Pub Date : 2025-04-06DOI: 10.1016/j.fishres.2025.107362
Yi Huang , Ulf Dieckmann , Mikko Heino
China ranks as the first fishery nation globally in terms of its fishery production, with a total production of more than 67 million metric tons in 2022. More than 16 million people work in and earn their livelihoods from fisheries, directly or indirectly. A better understanding of the characteristics of this large group of people could lead to an improved appreciation of the human dimensions of China’s fisheries. In this study, we analyze longitudinal social-survey data from 1989 to 2015 to derive several key indicators representing the socio-economic status of China’s fishery population. We find that, first, the size of the fishery population is shrinking. Second, the average age of the fishery population is increasing but at a slower rate than in the total population. Third, the education levels of the fishery population are rising but remain below those of urban residents. Fourth, the incomes of the fishery population have grown considerably, albeit more slowly than those of the general rural population and the urban population. Fifth, the employment of the fishery population is exhibiting a high degree of dynamism, with high rates of occupational mobility between the fishing sector and other sectors.
{"title":"Socio-economic status and occupational mobility of China’s Fishery Population: A quantitative analysis based on social-survey data","authors":"Yi Huang , Ulf Dieckmann , Mikko Heino","doi":"10.1016/j.fishres.2025.107362","DOIUrl":"10.1016/j.fishres.2025.107362","url":null,"abstract":"<div><div>China ranks as the first fishery nation globally in terms of its fishery production, with a total production of more than 67 million metric tons in 2022. More than 16 million people work in and earn their livelihoods from fisheries, directly or indirectly. A better understanding of the characteristics of this large group of people could lead to an improved appreciation of the human dimensions of China’s fisheries. In this study, we analyze longitudinal social-survey data from 1989 to 2015 to derive several key indicators representing the socio-economic status of China’s fishery population. We find that, first, the size of the fishery population is shrinking. Second, the average age of the fishery population is increasing but at a slower rate than in the total population. Third, the education levels of the fishery population are rising but remain below those of urban residents. Fourth, the incomes of the fishery population have grown considerably, albeit more slowly than those of the general rural population and the urban population. Fifth, the employment of the fishery population is exhibiting a high degree of dynamism, with high rates of occupational mobility between the fishing sector and other sectors.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107362"},"PeriodicalIF":2.2,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783656","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}
The carbon isotopic compositions of otolith can be used to retrospectively estimate fish field metabolic rates (FMR) and are advantageous for practical applications, particularly for small-sized fish whose metabolic rates are challenging to measure in the field. Based on the proportional contribution of metabolism-derived carbon to otolith carbon, this study validated an approach for juveniles of the anadromous fish species, chum salmon Oncorhynchus keta, by integrating respirometry experiments and stable isotope ratio mass spectrometry (SIA). The isotopic results showed that the compositions of otolith carbon isotope (δ13Cotolith) values were negatively correlated with body mass, aligning with the mass-specific allometric theory. The ratio of metabolism-derived carbon in otoliths (Cresp) was calculated based on the carbon isotope compositions of the otolith, dissolved inorganic carbon in water (DIC), and diet. The results indicated that up to nearly 50 % of the carbon in juvenile chum salmon otoliths was metabolism-origin. Further, temperature gradient experiments showed that the Cresp values increased until around a temperature of 15℃ and fell significantly at 20℃, suggesting that the factorial FMR was restricted at temperatures exceeding the optimal temperature for metabolism (Topt). Thus, the relationship between metabolic rate and Cresp was validated within the temperature range of 9–15℃. Nonetheless, as a cool-water species, wild chum salmon rarely experience water masses above 15℃. Therefore, our results were feasible to estimate the FMR of juvenile chum salmon in the wild and could be used for reconstructing their metabolic histories, thereby providing insights into the metabolic strategies associated with migration traits.
