Pub Date : 2024-10-31DOI: 10.3389/fmars.2024.1483796
Carolina Merca, Annette Simone Boerlage, Anders Ringgaard Kristensen, Dan Børge Jensen
The sustainability of the salmon farming industry is being challenged by increased mortality rates. Scotland’s open-source salmon production data provides the possibility of developing an industry-wide mortality monitoring model, valuable for identifying and addressing unexpected increases in mortality without needing data sharing agreements across different companies. This study aimed to utilize these data to develop a hierarchical dynamic linear model (DLM) for monitoring monthly mortality of maricultured Atlantic salmon in Scotland. We evaluated whether considering the hierarchical structure present in the data (country, region, and site) would improve mortality predictions when compared to the production cycle level DLMs developed in a previous study. Our findings demonstrated that the hierarchical DLM outperformed the production cycle level DLMs, confirming the value of this more complex modelling approach. Nevertheless, the hierarchical model, like the production cycle level DLMs, exhibited some uncertainty in the mortality predictions. When mortality is higher than expected, site level warnings are generated, which can encourage producers and inspectors to further investigate the cause. Between 2015 and 2020, approximately 25% of the production cycles and 50% of the sites encountered at least one warning, with most warnings happening in the summer and autumn months. Additionally, the hierarchical model enabled monitoring mortality at multiple levels. This information is useful for various stakeholders as part of a monitoring system, offering insights into mortality trends at national, regional, and sites levels that may benefit from strategic resource management. Recommendations for model improvements include utilizing shorter data aggregation periods, such as weekly, which are not currently available as open-source data.
{"title":"Monitoring monthly mortality of maricultured Atlantic salmon (Salmo salar L.) in Scotland II. A hierarchical dynamic linear model","authors":"Carolina Merca, Annette Simone Boerlage, Anders Ringgaard Kristensen, Dan Børge Jensen","doi":"10.3389/fmars.2024.1483796","DOIUrl":"https://doi.org/10.3389/fmars.2024.1483796","url":null,"abstract":"The sustainability of the salmon farming industry is being challenged by increased mortality rates. Scotland’s open-source salmon production data provides the possibility of developing an industry-wide mortality monitoring model, valuable for identifying and addressing unexpected increases in mortality without needing data sharing agreements across different companies. This study aimed to utilize these data to develop a hierarchical dynamic linear model (DLM) for monitoring monthly mortality of maricultured Atlantic salmon in Scotland. We evaluated whether considering the hierarchical structure present in the data (country, region, and site) would improve mortality predictions when compared to the production cycle level DLMs developed in a previous study. Our findings demonstrated that the hierarchical DLM outperformed the production cycle level DLMs, confirming the value of this more complex modelling approach. Nevertheless, the hierarchical model, like the production cycle level DLMs, exhibited some uncertainty in the mortality predictions. When mortality is higher than expected, site level warnings are generated, which can encourage producers and inspectors to further investigate the cause. Between 2015 and 2020, approximately 25% of the production cycles and 50% of the sites encountered at least one warning, with most warnings happening in the summer and autumn months. Additionally, the hierarchical model enabled monitoring mortality at multiple levels. This information is useful for various stakeholders as part of a monitoring system, offering insights into mortality trends at national, regional, and sites levels that may benefit from strategic resource management. Recommendations for model improvements include utilizing shorter data aggregation periods, such as weekly, which are not currently available as open-source data.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.3389/fmars.2024.1460657
Xiaokang Luo, Yajuan Yuan, Wei Zhang, Wei Huang, Shimin Ou, Chunsheng Ji, Jun Cao
Gas hydrates are globally acknowledged as a significant strategic alternative energy source, and there is a consensus on the necessity to enhance their exploration. However, gas hydrates are highly prone to decomposition under variations in external environmental conditions, which can result in subsea methane seepage activities. Consequently, investigating subsea methane seepage activities holds substantial theoretical and practical significance for exploring gas hydrates. This paper evaluates the history of methane seepage activities in the Qiongdongnan Basin (QDNB) by analyzing the carbon and oxygen isotopic characteristics of benthic foraminifera and the geochemical properties of pore water from gravity sediment cores at sites QH-CL4 and QH-CL40. The results indicate that since the Marine isotope stage2 (MIS2), continuous micro-methane seepage activity has been present in the QDNB, characterized by a slight negative deviation in the carbon isotopes of benthic foraminifera. Methane seepage activity intensified during 14.6 ka BP and between 19.64–23.22 ka BP. This increase is thought to be associated with rising seawater temperature during the Bølling–Allerød interstadial and declining sea level during the Last Glacial Maximum, respectively. Moreover, current geochemical characteristics of pore water reveal strong methane seepage activity, with flux as high as 28.968 mmol·m-²·a-¹. This ongoing activity has led to gas hydrate formation within shallow layers while also causing negative deviations in pore water salinity.
