The export and transformation of riverine dissolved organic matter (DOM) at the river-sea interface are critical to understanding carbon budgets in tropical regions, yet remain underexplored in small watersheds. This study analyzed dissolved organic carbon (DOC), chromophoric (CDOM), and fluorescent DOM (FDOM) over five cruises from summer 2021 to summer 2022 in the Suixi Estuary-Zhanjiang Bay continuum, a eutrophic tropical transition zone in the northwestern South China Sea. Seasonal variations were pronounced for DOM in the continuum and two endmembers. Freshwater DOM, dominated by terrestrial organic materials, was closely tied to soil leaching and erosion, correlating with precipitation patterns. Conversely, seawater DOM, enriched in protein-like FDOM, varied with the West-Guangdong Coastal Current and its associated primary production. Linear decreases in DOM with increasing salinity indicate that conservative mixing largely shapes DOM distributions in the continuum, especially for humic-like FDOM. Non-conservative processes, including flocculation, phytoplankton production, and microbial transformation, variably alter DOM components across seasons. The Suixi River in summer contributed considerably but disproportionately to the annual DOM flux (47-59%), due to intense soil leaching processes that mobilize refractory terrigenous DOM. The deviation observed in the Suixi River’s DOC-CDOM relationship from that of global rivers, coupled with a distinctive single-peak pattern between the carbon-specific absorption coefficient and water yield in global rivers, highlights the critical role of watershed nature in influencing river-exported DOM composition. The notably high DOC and CDOM yields for the Suixi River further emphasize the importance of small, tropical rivers in shaping the estuarine and coastal carbon budget.
{"title":"Seasonal dynamics of dissolved organic matter in a small tropical estuary-coastal bay continuum: distribution, transformation, flux, and global perspectives","authors":"Pengfei Liu, Kuan Jiang, Qi Tan, Fajin Chen, Renming Jia, Chao Wang","doi":"10.3389/fmars.2024.1511427","DOIUrl":"https://doi.org/10.3389/fmars.2024.1511427","url":null,"abstract":"The export and transformation of riverine dissolved organic matter (DOM) at the river-sea interface are critical to understanding carbon budgets in tropical regions, yet remain underexplored in small watersheds. This study analyzed dissolved organic carbon (DOC), chromophoric (CDOM), and fluorescent DOM (FDOM) over five cruises from summer 2021 to summer 2022 in the Suixi Estuary-Zhanjiang Bay continuum, a eutrophic tropical transition zone in the northwestern South China Sea. Seasonal variations were pronounced for DOM in the continuum and two endmembers. Freshwater DOM, dominated by terrestrial organic materials, was closely tied to soil leaching and erosion, correlating with precipitation patterns. Conversely, seawater DOM, enriched in protein-like FDOM, varied with the West-Guangdong Coastal Current and its associated primary production. Linear decreases in DOM with increasing salinity indicate that conservative mixing largely shapes DOM distributions in the continuum, especially for humic-like FDOM. Non-conservative processes, including flocculation, phytoplankton production, and microbial transformation, variably alter DOM components across seasons. The Suixi River in summer contributed considerably but disproportionately to the annual DOM flux (47-59%), due to intense soil leaching processes that mobilize refractory terrigenous DOM. The deviation observed in the Suixi River’s DOC-CDOM relationship from that of global rivers, coupled with a distinctive single-peak pattern between the carbon-specific absorption coefficient and water yield in global rivers, highlights the critical role of watershed nature in influencing river-exported DOM composition. The notably high DOC and CDOM yields for the Suixi River further emphasize the importance of small, tropical rivers in shaping the estuarine and coastal carbon budget.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"20 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992623","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 : 2025-01-20DOI: 10.3389/fmars.2024.1524585
Arun Mishra, Enriko Siht, Germo Väli, Taavi Liblik, Natalja Buhhalko, Urmas Lips
A hydrodynamic model coupled with a particle tracking model was used to identify the pathways and accumulation areas of microplastics (MP) in the Gulf of Finland (GoF) over a three-year period (2018-2020). Two key sources, wastewater treatment plants (WWTPs) and rivers, were considered, focusing on polypropylene (PP)/polyethylene (PE) and polyethylene terephthalate (PET) particles sized 20-500 μm. Rivers contribute 76% of total MP entering the gulf, while WWTPs account for the remaining 24%. Most of the MP accumulates inside the gulf and does not drift to the Baltic Proper. The eastern part of the gulf exhibits the highest surface concentrations of particles influenced by the Neva River. In the water column, MP concentrations were notably high in shallow coastal areas, decreasing gradually offshore. Potential MP accumulation zones were identified primarily between longitudes 28°E and 30°E, particularly near the major rivers Narva and Kymi and in the easternmost gulf related to the Neva River discharge. The MP concentrations in the surface layer and water column were higher in winter while settling was more intense in summer. Short-term variability in the surface layer was caused by (sub)mesoscale advection and divergence/convergence, while in the near-bottom layer, strong bottom currents and consequent resuspension elevated the concentrations.
