Pub Date : 2025-01-17DOI: 10.3389/fmars.2024.1439266
Li Kang, Huang Huamei, Yan Ran, Zhang Shengpeng, Dong Di, Peng Bo
Mangrove plantation is a fundamental approach for the sustainable management of tropical and subtropical coasts to capture and store atmospheric carbon. However, it is unknown whether the carbon accumulation potential of planted mangroves is as much as that of natural mangroves. Moreover, the effects of tree species, forest age, and hydrodynamic conditions on carbon storage are still unclear. This study investigated the carbon storage potential and influencing factors for planted mangroves in Kaozhouyang, Huidong County, Guangdong Province. The Vegetation carbon stock was calculated by community parameters collected from field investigation, and ecosystem carbon stock was calculated by the sum of vegetation and sediment. The results showed that mangrove plantation significantly increased the carbon stock of the vegetation and soil (vegetation carbon stock = 9.9645.06 t C/ha; soil carbon stock = 70.37-110.64 t C/ha) compared with the nonvegetation mudflat (63.73 t C/ha). However, the ecosystem carbon stock of the planting sites was still lower than that of natural Avicennia marina (282.86 t C/ha), with the significant difference mainly reflected on the soil carbon stock (p < 0.05). Further results revealed that carbon accumulation was affected by forest age, tree species, and tidal level. The vegetation biomass/carbon stock gradually increased with forest age (p < 0.05), but the difference was not significant for soil carbon stock, which indicated that the carbon accumulation was mainly concentrated on the vegetation at the early stage of mangrove restoration. In addition, suitable habitat conditions (landward) and fast-growing species (Sonneratia apetala) are more beneficial to carbon accumulation. Our results suggest that mangrove plantations can achieve carbon storage and sequestration in vegetation and soil for increasing carbon sinks with suitable species selection and management.
红树林种植是热带和亚热带海岸可持续管理的基本途径，可以捕获和储存大气中的碳。然而，人工红树林的碳积累潜力是否与天然红树林一样多，目前尚不清楚。此外，树种、林龄和水动力条件对碳储量的影响尚不清楚。以广东省惠东县考洲阳人工林为研究对象，研究了人工林的碳储量潜力及其影响因素。植被碳储量由野外调查收集的群落参数计算，生态系统碳储量由植被与沉积物之和计算。结果表明：人工林显著增加了植被和土壤碳储量(植被碳储量= 9.9645.06 t C/ha；土壤碳储量为70.37 ~ 110.64 t C/ha)，而非植被泥滩的碳储量为63.73 t C/ha。但人工林生态系统碳储量仍低于天然海桐地（282.86 t C/ha），差异主要体现在土壤碳储量(p <；0.05)。结果表明，林龄、树种和潮位对碳积累有一定的影响。植被生物量/碳储量随林龄逐渐增加(p <；0.05)，但土壤碳储量差异不显著，说明红树林恢复初期碳积累主要集中在植被上。此外，适宜的生境条件（向陆）和速生物种（无瓣海桑）更有利于碳积累。研究结果表明，通过适当的树种选择和管理，红树林人工林可以在植被和土壤中实现碳的储存和封存，增加碳汇。
{"title":"Carbon storage potential and influencing factors of mangrove plantation in Kaozhouyang, Guangdong Province, South China","authors":"Li Kang, Huang Huamei, Yan Ran, Zhang Shengpeng, Dong Di, Peng Bo","doi":"10.3389/fmars.2024.1439266","DOIUrl":"https://doi.org/10.3389/fmars.2024.1439266","url":null,"abstract":"Mangrove plantation is a fundamental approach for the sustainable management of tropical and subtropical coasts to capture and store atmospheric carbon. However, it is unknown whether the carbon accumulation potential of planted mangroves is as much as that of natural mangroves. Moreover, the effects of tree species, forest age, and hydrodynamic conditions on carbon storage are still unclear. This study investigated the carbon storage potential and influencing factors for planted mangroves in Kaozhouyang, Huidong County, Guangdong Province. The Vegetation carbon stock was calculated by community parameters collected from field investigation, and ecosystem carbon stock was calculated by the sum of vegetation and sediment. The results showed that mangrove plantation significantly increased the carbon stock of the vegetation and soil (vegetation carbon stock = 9.9645.06 t C/ha; soil carbon stock = 70.37-110.64 t C/ha) compared with the nonvegetation mudflat (63.73 t C/ha). However, the ecosystem carbon stock of the planting sites was still lower than that of natural <jats:italic>Avicennia marina</jats:italic> (282.86 t C/ha), with the significant difference mainly reflected on the soil carbon stock (p &lt; 0.05). Further results revealed that carbon accumulation was affected by forest age, tree species, and tidal level. The vegetation biomass/carbon stock gradually increased with forest age (p &lt; 0.05), but the difference was not significant for soil carbon stock, which indicated that the carbon accumulation was mainly concentrated on the vegetation at the early stage of mangrove restoration. In addition, suitable habitat conditions (landward) and fast-growing species (<jats:italic>Sonneratia apetala</jats:italic>) are more beneficial to carbon accumulation. Our results suggest that mangrove plantations can achieve carbon storage and sequestration in vegetation and soil for increasing carbon sinks with suitable species selection and management.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"99 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988986","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}