全球公认天然气水合物是一种重要的战略替代能源，加强对其勘探的必要性已成为共识。然而，天然气水合物在外部环境条件变化时极易分解，从而导致海底甲烷渗流活动。因此，研究水下甲烷渗流活动对勘探天然气水合物具有重要的理论和实践意义。本文通过分析 QH-CL4 和 QH-CL40 地点重力沉积岩芯中底栖有孔虫的碳氧同位素特征和孔隙水地球化学性质，评估了琼东南盆地（QDNB）甲烷渗流活动的历史。结果表明，自海洋同位素第二阶段（MIS2）以来，QDNB 一直存在微甲烷渗流活动，其特征是底栖有孔虫的碳同位素出现了轻微的负偏差。甲烷渗流活动在 14.6 ka BP 和 19.64-23.22 ka BP 期间加剧。这种增加被认为分别与博林-阿勒罗德间歇期海水温度上升和末次冰期海平面下降有关。此外，目前孔隙水的地球化学特征显示，甲烷渗出活动十分活跃，流量高达 28.968 mmol-m-²-a-¹。这种持续不断的活动导致了浅层气体水合物的形成，同时也造成了孔隙水盐度的负偏差。
{"title":"Methane seepage activities in the Qiongdongnan Basin since MIS2","authors":"Xiaokang Luo, Yajuan Yuan, Wei Zhang, Wei Huang, Shimin Ou, Chunsheng Ji, Jun Cao","doi":"10.3389/fmars.2024.1460657","DOIUrl":"https://doi.org/10.3389/fmars.2024.1460657","url":null,"abstract":"Gas hydrates are globally acknowledged as a significant strategic alternative energy source, and there is a consensus on the necessity to enhance their exploration. However, gas hydrates are highly prone to decomposition under variations in external environmental conditions, which can result in subsea methane seepage activities. Consequently, investigating subsea methane seepage activities holds substantial theoretical and practical significance for exploring gas hydrates. This paper evaluates the history of methane seepage activities in the Qiongdongnan Basin (QDNB) by analyzing the carbon and oxygen isotopic characteristics of benthic foraminifera and the geochemical properties of pore water from gravity sediment cores at sites QH-CL4 and QH-CL40. The results indicate that since the Marine isotope stage2 (MIS2), continuous micro-methane seepage activity has been present in the QDNB, characterized by a slight negative deviation in the carbon isotopes of benthic foraminifera. Methane seepage activity intensified during 14.6 ka BP and between 19.64–23.22 ka BP. This increase is thought to be associated with rising seawater temperature during the Bølling–Allerød interstadial and declining sea level during the Last Glacial Maximum, respectively. Moreover, current geochemical characteristics of pore water reveal strong methane seepage activity, with flux as high as 28.968 mmol·m<jats:sup>-</jats:sup>²·a<jats:sup>-</jats:sup>¹. This ongoing activity has led to gas hydrate formation within shallow layers while also causing negative deviations in pore water salinity.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.3389/fmars.2024.1469015
Jun-Ho Hyung, Seung Joo Moon, Hangy Lee, Jaeyeon Park
Distribution patterns of benthic dinoflagellates that are widely observed in tropical and temperate waters and have toxic potential are changing in response to ocean climate change. Although there have been no outbreaks associated with the genus Coolia affecting humans, it is crucial to understand their changing distribution and clearly identify the species in the study area to prepare for potential toxic events. In this study, five strains of Coolia species were isolated from macroalgae samples collected from Jeju Island and the eastern coastal waters of Korea. Through morphological and molecular analysis of these isolates, one strain was identified as Coolia palmyrensis, marking the first report of this species in Korea, and four strains as C. malayensis. One of the C. malayensis strains was isolated in Pohang on the eastern coast of Korea, where it had not been previously reported. From 2021 to 2023, monitoring of Jeju Island using a quantitative polymerase chain reaction (PCR) assay revealed that C. palmyrensis cells occurred mostly in autumn, with a maximum density of 242 cells g-1, and overwintering populations were observed in 2023. However, C. malayensis cells were not observed in this area. Additionally, C. malayensis was observed in Pohang and Ulsan, located further north than Jeju Island with maximum cell densities of 537 and 201 cells g-1, respectively. These data and our decade of monitoring experience confirmed the introduction and establishment of C. palmyrensis and habitat shift of C. malayensis in Korean coastal waters. This study provides advances for understanding of the relationships between climate-driven alterations and biogeographic distribution of these species.
