Fabio Fiorentino, Germana Garofalo, Gioacchino Bono, Sergio Vitale
As deep-water red shrimp (DWRS) trawl fisheries gain importance in the Mediterranean, their impact on fragile deep-sea ecosystems requires careful management. We reviewed the historical development of DWRS fisheries in the Mediterranean to propose a harvest strategy that would enhance fishery sustainability, while preserving habitat and community integrity. We considered two representative typologies of DWRS fisheries: a domestic fleet operating within the Italian territorial waters of the Ligurian Sea, and a distant fleet operating mostly in international waters of the central-eastern Mediterranean and sharing shrimp stocks with non-European countries. Our proposed management approach is based on three main harvesting measures: (i) preventing the uncontrolled growth in number of trawlers, (ii) adopting a catch control regime, and (iii) identifying a network of deep-water areas designated alternately for fishing and conservation purposes. As with fisheries in other regions, new fishing grounds should be explored using “encounter protocols” to avoid areas hosting species indicators of Vulnerable Marine Ecosystems. Additionally, empirical indicators such as catch rate thresholds derived from fishers’ experience, could be used to move from one fishing ground to another to avoid local depletion of DWRS abundance and a decrease in fishery profitability.
{"title":"Learning from the history of red shrimp fisheries in the Mediterranean to improve sustainability of deep-water bottom trawling","authors":"Fabio Fiorentino, Germana Garofalo, Gioacchino Bono, Sergio Vitale","doi":"10.1093/icesjms/fsae031","DOIUrl":"https://doi.org/10.1093/icesjms/fsae031","url":null,"abstract":"As deep-water red shrimp (DWRS) trawl fisheries gain importance in the Mediterranean, their impact on fragile deep-sea ecosystems requires careful management. We reviewed the historical development of DWRS fisheries in the Mediterranean to propose a harvest strategy that would enhance fishery sustainability, while preserving habitat and community integrity. We considered two representative typologies of DWRS fisheries: a domestic fleet operating within the Italian territorial waters of the Ligurian Sea, and a distant fleet operating mostly in international waters of the central-eastern Mediterranean and sharing shrimp stocks with non-European countries. Our proposed management approach is based on three main harvesting measures: (i) preventing the uncontrolled growth in number of trawlers, (ii) adopting a catch control regime, and (iii) identifying a network of deep-water areas designated alternately for fishing and conservation purposes. As with fisheries in other regions, new fishing grounds should be explored using “encounter protocols” to avoid areas hosting species indicators of Vulnerable Marine Ecosystems. Additionally, empirical indicators such as catch rate thresholds derived from fishers’ experience, could be used to move from one fishing ground to another to avoid local depletion of DWRS abundance and a decrease in fishery profitability.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"98 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140156849","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}
Daniel E Duplisea, Marie-Julie Roux, Stéphane Plourde, Peter S Galbraith, Marjolaine Blais, Hugues P Benoît, Bernard Sainte-Marie, Diane Lavoie, Hugo Bourdages
Open data that can be easily incorporated into analyses are essential for developing ecosystem approaches to marine ecological management: a common goal in fisheries policy in many countries. Although it is not always clear what constitutes an ecosystem approach, it always involves scientists working with a large variety of data and information, including data from physical and oceanographic sampling, multispecies surveys, and other sources describing human pressures. This can be problematic for analysts because these data, even when available, are often held in disparate datasets that do not necessarily correspond at appropriate temporal and spatial scales. Data can often only be obtained by specific requests to individuals in governmental agencies who are delivering on an increasing number of data requests as interest grows in practical ecosystem approach implementation. This data access model is not sustainable and hinders the momentum for ecosystem approach development. We describe a data bundling R package that makes data and climate projections available at appropriate scales to facilitate development of an ecosystem approach for the Gulf of St. Lawrence, Canada. This approach integrates closely with the present workflow of most government analysts, academics in fisheries, and scientists in private industry. The approach conforms with open data initiatives and makes data easily available globally while relieving some of the burden of data provision that can fall to some individuals in government laboratories. The structure and approach are generic, adaptable, and transferable to other regions and jurisdictions.