Submerged artificial sandbars (SABs) are increasingly favored as an efficient method for beach nourishment, helping to mitigate beach erosion and maintain the sediment transport budget, thus promoting ecological stability. A comprehensive understanding of the morphodynamical evolution of the submerged artificial sandbar-beach profile is essential. This study employs a scaled-down moving-bed flume test to examine the dynamic geomorphological evolution of the submerged artificial sandbar-beach system under regular wave conditions. Twenty experiments, each with different wave heights and periods representative of the Zhejiang coast, were conducted. The study investigated the profile evolution and wave parameters of the submerged artificial sandbar-beach model. The results reveal low wave reflection in front of the sandbar, indicating that under the tested wave conditions, the sandbar primarily serves as a sediment source rather than effectively reflecting wave energy. In all scenarios, the top of the sandbar migrates shoreward, and the sandbar’s contour shape becomes asymmetric. For smaller wave periods, localized erosion occurs in the troughs, while larger periods result in complete siltation. Continuous sediment transport into the trough characterizes the beach face, with sediment movement controlled by wave height and period. A linear or nonlinear relationship between sandbar erosion depth, beach slope, and wave parameters (height, period) is established, providing an empirical model for SAB-beach profiles. These findings enhance the understanding of SAB-beach systems and offer valuable insights for coastal protection and disaster prevention in engineering applications.
{"title":"Experimental study on the evolution of submerged artificial sandbar-beach profile under the regular waves condition","authors":"Wenliang Zhang, Junli Guo, Lianqiang Shi, Zhuocheng Liu, Qinghua Ye, Cuiping Kuang, Yu Peng, Huangzhe Qi","doi":"10.3389/fmars.2024.1530904","DOIUrl":"https://doi.org/10.3389/fmars.2024.1530904","url":null,"abstract":"Submerged artificial sandbars (SABs) are increasingly favored as an efficient method for beach nourishment, helping to mitigate beach erosion and maintain the sediment transport budget, thus promoting ecological stability. A comprehensive understanding of the morphodynamical evolution of the submerged artificial sandbar-beach profile is essential. This study employs a scaled-down moving-bed flume test to examine the dynamic geomorphological evolution of the submerged artificial sandbar-beach system under regular wave conditions. Twenty experiments, each with different wave heights and periods representative of the Zhejiang coast, were conducted. The study investigated the profile evolution and wave parameters of the submerged artificial sandbar-beach model. The results reveal low wave reflection in front of the sandbar, indicating that under the tested wave conditions, the sandbar primarily serves as a sediment source rather than effectively reflecting wave energy. In all scenarios, the top of the sandbar migrates shoreward, and the sandbar’s contour shape becomes asymmetric. For smaller wave periods, localized erosion occurs in the troughs, while larger periods result in complete siltation. Continuous sediment transport into the trough characterizes the beach face, with sediment movement controlled by wave height and period. A linear or nonlinear relationship between sandbar erosion depth, beach slope, and wave parameters (height, period) is established, providing an empirical model for SAB-beach profiles. These findings enhance the understanding of SAB-beach systems and offer valuable insights for coastal protection and disaster prevention in engineering applications.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"96 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988036","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 : 2025-01-16DOI: 10.3389/fmars.2024.1484944
Sydney N. Zotto, Robin C. Dunkin, Juliana D. Limon, Maia S. Smith, Lisabet M. Hortensius, Margaret E. Martinez, Pádraig J. Duignan, Cara Field, Esteban Soto, Dane Whitaker, Carlos Rios, Maurice Byukusenge, Bhushan Jayarao, Suresh V. Kuchipudi, Amy C. Kinsley
Klebsiella pneumoniae is a Gram-negative, facultative anaerobic, and non-motile bacillus frequently observed in mammals. A hypermucoviscous (HMV) phenotype of K. pneumoniae is reported in stranded California sea lions (CSL) causing pleuritis and bronchopneumonia as a persistent cause of strandings. We describe an increase in cases of HMV and non-HMV K. pneumoniae in stranded CSLs along the California coast between 2017 to 2022. 2,146 live-stranded CSLs were rescued by The Marine Mammal Center (Sausalito, California). 47 of these tested positive for K. pneumoniae, with a rise in annual incidence from 0.92% (3/331) in 2017 to 8.5% (14/165) and 7.2% (23/320) in 2021 and 2022, respectively. These strandings occurred across 965 kilometers along the North-Central California coast from Bodega Bay, Sonoma, to Avila Beach, San Luis Obispo. A similar pattern was observed in beach-cast CSL carcasses by the Long Marine Laboratory (LML) Stranding Network in Santa Cruz, California who had 8 CSLs test positive for K. pneumoniae with an annual incidence rate of 2.0% (1/50) and 10.1% (7/69) in 2021 and 2022, respectively, with no cases reported prior to 2021. We applied whole-genome sequencing (WGS) to 8 isolates obtained by LML in 2022. WGS analysis revealed high nucleotide similarity between any pair of isolates. Multilocus Sequence Typing showed that all isolates belonged to Sequence type 65 and contained the K2 polysaccharide capsule and siderophore aerobactin, which are all characteristics of hypervirulent K. pneumoniae. We discuss possible causes for this trend and a need for research on K. pneumoniae in free-ranging CSLs in California.