{"title":"First report of Coolia palmyrensis in Korea: seasonal and spatial distribution of C. palmyrensis and C. malayensis in Korean coastal waters","authors":"Jun-Ho Hyung, Seung Joo Moon, Hangy Lee, Jaeyeon Park","doi":"10.3389/fmars.2024.1469015","DOIUrl":"https://doi.org/10.3389/fmars.2024.1469015","url":null,"abstract":"Distribution patterns of benthic dinoflagellates that are widely observed in tropical and temperate waters and have toxic potential are changing in response to ocean climate change. Although there have been no outbreaks associated with the genus <jats:italic>Coolia</jats:italic> affecting humans, it is crucial to understand their changing distribution and clearly identify the species in the study area to prepare for potential toxic events. In this study, five strains of <jats:italic>Coolia</jats:italic> species were isolated from macroalgae samples collected from Jeju Island and the eastern coastal waters of Korea. Through morphological and molecular analysis of these isolates, one strain was identified as <jats:italic>Coolia palmyrensis</jats:italic>, marking the first report of this species in Korea, and four strains as <jats:italic>C. malayensis</jats:italic>. One of the <jats:italic>C</jats:italic>. <jats:italic>malayensis</jats:italic> strains was isolated in Pohang on the eastern coast of Korea, where it had not been previously reported. From 2021 to 2023, monitoring of Jeju Island using a quantitative polymerase chain reaction (PCR) assay revealed that <jats:italic>C</jats:italic>. <jats:italic>palmyrensis</jats:italic> cells occurred mostly in autumn, with a maximum density of 242 cells g<jats:sup>-1</jats:sup>, and overwintering populations were observed in 2023. However, <jats:italic>C</jats:italic>. <jats:italic>malayensis</jats:italic> cells were not observed in this area. Additionally, <jats:italic>C</jats:italic>. <jats:italic>malayensis</jats:italic> was observed in Pohang and Ulsan, located further north than Jeju Island with maximum cell densities of 537 and 201 cells g<jats:sup>-1</jats:sup>, respectively. These data and our decade of monitoring experience confirmed the introduction and establishment of <jats:italic>C</jats:italic>. <jats:italic>palmyrensis</jats:italic> and habitat shift of <jats:italic>C</jats:italic>. <jats:italic>malayensis</jats:italic> in Korean coastal waters. This study provides advances for understanding of the relationships between climate-driven alterations and biogeographic distribution of these species.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.3389/fmars.2024.1392680
Svetlana Pakhomova, Anfisa Berezina, Igor Zhdanov, Evgeniy Yakushev
Little is known about the role of remote and sparsely populated Arctic coastal zones in the microplastic cycle. Distribution of microplastics was studied in the Svalbard fjords in June – July 2022 with the main goal of assessing rivers’ role in the fate of microplastic in Arctic coastal waters. Surface microplastics (0 – 20 cm depth, 500 – 5000 µm size) were sampled with a neuston net in triplicate per study site in parallel with sampling of subsurface microplastics with a pump system (1.5 m depth, 100 – 5000 µm size). The central part of Isfjorden and its several branches covering populated and unpopulated fjords were studied; the sampling was conducted during an intense riverine discharge in all studied sites. Maximum abundance of surface microplastics (71,400 items/km2 or 0.19 iterms/m3, 0.19 mg/m3) was found along the river plume border in the middle of populated Adventfjorden indicating importance of both local sources and surface hydrodynamics in the formation of microplastics accumulation hotspots. All other unpopulated fjords were free of the floating on the sea surface microplastics as river discharge prevented transport of microplastics inside the fjords. The highest concentration of subsurface microplastics was found in the central part of Isfjorden and the lowest – in river plume waters, which also indicates the removal of microplastics from the inner part of fjords during an intensive river discharge. Our results may suggest that Arctic rivers flowing through unpopulated areas bring clean water and thereby reduce level of microplastic pollution in the coastal waters. In contrast to the rest of the world’s ocean, rivers are not the main source of microplastic pollution in the Arctic Ocean.
