Fisheries Research最新文献

{"title":"Adding splines to the SAM model improves stock assessment","authors":"Silius M. Vandeskog ,&nbsp;Magne Aldrin ,&nbsp;Daniel Howell ,&nbsp;Edvin Fuglebakk","doi":"10.1016/j.fishres.2025.107461","DOIUrl":"10.1016/j.fishres.2025.107461","url":null,"abstract":"<div><div>The stock assessment model SAM contains multiple age-dependent parameters that must be manually grouped together to obtain robust inference. This can make the model selection process slow, non-extensive and highly subjective, while producing unrealistic parameter estimates with discrete jumps. We propose to model age-dependent SAM parameters using spline functions, which can produce smoother parameter estimates, while making the model selection process faster, more automatic and less subjective. We develop a SAM spline model and compare it, using simulation studies and cross- and forward-validation methods, with published SAM models for 17 different fish stocks. The results show that our automated spline models overall outcompete the final accepted SAM models from <span>stockassessment.org</span>. We also demonstrate how our proposed spline model can be employed as a diagnostics tool for improving and better understanding properties of other SAM models.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107461"},"PeriodicalIF":2.2,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703003","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":"Marine fishing fleet in the Soviet Union: A review of its structure and dynamics","authors":"Alexander G. Dvoretsky,&nbsp;Vladimir G. Dvoretsky","doi":"10.1016/j.fishres.2025.107455","DOIUrl":"10.1016/j.fishres.2025.107455","url":null,"abstract":"<div><div>The Soviet Union was a prominent player in the marine living resource sector for a long time, owing to its powerful fishing fleet. In this paper, we summarized information on the fleet structure and analyzed its long-term dynamics during the postwar period (1946–1991). In terms of vessel type and project diversity, trawlers were the leading category, followed by transport vessels (carriers and reefers), processing vessels, and seiners. These categories also represented the largest share of the total fleet in terms of their relative contributions. The fleet modernization resulted in vessel types with greater length, speed, engine power, and processing capabilities. The number of vessels (NV) and total gross tonnage (TGT) increased in all categories except for whalers and sealers. The most pronounced increase in NV and TGT occurred from the mid-1950s to the mid-1970s. Medium-sized trawlers were the dominant category in terms of NV until 1978, while large-sized trawlers were the most common from 1979 to 1991. The observed positive changes in fleet structure reflected broader trends, including the modernization of the fishing sector, the reallocation of fishing efforts to high seas, and the impact of marine organism stock fluctuations. These changes aligned closely with global patterns in the industry. However, negative trends began to manifest in the 1980s, linked to inadequate management practices and challenges in advancing fleet modernization. Our study introduces novel insights for comparative analyses and retrospective studies on stock fluctuations in relation to fleet dynamics.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107455"},"PeriodicalIF":2.2,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144687313","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":"Effects of light emitting diodes on the escape of mulloway, Argyrosomus japonicus and other species from bycatch reduction devices in southeastern Australian penaeid trawls","authors":"Matt K. Broadhurst","doi":"10.1016/j.fishres.2025.107479","DOIUrl":"10.1016/j.fishres.2025.107479","url":null,"abstract":"<div><div>Bycatch reduction devices (BRDs) have been mandated in most Australian penaeid-trawl fisheries, including those in New South Wales (NSW), where several options are available for fishers to exclude unwanted catches based primarily on size (‘mechanical-separating BRDs’) or behaviour (‘behavioural-separating BRDs’). In NSW diurnal estuarine-trawl fisheries (targeting school prawns, <em>Metapenaeus macleayi</em>) combinations of mechanical- and behavioural-separating BRDs can exclude most bycatch, but at certain times and locations there remain priority species of concern, including mulloway, <em>Argryosomous japonicus</em>. Here, the utility of adding green or blue light emitting diodes (LEDs) to the escape exits of a mechanical- (‘Nordmøre-grid’) and a behavioural-separating BRD (‘fisheye’) was investigated for improving species or size selection. Six green or blue LEDs had no effects on mulloway escaping from Nordmøre-grids, but four green LEDs precluded all from escaping through a fisheye. Other species significantly affected by LEDs included narrowbanded sole, <em>Synclidopus macleayanus</em> and largetooth flounder, <em>Pseudorhombus arsius</em> with greater catches of both (across all sizes) in green-illuminated Nordmøre-grids. However, catches of narrowbanded sole were not affected by green-illuminated fisheyes. Mean catches of the targeted school prawns were also consistently greater with illuminated BRDs, although the differences were not significant. While adding green LEDs to the escape exits of both BRDs will not benefit the exclusion of mulloway, future research warrants testing reduced bar spaces in the Nordmøre-grids to mechanically exclude more fish, but with green LEDs to potentially maintain catches of school prawns.