易于纳入分析的开放数据对于制定海洋生态管理的生态系统方法至关重要:这是许多国家渔业政策的共同目标。尽管生态系统方法的构成并不总是很明确,但它总是涉及科学家与大量数据和信息的合作,包括来自物理和海洋学采样、多物种调查以及描述人类压力的其他来源的数据。这对分析人员来说可能是个问题,因为这些数据即使可用,也往往保存在不同的数据集中,不一定在适当的时间和空间尺度上对应。数据通常只能通过向政府机构中的个人提出具体请求来获取,而随着人们对实际生态系统方法实施兴趣的增加,政府机构正在满足越来越多的数据请求。这种数据访问模式是不可持续的,会阻碍生态系统方法的发展势头。我们介绍了一个数据捆绑 R 软件包,该软件包可提供适当尺度的数据和气候预测,以促进加拿大圣劳伦斯湾生态系统方法的发展。该方法与大多数政府分析人员、渔业学者和私营企业科学家目前的工作流程紧密结合。该方法符合开放数据倡议,可在全球范围内轻松获取数据,同时减轻政府实验室某些人员提供数据的负担。这种结构和方法具有通用性和适应性,可移植到其他地区和辖区。
{"title":"Facilitating an ecosystem approach through open data and information packaging","authors":"Daniel E Duplisea, Marie-Julie Roux, Stéphane Plourde, Peter S Galbraith, Marjolaine Blais, Hugues P Benoît, Bernard Sainte-Marie, Diane Lavoie, Hugo Bourdages","doi":"10.1093/icesjms/fsae024","DOIUrl":"https://doi.org/10.1093/icesjms/fsae024","url":null,"abstract":"Open data that can be easily incorporated into analyses are essential for developing ecosystem approaches to marine ecological management: a common goal in fisheries policy in many countries. Although it is not always clear what constitutes an ecosystem approach, it always involves scientists working with a large variety of data and information, including data from physical and oceanographic sampling, multispecies surveys, and other sources describing human pressures. This can be problematic for analysts because these data, even when available, are often held in disparate datasets that do not necessarily correspond at appropriate temporal and spatial scales. Data can often only be obtained by specific requests to individuals in governmental agencies who are delivering on an increasing number of data requests as interest grows in practical ecosystem approach implementation. This data access model is not sustainable and hinders the momentum for ecosystem approach development. We describe a data bundling R package that makes data and climate projections available at appropriate scales to facilitate development of an ecosystem approach for the Gulf of St. Lawrence, Canada. This approach integrates closely with the present workflow of most government analysts, academics in fisheries, and scientists in private industry. The approach conforms with open data initiatives and makes data easily available globally while relieving some of the burden of data provision that can fall to some individuals in government laboratories. The structure and approach are generic, adaptable, and transferable to other regions and jurisdictions.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"11 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126156","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}
César González-Pola, Katherine E Mills, Agnieszka Beszczynska-Möller, Eileen Bresnan, Silvana N R Birchenough
The “Symposium on Decadal Variability of the North Atlantic and its Marine Ecosystems: 2010–2019” took place in Bergen, Norway, from 20 to 22 May 2022. This event, hosted by the Institute of Marine Research, was jointly sponsored by ICES and NAFO and constitutes the fourth in a series of these symposia that started in 1991. The first symposium’s aim was to review the hydrobiological variability in the decade of the 1980s, addressing the physical environment, plankton, invertebrates, and fish. Subsequent symposia maintained the classical structure, whilst a new theme session covering social sciences was added to the programme in the 2022 edition. Studies of climate impacts on marine ecosystems and living marine resources, including trends and regime shifts, emerged from increasingly longer ecosystem time series across the North Atlantic and subarctic regions. This symposium collection presents key findings discussed during the symposium. Whilst some progress has been made in advancing our ability to understand new trends and patterns of climate change and variability across physical, plankton, and fish communities, more work is needed to integrate these physical-ecological processes and scales with social science.