{"title":"Microplastic fate in Arctic coastal waters: accumulation hotspots and role of rivers in Svalbard","authors":"Svetlana Pakhomova, Anfisa Berezina, Igor Zhdanov, Evgeniy Yakushev","doi":"10.3389/fmars.2024.1392680","DOIUrl":"https://doi.org/10.3389/fmars.2024.1392680","url":null,"abstract":"Little is known about the role of remote and sparsely populated Arctic coastal zones in the microplastic cycle. Distribution of microplastics was studied in the Svalbard fjords in June – July 2022 with the main goal of assessing rivers’ role in the fate of microplastic in Arctic coastal waters. Surface microplastics (0 – 20 cm depth, 500 – 5000 µm size) were sampled with a neuston net in triplicate per study site in parallel with sampling of subsurface microplastics with a pump system (1.5 m depth, 100 – 5000 µm size). The central part of Isfjorden and its several branches covering populated and unpopulated fjords were studied; the sampling was conducted during an intense riverine discharge in all studied sites. Maximum abundance of surface microplastics (71,400 items/km<jats:sup>2</jats:sup> or 0.19 iterms/m<jats:sup>3</jats:sup>, 0.19 mg/m<jats:sup>3</jats:sup>) was found along the river plume border in the middle of populated Adventfjorden indicating importance of both local sources and surface hydrodynamics in the formation of microplastics accumulation hotspots. All other unpopulated fjords were free of the floating on the sea surface microplastics as river discharge prevented transport of microplastics inside the fjords. The highest concentration of subsurface microplastics was found in the central part of Isfjorden and the lowest – in river plume waters, which also indicates the removal of microplastics from the inner part of fjords during an intensive river discharge. Our results may suggest that Arctic rivers flowing through unpopulated areas bring clean water and thereby reduce level of microplastic pollution in the coastal waters. In contrast to the rest of the world’s ocean, rivers are not the main source of microplastic pollution in the Arctic Ocean.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.3389/fmars.2024.1380594
Anchita Casaubon, Torben Riehl
Accurate taxonomic classification of deep-sea taxa is often impeded by the presence of highly morphologically similar but genetically distinct species. This issue is particularly pronounced in the isopods of the deep-sea family Macrostylidae, which exhibit remarkably low morphological variation despite significant genetic diversity. In this study, we present the first application of geometric morphometric techniques to 41 specimens across five species of deep-sea macrostylid isopods collected from Icelandic waters. Our results suggest that geometric morphometric techniques can effectively discriminate between macrostylid species. These techniques, hence, promise to be an important addition to the toolset of macrostylid taxonomists.
{"title":"Shape matters: investigating the utility of geometric morphometric techniques in the deep-sea isopod family Macrostylidae (Isopoda: Asellota)","authors":"Anchita Casaubon, Torben Riehl","doi":"10.3389/fmars.2024.1380594","DOIUrl":"https://doi.org/10.3389/fmars.2024.1380594","url":null,"abstract":"Accurate taxonomic classification of deep-sea taxa is often impeded by the presence of highly morphologically similar but genetically distinct species. This issue is particularly pronounced in the isopods of the deep-sea family Macrostylidae, which exhibit remarkably low morphological variation despite significant genetic diversity. In this study, we present the first application of geometric morphometric techniques to 41 specimens across five species of deep-sea macrostylid isopods collected from Icelandic waters. Our results suggest that geometric morphometric techniques can effectively discriminate between macrostylid species. These techniques, hence, promise to be an important addition to the toolset of macrostylid taxonomists.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extracellular polymeric substances, such as transparent exopolymer particles (TEP) composed of acidic polysaccharides, are important particulate organic carbon (POC) components of marine environments that affect particle dynamics and ocean carbon export. However, how polymeric substances interact with and shape bacterial communities associated with marine particles is poorly understood. This study investigated whether the composition of particle-associated bacterial communities differs between sinking and suspended particles, which differ in their polymeric substance contents, in the upper water column of the subtropical, oligotrophic Kuroshio region. Bacterial taxa likely involved in polymer degradation (Alphaproteobacteria, Gammaproteobacteria, and Bacteroidia) were enriched on sinking particles with a lower TEP: POC ratio, indicating that bacterial degradation of polymeric substances promotes particle sinking by removing positively buoyant polymers. By contrast, suspended particles were increasingly enriched for Bdellovibrionota and Desulfobacterota as the TEP: POC ratio increased. These taxa, which include predatory microbes, seem to prefer polymer-rich environments with a high density of potential prey. Planctomycetota were not significantly related to the TEP: POC ratio, indicating their broad niche breadth on particles’ polymeric substance contents. The results suggest that the bacterial niche differentiation associated with the particle polymeric-substance gradient shapes bacterial communities in a subtropical ocean.