{"title":"Evaluating the metabolic response to temperature using otolith carbon isotopes as an intrinsic metabolic tracer in juvenile chum salmon Oncorhynchus keta","authors":"Yuxiao Gou , Shiono Miki , Yuki Iino , Takaaki K. Abe , Ryuji Hattori , Ming-Tsung Chung , Kotaro Shirai , Takashi Kitagawa","doi":"10.1016/j.fishres.2025.107360","DOIUrl":"10.1016/j.fishres.2025.107360","url":null,"abstract":"<div><div>The carbon isotopic compositions of otolith can be used to retrospectively estimate fish field metabolic rates (FMR) and are advantageous for practical applications, particularly for small-sized fish whose metabolic rates are challenging to measure in the field. Based on the proportional contribution of metabolism-derived carbon to otolith carbon, this study validated an approach for juveniles of the anadromous fish species, chum salmon <em>Oncorhynchus keta</em>, by integrating respirometry experiments and stable isotope ratio mass spectrometry (SIA). The isotopic results showed that the compositions of otolith carbon isotope (<em>δ</em><sup>13</sup>C<sub><em>otolith</em></sub>) values were negatively correlated with body mass, aligning with the mass-specific allometric theory. The ratio of metabolism-derived carbon in otoliths (<em>C</em><sub>resp</sub>) was calculated based on the carbon isotope compositions of the otolith, dissolved inorganic carbon in water (DIC), and diet. The results indicated that up to nearly 50 % of the carbon in juvenile chum salmon otoliths was metabolism-origin. Further, temperature gradient experiments showed that the <em>C</em><sub>resp</sub> values increased until around a temperature of 15℃ and fell significantly at 20℃, suggesting that the factorial FMR was restricted at temperatures exceeding the optimal temperature for metabolism (<em>T</em><sub>opt</sub>). Thus, the relationship between metabolic rate and <em>C</em><sub>resp</sub> was validated within the temperature range of 9–15℃. Nonetheless, as a cool-water species, wild chum salmon rarely experience water masses above 15℃. Therefore, our results were feasible to estimate the FMR of juvenile chum salmon in the wild and could be used for reconstructing their metabolic histories, thereby providing insights into the metabolic strategies associated with migration traits.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107360"},"PeriodicalIF":2.2,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783657","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}
Pub Date : 2025-04-05DOI: 10.1016/j.fishres.2025.107356
Christopher A. Griffiths, Emilia Björklund, Nuno Prista, Axel Hjelm, Katja Norén, Lisa Sörman, Ronja Risberg, Massimiliano Cardinale, Mikaela Bergenius Nord
Reported landings from commercial fisheries are a main source of information on the removed biomass of a species and/or stock from the sea. In many fisheries, however, on-board processing to meet market demand causes a discrepancy between the landed weight and original live weight, necessitating the use of correction factors during data preparation for stock assessment and advice. One such fishery is for northern shrimp (Pandalus borealis) in the Skagerrak, Kattegat and northern North Sea. In this fishery, large, often female shrimp are boiled in salt water while on-board to maximise sale prices and scientists currently use a correction factor of 1.13 to account for the weight loss of shrimp from boiling. Here, we investigated this correction factor by conducting a weight loss experiment on-board the Swedish shrimp fishery between 2022 and 2024. We estimate that shrimps lose 10.26 % of their weight during boiling which corresponds to a correction factor of 1.11. Further, we find that weight loss likely varies on a seasonal basis, with more weight being lost during Q2 and Q3 compared to Q1 and Q4, potentially due to changes in the biology of the species as well as environmental conditions. Our findings suggest that the current correction factor used in the assessment of the stock should be reduced for the Swedish fishery and should preferably vary based on when the shrimp are caught. The experimental methodology used here could also be used to estimate weight loss in other shrimp fisheries.
