Fisheries Oceanography最新文献

Winter Diets of Pacific Salmon in the North Pacific 北太平洋太平洋鲑鱼的冬季饮食

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-06-26 DOI: 10.1111/fog.70002

Jackie King, Emily Fergusson, Aleskey Somov, Todd Miller, Evgeny A. Pakhomov, Matthew R. Baker, Kelsey Flynn

{"title":"Winter Diets of Pacific Salmon in the North Pacific","authors":"Jackie King, Emily Fergusson, Aleskey Somov, Todd Miller, Evgeny A. Pakhomov, Matthew R. Baker, Kelsey Flynn","doi":"10.1111/fog.70002","DOIUrl":"https://doi.org/10.1111/fog.70002","url":null,"abstract":"The winter feeding ecology of Pacific salmon and Steelhead trout in the North Pacific Ocean was investigated, with a focus on species-specific diets and interannual and spatial variability in diet composition. We used results from the 2022 International Year of the Salmon Pan-Pacific Expedition to examine diet composition across the North Pacific and compared our findings with earlier surveys conducted in 2009–2011 and 2019–2020. Stomach contents were dominated by prey items typically associated with that species' diet: primarily cnidarians for Chum salmon, cephalopods and fish for Coho and Chinook salmon, and euphausiids for Pink and Sockeye salmon. The diet of Steelhead trout, encountered in one region in 2022, was composed of cephalopods, fish, and euphausiids. Some significant interannual and regional variability was observed, particularly in the eastern North Pacific, where prey resources have been noted to be more limited. This suggests that prey partitioning and adaptability may influence interspecific competition. Chum and Sockeye salmon exhibited interannual variability in most regions where multiple years of surveys were conducted. Pink salmon had the most spatial variability in winter diet with differences detected in all regions. We found minimal evidence of diet shifts based on size, with some exceptions in Chum and Sockeye salmon. Overall, these findings contribute to a deeper understanding of the trophic dynamics and feeding strategies of Pacific salmon during the winter months in the open ocean, highlighting the potential for competition and the importance of fine-scale spatial analyses for future research on salmon ecology and conservation.","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"118-138"},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fog.70002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228005","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}

引用次数: 0

Oceanographic Condition of the Habitat and Distribution of Atlantic Chub Mackerel Scomber colias (Actinopteri: Scombridae) in Southwestern Atlantic 西南大西洋鲭鱼（放线纲：鲭鱼科）生境和分布的海洋学条件

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-06-18 DOI: 10.1111/fog.70001

Joana Leal da Silva, José Ricardo Munari Faccin, Paulo Ricardo Schwingel

{"title":"Oceanographic Condition of the Habitat and Distribution of Atlantic Chub Mackerel Scomber colias (Actinopteri: Scombridae) in Southwestern Atlantic","authors":"Joana Leal da Silva, José Ricardo Munari Faccin, Paulo Ricardo Schwingel","doi":"10.1111/fog.70001","DOIUrl":"https://doi.org/10.1111/fog.70001","url":null,"abstract":"The Atlantic chub mackerel, Scomber colias Gmelin, 1789, is a pelagic species, found in schools throughout the Atlantic Ocean. The objective of the present study is to identify the relationship between oceanographic conditions and catches of the Atlantic chub mackerel fishing resource in the Southwest Atlantic Ocean (21°S–29°S). The generalized additive model (GAM) was used to determine the influence of oceanographic variables on the catch per unit effort (CPUE) of S. colias. Fishing for Atlantic chub mackerel by the purse seine fleet in the Southwest Atlantic is irregular and is related to resource availability. From 2007 onward, the fleet expanded its operating area, which may have increased the CPUE between 2008 and 2012. GAM model results showed that sea surface temperature (SST) had a nonlinear effect on CPUE, peaking between 24°C and 26°C. Chlorophyll-a also influenced CPUE; however, its effect was weaker, with higher CPUE values linked to lower chlorophyll-a concentrations. The Oceanic Niño Index (ONI) exhibited a nonlinear effect, with both El Niño and La Niña periods associated with lower CPUE than during neutral conditions.","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"107-117"},"PeriodicalIF":2.7,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fog.70001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228078","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}

引用次数: 0

Insights Into the Relationship of Climate Events With the Distribution of Black Skipjack (Euthynnus lineatus) Catches in the Eastern Pacific 气候事件与东太平洋黑鲣渔获分布关系的研究

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-06-13 DOI: 10.1111/fog.70000