{"title":"Structuring of particle-associated bacterial communities along the extracellular polymeric substance gradient of sinking and suspended particles in an oligotrophic, subtropical region of the western North Pacific Ocean","authors":"Akiko Ebihara, Hideki Fukuda, Yosuke Yamada, Taichi Yokokawa, Takeshi Miki, Toshi Nagata","doi":"10.3389/fmars.2024.1462522","DOIUrl":"https://doi.org/10.3389/fmars.2024.1462522","url":null,"abstract":"Extracellular polymeric substances, such as transparent exopolymer particles (TEP) composed of acidic polysaccharides, are important particulate organic carbon (POC) components of marine environments that affect particle dynamics and ocean carbon export. However, how polymeric substances interact with and shape bacterial communities associated with marine particles is poorly understood. This study investigated whether the composition of particle-associated bacterial communities differs between sinking and suspended particles, which differ in their polymeric substance contents, in the upper water column of the subtropical, oligotrophic Kuroshio region. Bacterial taxa likely involved in polymer degradation (Alphaproteobacteria, Gammaproteobacteria, and Bacteroidia) were enriched on sinking particles with a lower TEP: POC ratio, indicating that bacterial degradation of polymeric substances promotes particle sinking by removing positively buoyant polymers. By contrast, suspended particles were increasingly enriched for Bdellovibrionota and Desulfobacterota as the TEP: POC ratio increased. These taxa, which include predatory microbes, seem to prefer polymer-rich environments with a high density of potential prey. Planctomycetota were not significantly related to the TEP: POC ratio, indicating their broad niche breadth on particles’ polymeric substance contents. The results suggest that the bacterial niche differentiation associated with the particle polymeric-substance gradient shapes bacterial communities in a subtropical ocean.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.3389/fmars.2024.1481840
Sarah Tubbs, Per Berggren
Bycatch is the most significant threat to marine mammals globally. There are increasing requirements for national governments to fulfil their obligations to international agreements and treaties to assess fisheries catch and bycatch of non-target species. Questionnaire surveys represent one low-cost method to collect data to estimate fisheries catch and bycatch of vulnerable species including marine mammals. Questionnaire surveys can be particularly advantageous when bycatch is being investigated on large spatial and temporal scales, or in data-poor areas. This review aims to provide the necessary guidance required to design and conduct questionnaire studies investigating marine mammal bycatch. To do so, a systematic review was conducted of the methods used in 91 peer-reviewed or grey literature questionnaire studies from 1990 to 2023 investigating marine mammal bycatch. Literature was searched, screened, and analysed following the RepOrting standards for Systematic Evidence Syntheses (ROSES) protocols. A narrative synthesis and critical evaluation of the methods used were conducted and best practice recommendations are proposed. The recommendations include suggestions for how to generate representative samples, the steps that should be followed when designing a questionnaire instrument, how to collect reliable data, how to reduce under-reporting and interviewer bias, and how weighting or model-based bycatch estimation techniques can be used to reduce sampling bias. The review’s guidance and best practice recommendations provide much-needed resources to develop and employ questionnaire studies that produce robust bycatch estimates for marine mammal populations where they are currently missing. Recommendations can be used by scientists and decision-makers across the globe. Whilst the focus of this review is on using questionnaires to investigate marine mammal bycatch, the information and recommendations will also be useful for those investigating bycatch of any other non-target species.
{"title":"Questionnaire surveys to investigate marine mammal fisheries bycatch: systematic review and best practice","authors":"Sarah Tubbs, Per Berggren","doi":"10.3389/fmars.2024.1481840","DOIUrl":"https://doi.org/10.3389/fmars.2024.1481840","url":null,"abstract":"Bycatch is the most significant threat to marine mammals globally. There are increasing requirements for national governments to fulfil their obligations to international agreements and treaties to assess fisheries catch and bycatch of non-target species. Questionnaire surveys represent one low-cost method to collect data to estimate fisheries catch and bycatch of vulnerable species including marine mammals. Questionnaire surveys can be particularly advantageous when bycatch is being investigated on large spatial and temporal scales, or in data-poor areas. This review aims to provide the necessary guidance required to design and conduct questionnaire studies investigating marine mammal bycatch. To do so, a systematic review was conducted of the methods used in 91 peer-reviewed or grey literature questionnaire studies from 1990 to 2023 investigating marine mammal bycatch. Literature was searched, screened, and analysed following the RepOrting standards for Systematic Evidence Syntheses (ROSES) protocols. A narrative synthesis and critical evaluation of the methods used were conducted and best practice recommendations are proposed. The recommendations include suggestions for how to generate representative samples, the steps that should be followed when designing a questionnaire instrument, how to collect reliable data, how to reduce under-reporting and interviewer bias, and how weighting or model-based bycatch estimation techniques can be used to reduce sampling bias. The review’s guidance and best practice recommendations provide much-needed resources to develop and employ questionnaire studies that produce robust bycatch estimates for marine mammal populations where they are currently missing. Recommendations can be used by scientists and decision-makers across the globe. Whilst the focus of this review is on using questionnaires to investigate marine mammal bycatch, the information and recommendations will also be useful for those investigating bycatch of any other non-target species.