{"title":"Decadal (2010–2019) variability in the marine ecosystems of the North Atlantic","authors":"César González-Pola, Katherine E Mills, Agnieszka Beszczynska-Möller, Eileen Bresnan, Silvana N R Birchenough","doi":"10.1093/icesjms/fsae029","DOIUrl":"https://doi.org/10.1093/icesjms/fsae029","url":null,"abstract":"The “Symposium on Decadal Variability of the North Atlantic and its Marine Ecosystems: 2010–2019” took place in Bergen, Norway, from 20 to 22 May 2022. This event, hosted by the Institute of Marine Research, was jointly sponsored by ICES and NAFO and constitutes the fourth in a series of these symposia that started in 1991. The first symposium’s aim was to review the hydrobiological variability in the decade of the 1980s, addressing the physical environment, plankton, invertebrates, and fish. Subsequent symposia maintained the classical structure, whilst a new theme session covering social sciences was added to the programme in the 2022 edition. Studies of climate impacts on marine ecosystems and living marine resources, including trends and regime shifts, emerged from increasingly longer ecosystem time series across the North Atlantic and subarctic regions. This symposium collection presents key findings discussed during the symposium. Whilst some progress has been made in advancing our ability to understand new trends and patterns of climate change and variability across physical, plankton, and fish communities, more work is needed to integrate these physical-ecological processes and scales with social science.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"10 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140100078","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}
Osvaldo Ernesto Chacate, Janet Claire Coetzee, Bjørn Erik Axelsen
Deep scattering layers (DSL) in oligotrophic systems are typically comprised of a variety of coexisting organisms, including fish, zooplankton, jellyfish, and squid, and hence there is uncertainty about the proportion of the acoustic backscatter in these layers that can be attributed to mesopelagic fish. Here, acoustic targets were classified using a multi-frequency acoustic classification algorithm based on data collected in the Indian Ocean at 18, 38, 70, and 120 kHz during three acoustic surveys in 2018. Frequency-dependent backscattering strength information (∆Sv) was extracted from acoustic data that coincided with trawl hauls dominated by mesopelagic fish. Five ∆Sv frequency pairs were used to separate the acoustic backscattering into three broad scattering categories, i.e. mesopelagic fish, crustacean-like/tunicates, and squids/others. Results indicated that the DSL is highly diverse and dominated by mesopelagic fish, with average densities at a regional scale ranging from 12.0 (±10.9) to 26.0 (±21.7) g m−2, and proportions of the acoustic backscatter attributed to mesopelagic fish ranging from 0.5 to 0.7. These estimates are generally lower than previously estimated for other regions of the Indian Ocean. The situation may well be similar elsewhere, particularly in oligotrophic systems, with potential ramifications for global mesopelagic fish biomass estimates.
{"title":"Hydro-acoustic classification and abundance estimation of mesopelagic fish in deep scattering layers (DSL) of the Indian Ocean","authors":"Osvaldo Ernesto Chacate, Janet Claire Coetzee, Bjørn Erik Axelsen","doi":"10.1093/icesjms/fsae028","DOIUrl":"https://doi.org/10.1093/icesjms/fsae028","url":null,"abstract":"Deep scattering layers (DSL) in oligotrophic systems are typically comprised of a variety of coexisting organisms, including fish, zooplankton, jellyfish, and squid, and hence there is uncertainty about the proportion of the acoustic backscatter in these layers that can be attributed to mesopelagic fish. Here, acoustic targets were classified using a multi-frequency acoustic classification algorithm based on data collected in the Indian Ocean at 18, 38, 70, and 120 kHz during three acoustic surveys in 2018. Frequency-dependent backscattering strength information (∆Sv) was extracted from acoustic data that coincided with trawl hauls dominated by mesopelagic fish. Five ∆Sv frequency pairs were used to separate the acoustic backscattering into three broad scattering categories, i.e. mesopelagic fish, crustacean-like/tunicates, and squids/others. Results indicated that the DSL is highly diverse and dominated by mesopelagic fish, with average densities at a regional scale ranging from 12.0 (±10.9) to 26.0 (±21.7) g m−2, and proportions of the acoustic backscatter attributed to mesopelagic fish ranging from 0.5 to 0.7. These estimates are generally lower than previously estimated for other regions of the Indian Ocean. The situation may well be similar elsewhere, particularly in oligotrophic systems, with potential ramifications for global mesopelagic fish biomass estimates.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"67 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140100050","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}
Alisa A Abookire, Louise A Copeman, Michael A Litzow, Benjamin J Laurel
Warming temperatures in the Gulf of Alaska have been linked to recruitment failure in Pacific cod (Gadus macrocephalus), but the mechanisms and timing of mortality events for juveniles are unclear. To date, limited research has focused on overwintering success, and the knowledge of juvenile ecology and physiology is based entirely on summer observations. Here, we investigate the changes in body condition, diet composition, and tissue-specific fatty acid (FA) storage for age-0 Pacific cod in Kodiak, Alaska, from February to December during 2018 and 2020. We observed protracted nearshore residency from June to December. Cod body condition (Kdry) and predicted weight at length were lowest in October, November, and December. Although not different interannually, diet composition varied seasonally, which corresponded to an increase in cod length. A range of condition metrics (HSIwet, FA concentration in liver tissue, and the % of whole body FAs stored in the liver) began to increase in September. Cod prioritized growth during the summer, while in the autumn and pre-winter they allocated more energy into lipid storage. We conclude that seasonal changes in tissue-specific FA storage and pre-winter fish conditions are important factors to consider for understanding overwintering potential of juvenile Pacific cod.
