Aquatic Conservation-Marine and Freshwater Ecosystems最新文献

{"title":"Trends in Marine Mammal Bycatch in US Fisheries From 1990 to 2017","authors":"Amelia-Jane L. Allerton,&nbsp;Eric V. C. Schneider,&nbsp;Jeremy J. Kiszka,&nbsp;Brendan S. Talwar","doi":"10.1002/aqc.70008","DOIUrl":"https://doi.org/10.1002/aqc.70008","url":null,"abstract":"<p>Bycatch is the greatest threat facing marine mammals globally. In the United States (US), there have been significant efforts to reduce marine mammal bycatch in commercial fisheries, particularly through the implementation of the 1994 amendments to the Marine Mammal Protection Act. However, trends in marine mammal bycatch in US commercial fisheries have not been evaluated in over a decade. We assessed trends in US marine mammal bycatch for 130 stocks of 51 species from 1990 to 2017 according to taxon, region and gear type based on National Marine Fisheries Service Stock Assessment Reports using the bycatch metric ‘mortalities and serious injuries’. We estimated that total annual marine mammal bycatch in US fisheries was 4296 ± 1789 individuals (mean ± SD), with the majority of bycatch occurring in gillnets (83%). The proportion of pinniped bycatch (52%) was slightly higher than that of cetaceans (48%). After decreasing from 1990 to 2002, there was no change in total marine mammal bycatch in all US fisheries from 2002 to 2017, although pinniped bycatch continued to decline throughout the series. Whereas reductions in marine mammal bycatch continued through 2017 in the Atlantic–Gulf of Mexico–Caribbean region, reductions in the Pacific and Alaskan regions had halted or reversed by 2006. Although a more fine-scale evaluation is needed to determine the exact drivers of changes in marine mammal bycatch, our results agree with previous studies in suggesting some success of US bycatch mitigation measures.</p>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/aqc.70008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Newly Formed Ribb Reservoir Could Serve as a Refugia for Conserving Ethiopia's Globally Unique Labeobarbus Species Flock","authors":"Abebe Getahun,&nbsp;Minwyelet Mingist,&nbsp;Biniam Hailu,&nbsp;Dagnew Mequanent,&nbsp;Michael S. Cooperman","doi":"10.1002/aqc.70074","DOIUrl":"https://doi.org/10.1002/aqc.70074","url":null,"abstract":"<div>\u0000 \u0000 <p>The 17 species of <i>Labeobarbus</i> found in Lake Tana constitute the only extant cyprinid species flock in the world but extensive water development projects are impacting their habitats. Here, we assess if the <i>Labeobarbus</i> spp. are established above the Ribb Dam, constructed in 2017, and if so, the condition of the individuals and if there is evidence of local recruitment. Fish samplings were conducted once a month during the <i>Labeobarbus</i> species' spawning season of July to the end of September 2022, using monofilament and multifilament gillnets at three locations upstream of the Ribb Dam. We collected 10 <i>Labeobarbus</i> spp., with <i>L. intermedius</i> (40.7%) being the most abundant followed by <i>L. brevicephalus</i> (23.0%) and <i>L. nedgia</i> (22.2%). <i>Labeobarbus</i> fork lengths ranged from 7.8 to 43.0 cm and there were no notable gaps across the size ranges. Fulton's condition factors for species where <i>n</i> ≥ 20 were 1.30–1.54 (good), like Lake Tana populations. Our collection included sexually immature and first-time maturing individuals, indicating <i>Labeobarbus</i> are reproducing and recruiting successfully in the watershed above the dam. Our results suggest that the Ribb River watershed above Ribb Dam may serve as a refugia for at least some of the 17 species of the species flock. However, challenges remain before the upper watershed should be viewed as a viable long-term habitat for <i>Labeobarbus</i>, including the need for a fisheries management program, pollution control and mitigation of catchment degradation in the uplands that is leading to the rapid infilling of the reservoir, where current estimates suggest a 30-year reservoir life span.