{"title":"Shrinking shrimp - Investigating the weight loss of northern shrimp Pandalus borealis following boiling","authors":"Christopher A. Griffiths, Emilia Björklund, Nuno Prista, Axel Hjelm, Katja Norén, Lisa Sörman, Ronja Risberg, Massimiliano Cardinale, Mikaela Bergenius Nord","doi":"10.1016/j.fishres.2025.107356","DOIUrl":"10.1016/j.fishres.2025.107356","url":null,"abstract":"<div><div>Reported landings from commercial fisheries are a main source of information on the removed biomass of a species and/or stock from the sea. In many fisheries, however, on-board processing to meet market demand causes a discrepancy between the landed weight and original live weight, necessitating the use of correction factors during data preparation for stock assessment and advice. One such fishery is for northern shrimp (<em>Pandalus borealis)</em> in the Skagerrak, Kattegat and northern North Sea. In this fishery, large, often female shrimp are boiled in salt water while on-board to maximise sale prices and scientists currently use a correction factor of 1.13 to account for the weight loss of shrimp from boiling. Here, we investigated this correction factor by conducting a weight loss experiment on-board the Swedish shrimp fishery between 2022 and 2024. We estimate that shrimps lose 10.26 % of their weight during boiling which corresponds to a correction factor of 1.11. Further, we find that weight loss likely varies on a seasonal basis, with more weight being lost during Q2 and Q3 compared to Q1 and Q4, potentially due to changes in the biology of the species as well as environmental conditions. Our findings suggest that the current correction factor used in the assessment of the stock should be reduced for the Swedish fishery and should preferably vary based on when the shrimp are caught. The experimental methodology used here could also be used to estimate weight loss in other shrimp fisheries.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107356"},"PeriodicalIF":2.2,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777090","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}
Pub Date : 2025-04-05DOI: 10.1016/j.fishres.2025.107357
Johanna Faure , Clara Péron , Rob Jones , Michael Grima , Colette Appert , Nicolas Gasco , Timothy Lamb , Philippe Ziegler , Jaimie Cleeland
Elasmobranchs, including sharks, skates and rays, are often characterised by low reproductive rates, rendering their populations susceptible to declines in abundance caused by elevated mortality rates. While skates are occasionally targeted by commercial fisheries, they are commonly caught as incidental bycatch in demersal fisheries. The release of captured individuals that are still alive is often used as a management measure to prevent declines in skate populations. Upon capture, a visual assessment of skate physical condition is necessary to avoid discarding of dead or badly injured individuals. Good handling practices are also required to promote post-release survival. Our study investigated skate handling practices and the condition assessment method of Patagonian toothfish longline fisheries operating in the Southern Indian Ocean. A total of 171 longline captured skates were photographed, and the images analysed by specialist veterinarians trained in elasmobranch health to characterise injuries and qualitatively predict the physical and physiological consequences of each injury type on skate post-release survival. We found 13 types of injury, 10 of which were attributed to the capture process. Among these injuries, two were deemed irreversible, prompting a recommendation to retain the individual at all times. The majority of the examined injuries ranged from superficial to severe, particularly in cases of mouth/jaw damage. Based on these results, we developed best-practice handling guidelines and condition assessments, in form of posters and a comprehensive video tutorial. They provide clear guidance for managers and longline fishing crew for addressing 1) the condition of individuals that should be retained or released at sea alive and 2) handling practices to minimise further injury prior to the release. The guidelines for handling practices and condition assessments developed here can also be easily adapted to manage skate bycatch in other longline fisheries.
{"title":"Condition assessment and best-practice handling guidelines for skate (Rajiformes) bycatch: Lessons from demersal longline fisheries in the Southern Indian Ocean","authors":"Johanna Faure , Clara Péron , Rob Jones , Michael Grima , Colette Appert , Nicolas Gasco , Timothy Lamb , Philippe Ziegler , Jaimie Cleeland","doi":"10.1016/j.fishres.2025.107357","DOIUrl":"10.1016/j.fishres.2025.107357","url":null,"abstract":"<div><div>Elasmobranchs, including sharks, skates and rays, are often characterised by low reproductive rates, rendering their populations susceptible to declines in abundance caused by elevated mortality rates. While skates are occasionally targeted by commercial fisheries, they are commonly caught as incidental bycatch in demersal fisheries. The release of captured individuals that are still alive is often used as a management measure to prevent declines in skate populations. Upon capture, a visual assessment of skate physical condition is necessary to avoid discarding of dead or badly injured individuals. Good handling practices are also required to promote post-release survival. Our study investigated skate handling practices and the condition assessment method of Patagonian toothfish longline fisheries operating in the Southern Indian Ocean. A total of 171 longline captured skates were photographed, and the images analysed by specialist veterinarians trained in elasmobranch health to characterise injuries and qualitatively predict the physical and physiological consequences of each injury type on skate post-release survival. We found 13 types of injury, 10 of which were attributed to the capture process. Among these injuries, two were deemed irreversible, prompting a recommendation to retain the individual at all times. The majority of the examined injuries ranged from superficial to severe, particularly in cases of mouth/jaw damage. Based on these results, we developed best-practice handling guidelines and condition assessments, in form of posters and a comprehensive video tutorial. They provide clear guidance for managers and longline fishing crew for addressing 1) the condition of individuals that should be retained or released at sea alive and 2) handling practices to minimise further injury prior to the release. The guidelines for handling practices and condition assessments developed here can also be easily adapted to manage skate bycatch in other longline fisheries.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107357"},"PeriodicalIF":2.2,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777092","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 : 2025-04-05DOI: 10.1016/j.fishres.2025.107345