{"title":"Klebsiella pneumoniae in stranded California sea lions (Zalophus californianus) of Central California between 2017-2022","authors":"Sydney N. Zotto, Robin C. Dunkin, Juliana D. Limon, Maia S. Smith, Lisabet M. Hortensius, Margaret E. Martinez, Pádraig J. Duignan, Cara Field, Esteban Soto, Dane Whitaker, Carlos Rios, Maurice Byukusenge, Bhushan Jayarao, Suresh V. Kuchipudi, Amy C. Kinsley","doi":"10.3389/fmars.2024.1484944","DOIUrl":"https://doi.org/10.3389/fmars.2024.1484944","url":null,"abstract":"<jats:italic>Klebsiella pneumoniae</jats:italic> is a Gram-negative, facultative anaerobic, and non-motile bacillus frequently observed in mammals. A hypermucoviscous (HMV) phenotype of <jats:italic>K. pneumoniae</jats:italic> is reported in stranded California sea lions (CSL) causing pleuritis and bronchopneumonia as a persistent cause of strandings. We describe an increase in cases of HMV and non-HMV <jats:italic>K. pneumoniae</jats:italic> in stranded CSLs along the California coast between 2017 to 2022. 2,146 live-stranded CSLs were rescued by The Marine Mammal Center (Sausalito, California). 47 of these tested positive for <jats:italic>K. pneumoniae</jats:italic>, with a rise in annual incidence from 0.92% (3/331) in 2017 to 8.5% (14/165) and 7.2% (23/320) in 2021 and 2022, respectively. These strandings occurred across 965 kilometers along the North-Central California coast from Bodega Bay, Sonoma, to Avila Beach, San Luis Obispo. A similar pattern was observed in beach-cast CSL carcasses by the Long Marine Laboratory (LML) Stranding Network in Santa Cruz, California who had 8 CSLs test positive for <jats:italic>K. pneumoniae</jats:italic> with an annual incidence rate of 2.0% (1/50) and 10.1% (7/69) in 2021 and 2022, respectively, with no cases reported prior to 2021. We applied whole-genome sequencing (WGS) to 8 isolates obtained by LML in 2022. WGS analysis revealed high nucleotide similarity between any pair of isolates. Multilocus Sequence Typing showed that all isolates belonged to Sequence type 65 and contained the K2 polysaccharide capsule and siderophore aerobactin, which are all characteristics of hypervirulent <jats:italic>K. pneumoniae.</jats:italic> We discuss possible causes for this trend and a need for research on <jats:italic>K. pneumoniae</jats:italic> in free-ranging CSLs in California.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"23 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988034","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}
In light of ongoing global warming and the accelerated melting of Antarctic sea ice, this study aims to analyze the recent changes in the principal modes of Antarctic sea ice over the past decade, utilizing Empirical Orthogonal Function (EOF) and Singular Value Decomposition (SVD) techniques. The results indicate that Antarctic sea ice has shifted from a growth trend of 1.7% per year in the previous decade to a melting trend in almost all regions, except the Amundsen Sea. The decline is particularly pronounced during autumn and winter, with rates of -7.1% and -6.5% per year, respectively. The Weddell Sea and West Pacific exhibit the fastest declines at -6.1% and -5.8% per year, leading to an overall average melting trend of -4.6% per year. Furthermore, the dominant mode of Antarctic sea ice has shifted from the Antarctic Dipole (ADP) pattern in the previous decade to a melting trend in the most recent period. This transition is closely linked to the increase in sea surface temperatures (SST) and surface air temperatures (SAT) in the Southern Ocean, which contribute to the pronounced ice melt observed in recent years. This research enhances our understanding of Antarctic sea ice dynamics and provides valuable insights for future studies on sea ice variability and prediction.