</p>\u0000 </div>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From Nets to Knowledge—Fishers Unveil Threatened Guitarfish Catch Drivers and Fishing Grounds","authors":"Masiat Alam Zubair,&nbsp;Md. Sazidul Islam,&nbsp;Shawnujjaman Khan,&nbsp;Nazia Hosssain,&nbsp;Alifa Bintha Haque","doi":"10.1002/aqc.70062","DOIUrl":"https://doi.org/10.1002/aqc.70062","url":null,"abstract":"<div>\u0000 \u0000 <p>The artisanal fishing in the Bay of Bengal has been characterized by complex heterogeneity. A lack of comprehensive data on threatened elasmobranchs (sharks and rays), including guitarfish, hinders evidence-based management. This study evaluated the status of guitarfish, focusing on the effects of artisanal fishing and the socioeconomic circumstances of fishers impacting catch and perceived catch trends. The impacts were assessed spatially and temporally in coastal Bangladesh. Interviews were conducted with 150 artisanal fishers in primary fish landing locations and fishing communities. The analysis showed a notable decrease in the perceived catch of various guitarfish species. Catch decreased significantly for <i>Glaucostegus granulatus</i>, sharpnose guitarfish, and <i>Rhina ancylostoma</i>, bowmouth guitarfish in the past decade. The decrease was linked to overfishing, illegal/harmful fishing techniques and injuries from fishing equipment. Fishing-related (soak time, gear, depth at fishing and vessel length) and socioeconomic drivers (income and debt levels) were found to impact guitarfish catch levels. Socioeconomic factors complicate the situation because these factors influence fishers' fishing habits, perspectives and decision-making. Guitarfish were caught both as a target and incidentally. Most captures occurred in the southcentral region of Bangladesh. Four hotspots of guitarfish catches were identified based on the fishers' knowledge. The critical habitats in the Ganges-Brahmaputra-Meghna (GBM) delta mouth area are vital habitats for guitarfish, highlighting the need to protect these ecosystems using spatial management tools. To tackle the complex issues of guitarfish conservation, the local fishing communities need a holistic strategy combining biological knowledge, socioeconomic factors and specific codesigned initiatives. Although fishers may lack formal education, there is a distinct potential for specialized and bilateral conservation education programmes to empower fishing communities and promote sustainable practices. Conservation measures should focus on mixed methods, such as community engagement, enhanced socioeconomic circumstances and efficient spatial and fishing technique management.</p>\u0000 </div>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Artificial Reefs on the Macrobenthic Community Structure Through Functional Trait Analysis","authors":"Jiao Wang,&nbsp;Shaoyu Jiang,&nbsp;Debin Sun,&nbsp;Fan Yi,&nbsp;Hang Liu,&nbsp;Linlin Chen,&nbsp;Baoquan Li,&nbsp;Jing Chen","doi":"10.1002/aqc.70068","DOIUrl":"https://doi.org/10.1002/aqc.70068","url":null,"abstract":"<div>\u0000 \u0000 <p>Artificial reefs enhance marine biodiversity by increasing habitat complexity and heterogeneity, which in turn provide living space for various marine species. Macrobenthos, an important component of aquatic ecosystems, with limited mobility and sensitivity to environmental changes, commonly serve as indicators of aquatic ecosystem health. This study, conducted in the summer and autumn of 2022 in Sishili Bay (SB) and the Changdao Archipelago (CA), Yantai, China, aimed to evaluate the effects of artificial reefs on macrobenthic community structure using functional trait analysis. The nonmetric multidimensional scaling (nMDS) analysis based on species abundance and occurrence frequency did not reveal any clear separation between areas inside and outside the artificial reefs. However, the construction of artificial reefs increased the species number of macrobenthos, especially the Mollusca species. Feeding type, a key functional trait, distinguished areas inside and outside artificial reefs, with significant spatial and temporal variations. The key species driving differences between reef and nonreef areas include the carnivorous <i>Lumbrineris longifolia</i> and <i>Glycinde bonhourei</i> and the omnivorous <i>Eriopisella sechellensis</i> and <i>Sigambra bassi</i>, which were pivotal in the observed variations in relative abundance. Functional richness (FRic) and species richness (<i>S</i>) showed consistent patterns of variation, both contributing to improving the community stability in summer. However, in autumn, community stability was reduced by the extraordinary dominance of a single species. Multiple environmental factors rather than a single one significantly influenced species distribution and diversity, reflecting the complex interplay of reefs and seasonal dynamics. This study used functional trait analysis to assess the impact of artificial reefs on macrobenthic community structure, offering a more effective measure than species-level assessments.