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.3389/fmars.2024.1449369
Eduardo A. Flores, Marcel Ramos, Boris Dewitte, Orlando Astudillo, Lucas Glasner
The Humboldt Archipelago (HAp), located off north-central Chile (~28° - 33° S) is one of the most productive marine zones of the Humboldt Current System (HCS). This area lies within a permanent upwelling zone, characterized by two upwelling centers, 100 km apart, that define the Coquimbo Bays System (CBS). The resulting increase in primary productivity and larval retention are mentioned as the main factors that explain the high biodiversity. However, how these upwelling centers interact remains unclear due to the interplay of various physical features such as the general circulation, the meso- and submeso-scale structures (e.g., eddies), and remote and local forcings (e.g., winds, topography) that affect larval transport in the HAp. In this study, we focus on the role played by geostrophic and Ekman currents in controlling the retention (and dispersion) of particles in these centers based on the analyses of satellite data and hydrodynamic model outputs. Lagrangian models are in particular carried out to document particles’ transport during selected oceanic conditions corresponding to whether Ekman transport or geostrophic recirculation prevails or are debilitated. The latitudinal variation of the Ekman transport reveals two maxima at each upwelling center with differences in spatial extent but not in intensity. Mean zonal geostrophic current occurs in alternating flow at each upwelling center. Results of the Lagrangian experiments highlight the importance of the cross-shore geostrophic flow on larval transport, where an increased transport of particles to the north and northwest occurs at the southern upwelling center, while the northern upwelling center (where HAp is located) received particles from the south and retained particles released in the same area, which is related to the cyclonic geostrophic recirculation and lower Ekman transport. Particle retention increased with depth and under the relaxation and downwelling scenarios revealing the importance of wind alternation for larval retention. The CBS could act as an upwelling shadow in the south and an upwelling trap in the north where the onshore flow of geostrophic current could enhance larval retention and recruitment over longer periods when compared with the Ekman transport timescale.
{"title":"On the role of onshore geostrophic flow on larval retention in a permanent upwelling zone along north-central Chile","authors":"Eduardo A. Flores, Marcel Ramos, Boris Dewitte, Orlando Astudillo, Lucas Glasner","doi":"10.3389/fmars.2024.1449369","DOIUrl":"https://doi.org/10.3389/fmars.2024.1449369","url":null,"abstract":"The Humboldt Archipelago (HAp), located off north-central Chile (~28° - 33° S) is one of the most productive marine zones of the Humboldt Current System (HCS). This area lies within a permanent upwelling zone, characterized by two upwelling centers, 100 km apart, that define the Coquimbo Bays System (CBS). The resulting increase in primary productivity and larval retention are mentioned as the main factors that explain the high biodiversity. However, how these upwelling centers interact remains unclear due to the interplay of various physical features such as the general circulation, the meso- and submeso-scale structures (e.g., eddies), and remote and local forcings (e.g., winds, topography) that affect larval transport in the HAp. In this study, we focus on the role played by geostrophic and Ekman currents in controlling the retention (and dispersion) of particles in these centers based on the analyses of satellite data and hydrodynamic model outputs. Lagrangian models are in particular carried out to document particles’ transport during selected oceanic conditions corresponding to whether Ekman transport or geostrophic recirculation prevails or are debilitated. The latitudinal variation of the Ekman transport reveals two maxima at each upwelling center with differences in spatial extent but not in intensity. Mean zonal geostrophic current occurs in alternating flow at each upwelling center. Results of the Lagrangian experiments highlight the importance of the cross-shore geostrophic flow on larval transport, where an increased transport of particles to the north and northwest occurs at the southern upwelling center, while the northern upwelling center (where HAp is located) received particles from the south and retained particles released in the same area, which is related to the cyclonic geostrophic recirculation and lower Ekman transport. Particle retention increased with depth and under the relaxation and downwelling scenarios revealing the importance of wind alternation for larval retention. The CBS could act as an upwelling shadow in the south and an upwelling trap in the north where the onshore flow of geostrophic current could enhance larval retention and recruitment over longer periods when compared with the Ekman transport timescale.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.3389/fmars.2024.1445215