Carlos Javier Godínez-Padilla

{"title":"Insights Into the Relationship of Climate Events With the Distribution of Black Skipjack (Euthynnus lineatus) Catches in the Eastern Pacific","authors":"Carlos Javier Godínez-Padilla","doi":"10.1111/fog.70000","DOIUrl":"https://doi.org/10.1111/fog.70000","url":null,"abstract":"<div>\u0000 \u0000 The geographic distributions of marine species have been constantly changing, and current evidence suggests that climate variability may have a significant influence. In addition, vital features in search of the best habitat are prone to being caught incidentally and objectively by various fisheries. A historical database (2005–2021) of the tuna purse-seine fishery in the Eastern Pacific Ocean (EPO) was used in this study. This study aims to describe the environmental preferences and spatiotemporal distribution of bycatch black skipjack in the EPO using generalized additive models (GAMs). The results show that black skipjacks (BKJ) are caught as bycatch in all three types of sets made by the purse seine fleet in oceanic and coastal waters. The BKJ was affected by climate events such as El Niño and La Niña, which influenced its catchability and the expansion of its distribution up to 150° W through its presence on floating objects and environmental adaptability. Habitat preferences were shown towards warm waters (26°C–30°C) and areas of low atmospheric pressure (1005–1014 hPa) associated with the different physical oceanographic processes in the spring–summer months. This information contributes to the study of the behavior, movement, and habitat use of the species for fisheries management in both coastal and oceanic waters.\u0000 </div>","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"89-106"},"PeriodicalIF":2.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228069","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}

引用次数: 0

Spatial Structure and Decadal Spatiotemporal Distribution of the Anchoveta (Engraulis ringens) in the Marine Ecosystem of the Peruvian Current Between 1985 and 2024 1985 - 2024年秘鲁海流海洋生态系统中鳀鱼的空间结构和年代际时空分布

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-06-12 DOI: 10.1111/fog.12741

Pedro Ramiro Castillo, Han Xu, Gustavo Cuadros, Daniel Grados, Carlos Valdez, Rodolfo Cornejo, Marissela Pozada-Herrera

{"title":"Spatial Structure and Decadal Spatiotemporal Distribution of the Anchoveta (Engraulis ringens) in the Marine Ecosystem of the Peruvian Current Between 1985 and 2024","authors":"Pedro Ramiro Castillo, Han Xu, Gustavo Cuadros, Daniel Grados, Carlos Valdez, Rodolfo Cornejo, Marissela Pozada-Herrera","doi":"10.1111/fog.12741","DOIUrl":"https://doi.org/10.1111/fog.12741","url":null,"abstract":"<div>\u0000 \u0000 This paper presents the spatial structure with geostatistical analysis and decadal spatiotemporal distribution of anchoveta according to the Pacific Decadal Oscillation index, its implications for the anomalous events of the oceanographic conditions of the Northern Region of the Humboldt Current System (NRHCS), and areas of high anchoveta abundance found in the analyzed period. The acoustic data came from the Hydroacoustic Pelagic Resources Assessment Surveys carried on by the Instituto del Mar del Peru (IMARPE), and the oceanographic data came from satellite images of sea surface thermal anomalies (SSTA) between 1985 and 2024. The results showed that anchoveta has had a positive linear trend, with a high positive spatial autocorrelation and a structure spatially dependent on invironmental conditions in space and time. In the cold decadal periods, anchoveta were found a little far from the coast, distributed in high concentrations mainly in the north-central region, while in the warm decadal periods, they were found close to the coast and with greater abundance towards the central zone; exceptional was in the warm period of 1985–1988, where anchoveta distribution was wide and generally dispersed. The trend in the warm decadal periods was negative, and in the decadal periods, it was positively influenced by El Niño events: 1997–1998 and 2015–2016, with a decrease in biomass recorded in 1998 and 2015. In the last cold period, 2017–2024, it was influenced by the warm year of 2023. Between 2000 and 2024, anchoveta biomass averaged 8.26 million tons, with an average biomass of 7.46 million tons for the north-central region between 2004 and 2024.\u0000 </div>","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"70-88"},"PeriodicalIF":2.7,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228025","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}

引用次数: 0

Short-Term Prediction of Hilsa (Tenualosa ilisha) Catch in the Northern Bay of Bengal Using Advanced Machine Learning Algorithms 利用先进的机器学习算法对孟加拉湾北部海鲢捕获量的短期预测

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-06-11 DOI: 10.1111/fog.12746

Sandip Giri, A. P. Joshi, Prasanna Kanti Ghoshal, Sudheer Joseph, Kunal Chakraborty, Alakes Samanta, T. M. Balakrishnan Nair, T. Srinivasa Kumar