{"title":"Decadal transformations of antarctic sea ice modes","authors":"Benli Guo, Peng Yang, Jie Yuan, Honglian Xing, Wenjie Yuan, Yuanku Meng","doi":"10.3389/fmars.2024.1506715","DOIUrl":"https://doi.org/10.3389/fmars.2024.1506715","url":null,"abstract":"In light of ongoing global warming and the accelerated melting of Antarctic sea ice, this study aims to analyze the recent changes in the principal modes of Antarctic sea ice over the past decade, utilizing Empirical Orthogonal Function (EOF) and Singular Value Decomposition (SVD) techniques. The results indicate that Antarctic sea ice has shifted from a growth trend of 1.7% per year in the previous decade to a melting trend in almost all regions, except the Amundsen Sea. The decline is particularly pronounced during autumn and winter, with rates of -7.1% and -6.5% per year, respectively. The Weddell Sea and West Pacific exhibit the fastest declines at -6.1% and -5.8% per year, leading to an overall average melting trend of -4.6% per year. Furthermore, the dominant mode of Antarctic sea ice has shifted from the Antarctic Dipole (ADP) pattern in the previous decade to a melting trend in the most recent period. This transition is closely linked to the increase in sea surface temperatures (SST) and surface air temperatures (SAT) in the Southern Ocean, which contribute to the pronounced ice melt observed in recent years. This research enhances our understanding of Antarctic sea ice dynamics and provides valuable insights for future studies on sea ice variability and prediction.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"77 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988033","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 : 2025-01-16DOI: 10.3389/fmars.2024.1480699
Hojun Yoo, Hyoseob Kim, Tae Soon Kang, Jin Young Park, Jong Beom Kim
Detecting and responding appropriately to temporal changes in the shoreline is an important task for protecting coasts. Video monitoring has been utilized as a powerful tool for detecting shoreline changes. Existing shoreline-tracking methods include the threshold methods, colour intensity gradient methods, and neural networks, which involve ad-hoc assignment of the threshold values, drawing shore-normal transects, and heavy preliminary training for each coast with many data, respectively. The study applies a new boundary tracking method using Minimum Convolution of Gaussian Weight and Squared Differences (MCGWSD). The new method is fast and effective in a sense that it does not need ad-hoc threshold, drawing of transects, or pre-training. This method tracks boundary lines between two zones with no thickness by inversely tracking every pixel of the late image. The MCGWSD method is first examined for various image distortions, i.e. translation, linear deformation, angular deformation, and rotation of images. Images of a part of orange peel are chosen for the test, where a boundary line is artificially drawn, not necessarily following clear object boundary, but crosses over small patterns. The new method satisfactorily tracks the movement of boundary line at the tests. Then field video images of Jangsa Beach between 1 September 2020 and 15 September 2020, when typhoons Maysak and Haishen hit the coast, are examined to track the shoreline movement. Ground truth shoreline information at the coast during the time is not available, and results of existing colour intensity gradient method PIMACS are assumed true. According to PIMACS results on the beach width along two transects during the period, the shoreline underwent a movement up to 6 m. The new MCGWSD method tracks the shoreline position, and its results show good agreement with PIMACS results along two transects. The merits of the present method are that it produces shoreline change over the whole domain, and shore-normal transects are not needed. The present method effectively tracks the shoreline retreat or advance of as small as 1 pixel of image. The new method could be used for tracking shoreline change at arbitrary geometry even with sharp corners.