{"title":"Mapping microplastic pathways and accumulation zones in the Gulf of Finland, Baltic Sea – insights from modeling","authors":"Arun Mishra, Enriko Siht, Germo Väli, Taavi Liblik, Natalja Buhhalko, Urmas Lips","doi":"10.3389/fmars.2024.1524585","DOIUrl":"https://doi.org/10.3389/fmars.2024.1524585","url":null,"abstract":"A hydrodynamic model coupled with a particle tracking model was used to identify the pathways and accumulation areas of microplastics (MP) in the Gulf of Finland (GoF) over a three-year period (2018-2020). Two key sources, wastewater treatment plants (WWTPs) and rivers, were considered, focusing on polypropylene (PP)/polyethylene (PE) and polyethylene terephthalate (PET) particles sized 20-500 μm. Rivers contribute 76% of total MP entering the gulf, while WWTPs account for the remaining 24%. Most of the MP accumulates inside the gulf and does not drift to the Baltic Proper. The eastern part of the gulf exhibits the highest surface concentrations of particles influenced by the Neva River. In the water column, MP concentrations were notably high in shallow coastal areas, decreasing gradually offshore. Potential MP accumulation zones were identified primarily between longitudes 28°E and 30°E, particularly near the major rivers Narva and Kymi and in the easternmost gulf related to the Neva River discharge. The MP concentrations in the surface layer and water column were higher in winter while settling was more intense in summer. Short-term variability in the surface layer was caused by (sub)mesoscale advection and divergence/convergence, while in the near-bottom layer, strong bottom currents and consequent resuspension elevated the concentrations.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"107 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991356","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 : 2025-01-20DOI: 10.3389/fmars.2024.1521925
Siyu Liu, Guangxue Li, Xue Liu, Lulu Qiao, Nan Wang, Shidong Liu, Xiangdong Wang, Di Yu, Lei Zhang
Sediment resuspension primarily occurs within the bottom boundary layer (BBL) of water bodies, particularly in silty coastal environments, and helps form the fluid mud layer (FML). In this study, we report data on the water level, waves, currents, and suspended sediment concentration (SSC) collected from the Bohai Sea over one year, at a vertical resolution of 4 cm, by using the acoustic wave and current profiler, acoustic Doppler current profiler, and an acoustic backscattering system. The aim was to investigate the mechanisms of formation and disappearance of the FML as driven by wave–current interactions on silty seabeds The findings revealed a thin and stable FML within 4–12 cm of the seabed in shallow waters. Strong waves contributed more significantly to sediment resuspension than strong currents. Moreover, the SSC near the seabed was generally governed by the currents, while waves were predominant in this regard in stormy conditions. The index of intensity of the bottom shear β—defined as the ratio of the wave–current-induced shear stress to the critical shear stress—was identified as a sensitive indicator of variations in the SSC. Significant sediment resuspension occurred in case of the coupling of large wave and current events on the fine-grained seabed, when the value of β exceeded 10 for more than 20 h and the Rouse number persisted below 0.01 for over 30 h. Following the storm (β < 10), the sediment gradually accumulated, and this led to the formation of the FML. Prolonged periods in which the value of β surpassed 10 for over 10 h while that of the Rouse number remained below 0.01 for more than 30 h resulted in considerable sediment resuspension and the destruction of the FML. Our results highlight the profound impacts of wave–current interactions on the formation and disappearance of the FML within the BBL in silty, shallow marine environments. The work here offers critical insights into the dynamics of fine-particle sediment, and provides suggestions for mitigating the negative effects associated with the FML.