</p>\u0000 </div>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tour Operators as a Tool to Improve Information on Data-Deficient Cetacean Species","authors":"Rui Peres dos Santos,&nbsp;Yasmina Rodríguez,&nbsp;Richard Sears,&nbsp;Ramiro Magno,&nbsp;Rita Castilho","doi":"10.1002/aqc.70067","DOIUrl":"https://doi.org/10.1002/aqc.70067","url":null,"abstract":"<div>\u0000 \u0000 <p>Understanding the distribution and behaviour of species is crucial for ecosystem assessment and economic evaluations. Despite global research efforts, some cetacean species or populations remain data deficient. False killer whales (<i>Pseudorca crassidens</i>) are among these species, possibly due to their pelagic behaviour and high mobility. This study focused on the Azorean Archipelago, an ecologically rich region influenced by the Gulf Stream and North Atlantic Current, where false killer whales have been regularly observed over the last decade by the whale watching operators. Using opportunistic data collection from tourist operators, we established the first long-term study of false killer whales in the NE Atlantic Ocean. Results revealed sightings between April and October, with a peak from July to September. False killer whale groups were observed interacting with other species, particularly bottlenose dolphins (<i>Tursiops truncatus</i>). The photo-identification analysis produced an individual catalogue and identified associations between individuals and groups. Four of these animals presented dorsal fin injury patterns suggestive of interactions with fishing gear. Open population capture–recapture (openCR) models estimated a population of 198 individuals in the research area. This study demonstrates the importance of opportunistic data collection in understanding poorly studied species. The findings contribute insights into false killer whale presence, behaviour and potential threats in the studied region. Future research should expand to winter data collection, comprehensive fishery interaction studies and population dynamics assessments for effective conservation efforts.</p>\u0000 </div>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reducing Cetacean Interactions With Bottom Set-Nets and Purse Seining Using Acoustic Deterrent Devices in Southern Iberia","authors":"Ana Marçalo,&nbsp;Flávia Carvalho,&nbsp;Magda Frade,&nbsp;Luís Bentes,&nbsp;Pedro Monteiro,&nbsp;João Pontes,&nbsp;Sofia Alexandre,&nbsp;Frederico Oliveira,&nbsp;Allen Kingston,&nbsp;Karim Erzini,&nbsp;Jorge M. S. Gonçalves","doi":"10.1002/aqc.70061","DOIUrl":"https://doi.org/10.1002/aqc.70061","url":null,"abstract":"<div>\u0000 \u0000 <p>In southern Iberia (NE Atlantic), cetacean bycatch is reported in several fisheries, whereas depredation by bottlenose dolphin (<i>Tursiops truncatus</i>) is commonly observed in bottom set-net fisheries. This study tested the effectiveness of acoustic deterrent devices in discouraging small cetaceans from approaching bottom set-nets and purse seine to reduce interactions. The acoustic deterrent devices used in the study were dolphin deterrent devices and dolphin interactive devices for the bottom set-net fishery to reduce dolphin bycatch and depredation and dolphin deterrent devices in the purse seine fishery to reduce common dolphin (<i>Delphinus delphis</i>) bycatch. Data collection was carried out by at-sea observers and trained fishing vessel crew observers. Hauls with and without acoustic deterrent devices were compared and analysed to investigate differences in catch per unit effort, factors affecting the interaction, probability of interaction and habituation (in bottom set-nets only). In bottom set-nets, the depredation rate was significantly lower and reduced by about 50% in hauls using acoustic deterrent devices. Habituation of the bottlenose dolphins to the devices was observed but was gradual. In the purse seine fishery, common dolphin bycatch was reduced by 100% when using the acoustic deterrent devices. Overall, the results are promising, but the different interaction reduction efficiencies observed between gear types indicate that the potential application of acoustic deterrent devices should be considered on a métier-by-métier basis. Other mitigation measures should be developed, especially for static gears, in collaboration with the fishing sector in an inclusive management approach to reduce direct interactions between fisheries and cetaceans.