{"title":"Short-Term Prediction of Hilsa (Tenualosa ilisha) Catch in the Northern Bay of Bengal Using Advanced Machine Learning Algorithms","authors":"Sandip Giri, A. P. Joshi, Prasanna Kanti Ghoshal, Sudheer Joseph, Kunal Chakraborty, Alakes Samanta, T. M. Balakrishnan Nair, T. Srinivasa Kumar","doi":"10.1111/fog.12746","DOIUrl":"https://doi.org/10.1111/fog.12746","url":null,"abstract":"<div>\u0000 \u0000 Hilsa is a vital transboundary fishery resource in the Bay of Bengal (BoB), holding commercial, ecological, and cultural importance. This study aims to develop a short-term prediction of Hilsa catch in the northern BoB using a machine learning (ML) model. The prediction technique was developed considering the georeferenced Hilsa catch per unit effort (CPUE) as a function of environmental variables like surface salinity, sea surface temperature (SST), surface current speed, and direction. We employed two advanced ML algorithms, viz., random forest (RF) and 5. (XGBoost) to examine their efficacy in the short-term prediction of Hilsa for the northern BoB and compared the model performance with a baseline information obtained through multiple linear regression (MLR). Our analysis showed significant improvement in the prediction accuracy using advanced ML techniques where XGBoost again outperformed RF. The root mean square error (RMSE) values between observed and predicted CPUE for RF and XGBoost models were 5.72 and 5.63 kg/h, respectively. The correlation coefficient (r) between the observed and predicted catch were 0.90 and 0.93 for RF and XGBoost, respectively. SHapley Additive exPlanations (SHAP) analysis revealed the highest influence (58.38%) of surface current speed on the Hilsa CPUE. We generated the spatial prediction maps of Hilsa CPUE using the best performing (XGBoost) model with 85% prediction efficiency. This study showed the potential of the XGBoost model in developing a short-term prediction for Hilsa in the northern BoB, towards developing Hilsa fishery advisory for sustainable management of these fishery resources.\u0000 </div>","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"54-69"},"PeriodicalIF":2.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228173","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}

引用次数: 0

Adaptive Reproductive Strategies of Limpets in a Harvest-Influenced Environment 收获影响下帽贝的适应性繁殖策略

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-06-04 DOI: 10.1111/fog.12745

Joana Vasconcelos, Pablo Angulo, Olivia Martínez-Ruiz, Alberto Rodríguez Díaz, Víctor M. Tuset, Rodrigo Riera

{"title":"Adaptive Reproductive Strategies of Limpets in a Harvest-Influenced Environment","authors":"Joana Vasconcelos, Pablo Angulo, Olivia Martínez-Ruiz, Alberto Rodríguez Díaz, Víctor M. Tuset, Rodrigo Riera","doi":"10.1111/fog.12745","DOIUrl":"https://doi.org/10.1111/fog.12745","url":null,"abstract":"Limpet harvesting is a size-selective activity that primarily removes the largest individuals, leading to reduced reproductive output. This study investigates the fecundity strategies of two limpet species, Patella aspera and Patella crenata, inhabiting the rocky shores of Gran Canaria. Between September 2023 and April 2024, a total of 288 P. aspera and 364 P. crenata specimens were sampled from four coastal settlements. Both species exhibited determinate fecundity with synchronous spawning, as evidenced by the progression of dominant oocyte cohorts and the corresponding changes in oocyte size and number throughout the spawning season. Orientation and substrate type significantly influenced fecundity, with the North coast showing a higher number of vitellogenic oocytes, particularly in artificial substrates for P. crenata. Natural substrates on the North coast were associated with larger vitellogenic oocytes. Additionally, sex proportions were significantly affected by substrate type, with natural substrates containing a higher proportion of females. In artificial substrates, P. crenata exhibited notably higher gonadosomatic index values. The analysis of the gonadosomatic index and oocyte dynamics highlights the adaptive strategies of these limpets to local environmental conditions, contributing to our understanding of reproductive ecology in intertidal habitats. This research not only enhances our understanding of reproductive dynamics in limpets under varying environmental conditions but also emphasizes the importance of habitat and seasonal factors in shaping fecundity strategies. Such studies are crucial for conservation efforts, as they provide essential insights into how environmental pressures and human activities, like harvesting, impact the reproductive success and sustainability of these commercial species.","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"37-53"},"PeriodicalIF":2.7,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fog.12745","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228146","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}

引用次数: 0

Evaluating the Impact of Oceanographic Field Variability on Atlantic Mackerel Distribution Within Russian Fishing Grounds in the Northern Norwegian Sea 评估海洋场变率对挪威海北部俄罗斯渔场内大西洋鲭鱼分布的影响