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107479"},"PeriodicalIF":2.2,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679138","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":"Response to: Reassessing the drivers of capelin recruitment in Newfoundland since 1991.","authors":"Hannah M. Murphy ,&nbsp;Pierre Pepin ,&nbsp;Dominique Robert","doi":"10.1016/j.fishres.2025.107477","DOIUrl":"10.1016/j.fishres.2025.107477","url":null,"abstract":"<div><div>This Letter to the Editor is in response to Frank and Leggett (2025) where they pointed to discrepancies between how the maximum interval of onshore wind events was calculated in Murphy et al. (2018) and their own work, as well as an error in the <em>Pseudocalanus</em> spp. CVI index in 2012, which was used in a capelin recruitment model in Murphy et al. (2018). We acknowledge our error in how we calculated the maximum onshore wind intervals for the 10-d period post-hatch for the years 1991 – 2013. We conducted a reanalysis of these data for the years 1991 – 2013 and found similar results as Murphy et al. (2018): there was no relationship between the age-2 capelin recruitment index and the maximum onshore wind interval 10-d post hatch (linear regression: adjusted R² = 0.009, <em>p</em> = 0.3). The error in the <em>Pseudocalanus</em> spp. dataset was present before it reached the authors. The error was corrected in 2019. Using the correct value for mean <em>Pseudocalanus</em> spp. CVI density from June 1 to October 1 for 2012, <em>Pseudocalanus</em> spp. densities no longer predicted age-2 recruitment for the years 1999 – 2013 (linear regression: adjusted R² = 0.13, <em>p</em> = 0.1). Ongoing research is investigating the drivers of capelin larval survival since the collapse of the stock in 1991.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107477"},"PeriodicalIF":2.2,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679137","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":"Assessment of fecundity, spawning grounds and spawning season in Cape monkfish Lophius vomerinus off Namibia","authors":"Victoria Ndinelago Erasmus ,&nbsp;Warren M. Potts ,&nbsp;Ian Meiklejohn ,&nbsp;Warwick H.H. Sauer ,&nbsp;Amber-Robyn Childs","doi":"10.1016/j.fishres.2025.107473","DOIUrl":"10.1016/j.fishres.2025.107473","url":null,"abstract":"<div><div>Cape monkfish, <em>Lophius vomerinus</em> Valenciennes 1837 is an ecologically and economically important species off Namibia. There are knowledge gaps in the reproductive biology of this species. This study aimed to investigate the fecundity, spawning season, location of spawning grounds and spawning materials for <em>L. vomerinus</em> off Namibia using 360 530 specimens ranging in size from 10 to 130 cm TL. Our results identified spawning hotspots between 22⁰ and 25⁰S in deeper water (&gt; 250 m) for the 2001–2019 time series. Ripe gonads capable of spawning (Stage IV) were dominant in July (23.8 %) and August (26.2 %), while ripe testes were prevalent in April (52.5 %) and November (28.5 %). The discovery of the egg veil for the first time in this study is significant because this result provides important spawning information of this species, which was never recorded for <em>L. vomerinus</em> in its Namibian distribution. The location where the egg veil was discovered, off Swakopmund (22⁰30'S, 13⁰25'E), provides further evidence of the identified spawning hotspot areas, an area also identified as a monkfish consecutive hotspot fishing ground.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107473"},"PeriodicalIF":2.2,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656503","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":"Why is the Arabian Sea a hotspot for myctophids?","authors":"Eva García-Seoane ,&nbsp;Harald Gjøsæter ,&nbsp;Padmini Dalpadado ,&nbsp;Stein Kaartvedt","doi":"10.1016/j.fishres.2025.107453","DOIUrl":"10.1016/j.fishres.2025.107453","url":null,"abstract":"<div><div>Myctophids are the dominant mesopelagic fishes in most of the world’s oceans. They play a key ecological role and also have a potential for harvest. We here synthesize general traits of myctophid biology and address the success and life history strategy of the dominant myctophid species in the mesopelagic hotspot of the Arabian Sea. In this ocean, the biomass of myctophids is particularly high, but dominated by only a few species. With low abundance of competing small pelagic fish, much of the high production is channeled via zooplankton to the stocks of mesopelagic fishes. The ability of the successful species to tolerate low oxygen levels facilitates exploitation of these productive waters and reduces competition for prey. Simultaneously, the hypoxic waters provide refuge from predators. The myctophids in the Arabian Sea feed in warm waters at night and inhabit cooler, yet relatively warm waters during daytime. We hypothesize that this temperature regime