{"title":"Tracking shoreline change using minimum convolution of Gaussian weight and squared differences","authors":"Hojun Yoo, Hyoseob Kim, Tae Soon Kang, Jin Young Park, Jong Beom Kim","doi":"10.3389/fmars.2024.1480699","DOIUrl":"https://doi.org/10.3389/fmars.2024.1480699","url":null,"abstract":"Detecting and responding appropriately to temporal changes in the shoreline is an important task for protecting coasts. Video monitoring has been utilized as a powerful tool for detecting shoreline changes. Existing shoreline-tracking methods include the threshold methods, colour intensity gradient methods, and neural networks, which involve <jats:italic>ad-hoc</jats:italic> assignment of the threshold values, drawing shore-normal transects, and heavy preliminary training for each coast with many data, respectively. The study applies a new boundary tracking method using Minimum Convolution of Gaussian Weight and Squared Differences (MCGWSD). The new method is fast and effective in a sense that it does not need <jats:italic>ad-hoc</jats:italic> threshold, drawing of transects, or pre-training. This method tracks boundary lines between two zones with no thickness by inversely tracking every pixel of the late image. The MCGWSD method is first examined for various image distortions, i.e. translation, linear deformation, angular deformation, and rotation of images. Images of a part of orange peel are chosen for the test, where a boundary line is artificially drawn, not necessarily following clear object boundary, but crosses over small patterns. The new method satisfactorily tracks the movement of boundary line at the tests. Then field video images of Jangsa Beach between 1 September 2020 and 15 September 2020, when typhoons Maysak and Haishen hit the coast, are examined to track the shoreline movement. Ground truth shoreline information at the coast during the time is not available, and results of existing colour intensity gradient method PIMACS are assumed true. According to PIMACS results on the beach width along two transects during the period, the shoreline underwent a movement up to 6 m. The new MCGWSD method tracks the shoreline position, and its results show good agreement with PIMACS results along two transects. The merits of the present method are that it produces shoreline change over the whole domain, and shore-normal transects are not needed. The present method effectively tracks the shoreline retreat or advance of as small as 1 pixel of image. The new method could be used for tracking shoreline change at arbitrary geometry even with sharp corners.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"30 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988035","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 : 2025-01-16DOI: 10.3389/fmars.2024.1515098
Anna Gavioli, Giuseppe Castaldelli, David B. Eggleston, Robert R. Christian
IntroductionNon-native species are widely recognized as threats to biodiversity, ecosystems, and the services they provide to humans. The Mediterranean Sea has a high biodiversity of endemic species and is a hot spot of biological invasions. One of the most recent threats to Mediterranean ecosystems is the invasion of the Atlantic blue crab Callinectes sapidus.MethodsThe occurrences of the crab throughout the Mediterranean coastline were indexed from citizen science through the Global Biodiversity Information Facility. Using spatial analysis and linear mixed models, we investigated geomorphology (i.e., water depth and coastal wetlands extension), water physical variables (i.e., salinity and winter and summer water temperature), water quality variables (i.e., chlorophyll-a, nitrate and orthophosphate) and anthropogenic factors (i.e., ship density and population size) potentially affecting the blue crab occurrence along the coast.ResultsOur results showed that nitrate, as an indicator of riverine nutrient loading, and water depth, as an indicator of slope of the bottom, were the most influential variables in explaining the occurrences of blue crabs. Water temperature and salinity had lesser impacts; anthropogenic factors, such as the density of commercial marine traffic and human population size had no effect on blue crab occurrence.DiscussionThese results sug gest that benthic primary production and shallow water drive blue crab occurrences along the Mediterranean coasts. Even considering data limitations and gaps, our large-scale findings contribute to a broader understanding of the factors that drive blue crab invasion success which, in turn, can inform management actions and outline research needs.
外来物种被广泛认为对生物多样性、生态系统及其为人类提供的服务构成威胁。地中海拥有丰富的特有物种多样性，是生物入侵的热点地区。最近对地中海生态系统的威胁之一是大西洋蓝蟹（Callinectes sapidus）的入侵。方法通过全球生物多样性信息设施（Global Biodiversity Information Facility）检索公民科学资料，对整个地中海海岸线的大闸蟹发生情况进行索引。利用空间分析和线性混合模型，研究了可能影响沿海蓝蟹发生的地貌（即水深和滨海湿地扩展）、水体物理变量（即盐度和冬、夏水温）、水质变量（即叶绿素a、硝酸盐和正磷酸盐）和人为因素（即船舶密度和种群规模）。结果表明，硝态氮和水深是影响蓝蟹发生的主要因素，硝态氮是河流养分负荷的指标，水深是河底坡度的指标。水温和盐度的影响较小；海洋商业交通密度和人类种群规模等人为因素对蓝蟹的发生没有影响。这些结果表明，底栖初级生产和浅水推动了地中海沿岸蓝蟹的发生。即使考虑到数据的局限性和差距，我们的大规模发现有助于更广泛地了解驱动蓝蟹入侵成功的因素，这反过来又可以为管理行动提供信息并概述研究需求。
{"title":"From ecological to anthropogenic factors: unraveling the drivers of blue crab Callinectes sapidus occurrence along the Mediterranean coasts","authors":"Anna Gavioli, Giuseppe Castaldelli, David B. Eggleston, Robert R. Christian","doi":"10.3389/fmars.2024.1515098","DOIUrl":"https://doi.org/10.3389/fmars.2024.1515098","url":null,"abstract":"IntroductionNon-native species are widely recognized as threats to biodiversity, ecosystems, and the services they provide to humans. The Mediterranean Sea has a high biodiversity of endemic species and is a hot spot of biological invasions. One of the most recent threats to Mediterranean ecosystems is the invasion of the Atlantic blue crab <jats:italic>Callinectes sapidus</jats:italic>.MethodsThe occurrences of the crab throughout the Mediterranean coastline were indexed from citizen science through the Global Biodiversity Information Facility. Using spatial analysis and linear mixed models, we investigated geomorphology (i.e., water depth and coastal wetlands extension), water physical variables (i.e., salinity and winter and summer water temperature), water quality variables (i.e., chlorophyll-a, nitrate and orthophosphate) and anthropogenic factors (i.e., ship density and population size) potentially affecting the blue crab occurrence along the coast.ResultsOur results showed that nitrate, as an indicator of riverine nutrient loading, and water depth, as an indicator of slope of the bottom, were the most influential variables in explaining the occurrences of blue crabs. Water temperature and salinity had lesser impacts; anthropogenic factors, such as the density of commercial marine traffic and human population size had no effect on blue crab occurrence.DiscussionThese results sug gest that benthic primary production and shallow water drive blue crab occurrences along the Mediterranean coasts. Even considering data limitations and gaps, our large-scale findings contribute to a broader understanding of the factors that drive blue crab invasion success which, in turn, can inform management actions and outline research needs.