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-06-04 DOI: 10.1111/fog.12744

M. A. Lebedeva, M. V. Budyansky, M. Yu. Uleysky, P. A. Fayman, A. A. Didov, T. V. Belonenko, D. N. Klochkov

{"title":"Evaluating the Impact of Oceanographic Field Variability on Atlantic Mackerel Distribution Within Russian Fishing Grounds in the Northern Norwegian Sea","authors":"M. A. Lebedeva, M. V. Budyansky, M. Yu. Uleysky, P. A. Fayman, A. A. Didov, T. V. Belonenko, D. N. Klochkov","doi":"10.1111/fog.12744","DOIUrl":"https://doi.org/10.1111/fog.12744","url":null,"abstract":"<div>\u0000 \u0000 Based on fishing records from 2015, 2016, and 2020, this study analyzes the dependence of Atlantic mackerel catch distribution by the Russian fleet on oceanographic conditions in the northern part of the Norwegian Sea (north of 68.5° N). Four types of parameters characterizing fronts and frontal zones are considered: the Lagrangian indicator S, describing water dynamics, along with temperature, salinity, and density in the upper ocean layers, which are traditionally used to identify thermohaline fronts. Gradients of these characteristics are calculated based on these parameters, and the distance from fishing locations to the nearest fronts is evaluated. A unified methodology is applied to automatically define frontal zones using a probability distribution function. To eliminate the dependence of statistical analysis results on limited sampling, a comparison with a random sample was conducted. Histogram analysis of actual catches shows that fishing zones are often located 10–15 km from fronts. It was found that the density of the upper ocean layers has the greatest influence on the distribution of Atlantic mackerel fishing aggregations, while temperature fronts also significantly impact the formation of fishing aggregations.\u0000 </div>","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"27-36"},"PeriodicalIF":2.7,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228144","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}

引用次数: 0

New Fishing Strategies to Face Climate Change Effects on the Spanish Tropical Tuna Fisheries Off Indian Ocean 面对气候变化对印度洋西班牙热带金枪鱼渔业影响的新捕鱼策略

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-05-31 DOI: 10.1111/fog.12743

José Carlos Báez, Ivone A. Czerwinski, María Lourdes Ramos, José María Bellido, Marta Coll

{"title":"New Fishing Strategies to Face Climate Change Effects on the Spanish Tropical Tuna Fisheries Off Indian Ocean","authors":"José Carlos Báez, Ivone A. Czerwinski, María Lourdes Ramos, José María Bellido, Marta Coll","doi":"10.1111/fog.12743","DOIUrl":"https://doi.org/10.1111/fog.12743","url":null,"abstract":"Tropical tunas, including yellowfin (Thunnus albacares), are recognized as a crucial contributor to global food security. Moreover, yellowfin tuna is the most commercially valuable tropical tuna. The Spanish purse seine freezer fleet, actively operating in the Indian Ocean, emerges as a leading contributor to the global yellowfin tuna catch. Currently, the planet is undergoing a climate change, which is poised to alter habitats on a global scale, particularly impacting tropical regions by causing an increase in sea surface temperatures at an unprecedented rate as well as ocean deoxygenation. Consequently, it is foreseeable that large pelagic highly migratory species like tunas may shift their distribution areas, resulting in the translocation of the current fishing grounds. In this context, the main goal of this work is to study the potential shifts of the Spanish purse seine fishing grounds targeting yellowfin tuna within the tropical belt in the Indian Ocean. Our findings suggest that although the largest yellowfin tuna catches have moved northward in latitude, most of the fishing effort, indicated by the greater number of fishing sets, has been located toward the equatorial region. Present results can only be interpreted from a human perspective and following a commercial strategy in response to the management of yellowfin tuna. Therefore, according to the 38 years of the analyzed dataset, a shift in fleet dynamics is apparent. However, we suggest that this new fishing strategy could be not so much attributed to the movement of free schools toward higher latitudes but to complex trade-off strategies.","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"17-26"},"PeriodicalIF":2.7,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fog.12743","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228236","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}

引用次数: 0

Climate Oscillations Driving Phytoplankton Dynamics and Marine Productivity in Todos Santos Bay: Insights From the Southern California Current System 气候振荡驱动Todos Santos湾浮游植物动力学和海洋生产力：来自南加州洋流系统的见解

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-05-28 DOI: 10.1111/fog.12740

Perla González-Dávalos, Eliana Gómez-Ocampo, Josué Villegas-Mendoza, Mary Carmen Ruiz-De la Torre