{"title":"Impact of wave–current coupling on the bottom boundary layer in Bohai Bay","authors":"Siyu Liu, Guangxue Li, Xue Liu, Lulu Qiao, Nan Wang, Shidong Liu, Xiangdong Wang, Di Yu, Lei Zhang","doi":"10.3389/fmars.2024.1521925","DOIUrl":"https://doi.org/10.3389/fmars.2024.1521925","url":null,"abstract":"Sediment resuspension primarily occurs within the bottom boundary layer (BBL) of water bodies, particularly in silty coastal environments, and helps form the fluid mud layer (FML). In this study, we report data on the water level, waves, currents, and suspended sediment concentration (SSC) collected from the Bohai Sea over one year, at a vertical resolution of 4 cm, by using the acoustic wave and current profiler, acoustic Doppler current profiler, and an acoustic backscattering system. The aim was to investigate the mechanisms of formation and disappearance of the FML as driven by wave–current interactions on silty seabeds The findings revealed a thin and stable FML within 4–12 cm of the seabed in shallow waters. Strong waves contributed more significantly to sediment resuspension than strong currents. Moreover, the SSC near the seabed was generally governed by the currents, while waves were predominant in this regard in stormy conditions. The index of intensity of the bottom shear β—defined as the ratio of the wave–current-induced shear stress to the critical shear stress—was identified as a sensitive indicator of variations in the SSC. Significant sediment resuspension occurred in case of the coupling of large wave and current events on the fine-grained seabed, when the value of β exceeded 10 for more than 20 h and the Rouse number persisted below 0.01 for over 30 h. Following the storm (β &lt; 10), the sediment gradually accumulated, and this led to the formation of the FML. Prolonged periods in which the value of β surpassed 10 for over 10 h while that of the Rouse number remained below 0.01 for more than 30 h resulted in considerable sediment resuspension and the destruction of the FML. Our results highlight the profound impacts of wave–current interactions on the formation and disappearance of the FML within the BBL in silty, shallow marine environments. The work here offers critical insights into the dynamics of fine-particle sediment, and provides suggestions for mitigating the negative effects associated with the FML.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"20 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991604","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 : 2025-01-20DOI: 10.3389/fmars.2024.1501812
Andrea Mattia Pacifico, Luca Mulazzani, Giulio Malorgio
With the increasing adoption of the ecosystem approach as integral to sustainable development policies, the economic valuation of marine and coastal ecosystem services (ESs) has become relevant for informing decision-making processes. Through an integrated approach encompassing bibliometric, network, and content analyses, this review is aimed at analyzing the evolution trend, the main research clusters, and the research gaps of the scientific literature in the field of economic valuation of marine and coastal ESs. The bibliometric results showed that the research field is experiencing an evolving positive trend and represents a challenging research topic. From the network and overlay visualization of keyword co-occurrences, it emerged that the research clusters comprehensively address the key policy-relevant issues. In the content analysis, an examination of the estimated ESs and the economic valuation methods used by studies with the highest impact on scientific research was conducted. The findings suggest that while studies provide valuable data and insights, their practical applicability in policymaking is limited, due to contextual relevance and bias issues. Overall, the review underscores the need for a paradigm shift to better inform real-world policy decisions, identifying the Marine Spatial Planning (MSP) process as a key framework for bridging these gaps in future research and policy implementation.