{"title":"Seasonal shift in energy allocation from somatic growth to lipid storage and the link between pre-winter condition and overwintering potential in juvenile Pacific cod","authors":"Alisa A Abookire, Louise A Copeman, Michael A Litzow, Benjamin J Laurel","doi":"10.1093/icesjms/fsae023","DOIUrl":"https://doi.org/10.1093/icesjms/fsae023","url":null,"abstract":"Warming temperatures in the Gulf of Alaska have been linked to recruitment failure in Pacific cod (Gadus macrocephalus), but the mechanisms and timing of mortality events for juveniles are unclear. To date, limited research has focused on overwintering success, and the knowledge of juvenile ecology and physiology is based entirely on summer observations. Here, we investigate the changes in body condition, diet composition, and tissue-specific fatty acid (FA) storage for age-0 Pacific cod in Kodiak, Alaska, from February to December during 2018 and 2020. We observed protracted nearshore residency from June to December. Cod body condition (Kdry) and predicted weight at length were lowest in October, November, and December. Although not different interannually, diet composition varied seasonally, which corresponded to an increase in cod length. A range of condition metrics (HSIwet, FA concentration in liver tissue, and the % of whole body FAs stored in the liver) began to increase in September. Cod prioritized growth during the summer, while in the autumn and pre-winter they allocated more energy into lipid storage. We conclude that seasonal changes in tissue-specific FA storage and pre-winter fish conditions are important factors to consider for understanding overwintering potential of juvenile Pacific cod.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"9 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140074053","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}
Forage fish species provide essential linkages for energy transfer within pelagic marine food webs. Capelin (Mallotus villosus), the focal forage fish in coastal Newfoundland, Canada, suffered a stock collapse in 1991 and has not recovered. Despite this collapse, capelin continue to provide locally abundant prey aggregations. Here, I synthesize the lessons learned from a long-term capelin-predator research program (2004–2022) on the northeast Newfoundland coast during the postcollapse period. I highlight the importance of simultaneously estimating forage fish biomass and predator responses in a multispecies and multiyear context. High interannual variation in capelin spawning timing and biomass was observed. Lower capelin biomass consistently resulted in predator species- and assemblage-level dietary shifts toward a higher diversity of lower trophic level, alternative prey. Energetic foraging costs of seabirds also increased under lower capelin biomass, but responses differed among species. Summer capelin consumption by dominant seabirds (9389 tonnes) and whales (778 tonnes) indicated predator energetic requirements and revealed higher natural mortality relative to fishery-based (1289 tonnes) mortality. Overall, this case study illustrated that, despite high observed behavioural plasticity, varying species-specific predator responses to changing capelin biomass integrated to increase potential competitive interactions under low capelin biomass, providing a basis for ecosystem-level change.