</p>\u0000 </div>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143248833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mixed-Age Releases of the Endangered Pinto Abalone (Haliotis kamtschatkana) to Maximize Hatchery Production and Survival in the Wild","authors":"Kathleen A. Sowul,&nbsp;Joshua V. Bouma,&nbsp;Henry S. Carson,&nbsp;Taylor N. Frierson,&nbsp;Emily L. Loose,&nbsp;Caitlin S. O'Brien,&nbsp;Bethany C. Stevick","doi":"10.1002/aqc.70049","DOIUrl":"https://doi.org/10.1002/aqc.70049","url":null,"abstract":"<div>\u0000 \u0000 <p>The Washington State recovery programme for endangered pinto abalone (<i>Haliotis kamtschatkana</i>) relies on captive breeding. From 2009 to 2017, juveniles from wild parent crosses were released after an average of 20 months in the hatchery (average size 24 mm), and the results of a mark-recapture experiment suggested that size-at-release was not important to survival. The results of a pilot study suggested that abalone released at 9-month age survived at similar rates to previous releases at 20 months but that there was a significant cost to growth and survival for the 14-month releases. From 2019 to 2022, an average of 7000 mixed-age juveniles were released on a different subset of 24 restoration sites each year. Larger individuals (&gt; 5 mm) from each family were released at 9 months (first years), with the remainder held in the hatchery to be released at 20 months (second years). The resulting survival at successful sites from 9- to 32-month age was 0.6%–6.1% for first years and 0.6%–4.5% for second years. In two out of three trials, there was little or no evidence of reduced survival or growth as a result of releasing almost a year early. When combined with the cost savings of rearing animals for a shorter duration, possible benefits to growth, reduction in hatchery acclimatization or selection, better rotation of hatchery resources and culture space and mixing 2 years of genetic crosses into one release, we suggest that mixed-age releases are the most efficient way forward for the conservation of pinto abalone.</p>\u0000 </div>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143248700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drivers of the Distributions of Stream-Dwelling Crayfishes in the New River Catchment, United States","authors":"Joshua B. Mouser,&nbsp;Zachary J. Loughman,&nbsp;Bryan L. Brown,&nbsp;Robert P. Creed,&nbsp;Emmanuel A. Frimpong","doi":"10.1002/aqc.70041","DOIUrl":"https://doi.org/10.1002/aqc.70041","url":null,"abstract":"<p>Crayfish are keystone species and ecosystem engineers in aquatic ecosystems, and many species require conservation to support their continued persistence. Unfortunately, managers often lack basic data needed to make effective conservation decisions. This lack of data is especially true within the New River catchment, United States, where there are 12 known crayfish species, but it is unclear which of those species are native to the catchment, and there is scant ecological and life history data available for many species. Therefore, our objective was to investigate coarse-scale occurrence drivers of crayfishes in the New River catchment. We used generalized linear mixed effects models to predict occurrence of eight taxa based on instream and landscape-scale environmental data and biotic interactions. We found that increasing anthropogenic disturbance led to declines in <i>Faxonius</i> spp. (either <i>Faxonius obscurus</i> or <i>Faxonius sanbornii</i> but could not be identified to species) and <i>Cambarus smilax</i>. In contrast, disturbance had a positive relationship only with <i>Faxonius cristavarius</i>. The presence of <i>F. cristavarius</i> was negatively associated with most species. Embeddedness, substrate, per cent riffle, stream size and lithology were additional variables that were related to crayfish occurrence. Our results reveal that increasing human-mediated changes and invasive crayfish species threaten the persistence of native crayfishes in the New River catchment.