{"title":"Are the economic valuations of marine and coastal ecosystem services supporting policymakers? A systematic review and remaining gaps and challenges","authors":"Andrea Mattia Pacifico, Luca Mulazzani, Giulio Malorgio","doi":"10.3389/fmars.2024.1501812","DOIUrl":"https://doi.org/10.3389/fmars.2024.1501812","url":null,"abstract":"With the increasing adoption of the ecosystem approach as integral to sustainable development policies, the economic valuation of marine and coastal ecosystem services (ESs) has become relevant for informing decision-making processes. Through an integrated approach encompassing bibliometric, network, and content analyses, this review is aimed at analyzing the evolution trend, the main research clusters, and the research gaps of the scientific literature in the field of economic valuation of marine and coastal ESs. The bibliometric results showed that the research field is experiencing an evolving positive trend and represents a challenging research topic. From the network and overlay visualization of keyword co-occurrences, it emerged that the research clusters comprehensively address the key policy-relevant issues. In the content analysis, an examination of the estimated ESs and the economic valuation methods used by studies with the highest impact on scientific research was conducted. The findings suggest that while studies provide valuable data and insights, their practical applicability in policymaking is limited, due to contextual relevance and bias issues. Overall, the review underscores the need for a paradigm shift to better inform real-world policy decisions, identifying the Marine Spatial Planning (MSP) process as a key framework for bridging these gaps in future research and policy implementation.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"6 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991353","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 : 2025-01-20DOI: 10.3389/fmars.2024.1471204
Brianna Coffey, Cortni Borgerson, Pankaj Lal, Colette J. Feehan
Seaweed farming is increasingly recognized as a sustainable marine resource management opportunity, but it also poses socioeconomic and environmental risks that require careful evaluation. This quick scoping review (QSR) examines the current state of knowledge on upscaling seaweed farming through co-location with offshore wind energy production. A total of 240 published records from 2001 to 2022 were analyzed, including studies on general seaweed farming and its integration with offshore wind energy, both of which have shown a significant increase in annual publication rates over time. Geographically, the majority of studies on general seaweed farming were conducted in Asia, while most research on wind-focused integration was carried out in Europe. Differences in cultivated species were evident, with red seaweeds dominating the general literature and brown seaweeds dominating wind-focused studies. Ecosystem service analysis revealed that provisioning services were disproportionately emphasized, while cultural services were underrepresented in wind-focused studies as compared to the general literature. Environmental constraints were the most frequently cited challenges across both datasets, but their nature differed: general literature highlighted issues such as pests, diseases, and epiphytes that reduce farm yield, while wind-focused studies emphasized risks of farms to local species, habitats, and ecosystems. While environmental knowledge gaps were the most frequently cited overall, legal knowledge gaps were predominant in wind-focused studies. These findings underscore the need for more geographically and taxonomically diverse studies on seaweed-wind multi-use, along with further investigation into cultural services in offshore contexts, strategies for mitigating environmental risks, and the development of frameworks for shared governance to advance sustainable ocean development.
{"title":"Co-location of seaweed farming with offshore wind energy: a quick scoping review","authors":"Brianna Coffey, Cortni Borgerson, Pankaj Lal, Colette J. Feehan","doi":"10.3389/fmars.2024.1471204","DOIUrl":"https://doi.org/10.3389/fmars.2024.1471204","url":null,"abstract":"Seaweed farming is increasingly recognized as a sustainable marine resource management opportunity, but it also poses socioeconomic and environmental risks that require careful evaluation. This quick scoping review (QSR) examines the current state of knowledge on upscaling seaweed farming through co-location with offshore wind energy production. A total of 240 published records from 2001 to 2022 were analyzed, including studies on general seaweed farming and its integration with offshore wind energy, both of which have shown a significant increase in annual publication rates over time. Geographically, the majority of studies on general seaweed farming were conducted in Asia, while most research on wind-focused integration was carried out in Europe. Differences in cultivated species were evident, with red seaweeds dominating the general literature and brown seaweeds dominating wind-focused studies. Ecosystem service analysis revealed that provisioning services were disproportionately emphasized, while cultural services were underrepresented in wind-focused studies as compared to the general literature. Environmental constraints were the most frequently cited challenges across both datasets, but their nature differed: general literature highlighted issues such as pests, diseases, and epiphytes that reduce farm yield, while wind-focused studies emphasized risks of farms to local species, habitats, and ecosystems. While environmental knowledge gaps were the most frequently cited overall, legal knowledge gaps were predominant in wind-focused studies. These findings underscore the need for more geographically and taxonomically diverse studies on seaweed-wind multi-use, along with further investigation into cultural services in offshore contexts, strategies for mitigating environmental risks, and the development of frameworks for shared governance to advance sustainable ocean development.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"10 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991357","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 : 2025-01-20DOI: 10.3389/fmars.2024.1510364
Haiming Song, Xinting Wang, Xiaomeng Huan, Lin Yang
Mariculture constitutes the primary origin of microplastic pollution, necessitating immediate action to address microplastic pollution by focusing on both the supply and demand aspects of fishing gear. Based on the cooperative management model of mariculture microplastic pollution, this paper develops an evolutionary game model that incorporates the interactions among fishing gear enterprises, fishermen, and the government. It then proceeds to examine the government’s strategy for managing mariculture microplastic pollution through game theory and simulation analysis. The main findings obtained are as follows. (1) The management of mariculture microplastic pollution can be improved on both the supply chain and market aspects by implementing subsidies. The likelihood of receiving government subsidies boosts the production of environmentally-friendly fishing gear by fishing gear enterprises and the purchase of such gear by fishermen. (2) Based on the cost-benefit variations for fishing gear enterprises, fishermen, and the government, the evolutionary game model reaches distinct equilibrium states, leading to corresponding adjustments in the optimal government subsidy strategy. (3) While there are some positive effects of subsidies, increasing government subsidies does not necessarily lead to better outcomes. As the total amount of subsidies increases, the best practice for governments would be to phase out subsidies for environmentally-friendly fishing gear. Accordingly, the government should build a multi-subject collaborative governance model, reasonably control subsidies amount, prevent the adverse consequences of excessive subsidies, and optimize the structure of subsidy recipients.