{"title":"Variable forage fish biomass and phenology influence marine predator diet, foraging behavior, and species interactions in coastal Newfoundland, Canada","authors":"Gail K Davoren","doi":"10.1093/icesjms/fsae021","DOIUrl":"https://doi.org/10.1093/icesjms/fsae021","url":null,"abstract":"Forage fish species provide essential linkages for energy transfer within pelagic marine food webs. Capelin (Mallotus villosus), the focal forage fish in coastal Newfoundland, Canada, suffered a stock collapse in 1991 and has not recovered. Despite this collapse, capelin continue to provide locally abundant prey aggregations. Here, I synthesize the lessons learned from a long-term capelin-predator research program (2004–2022) on the northeast Newfoundland coast during the postcollapse period. I highlight the importance of simultaneously estimating forage fish biomass and predator responses in a multispecies and multiyear context. High interannual variation in capelin spawning timing and biomass was observed. Lower capelin biomass consistently resulted in predator species- and assemblage-level dietary shifts toward a higher diversity of lower trophic level, alternative prey. Energetic foraging costs of seabirds also increased under lower capelin biomass, but responses differed among species. Summer capelin consumption by dominant seabirds (9389 tonnes) and whales (778 tonnes) indicated predator energetic requirements and revealed higher natural mortality relative to fishery-based (1289 tonnes) mortality. Overall, this case study illustrated that, despite high observed behavioural plasticity, varying species-specific predator responses to changing capelin biomass integrated to increase potential competitive interactions under low capelin biomass, providing a basis for ecosystem-level change.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"37 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140074082","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}
Luca Schiavon, Santiago G Ceballos, Michael Matschiner, Emiliano Trucchi, Mario La Mesa, Emilio Riginella, Magnus Lucassen, Felix C Mark, Kevin Bilyk, Rafaella Franch, Andreas Walberg, Elisa Boscari, Lorenzo Zane, Chiara Papetti
Hybridization and introgression are recognized as mechanisms promoting genetic variability during evolutionary radiations. We examined the impact of introgression in the process of speciation, focusing on the Antarctic icefish genus Chionodraco. Our analyses confirmed that the three Chionodraco species (Chionodraco hamatus, Chionodraco myersi, and Chionodraco rastrospinosus) were genetically distinctive, despite signals of past interspecific gene flow between C. hamatus and C. myersi that likely occurred during interglacial periods. However, in this study, no recent hybrids were identified. The lack of contemporary hybridization may be due to life-history traits and the type of marker used in the analysis. Our study emphasizes the importance of genomic approaches to detect subtle patterns of past hybridization accurately and highlights the significance of historical climate events in the demographic and evolutionary history of Antarctic notothenioids. Polar regions, and especially the Antarctic Peninsula, are now experiencing the fastest climate changes due to global warming. Understanding the impact of past climate events is fundamental to trace current modifications in species’ genetic variability and distributions and predict future evolutionary trajectories. This knowledge is also vital for conservation efforts, including the implementation of marine protected areas.
杂交和引种被认为是进化辐射过程中促进遗传变异的机制。我们以南极冰鱼属 Chionodraco 为重点,研究了引种在物种演化过程中的影响。我们的分析证实,尽管过去在 C. hamatus 和 C. myersi 之间可能发生过种间基因流动,但三个 Chionodraco 种(Chionodraco hamatus、Chionodraco myersi 和 Chionodraco rastrospinosus)在基因上是独特的。然而,在这项研究中,没有发现最近的杂交种。缺乏当代杂交可能是由于生活史特征和分析中使用的标记类型造成的。我们的研究强调了基因组学方法在准确检测过去杂交的微妙模式方面的重要性,并突出了历史气候事件在南极蝾螈的人口和进化史中的重要意义。由于全球变暖,极地地区尤其是南极半岛目前正经历着最快的气候变化。了解过去气候事件的影响对于追踪当前物种遗传变异和分布的变化以及预测未来的进化轨迹至关重要。这些知识对于保护工作也至关重要,包括实施海洋保护区。
{"title":"Limited interspecific gene flow in the evolutionary history of the icefish genus Chionodraco","authors":"Luca Schiavon, Santiago G Ceballos, Michael Matschiner, Emiliano Trucchi, Mario La Mesa, Emilio Riginella, Magnus Lucassen, Felix C Mark, Kevin Bilyk, Rafaella Franch, Andreas Walberg, Elisa Boscari, Lorenzo Zane, Chiara Papetti","doi":"10.1093/icesjms/fsae019","DOIUrl":"https://doi.org/10.1093/icesjms/fsae019","url":null,"abstract":"Hybridization and introgression are recognized as mechanisms promoting genetic variability during evolutionary radiations. We examined the impact of introgression in the process of speciation, focusing on the Antarctic icefish genus Chionodraco. Our analyses confirmed that the three Chionodraco species (Chionodraco hamatus, Chionodraco myersi, and Chionodraco rastrospinosus) were genetically distinctive, despite signals of past interspecific gene flow between C. hamatus and C. myersi that likely occurred during interglacial periods. However, in this study, no recent hybrids were identified. The lack of contemporary hybridization may be due to life-history traits and the type of marker used in the analysis. Our study emphasizes the importance of genomic approaches to detect subtle patterns of past hybridization accurately and highlights the significance of historical climate events in the demographic and evolutionary history of Antarctic notothenioids. Polar regions, and especially the Antarctic Peninsula, are now experiencing the fastest climate changes due to global warming. Understanding the impact of past climate events is fundamental to trace current modifications in species’ genetic variability and distributions and predict future evolutionary trajectories. This knowledge is also vital for conservation efforts, including the implementation of marine protected areas.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"15 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140017558","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}