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"30 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988414","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 : 2025-01-15DOI: 10.3389/fmars.2024.1510119
Shaodong Wang, Hui Du, Gang Wei, Zhentao Chen, Jianqiao Shi, Zhenyang Lan
The research on the propagation and evolution of the second-mode internal solitary waves(ISWs) is receiving more and more attention. In this study, second-mode internal solitary waves in continuous stratification are physically simulated in a laboratory-stratified fluid flume. Meanwhile, the second-mode ISWs and their induced flow field in the same stratification environment are solved based on the eigenvalue problem of the TG equation (Taylor-Goldstein), combined with the weakly non-linear ISW theoretical models. The experimental and theoretical results show that the symmetry of the second-mode ISW wave-flow field can be improved as the thickness ratio of the upper fluid layer and lower one approaches 1. The ISW speed and horizontal and vertical velocity range values in the continuous pycnocline are positively correlated with the changing ISW amplitude, while only the wavelength is negatively correlated with the iSW amplitude. The waveflow fields of the second-mode ISWs calculated by Korteweg-de Vries (KdV) and extended KdV (eKdV) models in the large amplitude cases are more consistent with the experimental results than those in the small amplitude cases. The two theoretical models used to describe second-mode ISWs can be significantly improved when the thickness ratio of the upper and lower fluid layers approaches 1. In this case, the eKdV model is more applicable than the KdV model.
{"title":"Experimental investigation of the second-mode internal solitary wave in continuous pycnocline and the applicability of weakly nonlinear theoretical models","authors":"Shaodong Wang, Hui Du, Gang Wei, Zhentao Chen, Jianqiao Shi, Zhenyang Lan","doi":"10.3389/fmars.2024.1510119","DOIUrl":"https://doi.org/10.3389/fmars.2024.1510119","url":null,"abstract":"The research on the propagation and evolution of the second-mode internal solitary waves(ISWs) is receiving more and more attention. In this study, second-mode internal solitary waves in continuous stratification are physically simulated in a laboratory-stratified fluid flume. Meanwhile, the second-mode ISWs and their induced flow field in the same stratification environment are solved based on the eigenvalue problem of the TG equation (Taylor-Goldstein), combined with the weakly non-linear ISW theoretical models. The experimental and theoretical results show that the symmetry of the second-mode ISW wave-flow field can be improved as the thickness ratio of the upper fluid layer and lower one approaches 1. The ISW speed and horizontal and vertical velocity range values in the continuous pycnocline are positively correlated with the changing ISW amplitude, while only the wavelength is negatively correlated with the iSW amplitude. The waveflow fields of the second-mode ISWs calculated by Korteweg-de Vries (KdV) and extended KdV (eKdV) models in the large amplitude cases are more consistent with the experimental results than those in the small amplitude cases. The two theoretical models used to describe second-mode ISWs can be significantly improved when the thickness ratio of the upper and lower fluid layers approaches 1. In this case, the eKdV model is more applicable than the KdV model.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"23 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986525","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 : 2025-01-15DOI: 10.3389/fmars.2024.1468210
Wanping Zeng, Guihua Wang
IntroductionClimate change presents a critical global challenge, requiring states to develop and implement robust legal and policy frameworks. The 2024 Advisory Opinion issued by the International Tribunal for the Law of the Sea (ITLOS) in Case No. 31 highlights the legal obligations of states under the United Nations Convention on the Law of the Sea (UNCLOS) to address climate change, emphasizing the role of the marine environment in this context.MethodsThis study conducts a comprehensive analysis of the Advisory Opinion and examines its implications for China’s existing climate change legal framework. The analysis identifies key challenges, including expanded legal responsibilities, the harmonization of international law with domestic legislation, and the increased risk of international climate litigation for domestic enterprises.ResultsThe Advisory Opinion establishes a higher standard for China’s legislative response to climate change, necessitating the integration of its international obligations into its domestic legal framework. Key findings reveal gaps in China’s current legal system and emphasize the need for proactive measures to align with international standards.DiscussionTo address these challenges, the paper proposes several recommendations: developing a comprehensive legal framework for climate change, reinforcing due diligence obligations, establishing a robust climate monitoring and assessment system, and enhancing the capacity of domestic enterprises to handle international climate litigation. These measures aim to position China as a proactive contributor to global climate governance.ConclusionThe study provides valuable insights for advancing China’s climate change law and aligning it with the international legal framework. The proposed measures serve as essential guidance for China to assume greater responsibility and influence within the global climate legal system.
