Pub Date : 2025-01-29DOI: 10.3389/fmars.2024.1461655
Lacey Jeroue, Craig Faunce, Andy Kingham, Jaclyn Smith
Seafarers working in remote ports and onboard fishing vessels often face isolated, high-risk environments, making them vulnerable to sexual harassment, intimidation, and assault. In the United States and other countries, scientists, called fishery observers, are required by the government to be deployed alongside fishing crews for extended periods to collect essential fisheries data and report potential fishing regulation violations they witness. Although many fishery observers who experience harassment submit official report statements, the true prevalence of the problem is unknown due to nondisclosure. This study uses anonymous responses from annual surveys distributed to North Pacific groundfish and halibut fishery observers to understand barriers to disclosure and estimate disclosure rates. By adjusting the annual counts of observers who submitted official harassment statements with these estimated disclosure rates, we provide the first estimates of the true number of victimized observers (prevalence) each year in a federal fisheries monitoring program in the United States. Model selection suggested that disclosure was influenced by the type of harassment experienced and not by observer demographics or employment year. Estimated disclosure rates (victimized observers who reported annually via official statement) were lowest for sexual harassment (0.18; 95% CI 0.11-0.29); higher for intimidation, coercion and hostile work environments (0.37; 95% CI 0.28-0.47); and highest for assault (0.57; 95% CI 0.41-0.73). Overall, 45% (95% CI 39-51%) of observers who experienced victimization disclosed harassment in a given year. We estimate that 22-38% of observers were victimized annually during the 2016-2022 study period, with rates of 24-60% for females and 12-24% for males. Victimization rates computed from raw survey summary statistics suffer from self-selection bias while rates derived solely from submission of official statements suffer from bias in underreporting. Supplementing official statements with estimates of disclosure rates from anonymous survey data provides a means of mitigating for these two forms of biases to obtain estimates of victimization untangled from fluctuations in reporting tendencies. When disclosure and victimization are teased apart, the effectiveness of risk reduction strategies can be better assessed over time.
{"title":"Estimates of disclosure and victimization rates for fishery observers in the maritime workplace","authors":"Lacey Jeroue, Craig Faunce, Andy Kingham, Jaclyn Smith","doi":"10.3389/fmars.2024.1461655","DOIUrl":"https://doi.org/10.3389/fmars.2024.1461655","url":null,"abstract":"Seafarers working in remote ports and onboard fishing vessels often face isolated, high-risk environments, making them vulnerable to sexual harassment, intimidation, and assault. In the United States and other countries, scientists, called fishery observers, are required by the government to be deployed alongside fishing crews for extended periods to collect essential fisheries data and report potential fishing regulation violations they witness. Although many fishery observers who experience harassment submit official report statements, the true prevalence of the problem is unknown due to nondisclosure. This study uses anonymous responses from annual surveys distributed to North Pacific groundfish and halibut fishery observers to understand barriers to disclosure and estimate disclosure rates. By adjusting the annual counts of observers who submitted official harassment statements with these estimated disclosure rates, we provide the first estimates of the true number of victimized observers (prevalence) each year in a federal fisheries monitoring program in the United States. Model selection suggested that disclosure was influenced by the type of harassment experienced and not by observer demographics or employment year. Estimated disclosure rates (victimized observers who reported annually via official statement) were lowest for sexual harassment (0.18; 95% CI 0.11-0.29); higher for intimidation, coercion and hostile work environments (0.37; 95% CI 0.28-0.47); and highest for assault (0.57; 95% CI 0.41-0.73). Overall, 45% (95% CI 39-51%) of observers who experienced victimization disclosed harassment in a given year. We estimate that 22-38% of observers were victimized annually during the 2016-2022 study period, with rates of 24-60% for females and 12-24% for males. Victimization rates computed from raw survey summary statistics suffer from self-selection bias while rates derived solely from submission of official statements suffer from bias in underreporting. Supplementing official statements with estimates of disclosure rates from anonymous survey data provides a means of mitigating for these two forms of biases to obtain estimates of victimization untangled from fluctuations in reporting tendencies. When disclosure and victimization are teased apart, the effectiveness of risk reduction strategies can be better assessed over time.