In response to ocean heating and hatchery production, pink salmon (Oncorhynchus gorbuscha) returning from the North Pacific Ocean steadily increased after 1975, leading to concerns about their influence on food webs and competition with other species. Using measurements of distance between scale annuli of 24 584 individual sockeye salmon (O. nerka), we examined growth during their 2 or 3 years at sea from 1977 to 2015 for eight populations in Alaska. We found significant, negative autocorrelations at 1 lag year in annual growth of sockeye salmon, with a consistent pattern of lower growth in odd years, i.e. opposite to the biennial pattern of pink salmon abundance. Peak pink salmon abundances reduced growth of sockeye salmon from 7 to 14% during the second year in the ocean compared with growth when pink salmon abundance was low, while third-year growth was reduced up to 17%. The overall effect of pink salmon abundance on sockeye growth was over two times greater than the effect of sockeye salmon abundance. Production hatcheries and ocean heating contribute to the competitive dominance of pink salmon, underscoring the need to consider this unintended anthropogenic effect on the growth and productivity of sockeye salmon throughout the North Pacific.
{"title":"Biennial patterns in Alaskan sockeye salmon ocean growth are associated with pink salmon abundance in the Gulf of Alaska and the Bering Sea","authors":"Peter S Rand, Gregory T Ruggerone","doi":"10.1093/icesjms/fsae022","DOIUrl":"https://doi.org/10.1093/icesjms/fsae022","url":null,"abstract":"In response to ocean heating and hatchery production, pink salmon (Oncorhynchus gorbuscha) returning from the North Pacific Ocean steadily increased after 1975, leading to concerns about their influence on food webs and competition with other species. Using measurements of distance between scale annuli of 24 584 individual sockeye salmon (O. nerka), we examined growth during their 2 or 3 years at sea from 1977 to 2015 for eight populations in Alaska. We found significant, negative autocorrelations at 1 lag year in annual growth of sockeye salmon, with a consistent pattern of lower growth in odd years, i.e. opposite to the biennial pattern of pink salmon abundance. Peak pink salmon abundances reduced growth of sockeye salmon from 7 to 14% during the second year in the ocean compared with growth when pink salmon abundance was low, while third-year growth was reduced up to 17%. The overall effect of pink salmon abundance on sockeye growth was over two times greater than the effect of sockeye salmon abundance. Production hatcheries and ocean heating contribute to the competitive dominance of pink salmon, underscoring the need to consider this unintended anthropogenic effect on the growth and productivity of sockeye salmon throughout the North Pacific.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"75 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140009960","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}
Offshore wind development (OWD) will generate much needed renewable energy, but it will also introduce several stressors to the marine ecosystem. Therefore, there is a need to develop information-rich monitoring programs to assess ecological impacts and inform solutions to mitigate adverse effects. This paper evaluates potential indicators of OWD impacts on fisheries resources that could be considered for monitoring programs, including indices of aggregate biomass, sensitive species, fish size, and trophic dynamics. Short-term (year-to-year) variability and the direction and strength of long-term trends were explored at both the scale of the US Southern New England wind energy area (WEA) and at the scale of the Southern New England region. The majority of candidate OWD indicators exhibited substantial temporal variability at either the WEA scale, the region scale, or both, highlighting the importance of addressing temporal variability in the design and duration of monitoring programs. Recommendations are provided to advance informative monitoring approaches both in the USA and elsewhere where such approaches are urgently needed. Among these is a recommendation for a minimum of 3–5 years of baseline data collection and continued monitoring for the lifetime of the wind project. This will enable an understanding of the temporal structure inherent to the time series of ecological indicators measured so that OWD impacts can be disentangled from those caused by other ecosystem pressures.