{"title":"On the obligations of states to respond to climate change and China’s legal consequences: based on the advisory opinion in case no. 31 of the international tribunal for the law of the sea","authors":"Wanping Zeng, Guihua Wang","doi":"10.3389/fmars.2024.1468210","DOIUrl":"https://doi.org/10.3389/fmars.2024.1468210","url":null,"abstract":"IntroductionClimate change presents a critical global challenge, requiring states to develop and implement robust legal and policy frameworks. The 2024 Advisory Opinion issued by the International Tribunal for the Law of the Sea (ITLOS) in Case No. 31 highlights the legal obligations of states under the United Nations Convention on the Law of the Sea (UNCLOS) to address climate change, emphasizing the role of the marine environment in this context.MethodsThis study conducts a comprehensive analysis of the Advisory Opinion and examines its implications for China’s existing climate change legal framework. The analysis identifies key challenges, including expanded legal responsibilities, the harmonization of international law with domestic legislation, and the increased risk of international climate litigation for domestic enterprises.ResultsThe Advisory Opinion establishes a higher standard for China’s legislative response to climate change, necessitating the integration of its international obligations into its domestic legal framework. Key findings reveal gaps in China’s current legal system and emphasize the need for proactive measures to align with international standards.DiscussionTo address these challenges, the paper proposes several recommendations: developing a comprehensive legal framework for climate change, reinforcing due diligence obligations, establishing a robust climate monitoring and assessment system, and enhancing the capacity of domestic enterprises to handle international climate litigation. These measures aim to position China as a proactive contributor to global climate governance.ConclusionThe study provides valuable insights for advancing China’s climate change law and aligning it with the international legal framework. The proposed measures serve as essential guidance for China to assume greater responsibility and influence within the global climate legal system.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"45 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986559","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 : 2025-01-15DOI: 10.3389/fmars.2024.1461982
Gersom Costas
The northeast Atlantic (NEA) mackerel (Scomber scombrus) is a commercially significant species, with expansive spawning migrations occurring along the continental shelf of northwestern Europe. To identify the main variables influencing the spatial distribution of mackerel eggs, this study analyzed data from egg surveys conducted by the Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS) of the International Council for the Exploration of the Sea (ICES). To achieve this objective, a Random Forest model was used to predict the presence of mackerel eggs based on temporal, geographical, and environmental variables. Applying the Random Forest model to the survey data revealed that the main variables affecting mackerel spawning were the bottom depth, latitude, temperature, and salinity. Subsequently, Quotient Analysis was used to determine the optimal ranges of the key variables identified as influencing mackerel spawning. The results demonstrated a clear preference for spawning at depths between 100 m and 200 m, as well as a consistent preference for the area between 43° and 44° North, corresponding to the Cantabrian Sea. Furthermore, the results indicated that mackerel exhibited a considerable range of temperature tolerance throughout the spawning process, with a preference for cooler waters in the Western area in recent years. Salinity seems to have an effect on spawning at salinities between 35.0 ppm to 35.5 ppm, but results were imprecise. These results contribute to our understanding of how environmental and geographical variables influence the spawning behavior of NEA mackerel.