Lei Xing , Arnaud Grüss , Nicolas Barrier , Jianfeng He , Jianye Tang
There is growing interest in developing and using ecosystem simulation models to advise fisheries management in the Southern Ocean. However, poor understanding of the impacts of uncertainty in ecosystem model parameters slows down progress towards operational ecosystem models. To address this issue, we explored uncertainty in the parameters estimated during the calibration of an OSMOSE ecosystem model for the Cooperation Sea (“OSMOSE-CooperationSea”) and the impacts of this uncertainty. Our investigations pertained to four types of calibrated parameters: (1) Plank.access, the proportion of the biomass of background species groups available to focal species groups; (2) Bioflux, the parameter controlling the flux of migratory species group biomasses across the modelled domain boundaries; (3) Mlarval, the instantaneous larval mortality of the focal species groups; and (4) Mnatural, the additional natural mortality of the focal species groups. Results with the Morris method suggested that the community in the Cooperation Sea was most sensitive to changes in the Mlarval parameter of mesopelagic fishes. The biomasses of large-size, long-lived species such as toothfishes, Adélie penguin (Pygoscelis adeliae), seals, and whales were most sensitive to the parameters specific to these species groups. By contrast, the biomasses of small-sized, short-lived species such as mesopelagic fishes and krill species were most sensitive to changes in the parameters specific to the predators of these species groups. Monte Carlo simulations indicated that community dynamics were more sensitive to the Mlarval and Mnatural parameters than to the Plank.access and Bioflux parameters. After gradually increasing the Mlarval or Mnatural parameter, the biomasses of Adélie penguin, seals and whales decreased, while the biomasses of mesopelagic fishes and Antarctic krill increased. By providing a comprehensive analysis of uncertainty in the parameters estimated during the calibration process, the present study represents an important step towards an operational ecosystem model for supporting ecosystem-based management in the Cooperation Sea. The present study will serve as a valuable basis for similar ecosystem modelling efforts in the Southern Ocean.
{"title":"Global sensitivity and uncertainty analyses of an ecosystem model for simulating food web dynamics in the Cooperation Sea, Southern Ocean","authors":"Lei Xing , Arnaud Grüss , Nicolas Barrier , Jianfeng He , Jianye Tang","doi":"10.1016/j.fishres.2025.107345","DOIUrl":"10.1016/j.fishres.2025.107345","url":null,"abstract":"<div><div>There is growing interest in developing and using ecosystem simulation models to advise fisheries management in the Southern Ocean. However, poor understanding of the impacts of uncertainty in ecosystem model parameters slows down progress towards operational ecosystem models. To address this issue, we explored uncertainty in the parameters estimated during the calibration of an OSMOSE ecosystem model for the Cooperation Sea (“OSMOSE-CooperationSea”) and the impacts of this uncertainty. Our investigations pertained to four types of calibrated parameters: (1) <em>Plank.access</em>, the proportion of the biomass of background species groups available to focal species groups; (2) <em>Bio</em><sub><em>flux</em></sub>, the parameter controlling the flux of migratory species group biomasses across the modelled domain boundaries; (3) <em>M</em><sub><em>larval</em></sub>, the instantaneous larval mortality of the focal species groups; and (4) <em>M</em><sub><em>natural</em></sub>, the additional natural mortality of the focal species groups. Results with the Morris method suggested that the community in the Cooperation Sea was most sensitive to changes in the <em>M</em><sub><em>larval</em></sub> parameter of mesopelagic fishes. The biomasses of large-size, long-lived species such as toothfishes, Adélie penguin (<em>Pygoscelis adeliae</em>), seals, and whales were most sensitive to the parameters specific to these species groups. By contrast, the biomasses of small-sized, short-lived species such as mesopelagic fishes and krill species were most sensitive to changes in the parameters specific to the predators of these species groups. Monte Carlo simulations indicated that community dynamics were more sensitive to the <em>M</em><sub><em>larval</em></sub> and <em>M</em><sub><em>natural</em></sub> parameters than to the <em>Plank.access</em> and <em>Bio</em><sub><em>flux</em></sub> parameters. After gradually increasing the <em>M</em><sub><em>larval</em></sub> or <em>M</em><sub><em>natural</em></sub> parameter, the biomasses of Adélie penguin, seals and whales decreased, while the biomasses of mesopelagic fishes and Antarctic krill increased. By providing a comprehensive analysis of uncertainty in the parameters estimated during the calibration process, the present study represents an important step towards an operational ecosystem model for supporting ecosystem-based management in the Cooperation Sea. The present study will serve as a valuable basis for similar ecosystem modelling efforts in the Southern Ocean.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107345"},"PeriodicalIF":2.2,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777093","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 : 2025-04-04DOI: 10.1016/j.fishres.2025.107359