{"title":"The impact of government subsidies on microplastic pollution control in mariculture: an evolutionary game theory analysis in Qingdao, China","authors":"Haiming Song, Xinting Wang, Xiaomeng Huan, Lin Yang","doi":"10.3389/fmars.2024.1510364","DOIUrl":"https://doi.org/10.3389/fmars.2024.1510364","url":null,"abstract":"Mariculture constitutes the primary origin of microplastic pollution, necessitating immediate action to address microplastic pollution by focusing on both the supply and demand aspects of fishing gear. Based on the cooperative management model of mariculture microplastic pollution, this paper develops an evolutionary game model that incorporates the interactions among fishing gear enterprises, fishermen, and the government. It then proceeds to examine the government’s strategy for managing mariculture microplastic pollution through game theory and simulation analysis. The main findings obtained are as follows. (1) The management of mariculture microplastic pollution can be improved on both the supply chain and market aspects by implementing subsidies. The likelihood of receiving government subsidies boosts the production of environmentally-friendly fishing gear by fishing gear enterprises and the purchase of such gear by fishermen. (2) Based on the cost-benefit variations for fishing gear enterprises, fishermen, and the government, the evolutionary game model reaches distinct equilibrium states, leading to corresponding adjustments in the optimal government subsidy strategy. (3) While there are some positive effects of subsidies, increasing government subsidies does not necessarily lead to better outcomes. As the total amount of subsidies increases, the best practice for governments would be to phase out subsidies for environmentally-friendly fishing gear. Accordingly, the government should build a multi-subject collaborative governance model, reasonably control subsidies amount, prevent the adverse consequences of excessive subsidies, and optimize the structure of subsidy recipients.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"26 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991352","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}
A 50-day feeding trial was conducted to evaluate the effects of dietary supplementation with different levels of compound lactic acid bacteria on the growth performance, antioxidant capacity, intestinal microbiota composition, and immunity of the Strongylocentrotus intermedius. In this study, S. intermedius with an initial body weight of 26.47 ± 0.27 g was used as the experimental subject. Based on dietary supplementation with compound lactic acid bacteria (containing 56.15% Lentilactobacillus and 20.59% Acetobacter) at different levels, the subjects were categorized into four experimental groups: 0% (RC), 0.5% (RL), 1% (RM), and 2% (RH). The dietary supplementation with compound lactic acid bacteria significantly improved the growth performance of S. intermedius in the RL, RM, and RH groups, including final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), and gonadosomatic index (GSI). Furthermore, antioxidant and immune indicators such as total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), acid phosphatase (ACP), alkaline phosphatase (AKP), and lysozyme (LZM) were significantly enhanced. Notably, compound lactic acid bacteria improved digestive enzyme activities in the intestine and reduced the feed conversion ratio (FCR). Supplementation with compound lactic acid bacteria reduced Arcobacter and Vibrio colonization in the intestinal tract and enhanced the expression of genes related to antioxidant, stress, and immune responses in the RM and RH groups. Overall, 1% compound lactic acid bacteria supplementation in the diet significantly improved growth performance, digestive capacity, non-specific immune ability, and intestinal microbial stability in S. intermedius.