{"title":"Analysis of the spatio-temporal variability of spawning mackerel in the Northeast Atlantic","authors":"Gersom Costas","doi":"10.3389/fmars.2024.1461982","DOIUrl":"https://doi.org/10.3389/fmars.2024.1461982","url":null,"abstract":"The northeast Atlantic (NEA) mackerel (<jats:italic>Scomber scombrus</jats:italic>) is a commercially significant species, with expansive spawning migrations occurring along the continental shelf of northwestern Europe. To identify the main variables influencing the spatial distribution of mackerel eggs, this study analyzed data from egg surveys conducted by the Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS) of the International Council for the Exploration of the Sea (ICES). To achieve this objective, a Random Forest model was used to predict the presence of mackerel eggs based on temporal, geographical, and environmental variables. Applying the Random Forest model to the survey data revealed that the main variables affecting mackerel spawning were the bottom depth, latitude, temperature, and salinity. Subsequently, Quotient Analysis was used to determine the optimal ranges of the key variables identified as influencing mackerel spawning. The results demonstrated a clear preference for spawning at depths between 100 m and 200 m, as well as a consistent preference for the area between 43° and 44° North, corresponding to the Cantabrian Sea. Furthermore, the results indicated that mackerel exhibited a considerable range of temperature tolerance throughout the spawning process, with a preference for cooler waters in the Western area in recent years. Salinity seems to have an effect on spawning at salinities between 35.0 ppm to 35.5 ppm, but results were imprecise. These results contribute to our understanding of how environmental and geographical variables influence the spawning behavior of NEA mackerel.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"49 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986526","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 : 2025-01-15DOI: 10.3389/fmars.2024.1499767
Siwen Gao, Chao Zhou, Lingling Jiang, Jingping Xu
The complex composition of seawater presents significant challenges for accurately estimating biogeochemical data through optical measurements, both in situ and via satellite data. To address the regional applicability of single bio-optical or remote sensing algorithms caused by these challenges, we explored a water optical classification method based on inherent optical properties and particle composition. The ratio of organic particulate matter to total suspended particulate matter concentration (POM/SPM) serves as an optical discriminator of water bodies based on the proportions of organic and mineral particles. The boundary value is determined by the relationship between the particulate backscattering coefficient bbp(λ) and POM/SPM. By analyzing in situ data collected from the coastal waters of Qinhuangdao in the Bohai Sea, China, we developed empirical algorithms to estimate both the POM/SPM ratio and chlorophyll-a (Chl-a) concentration, the latter being a key parameter derived from current ocean remote sensing that indicates phytoplankton abundance. The evaluation of our algorithms demonstrates that accounting for POM/SPM variations significantly improves Chl-a estimate accuracy across the optically-complex coastal waters near Qinhuangdao compared to algorithms that do not consider changes in particle composition, such as the well-known OC4Me algorithm. Furthermore, we determined the distribution of monthly averaged Chl-a concentration and POM/SPM ratio on the coast of Qinhuangdao, Bohai Sea, in 2023. Our results show, for the first time, that the monthly average variations of the POM/SPM ratio in the Bohai Sea and Chl-a concentrations exhibit pronounced seasonal fluctuations.
{"title":"Particle composition-based water classification method for estimating chlorophyll-a in coastal waters from OLCI images","authors":"Siwen Gao, Chao Zhou, Lingling Jiang, Jingping Xu","doi":"10.3389/fmars.2024.1499767","DOIUrl":"https://doi.org/10.3389/fmars.2024.1499767","url":null,"abstract":"The complex composition of seawater presents significant challenges for accurately estimating biogeochemical data through optical measurements, both <jats:italic>in situ</jats:italic> and via satellite data. To address the regional applicability of single bio-optical or remote sensing algorithms caused by these challenges, we explored a water optical classification method based on inherent optical properties and particle composition. The ratio of organic particulate matter to total suspended particulate matter concentration (POM/SPM) serves as an optical discriminator of water bodies based on the proportions of organic and mineral particles. The boundary value is determined by the relationship between the particulate backscattering coefficient <jats:italic>b<jats:sub>bp</jats:sub></jats:italic>(λ) and POM/SPM. By analyzing <jats:italic>in situ</jats:italic> data collected from the coastal waters of Qinhuangdao in the Bohai Sea, China, we developed empirical algorithms to estimate both the POM/SPM ratio and chlorophyll-a (Chl-a) concentration, the latter being a key parameter derived from current ocean remote sensing that indicates phytoplankton abundance. The evaluation of our algorithms demonstrates that accounting for POM/SPM variations significantly improves Chl-a estimate accuracy across the optically-complex coastal waters near Qinhuangdao compared to algorithms that do not consider changes in particle composition, such as the well-known OC4Me algorithm. Furthermore, we determined the distribution of monthly averaged Chl-a concentration and POM/SPM ratio on the coast of Qinhuangdao, Bohai Sea, in 2023. Our results show, for the first time, that the monthly average variations of the POM/SPM ratio in the Bohai Sea and Chl-a concentrations exhibit pronounced seasonal fluctuations.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"27 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986522","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：