Élida Jeronimo Gouveia , Diego Corrêa Alves , Miguel Petrere Jr. , Angelo Antonio Agostinho
The introduction of species has negative effects on biodiversity and ecosystem functioning, with these impacts typically mediated by interspecific relationships. This study aimed to assess intraspecific and interspecific interactions, the effect of flood duration on the abundance of the congeners Megaleporinus piavussu (native) and M. macrocephalus (non-native), as well as variations in life-history traits across temporal scale for native species (pre- and post-invasion) and spatial scale for the non-native species (original and invaded environment). We tested the interaction effects between both species in population dynamics models. In contrast, life-history traits estimates for both species were obtained using length-frequency. The significant intraspecific competition coefficient suggests a negative impact on the annual per capita growth rate of both species. Only the native species population exhibited a significant interspecific competition coefficient. Flood duration positively affected the growth rate of both species, with more pronounced effects on the population of M. piavussu. During coexistence periods of the species (post-invasion period and invaded environments), a higher mean condition factor, female dominance, asymptotic length, longevity, and total mortality, including fishing mortality, were registered. On the other hand, the pre-invasion period for M. piavussu and the original environment for M. macrocephalus showed numerically lower values for life-history traits. Our findings suggest that the impact of the interspecific competition coefficient may be more pronounced for native species than for non-native species. Furthermore, the life history attributes of these species varied between the evaluated periods and locations in response to environmental conditions and food resource availability.
{"title":"Interactions and spatiotemporal variations in the life history attributes of a non-native species in the upper Paraná River and its native congener","authors":"Élida Jeronimo Gouveia , Diego Corrêa Alves , Miguel Petrere Jr. , Angelo Antonio Agostinho","doi":"10.1016/j.fishres.2025.107359","DOIUrl":"10.1016/j.fishres.2025.107359","url":null,"abstract":"<div><div>The introduction of species has negative effects on biodiversity and ecosystem functioning, with these impacts typically mediated by interspecific relationships. This study aimed to assess intraspecific and interspecific interactions, the effect of flood duration on the abundance of the congeners <em>Megaleporinus piavussu</em> (native) and <em>M. macrocephalus</em> (non-native), as well as variations in life-history traits across temporal scale for native species (pre- and post-invasion) and spatial scale for the non-native species (original and invaded environment). We tested the interaction effects between both species in population dynamics models. In contrast, life-history traits estimates for both species were obtained using length-frequency. The significant intraspecific competition coefficient suggests a negative impact on the annual per capita growth rate of both species. Only the native species population exhibited a significant interspecific competition coefficient. Flood duration positively affected the growth rate of both species, with more pronounced effects on the population of <em>M. piavussu</em>. During coexistence periods of the species (post-invasion period and invaded environments), a higher mean condition factor, female dominance, asymptotic length, longevity, and total mortality, including fishing mortality, were registered. On the other hand, the pre-invasion period for <em>M. piavussu</em> and the original environment for <em>M. macrocephalus</em> showed numerically lower values for life-history traits. Our findings suggest that the impact of the interspecific competition coefficient may be more pronounced for native species than for non-native species. Furthermore, the life history attributes of these species varied between the evaluated periods and locations in response to environmental conditions and food resource availability.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107359"},"PeriodicalIF":2.2,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768253","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 : 2025-04-02DOI: 10.1016/j.fishres.2025.107352
Faye R.V. Brinkman , Szymon Smoliński , Heino O. Fock , Mohammad Hadi Bordbar , Anja Kreiner , Moses S. Kalola , Margit R. Wilhelm
The sardine (Sardinops sagax) population in northern Benguela, Namibia, supported high catches in the 1950s-1960s and collapsed by the late 1960s. Despite a fishing moratorium since 2018, the population has shown no signs of recovery by 2023. In this study, a 48-year (1974–2021) biochronology was developed using archived sardine otoliths. Otolith increment widths, used as a proxy for annual fish growth, were analysed using linear mixed effects models to explore intrinsic (within individual) and extrinsic (sardine biomass, sea surface temperature and upwelling) factors contributing to annual variations in fish growth. The absence of otolith data from before the population collapse in the late 1960s meant that the analysis of predicted annual sardine otolith growth post-collapse showed short-term fluctuations but no significant long-term growth rate changes. Predicted annual sardine growth was significantly negatively linked with SST in Austral spring, and positively linked with upwelling in summer for the area 17–20 ºS (northern Namibia). The results suggest environmental conditions play a dominant role in driving sardine growth, exacerbated by the extremely low sardine biomass, which may be indicative of depensation. The study provides insight on the reasons behind the lack of recovery in sardine biomass. Therefore, otolith biochronologies provides a broader understanding of how small pelagic fish stocks respond to environmental changes.