{"title":"Ecological indicators to monitor offshore wind interactions with fisheries resources","authors":"Elizabeth T Methratta","doi":"10.1093/icesjms/fsae017","DOIUrl":"https://doi.org/10.1093/icesjms/fsae017","url":null,"abstract":"Offshore wind development (OWD) will generate much needed renewable energy, but it will also introduce several stressors to the marine ecosystem. Therefore, there is a need to develop information-rich monitoring programs to assess ecological impacts and inform solutions to mitigate adverse effects. This paper evaluates potential indicators of OWD impacts on fisheries resources that could be considered for monitoring programs, including indices of aggregate biomass, sensitive species, fish size, and trophic dynamics. Short-term (year-to-year) variability and the direction and strength of long-term trends were explored at both the scale of the US Southern New England wind energy area (WEA) and at the scale of the Southern New England region. The majority of candidate OWD indicators exhibited substantial temporal variability at either the WEA scale, the region scale, or both, highlighting the importance of addressing temporal variability in the design and duration of monitoring programs. Recommendations are provided to advance informative monitoring approaches both in the USA and elsewhere where such approaches are urgently needed. Among these is a recommendation for a minimum of 3–5 years of baseline data collection and continued monitoring for the lifetime of the wind project. This will enable an understanding of the temporal structure inherent to the time series of ecological indicators measured so that OWD impacts can be disentangled from those caused by other ecosystem pressures.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"43 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140010217","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}
Arjay Cayetano, Christoph Stransky, Andreas Birk, Thomas Brey
Determination of individual age is one essential step in the accurate assessment of fish stocks. In non-tropical environments, the manual count of ring-like growth patterns in fish otoliths (ear stones) is the standard method. It relies on visual means and individual judgment and thus is subject to bias and interpretation errors. The use of automated pattern recognition based on machine learning may help to overcome this problem. Here, we employ two deep learning methods based on Convolutional Neural Networks (CNNs). The first approach utilizes the Mask R-CNN algorithm to perform object detection on the major otolith reading axes. The second approach employs the U-Net architecture to perform semantic segmentation on the otolith image in order to segregate the regions of interest. For both methods, we applied a simple postprocessing to count the rings on the output masks returned, which corresponds to the age prediction. Multiple benchmark tests indicate the promising performance of our implemented approaches, comparable to recently published methods based on classical image processing and traditional CNN implementation. Furthermore, our algorithms showed higher robustness compared to the existing methods, while also having the capacity to extrapolate missing age groups and to adapt to a new domain or data source.
{"title":"Fish age reading using deep learning methods for object-detection and segmentation","authors":"Arjay Cayetano, Christoph Stransky, Andreas Birk, Thomas Brey","doi":"10.1093/icesjms/fsae020","DOIUrl":"https://doi.org/10.1093/icesjms/fsae020","url":null,"abstract":"Determination of individual age is one essential step in the accurate assessment of fish stocks. In non-tropical environments, the manual count of ring-like growth patterns in fish otoliths (ear stones) is the standard method. It relies on visual means and individual judgment and thus is subject to bias and interpretation errors. The use of automated pattern recognition based on machine learning may help to overcome this problem. Here, we employ two deep learning methods based on Convolutional Neural Networks (CNNs). The first approach utilizes the Mask R-CNN algorithm to perform object detection on the major otolith reading axes. The second approach employs the U-Net architecture to perform semantic segmentation on the otolith image in order to segregate the regions of interest. For both methods, we applied a simple postprocessing to count the rings on the output masks returned, which corresponds to the age prediction. Multiple benchmark tests indicate the promising performance of our implemented approaches, comparable to recently published methods based on classical image processing and traditional CNN implementation. Furthermore, our algorithms showed higher robustness compared to the existing methods, while also having the capacity to extrapolate missing age groups and to adapt to a new domain or data source.","PeriodicalId":51072,"journal":{"name":"ICES Journal of Marine Science","volume":"47 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140009961","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}