Jacqueline R. Huard, Victoria Hemming, Matthew R. Baker, Jennifer Blancard, Ian Bruce, Sarah Cook, Gail K. Davoren, Phillip Dionne, Virginia East, J. Mark Hipfner, Nicola R. Houtman, Brian A. Koval, Dayv Lowry, Rowen Monks, Graham Nicholas, Beatrice Proudfoot, Micah Quindazzi, Timothy Quinn, Clifford L. K. Robinson, Emily M. Rubidge, Dianne Sanford, James R. Selleck, Anne Shaffer, Nikki Wright, Jennifer Yakimishyn, Tara G. Martin
Like many forage fish species, Pacific sand lance (Ammodytes personatus) play a key role in nearshore marine ecosystems as an important prey source for a diverse array of predators in the northeastern Pacific. However, the primary threats to Pacific sand lance and their habitat are poorly defined due to a lack of systematic data. Crucial information needed to assess their population status is also lacking including basic knowledge of their local and regional abundance and distribution. Sand lance are currently listed as ‘not evaluated’ under the IUCN red list and they have not been assessed by US and Canadian agencies. This hampers management and policy efforts focused on their conservation. To address this knowledge gap, we conducted a three-part, structured expert elicitation to assess the vulnerability of Salish Sea sand lance populations. Experts were asked to list and rank key threats to Salish Sea sand lance and/or their habitat, to further quantify the vulnerability of sand lance to identified threats using a vulnerability matrix, and to predict the population trajectory in 25 years from today. Impacts associated with climate change (e.g. sea level rise, sea temperature rise, ocean acidification, and extreme weather) consistently ranked high as threats of concern in the ranking exercise and quantified vulnerability scores. Nearly every expert predicted the population will have declined from current levels in 25 years. These results suggest sand lance face numerous threats and may be in decline under current conditions. This research provides vital information about which threats pose the greatest risk to the long-term health of sand lance populations and their habitat. Managers can use this information to prioritize which threats to address. Future research to reliably quantify population size, better understand the roles of natural and anthropogenic impacts, and to identify the most cost-effective actions to mitigate multiple threats, is recommended.
{"title":"Threat assessment for Pacific sand lance (Ammodytes personatus) in the Salish Sea","authors":"Jacqueline R. Huard, Victoria Hemming, Matthew R. Baker, Jennifer Blancard, Ian Bruce, Sarah Cook, Gail K. Davoren, Phillip Dionne, Virginia East, J. Mark Hipfner, Nicola R. Houtman, Brian A. Koval, Dayv Lowry, Rowen Monks, Graham Nicholas, Beatrice Proudfoot, Micah Quindazzi, Timothy Quinn, Clifford L. K. Robinson, Emily M. Rubidge, Dianne Sanford, James R. Selleck, Anne Shaffer, Nikki Wright, Jennifer Yakimishyn, Tara G. Martin","doi":"10.3389/fmars.2024.1445215","DOIUrl":"https://doi.org/10.3389/fmars.2024.1445215","url":null,"abstract":"Like many forage fish species, Pacific sand lance (<jats:italic>Ammodytes personatus</jats:italic>) play a key role in nearshore marine ecosystems as an important prey source for a diverse array of predators in the northeastern Pacific. However, the primary threats to Pacific sand lance and their habitat are poorly defined due to a lack of systematic data. Crucial information needed to assess their population status is also lacking including basic knowledge of their local and regional abundance and distribution. Sand lance are currently listed as ‘not evaluated’ under the IUCN red list and they have not been assessed by US and Canadian agencies. This hampers management and policy efforts focused on their conservation. To address this knowledge gap, we conducted a three-part, structured expert elicitation to assess the vulnerability of Salish Sea sand lance populations. Experts were asked to list and rank key threats to Salish Sea sand lance and/or their habitat, to further quantify the vulnerability of sand lance to identified threats using a vulnerability matrix, and to predict the population trajectory in 25 years from today. Impacts associated with climate change (e.g. sea level rise, sea temperature rise, ocean acidification, and extreme weather) consistently ranked high as threats of concern in the ranking exercise and quantified vulnerability scores. Nearly every expert predicted the population will have declined from current levels in 25 years. These results suggest sand lance face numerous threats and may be in decline under current conditions. This research provides vital information about which threats pose the greatest risk to the long-term health of sand lance populations and their habitat. Managers can use this information to prioritize which threats to address. Future research to reliably quantify population size, better understand the roles of natural and anthropogenic impacts, and to identify the most cost-effective actions to mitigate multiple threats, is recommended.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.3389/fmars.2024.1440587