{"title":"Post-collapse somatic growth and population recovery failure of sardine (Sardinops sagax) in the northern Benguela from otolith biochronologies","authors":"Faye R.V. Brinkman , Szymon Smoliński , Heino O. Fock , Mohammad Hadi Bordbar , Anja Kreiner , Moses S. Kalola , Margit R. Wilhelm","doi":"10.1016/j.fishres.2025.107352","DOIUrl":"10.1016/j.fishres.2025.107352","url":null,"abstract":"<div><div>The sardine (<em>Sardinops sagax)</em> population in northern Benguela, Namibia, supported high catches in the 1950s-1960s and collapsed by the late 1960s. Despite a fishing moratorium since 2018, the population has shown no signs of recovery by 2023. In this study, a 48-year (1974–2021) biochronology was developed using archived sardine otoliths. Otolith increment widths, used as a proxy for annual fish growth, were analysed using linear mixed effects models to explore intrinsic (within individual) and extrinsic (sardine biomass, sea surface temperature and upwelling) factors contributing to annual variations in fish growth. The absence of otolith data from before the population collapse in the late 1960s meant that the analysis of predicted annual sardine otolith growth post-collapse showed short-term fluctuations but no significant long-term growth rate changes. Predicted annual sardine growth was significantly negatively linked with SST in Austral spring, and positively linked with upwelling in summer for the area 17–20 ºS (northern Namibia). The results suggest environmental conditions play a dominant role in driving sardine growth, exacerbated by the extremely low sardine biomass, which may be indicative of depensation. The study provides insight on the reasons behind the lack of recovery in sardine biomass. Therefore, otolith biochronologies provides a broader understanding of how small pelagic fish stocks respond to environmental changes.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107352"},"PeriodicalIF":2.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747645","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 : 2025-04-02DOI: 10.1016/j.fishres.2025.107354
Nick Caputi , Simon de Lestang , Rick Fletcher , Michael Fogarty , Gretta Pecl , Jason How
While the need for ecosystem-based fisheries management (EBFM) has been long recognised, the escalating demands and serious threats that climate change poses to our marine ecosystems and the industries and human societies that depend on them, have increased the urgency for its adoption. Given this importance, EBFM was the overarching theme of the 5-day International Lobster and Crab conference held during October 2023 in Western Australia which included a special EBFM workshop that examined the following five concepts: species sustainability, ecosystem sustainability, economic outcomes, social amenity and social impacts. The workshop presentations covered the breadth of EBFM issues including the ecosystem effects of fishing, social, economic, environmental impacts and climate change, bycatch, governance issues in addition to the management of targeted lobster and crab stocks. The major outcomes and conclusions for fisheries management policy identified during the workshop included: (a) the need to take a ‘whole-of-resource’ approach rather than focusing on the effect of a particular fishery; (b) explicit recognition of socio-economic objectives in harvest strategies; (c) incorporating climate change within fisheries management systems; (d) assessment of stationarity assumptions in biological parameters; (e) recognising that regime shifts can result in major shifts in abundance and distribution of stocks; (f) importance of proper governance and compliance in fisheries management; (g) minimising fisheries interactions with protected species; (h) importance of long-term fishery-independent surveys for target species and ecosystem issues; (i) recovery of lost fishing gear; (j) recognition of spatial processes in the management of fisheries and the formation of marine protected areas; (k) importance of considering traditional knowledge alongside western science in fisheries assessment and management; and (l) acknowledging the need for ecosystem-based management which also takes into account the non-fisheries sectors competing for the same spatial area of the resource.