{"title":"Climate Oscillations Driving Phytoplankton Dynamics and Marine Productivity in Todos Santos Bay: Insights From the Southern California Current System","authors":"Perla González-Dávalos, Eliana Gómez-Ocampo, Josué Villegas-Mendoza, Mary Carmen Ruiz-De la Torre","doi":"10.1111/fog.12740","DOIUrl":"https://doi.org/10.1111/fog.12740","url":null,"abstract":"<div>\u0000 \u0000 This study explores the impacts of climatic phenomena, including the El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), marine heatwaves (MHWs), and the North Pacific Gyre Oscillation (NPGO), on phytoplankton dynamics in Todos Santos Bay (TSB) from 2010 to 2022. Analysis of the anomalies of the sea surface temperature (SSTa), phytoplankton biomass (CHLa), upwelling indices (Bakun and BEUTI), and absolute dynamic topography (ADTa) revealed substantial effects on nutrient dynamics and primary productivity. The results indicate a significant reduction in phytoplankton biomass during El Niño due to increased ADT that weakened nutrient upwelling. In contrast, La Niña periods were associated with enhanced nutrient flow and phytoplankton biomass due to intensified coastal upwelling. The study also highlights the impact of the NPGO’s warm phase in reducing the influx of cold, nutrient-rich subarctic water, influencing the phytoplankton community structure towards smaller phytoplankton and dinoflagellates. Notably, a positive correlation was found between ADTa and the dominance of smaller phytoplankton and dinoflagellates, suggesting that higher sea levels and increased stratification favor these groups over larger phytoplankton like diatoms. This shift suggests potential long-term ecological implications, including effects on marine biodiversity and fisheries. The findings underscore the complex interplay between global climatic phenomena and marine ecosystem productivity, emphasizing the necessity of adaptive ecosystem management in the face of climatic variability.\u0000 </div>","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 6","pages":"1-16"},"PeriodicalIF":2.7,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228111","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}

引用次数: 0

Insights Into the Feeding Ecology of Young-of-the-Year Bigeye Tuna (Thunnus obesus) in the Southwestern Atlantic Ocean 西南大西洋中年轻的大眼金枪鱼（Thunnus obesus）的摄食生态

IF 2.7 2区农林科学

Fisheries Oceanography Pub Date : 2025-05-23 DOI: 10.1111/fog.12742

Juliano Lauser Coletto, Stefan Cruz Weigert, José Henrique Muelbert, Juliana Couto Di Tullio, Eduardo Resende Secchi, Silvina Botta

{"title":"Insights Into the Feeding Ecology of Young-of-the-Year Bigeye Tuna (Thunnus obesus) in the Southwestern Atlantic Ocean","authors":"Juliano Lauser Coletto, Stefan Cruz Weigert, José Henrique Muelbert, Juliana Couto Di Tullio, Eduardo Resende Secchi, Silvina Botta","doi":"10.1111/fog.12742","DOIUrl":"https://doi.org/10.1111/fog.12742","url":null,"abstract":"Bigeye tuna (Thunnus obesus) is among the most prized tuna species sustaining fisheries worldwide. However, information on the feeding habits for the species is mostly restricted to the size range harvested by commercial fisheries. In this study, we report the diet composition of juvenile bigeye tuna schooling near the surface at night in the oceanic area of the southwestern Atlantic Ocean. We combined short-term dietary information derived from stomach content analysis (n = 14) with time-integrated diet information from carbon (δ13C) and nitrogen (δ15N) stable isotope analysis (n = 8) to characterize diet composition and estimate trophic position (TPbulk) of the individuals. The prey-specific index of relative importance (%PSIRI) indicated that Teleostei (79.1%) was the most important taxon, followed by Cephalopoda (7.6%) and Crustacea (3.9%). Myctophidae was the most frequent Teleostei in the diet (frequency of occurrence: 85.7%). The δ13C values on juvenile tuna muscle tissue ranged from −18.6‰ to −17.4‰ (mean ± SD: −18.1 ± 0.5‰) and δ15N values ranged from 7.2‰ to 8.4‰ (mean ± SD: 7.8 ± 0.3‰). TPbulk (4.15 ± 0.47) results corroborated a diet based on lanternfishes and the predation upon relatively small-sized oceanic squids. Our results address a knowledge gap by highlighting important trophic links for bigeye tuna before they reach a size suitable for exploitation.","PeriodicalId":51054,"journal":{"name":"Fisheries Oceanography","volume":"34 5","pages":"121-127"},"PeriodicalIF":2.7,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fog.12742","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144774088","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}

引用次数: 0