Titin Herawati, Windi Damayanti, Givanka A. Yuda, Yudi N. Ihsan, Buntora Pasaribu, Gentio Harsono, Marlina Marlina, Heny Suseno, Rizki A. Mustopa, Felin S. W. Karya, Choerunnisa Febriani, Noir P. Purba
Despite growing global concerns, there has been limited research on the characterization and distribution of microplastics in the Indonesian Throughflow (ITF) pathways, such as the Flores Sea. The Flores Sea is a component of the Indian–Pacific Current, a significant ocean current system that links the Pacific and Indian oceans and has the capacity to carry pollution over large marine ecosystems, making this research extremely important. Understanding the microplastic pollution in this area informs local environmental management. It provides insights into how these currents may distribute microplastics (MPs) across regional and global scales, impacting marine life and human health far beyond the immediate area. To respond to these concerns, this research aims to determine the characterization and distribution of MPs at six research sites in the Flores Sea that are precisely located within the ITF. This work exhibits an extensive dataset focusing on the occurrence, attributes, and dispersion of microplastics in the Flores Sea. The water sampling was carried out during a Jala Citra 3 by the Indonesian Navy from April to May 2023. Sea surface water samples were collected using a Neuston net, while sediment samples were taken from three stations at the shallowest depth using the Ekman Grab sampler. Additionally, abundance, size, shape, and color analyses were conducted using a light microscope, and microplastic types were identified through Raman spectroscopy. The results indicated that the Flores Sea waters and sediment are polluted with microplastics, with relative abundances ranging from 0.75 ± 0.49 to 2.13 ± 0.25 items/l samples. The most dominant shapes identified were filament (77.45%) and fragment (13.40%), with sizes varying between surface water 4.70 to 3799.25 μm and seabed from 67.20 mm to 2176.87 mm, while black (30.07%) and blue (24.51%) were reported as the common MPs colors. The identified polymers include PET and PE. This study confirms visual evidence of microplastics in the open waters of eastern Indonesia. While it may not fully capture the wide range of temporal variations, it establishes initial microplastic presence and dispersion levels. Given that the ITF influences both the Pacific and Indian Oceans, this research contributes to the global understanding of microplastic distribution across ocean basins, underscoring the need for coordinated international efforts to address marine pollution.
{"title":"Assessment of microplastic characterization and distribution from surface water and the seabed in the Flores Sea, Indonesia","authors":"Titin Herawati, Windi Damayanti, Givanka A. Yuda, Yudi N. Ihsan, Buntora Pasaribu, Gentio Harsono, Marlina Marlina, Heny Suseno, Rizki A. Mustopa, Felin S. W. Karya, Choerunnisa Febriani, Noir P. Purba","doi":"10.3389/fmars.2024.1440587","DOIUrl":"https://doi.org/10.3389/fmars.2024.1440587","url":null,"abstract":"Despite growing global concerns, there has been limited research on the characterization and distribution of microplastics in the Indonesian Throughflow (ITF) pathways, such as the Flores Sea. The Flores Sea is a component of the Indian–Pacific Current, a significant ocean current system that links the Pacific and Indian oceans and has the capacity to carry pollution over large marine ecosystems, making this research extremely important. Understanding the microplastic pollution in this area informs local environmental management. It provides insights into how these currents may distribute microplastics (MPs) across regional and global scales, impacting marine life and human health far beyond the immediate area. To respond to these concerns, this research aims to determine the characterization and distribution of MPs at six research sites in the Flores Sea that are precisely located within the ITF. This work exhibits an extensive dataset focusing on the occurrence, attributes, and dispersion of microplastics in the Flores Sea. The water sampling was carried out during a Jala Citra 3 by the Indonesian Navy from April to May 2023. Sea surface water samples were collected using a Neuston net, while sediment samples were taken from three stations at the shallowest depth using the Ekman Grab sampler. Additionally, abundance, size, shape, and color analyses were conducted using a light microscope, and microplastic types were identified through Raman spectroscopy. The results indicated that the Flores Sea waters and sediment are polluted with microplastics, with relative abundances ranging from 0.75 ± 0.49 to 2.13 ± 0.25 items/l samples. The most dominant shapes identified were filament (77.45%) and fragment (13.40%), with sizes varying between surface water 4.70 to 3799.25 μm and seabed from 67.20 mm to 2176.87 mm, while black (30.07%) and blue (24.51%) were reported as the common MPs colors. The identified polymers include PET and PE. This study confirms visual evidence of microplastics in the open waters of eastern Indonesia. While it may not fully capture the wide range of temporal variations, it establishes initial microplastic presence and dispersion levels. Given that the ITF influences both the Pacific and Indian Oceans, this research contributes to the global understanding of microplastic distribution across ocean basins, underscoring the need for coordinated international efforts to address marine pollution.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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