{"title":"Overview of the Ecosystem-Based Fisheries Management (EBFM) workshop at the International Conference on lobster and crab fisheries in 2023","authors":"Nick Caputi , Simon de Lestang , Rick Fletcher , Michael Fogarty , Gretta Pecl , Jason How","doi":"10.1016/j.fishres.2025.107354","DOIUrl":"10.1016/j.fishres.2025.107354","url":null,"abstract":"<div><div>While the need for ecosystem-based fisheries management (EBFM) has been long recognised, the escalating demands and serious threats that climate change poses to our marine ecosystems and the industries and human societies that depend on them, have increased the urgency for its adoption. Given this importance, EBFM was the overarching theme of the 5-day International Lobster and Crab conference held during October 2023 in Western Australia which included a special EBFM workshop that examined the following five concepts: species sustainability, ecosystem sustainability, economic outcomes, social amenity and social impacts. The workshop presentations covered the breadth of EBFM issues including the ecosystem effects of fishing, social, economic, environmental impacts and climate change, bycatch, governance issues in addition to the management of targeted lobster and crab stocks. The major outcomes and conclusions for fisheries management policy identified during the workshop included: (a) the need to take a ‘whole-of-resource’ approach rather than focusing on the effect of a particular fishery; (b) explicit recognition of socio-economic objectives in harvest strategies; (c) incorporating climate change within fisheries management systems; (d) assessment of stationarity assumptions in biological parameters; (e) recognising that regime shifts can result in major shifts in abundance and distribution of stocks; (f) importance of proper governance and compliance in fisheries management; (g) minimising fisheries interactions with protected species; (h) importance of long-term fishery-independent surveys for target species and ecosystem issues; (i) recovery of lost fishing gear; (j) recognition of spatial processes in the management of fisheries and the formation of marine protected areas; (k) importance of considering traditional knowledge alongside western science in fisheries assessment and management; and (l) acknowledging the need for ecosystem-based management which also takes into account the non-fisheries sectors competing for the same spatial area of the resource.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107354"},"PeriodicalIF":2.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747656","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 : 2025-04-01DOI: 10.1016/j.fishres.2025.107351
Jun Ren , Jia Wo , Qun Liu , Yupeng Ji , Binduo Xu , Ying Xue , Chongliang Zhang
Mixed fisheries contribute to a substantial proportion of global landings and pose great challenges to fisheries management. In order to construct the management scheme for multiple species simultaneously, the species co-occurrence needs to be explicitly delineated in mixed fisheries. However, the task is hindered by the lack of survey coverage and the constraints of common species distribution models in ignoring biotic interactions. In the present study, we investigated the spatio-temporal distribution patterns of mixed fisheries over large spatial and temporal scales, by implementing the Vector Autoregressive Spatio-Temporal model (VAST) on the basis of fishery-dependent data collected from fishing logs. The fishery-dependent surveys were conducted among the commercial fishing vessels operating in the Yellow and Bohai Seas from 2012 to 2022. We used the VAST to handle the problem of unbalanced sampling, inflated zeros and interspecific interactions, and divided the species into species complexes with clustering analyses according to their correlation in the spatial or spatio-temporal distributions. Our results indicated that the studied species in mixed fisheries could be divided into three species complexes, and the composition within each group depended on consideration of spatial or spatio-temporal correlations. We demonstrated significant differences in the spatial distribution and aggregation areas among the species complexes, and substantial seasonal variations in occurrence of spatio-temporal complexes, which should be informative for the assignment of management unit within the mixed fisheries. Our study demonstrated the approach to assessing the species co-occurrence of mixed fisheries using fishery-dependent data, which offers the opportunity for guiding the future management of mixed fisheries.
