turtle, is listed as a Species of Special Concern in North Carolina, where incidental bycatch in crab pots is a prominent threat. Efforts to reduce bycatch by installing bycatch reduction devices (BRDs) to funnel openings on crab pots have been met with resistance due to perceived negative impacts to blue crab catch. In 2020, the North Carolina Marine Fisheries Commission (NCMFC) designated Diamond-backed Terrapin Management Areas (DTMAs) in two waterbodies in North Carolina, within which North Carolina Division of Marine Fisheries (NCDMF) approved BRDs must be incorporated into all crab pots. While this regulatory measure was taken to mitigate fisheries impacts on diamond-backed terrapins, the NCDMF acknowledged the need to explore alternative gear modifications that exclude diamond-backed terrapins while minimizing impacts to target species catch. The primary goal of our study was to test the efficacy of industry-sourced gear modifications to crab pot funnel entries for diamond-backed terrapin exclusion and assess impacts of these modifications on blue crab catch. Results from fisheries-independent and fisheries-dependent testing show that narrow funnel designs (NFD) effectively exclude diamond-backed terrapins without significant reductions in catch or size of blue crabs. Our results highlight the effectiveness of collaboration between management agencies, researchers, and industry stakeholders to achieve broadly acceptable solutions to reduce diamond-backed terrapin bycatch in the commercial blue crab fishery.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"293 ","pages":"Article 107612"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684884","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}
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