{"title":"Growth performance, intestinal health, and non-specific immunity were significantly affected by feeding different compound lactic acid bacteria supplementation in sea urchin (Strongylocentrotus intermedius)","authors":"Yuntian Zhang, Rongwei Zhang, Yi Chen, Zhixu Guo, Xiangyu Meng, Yuzhe Han, Xiaoran Zhao, Tongjun Ren","doi":"10.3389/fmars.2025.1525330","DOIUrl":"https://doi.org/10.3389/fmars.2025.1525330","url":null,"abstract":"A 50-day feeding trial was conducted to evaluate the effects of dietary supplementation with different levels of compound lactic acid bacteria on the growth performance, antioxidant capacity, intestinal microbiota composition, and immunity of the <jats:italic>Strongylocentrotus intermedius</jats:italic>. In this study, <jats:italic>S. intermedius</jats:italic> with an initial body weight of 26.47 ± 0.27 g was used as the experimental subject. Based on dietary supplementation with compound lactic acid bacteria (containing 56.15% <jats:italic>Lentilactobacillus</jats:italic> and 20.59% <jats:italic>Acetobacter</jats:italic>) at different levels, the subjects were categorized into four experimental groups: 0% (RC), 0.5% (RL), 1% (RM), and 2% (RH). The dietary supplementation with compound lactic acid bacteria significantly improved the growth performance of <jats:italic>S. intermedius</jats:italic> in the RL, RM, and RH groups, including final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), and gonadosomatic index (GSI). Furthermore, antioxidant and immune indicators such as total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), acid phosphatase (ACP), alkaline phosphatase (AKP), and lysozyme (LZM) were significantly enhanced. Notably, compound lactic acid bacteria improved digestive enzyme activities in the intestine and reduced the feed conversion ratio (FCR). Supplementation with compound lactic acid bacteria reduced <jats:italic>Arcobacter</jats:italic> and <jats:italic>Vibrio</jats:italic> colonization in the intestinal tract and enhanced the expression of genes related to antioxidant, stress, and immune responses in the RM and RH groups. Overall, 1% compound lactic acid bacteria supplementation in the diet significantly improved growth performance, digestive capacity, non-specific immune ability, and intestinal microbial stability in <jats:italic>S. intermedius</jats:italic>.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"46 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991354","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 : 2025-01-20DOI: 10.3389/fmars.2025.1514378
Abdulrahman Ben-Hasan, Mohammad E. Al Mukaimi
Seasonality in fisheries is known when opening and closing dates are established, but it is much less defined in places lacking seasonal regulations. Highlighting fisheries seasonality is critical because, for one, it can influence seafood supply and prices. Here, we examine fisheries seasonality by analyzing extensive datasets of monthly commercial landings and prices spanning over twenty years for 22 major finfish stocks in Kuwait, where seasonal closures are uncommon. Additionally, we develop a questionnaire to obtain information from the recreational fishery—the only fishing sector composed of local fishers—to investigate whether peak commercial landing months overlap with local fishers’ knowledge. We found a distinct seasonality in finfish commercial landings: at the two ends of the spectrum, the strongly winter-spring finfish landings (60% or more of landing proportions), which plummet sharply over warmer months, and the strongly summer-fall finfish landings. Landings influenced seasonal mean prices, with higher landings generally meant lower prices and vice versa. Further, we found that months identified by local fishers as being the “best fishing seasons” are consistent with months of peak landings for most stocks, though fishing seasons for a few stocks diverged widely from seasonality in commercial landings. Broadly, our analysis underscores high seasonality unrelated to seasonal regulations and supports combining commercial landings and local fishers’ knowledge to understand fishery and finfish seasonality, particularly in data-limited situations.