{"title":"Identifying the spatio-temporal distribution patterns of mixed fisheries to inform multispecies management in the Yellow and Bohai Seas","authors":"Jun Ren , Jia Wo , Qun Liu , Yupeng Ji , Binduo Xu , Ying Xue , Chongliang Zhang","doi":"10.1016/j.fishres.2025.107351","DOIUrl":"10.1016/j.fishres.2025.107351","url":null,"abstract":"<div><div>Mixed fisheries contribute to a substantial proportion of global landings and pose great challenges to fisheries management. In order to construct the management scheme for multiple species simultaneously, the species co-occurrence needs to be explicitly delineated in mixed fisheries. However, the task is hindered by the lack of survey coverage and the constraints of common species distribution models in ignoring biotic interactions. In the present study, we investigated the spatio-temporal distribution patterns of mixed fisheries over large spatial and temporal scales, by implementing the Vector Autoregressive Spatio-Temporal model (VAST) on the basis of fishery-dependent data collected from fishing logs. The fishery-dependent surveys were conducted among the commercial fishing vessels operating in the Yellow and Bohai Seas from 2012 to 2022. We used the VAST to handle the problem of unbalanced sampling, inflated zeros and interspecific interactions, and divided the species into species complexes with clustering analyses according to their correlation in the spatial or spatio-temporal distributions. Our results indicated that the studied species in mixed fisheries could be divided into three species complexes, and the composition within each group depended on consideration of spatial or spatio-temporal correlations. We demonstrated significant differences in the spatial distribution and aggregation areas among the species complexes, and substantial seasonal variations in occurrence of spatio-temporal complexes, which should be informative for the assignment of management unit within the mixed fisheries. Our study demonstrated the approach to assessing the species co-occurrence of mixed fisheries using fishery-dependent data, which offers the opportunity for guiding the future management of mixed fisheries.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107351"},"PeriodicalIF":2.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747640","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 : 2025-04-01DOI: 10.1016/j.fishres.2025.107358
Eloy Martínez , Nuria Fernández , Diana Fernández-Márquez , Lucía Couceiro , Daniel Escobar-Ortega , Pablo Pita
In Galicia (NW Spain) commercial polychaete fisheries have increased their importance compared to other traditional fisheries in recent years, both in terms of catches and economic benefits. We performed a systematic review of scientific literature to analyze the main attributes and the impacts of polychaete fisheries. Official landings statistics in Galicia showed that Scoletoma laurentiana, Diopatra neapolitana, Arenicola marina, and Hediste diversicolor are the species that are sold as bait for recreational fisheries. By an online survey of recreational fishers, we found that 17 % of them collect their own polychaetes, while the majority also buy them with very different frequencies. We estimated that recreational harvest is roughly eight times higher than commercial harvest for some species. Interviews with various stakeholders, including scientists, managers, commercial harvesters, recreational fishers, and sellers, revealed both positive and negative aspects of polychaete fisheries. Challenges include the lack of biological and ecological studies on exploited species and the necessity for reliable stock assessment methods, including the need for weight conversion factors for key species. Additionally, more information on the local and imported polychaete value chains is crucial. Addressing these issues will contribute to the development of more sustainable polychaete harvesting, benefiting both the environment and local and global economies.
{"title":"Polychaete bait fisheries in Galicia (NW Spain)","authors":"Eloy Martínez , Nuria Fernández , Diana Fernández-Márquez , Lucía Couceiro , Daniel Escobar-Ortega , Pablo Pita","doi":"10.1016/j.fishres.2025.107358","DOIUrl":"10.1016/j.fishres.2025.107358","url":null,"abstract":"<div><div>In Galicia (NW Spain) commercial polychaete fisheries have increased their importance compared to other traditional fisheries in recent years, both in terms of catches and economic benefits. We performed a systematic review of scientific literature to analyze the main attributes and the impacts of polychaete fisheries. Official landings statistics in Galicia showed that <em>Scoletoma laurentiana</em>, <em>Diopatra neapolitana</em>, <em>Arenicola marina</em>, and <em>Hediste diversicolor</em> are the species that are sold as bait for recreational fisheries. By an online survey of recreational fishers, we found that 17 % of them collect their own polychaetes, while the majority also buy them with very different frequencies. We estimated that recreational harvest is roughly eight times higher than commercial harvest for some species. Interviews with various stakeholders, including scientists, managers, commercial harvesters, recreational fishers, and sellers, revealed both positive and negative aspects of polychaete fisheries. Challenges include the lack of biological and ecological studies on exploited species and the necessity for reliable stock assessment methods, including the need for weight conversion factors for key species. Additionally, more information on the local and imported polychaete value chains is crucial. Addressing these issues will contribute to the development of more sustainable polychaete harvesting, benefiting both the environment and local and global economies.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"285 ","pages":"Article 107358"},"PeriodicalIF":2.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747634","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号