combined with a high abundance of prey provides a favorable combination of foraging and digestion. To this adds that the location near the Equator provides a year-long favorable regular shift between length of day and night for foraging in upper waters and digestion in deep waters, though digestion may be constrained by low oxygen concentrations. Myctophid species from tropical habitats have shorter life spans than species from colder regions. We suggest that in tropical habitats, such as the Arabian Sea, extended spawning seasons are common for myctophids whereas restricted spawning seasons are more common in cold-water habitats. The Gulf of Oman, which is the upwelling region with the highest primary production in Indian Ocean, is recognized to have the greatest potential for any commercial exploitation of mesopelagic fish.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107453"},"PeriodicalIF":2.2,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656502","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":"Reproductive shift of the common octopus Octopus vulgaris Cuvier, 1797 increases vulnerability to recruitment overexploitation in the Western Mediterranean Sea","authors":"A. Suay ,&nbsp;J. Tena-Medialdea ,&nbsp;L. Silva ,&nbsp;M. Duque ,&nbsp;J.R. García-March","doi":"10.1016/j.fishres.2025.107472","DOIUrl":"10.1016/j.fishres.2025.107472","url":null,"abstract":"<div><div>The common octopus <em>Octopus vulgaris</em> Cuvier, 1797 is the most important commercial cephalopod in the Western Mediterranean. Due to its semelparous life cycle, the annual population reflects the recruitment success of the previous year. Reproductive shifts may result from the high dependence on environmental factors and fishery-induced demographic changes, as temperature controls the length of the first stages of the life cycle and fishing pressure selects certain segments of the population. Therefore, fishing closures must be adapted to match the reproductive peak to protect spawning individuals. Our study reports a reproductive shift and identifies key periods for optimising fishing closures in the Gulf of Valencia by following the reproductive parameters of 1596 individuals from September 2022 to August 2024. Weight-at-maturity was 778.78 ± 46.10 g for males and 1381.13 ± 125.61 g for females (BW_50 % ± SE). Seasonal variability was observed in the maturity of both sexes, sex ratio and monthly CPUE. Mature males dominated landings from December to August, while the female reproductive peak occurred from June to August. These results confirm a reproductive shift, as previous studies in the area indicated a peak from May to July. Given that the current closures do not align with the key reproductive periods, we propose a unified closure during the female spawning period to prevent recruitment overfishing. This study updates the knowledge on the reproductive cycle and provides robust biological evidence essential to readapt the management of the species in support of a sustainable exploitation of the stock.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107472"},"PeriodicalIF":2.2,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144631379","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":"Interpretability and identification of dimorphism in morphological indexes of Larimichthys crocea based on machine learning models","authors":"Liguo Ou ,&nbsp;Linlin Lu ,&nbsp;Weiguo Qian ,&nbsp;Bilin Liu","doi":"10.1016/j.fishres.2025.107475","DOIUrl":"10.1016/j.fishres.2025.107475","url":null,"abstract":"<div><div>The morphological indexes serve as a critical biological foundation for analyzing species dimorphism, play a pivotal role in population dynamics models and species assessments, and provide valuable, accurate, and cost-efficient biological information. Dimorphism identification holds significant importance for the conservation and sustainable development of <em>Larimichthys crocea</em> resources. Therefore, this study aims to validate the dimorphism effects of various morphological indexes using interpretable machine learning techniques and evaluate model performance and deviation in automatic identification. First, data visualization, significance analysis, correlation analysis, and principal component analysis (PCA) were applied to otolith morphology (OM) indexes and fish body morphology (FM) indexes. Then, the SHAP (SHapley Additive exPlanations) method of machine learning was used to analyze the importance of different morphological indexes and output the morphological indexes of importance. Finally, different machine learning models were used to analyze the identification performance and deviation of <em>Larimichthys crocea</em> dimorphism. The experimental results demonstrate that the SHAP method effectively prioritizes the importance of different morphological indexes, with the importance of OM indexes primarily concentrated in the sulcus. Within the machine learning models, OM indexes achieved a peak identification rate of 71 % (Random Forest), whereas FM indexes reached a maximum identification rate of 65 % (Random Forest and Support Vector Machine). The comparative analysis of the average effects of different models, including evaluation metrics and learning curves, demonstrates that OM indexes outperform FM indexes in terms of identification performance. The application of machine learning models not only enables a comprehensive analysis of the dimorphism in <em>Larimichthys crocea</em> but also offers effective strategies for the conservation of <em>Larimichthys crocea</em> resources and their associated biodiversity.