{"title":"Identifying unregulated fisheries seasonality through commercial landings and local fishers’ knowledge","authors":"Abdulrahman Ben-Hasan, Mohammad E. Al Mukaimi","doi":"10.3389/fmars.2025.1514378","DOIUrl":"https://doi.org/10.3389/fmars.2025.1514378","url":null,"abstract":"Seasonality in fisheries is known when opening and closing dates are established, but it is much less defined in places lacking seasonal regulations. Highlighting fisheries seasonality is critical because, for one, it can influence seafood supply and prices. Here, we examine fisheries seasonality by analyzing extensive datasets of monthly commercial landings and prices spanning over twenty years for 22 major finfish stocks in Kuwait, where seasonal closures are uncommon. Additionally, we develop a questionnaire to obtain information from the recreational fishery—the only fishing sector composed of local fishers—to investigate whether peak commercial landing months overlap with local fishers’ knowledge. We found a distinct seasonality in finfish commercial landings: at the two ends of the spectrum, the strongly winter-spring finfish landings (60% or more of landing proportions), which plummet sharply over warmer months, and the strongly summer-fall finfish landings. Landings influenced seasonal mean prices, with higher landings generally meant lower prices and vice versa. Further, we found that months identified by local fishers as being the “best fishing seasons” are consistent with months of peak landings for most stocks, though fishing seasons for a few stocks diverged widely from seasonality in commercial landings. Broadly, our analysis underscores high seasonality unrelated to seasonal regulations and supports combining commercial landings and local fishers’ knowledge to understand fishery and finfish seasonality, particularly in data-limited situations.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"58 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991355","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 : 2025-01-17DOI: 10.3389/fmars.2024.1525477
Yang Dong, Ren Wang, Jinqiang Liang, Yulin He, Jinfeng Ren, Wanzhong Shi, Xiaosong Wei, Hao Du, Xiangyang Xie, Arthur B. Busbey
IntroductionMilankovitch theory has extensive application in sequence stratigraphy and the establishment of time scales. However, it is rarely applied to shallow strata rich in hydrates. Cyclostratigraphic analysis of the Quaternary unconsolidated sediments can help identify climate and sea level changes that correspond to orbital cycles and improve our understanding of the dynamic evolution of hydrates.MethodsUsing the natural gamma-ray log data from the deepwater area well W01 in the Qiongdongnan Basin, Milankovitch cycle analysis was conducted to identify the primary astronomical period in W01. Anchored to existing AMS-14 C age from bivalve shell as reference point, an astronomical age scale of W01 was established. Simultaneously, through the analyses of major trace elements and total organic carbon content (TOC) in sediment samples, how astronomical orbital cycles influenced past environmental conditions. Furthermore, employing sedimentary noise models, the relative sea level change of well W01 was reconstructed.ResultsSedimentary cycles of 27.34 m and 6.73 m were identified in the GR data from well W01, corresponding to orbital periods of 405 kyr and 100 kyr eccentricity, with a duration of approximately 2.5 Myr. The spectral analysis of paleoenvironmental proxies reveals a sedimentary cycle of approximately 27 m, while the sedimentary noise model reconstructs the fluctuating rise in sea level change. An obliquity modulation period of approximately 170 kyr was identified in the TOC data, which may reflect the combined effects of obliquity and other orbital parameters.DiscussionSpectral analysis of paleoenvironmental indicators showed that long eccentricity cycle had varying degrees of influence on changes in paleoclimate, paleosalinity, and paleoredox conditions. Additionally, a 1.2 Myr cycle was identified as a significant factor influencing sea level changes during the early Pleistocene in the South China Sea (SCS). In addition, it is confirmed that the dominant period of the glacial-interglacial cycle in the SCS from 0.6 Ma to the present is 100 kyr period. Synthesize the above analysis, during phases of low amplitude in the 405 kyr cycle or minimum value of the 100 kyr cycle, which are associated with lower temperature, conditions become more conducive to hydrate accumulation.