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"20 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056227","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 : 2025-01-29DOI: 10.3389/fmars.2025.1503019
C. Melissa Miner, Helen D. Berry, Heath Bohlmann, Megan N. Dethier, Steven C. Fradkin, Rani Gaddam, Wendel W. Raymond, Peter T. Raimondi
IntroductionIn late June 2021, the Pacific Northwest region of the United States and Canada experienced an unprecedented atmospheric heatwave that co-occurred with one of the lowest day-time tide series of the year. Several consecutive days of air temperatures 10-20°C above normal, coupled with mid-afternoon low tides proved deadly for many rocky intertidal organisms, which live at the margin of land and sea.MethodsTo assess short (weeks) and longer-term (1 year) impacts of the heatwave on rocky intertidal communities, we used long-term monitoring data collected annually at 16 sites throughout Washington State.Results and discussionOur findings indicate that impacts were most severe at sites within the Salish Sea region of WA, where peak low tides occurred during the hottest, mid-afternoon hours. Focal species assemblages at Olympic coast sites, where low tides occurred in the morning, were largely spared. In addition, while the heatwave was associated with substantial short-term changes in acorn barnacle, rockweed, and California mussel assemblages, lasting impacts (1 year) were only observed in the mussel assemblage at the one Salish Sea site where this species is common. These findings will aid in forecasting both short-term and longer lasting impacts of future heatwave events and help direct potential mitigation efforts to regions and species assemblages where impacts will likely be greatest.
{"title":"Location and natural history are key to determining impact of the 2021 atmospheric heatwave on Pacific Northwest rocky intertidal communities","authors":"C. Melissa Miner, Helen D. Berry, Heath Bohlmann, Megan N. Dethier, Steven C. Fradkin, Rani Gaddam, Wendel W. Raymond, Peter T. Raimondi","doi":"10.3389/fmars.2025.1503019","DOIUrl":"https://doi.org/10.3389/fmars.2025.1503019","url":null,"abstract":"IntroductionIn late June 2021, the Pacific Northwest region of the United States and Canada experienced an unprecedented atmospheric heatwave that co-occurred with one of the lowest day-time tide series of the year. Several consecutive days of air temperatures 10-20°C above normal, coupled with mid-afternoon low tides proved deadly for many rocky intertidal organisms, which live at the margin of land and sea.MethodsTo assess short (weeks) and longer-term (1 year) impacts of the heatwave on rocky intertidal communities, we used long-term monitoring data collected annually at 16 sites throughout Washington State.Results and discussionOur findings indicate that impacts were most severe at sites within the Salish Sea region of WA, where peak low tides occurred during the hottest, mid-afternoon hours. Focal species assemblages at Olympic coast sites, where low tides occurred in the morning, were largely spared. In addition, while the heatwave was associated with substantial short-term changes in acorn barnacle, rockweed, and California mussel assemblages, lasting impacts (1 year) were only observed in the mussel assemblage at the one Salish Sea site where this species is common. These findings will aid in forecasting both short-term and longer lasting impacts of future heatwave events and help direct potential mitigation efforts to regions and species assemblages where impacts will likely be greatest.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"10 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056666","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 : 2025-01-29DOI: 10.3389/fmars.2025.1471650
Xizhen Liu, Bin Wang, Siyang Chen, Haiyan Jin, Yanpei Zhuang, Zhibing Jiang, Hongliang Li, Jianfang Chen