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107475"},"PeriodicalIF":2.2,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144631378","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":"From semi-controlled environment to field trials: Testing pot entrance designs for Atlantic cod (Gadus morhua)","authors":"Sara A. Berzosa ,&nbsp;Thomas Noack ,&nbsp;Juan Santos ,&nbsp;Uwe Lichtenstein ,&nbsp;Andrea M. Milanelli ,&nbsp;Lotte Kindt-Larsen ,&nbsp;Peter Ljungberg ,&nbsp;Flemming Dahlke ,&nbsp;Daniel Stepputtis","doi":"10.1016/j.fishres.2025.107470","DOIUrl":"10.1016/j.fishres.2025.107470","url":null,"abstract":"<div><div>Gillnet fishing is associated with challenges, including bycatch of endangered, threatened, and protected (ETP) species and conflicts with marine mammals. Fish pots represent a sustainable alternative to gillnets due to their low bycatch risk of ETP species; furthermore, they can be designed to minimize seal predation. However, improvements in catch efficiency are necessary to enable their commercial implementation. Among the key factors influencing pot catch efficiency, the design of the pot entrance plays a crucial role. Therefore, optimizing the entrance is essential to improve catches. This study evaluated the catch efficiency of different experimental pot entrance designs under commercial fishing conditions (e.g., commercial fishing vessel and fishing grounds), building on findings from previous experiments in semi-controlled environments. We investigated the effects of entrance design parameters, including funnel netting colour, funnel length, and acrylic fingers as fish retention device on the catch rates of Atlantic cod (<em>Gadus morhua</em>). The colour of the funnel netting (transparent vs. white) had no significant effect on catch efficiency. In contrast, increased funnel length and the addition of acrylic fingers at the entrance significantly improved catch rates. Catch performance was also compared with a pot design used by a commercial fisher, which yielded higher catch rates than all experimental variants, indicating that design features beyond entrance configuration contribute to overall efficiency. These findings demonstrate the value of integrating semi-controlled experiments with field trials and the need for further design optimizations to support the development of more effective and sustainable fishing gear.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107470"},"PeriodicalIF":2.2,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144631376","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":"Jesstimation: A novel approach for estimating more accurate fish ages from otolith zone counts and measurements","authors":"Jessica H. Farley ,&nbsp;J. Paige Eveson ,&nbsp;Kyne Krusic-Golub ,&nbsp;Naomi P. Clear ,&nbsp;Caroline Sanchez ,&nbsp;Simon J. Nicol","doi":"10.1016/j.fishres.2025.107463","DOIUrl":"10.1016/j.fishres.2025.107463","url":null,"abstract":"<div><div>Accurate estimates of age and growth are essential for conducting age-structured stock assessments and for developing effective management and conservation strategies. One of the most common methods for estimating fish age is by counting growth increments that have been deposited either daily or annually in otoliths. However, counts of daily increments become unreliable as fish grow older (typically beyond one year), and annual counts only provide integer age estimates (in years). For many research questions, a more precise fractional age is desirable. In theory, this can be calculated from the annual increment count if the fish’s birthday and the time of year when its annual increments were formed are known. However, in practice, individual birthdays are unknown and vary widely in species with protracted spawning seasons. Moreover, if the timing of the annual increment formation is protracted or variable, it becomes difficult to determine whether the most recent growth increment was deposited before or after the fish’s most recent birthday. To address these challenges, we present a novel method for converting annual increment counts into fractional ages using daily counts of young-of-the-year (YOY) fish and otolith measurements. Our approach does not require knowing the birthday of a fish or the precise timing of increment formation and provides a more accurate conversion of zone counts to age estimates - particularly for species with variable spawning periods. We demonstrate the method for western Pacific bigeye tuna (<em>Thunnus obesus</em>), a species that can spawn throughout the year in tropical waters and forms annuli in its otoliths over a six-month period.</div></div>","PeriodicalId":50443,"journal":{"name":"Fisheries Research","volume":"288 ","pages":"Article 107463"},"PeriodicalIF":2.2,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606014","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}