</p>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/aqc.70041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143248834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancing Management of the Main Predatory Sharks Along the Argentine Coast: Leveraging Habitat Use Knowledge and Historical Catch Data","authors":"Agustín M. De Wysiecki,&nbsp;Noela Sánchez-Carnero,&nbsp;Andrés C. Milessi,&nbsp;Andrés J. Jaureguizar","doi":"10.1002/aqc.70071","DOIUrl":"https://doi.org/10.1002/aqc.70071","url":null,"abstract":"<div>\u0000 \u0000 <p>This study investigates the spatial overlap in habitat use among four key predatory species—school shark (<i>Galeorhinus galeus</i>), broadnose sevengill shark (<i>Notorynchus cepedianus</i>), copper shark (<i>Carcharhinus brachyurus</i>) and sand tiger shark (<i>Carcharias taurus</i>)—along the Argentine coast to identify important areas for joint management. Leveraging habitat suitability predictions for these predators, we generated annual and seasonal maps to identify significant regions of habitat overlap. Notably, the coastal zone between the Uruguayan and northern Argentine coasts emerged as crucial for developing fishery management and conservation strategies for these four species. Historical catch data also identified important zones for recreational fishing and potential nursery sites, stressing the need for targeted management of the coastal area between Punta Rasa and Mar del Plata (36.3°–38° S). This highlights the necessity of comprehensive fishing regulations with stronger enforcement in the unregulated provincial waters of Chubut and Santa Cruz, as well as the Uruguayan coast. Our findings underscore the importance of integrating species-specific ecological data in designing marine protected areas and conservation strategies tailored to the unique life history and movement patterns of these sharks. Additionally, the study emphasizes the need for adaptive, multijurisdictional management strategies to accommodate the migratory nature of these species across provincial and national waters. The implications of these findings are discussed within the context of current chondrichthyan policy in Argentina, presenting a foundational basis for informing future management strategies aimed at sustaining shark populations in the Southwest Atlantic.</p>\u0000 </div>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143111120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abundance and Residency Patterns of Common Bottlenose Dolphins (Tursiops truncatus) in Freshwater-Influenced Estuaries of the Northern Gulf of Mexico","authors":"Thibaut Bouveroux,&nbsp;Carrie Sinclair,&nbsp;Kevin Barry,&nbsp;Lauren Clance,&nbsp;Joseph J. Hansen,&nbsp;Keith D. Mullin,&nbsp;Patricia Rosel,&nbsp;Ruth H. Carmichael","doi":"10.1002/aqc.70055","DOIUrl":"https://doi.org/10.1002/aqc.70055","url":null,"abstract":"<div>\u0000 \u0000 <p>Multiple stressors are affecting common bottlenose dolphins in the northern Gulf of Mexico, including two embayments in Alabama, Mobile Bay (MOB) and Perdido Bay (PER), where no comprehensive abundance estimates and residency data are currently available. This study provides the first seasonal abundance estimates and residency patterns for bottlenose dolphins in MOB and PER and discusses the effects of seasonal entry of large volumes of freshwater on dolphin abundance. In MOB, abundance estimates were larger in summer, with the highest abundance recorded in summer 2022 (1712 dolphins, 95% CI: 1520–1928) and the lowest in winter 2019–2020 (518 dolphins, 95% CI: 260–1032). The opposite pattern was found in PER, where abundances were larger in winter, with the highest abundance in winter 2021–2022 (191 dolphins, 95% CI: 157–232) and the lowest in summer 2020 (100 dolphins, 95% CI: 81–122). Stronger residency patterns were found in PER, with 28% (<i>n</i> = 52) encountered in more than three seasons compared to MOB where only 9% (<i>n</i> = 57) were encountered in more than three seasons, and considered resident dolphins. The two studied embayments support a larger number of dolphins than previously documented and likely provide seasonally different resources, indicating high and potentially complex use of these estuaries. Combined with other data concurrently collected in this area, this study will inform conservation management and strategies for these highly impacted dolphin stocks.</p>\u0000 </div>","PeriodicalId":55493,"journal":{"name":"Aquatic Conservation-Marine and Freshwater Ecosystems","volume":"35 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143111124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}