{"title":"Orbital cycle records in shallow unconsolidated sediments: implications for global carbon cycle and hydrate system evolution in deep-sea area sediments of the Qiongdongnan Basin","authors":"Yang Dong, Ren Wang, Jinqiang Liang, Yulin He, Jinfeng Ren, Wanzhong Shi, Xiaosong Wei, Hao Du, Xiangyang Xie, Arthur B. Busbey","doi":"10.3389/fmars.2024.1525477","DOIUrl":"https://doi.org/10.3389/fmars.2024.1525477","url":null,"abstract":"IntroductionMilankovitch theory has extensive application in sequence stratigraphy and the establishment of time scales. However, it is rarely applied to shallow strata rich in hydrates. Cyclostratigraphic analysis of the Quaternary unconsolidated sediments can help identify climate and sea level changes that correspond to orbital cycles and improve our understanding of the dynamic evolution of hydrates.MethodsUsing the natural gamma-ray log data from the deepwater area well W01 in the Qiongdongnan Basin, Milankovitch cycle analysis was conducted to identify the primary astronomical period in W01. Anchored to existing AMS-14 C age from bivalve shell as reference point, an astronomical age scale of W01 was established. Simultaneously, through the analyses of major trace elements and total organic carbon content (TOC) in sediment samples, how astronomical orbital cycles influenced past environmental conditions. Furthermore, employing sedimentary noise models, the relative sea level change of well W01 was reconstructed.ResultsSedimentary cycles of 27.34 m and 6.73 m were identified in the GR data from well W01, corresponding to orbital periods of 405 kyr and 100 kyr eccentricity, with a duration of approximately 2.5 Myr. The spectral analysis of paleoenvironmental proxies reveals a sedimentary cycle of approximately 27 m, while the sedimentary noise model reconstructs the fluctuating rise in sea level change. An obliquity modulation period of approximately 170 kyr was identified in the TOC data, which may reflect the combined effects of obliquity and other orbital parameters.DiscussionSpectral analysis of paleoenvironmental indicators showed that long eccentricity cycle had varying degrees of influence on changes in paleoclimate, paleosalinity, and paleoredox conditions. Additionally, a 1.2 Myr cycle was identified as a significant factor influencing sea level changes during the early Pleistocene in the South China Sea (SCS). In addition, it is confirmed that the dominant period of the glacial-interglacial cycle in the SCS from 0.6 Ma to the present is 100 kyr period. Synthesize the above analysis, during phases of low amplitude in the 405 kyr cycle or minimum value of the 100 kyr cycle, which are associated with lower temperature, conditions become more conducive to hydrate accumulation.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"50 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988030","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}
The study of oceanic internal waves remains a critical area of research within oceanography. With the rapid advancements in oceanic remote sensing and deep learning, it is now possible to extract valuable insights from vast datasets. In this context, by building datasets using deep learning models, we propose a novel stripe segmentation algorithm for oceanic internal waves, leveraging synthetic aperture radar (SAR) images based on the SegFormer architecture. Initially, a hierarchical transformer encoder transforms the image into multilevel feature maps. Subsequently, information from various layers is aggregated through a multilayer perceptron (MLP) decoder, effectively merging local and global contexts. Finally, a layer of MLP is utilized to facilitate the segmentation of oceanic internal waves. Comparative experimental results demonstrated that SegFormer outperformed other models, including U-Net, Fast-SCNN (Fast Segmentation Convolutional Neural Network), ORCNet (Ocular Region Context Network), and PSPNet (Pyramid Scene Parsing Network), efficiently and accurately segmenting marine internal wave stripes in SAR images. In addition, we discuss the results of oceanic internal wave detection under varying settings, further underscoring the effectiveness of the algorithm.
{"title":"Stripe segmentation of oceanic internal waves in SAR images based on SegFormer","authors":"Hong-Sheng Zhang, Ji-Yu Sun, Kai-Tuo Qi, Ying-Gang Zheng, Jiao-Jiao Lu, Yu Zhang","doi":"10.3389/fmars.2024.1456294","DOIUrl":"https://doi.org/10.3389/fmars.2024.1456294","url":null,"abstract":"The study of oceanic internal waves remains a critical area of research within oceanography. With the rapid advancements in oceanic remote sensing and deep learning, it is now possible to extract valuable insights from vast datasets. In this context, by building datasets using deep learning models, we propose a novel stripe segmentation algorithm for oceanic internal waves, leveraging synthetic aperture radar (SAR) images based on the SegFormer architecture. Initially, a hierarchical transformer encoder transforms the image into multilevel feature maps. Subsequently, information from various layers is aggregated through a multilayer perceptron (MLP) decoder, effectively merging local and global contexts. Finally, a layer of MLP is utilized to facilitate the segmentation of oceanic internal waves. Comparative experimental results demonstrated that SegFormer outperformed other models, including U-Net, Fast-SCNN (Fast Segmentation Convolutional Neural Network), ORCNet (Ocular Region Context Network), and PSPNet (Pyramid Scene Parsing Network), efficiently and accurately segmenting marine internal wave stripes in SAR images. In addition, we discuss the results of oceanic internal wave detection under varying settings, further underscoring the effectiveness of the algorithm.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"37 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988031","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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