The concentrations and distributions of particulate biogenic silica (PBSi) and its Q7 size-fractionated composition (>20 μm, 0.8–20 μm) of the Changjiang Estuary and its adjacent area were investigated during the summer of 2011. PBSi, primarily produced by diatoms in the surface waters of oceans, was examined for correlations with hydrographic conditions, nutrients, particulate organic carbon, and dissolved oxygen. The distribution of PBSi showed distinct patterns: high levels in nearshore, but relatively low further offshore; low concentrations in the surface layer, whereas relatively high concentrations in the bottom layer. Large-sized PBSi (>20 μm) prevailed in the surface layer, whereas small-sized PBSi (0.8–20 μm) dominated in the bottom layer. Temperature and nutrients were crucial factors controlling the grain size structure and distribution of PBSi. Further, we observed that the distinct zones of high PBSi values in the surface waters were affected by the Changjiang freshwater flushing, and those in the bottom waters were affected by the Yellow Sea Cold Water masses. Moreover, in the area where >20-μm PBSi prevailed, the silicate-to-nitrate ratio was less than 1 at most sampling stations, rendering silicate the limiting nutrient in this area. The PBSi/particulate organic carbon values in the surface waters of the study area ranged from 0.01 to 0.3. Areas exhibiting values exceeding 0.13 primarily clustered in nearshore waters, which was characterized by a dominance of large-sized (>20 μm) PBSi. The nearshore benthic waters exhibited anoxic conditions, where diatoms predominantly comprised the phytoplankton biomass and organic matter featured marine phytoplankton. Consequently, the proliferation of diatoms (siliceous phytoplankton) in the midupper water significantly contributed to the hypoxic conditions at the bottom, as diatoms underwent dissolution during sedimentation, leading to oxygen depletion.
{"title":"The size-fractionated composition of particulate biogenic silica and its ecological significance in the Changjiang Estuary area","authors":"Xizhen Liu, Bin Wang, Siyang Chen, Haiyan Jin, Yanpei Zhuang, Zhibing Jiang, Hongliang Li, Jianfang Chen","doi":"10.3389/fmars.2025.1471650","DOIUrl":"https://doi.org/10.3389/fmars.2025.1471650","url":null,"abstract":"The concentrations and distributions of particulate biogenic silica (PBSi) and its Q7 size-fractionated composition (>20 μm, 0.8–20 μm) of the Changjiang Estuary and its adjacent area were investigated during the summer of 2011. PBSi, primarily produced by diatoms in the surface waters of oceans, was examined for correlations with hydrographic conditions, nutrients, particulate organic carbon, and dissolved oxygen. The distribution of PBSi showed distinct patterns: high levels in nearshore, but relatively low further offshore; low concentrations in the surface layer, whereas relatively high concentrations in the bottom layer. Large-sized PBSi (>20 μm) prevailed in the surface layer, whereas small-sized PBSi (0.8–20 μm) dominated in the bottom layer. Temperature and nutrients were crucial factors controlling the grain size structure and distribution of PBSi. Further, we observed that the distinct zones of high PBSi values in the surface waters were affected by the Changjiang freshwater flushing, and those in the bottom waters were affected by the Yellow Sea Cold Water masses. Moreover, in the area where >20-μm PBSi prevailed, the silicate-to-nitrate ratio was less than 1 at most sampling stations, rendering silicate the limiting nutrient in this area. The PBSi/particulate organic carbon values in the surface waters of the study area ranged from 0.01 to 0.3. Areas exhibiting values exceeding 0.13 primarily clustered in nearshore waters, which was characterized by a dominance of large-sized (>20 μm) PBSi. The nearshore benthic waters exhibited anoxic conditions, where diatoms predominantly comprised the phytoplankton biomass and organic matter featured marine phytoplankton. Consequently, the proliferation of diatoms (siliceous phytoplankton) in the midupper water significantly contributed to the hypoxic conditions at the bottom, as diatoms underwent dissolution during sedimentation, leading to oxygen depletion.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"25 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056228","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}
IntroductionSea ice extent increased in the Pacific Arctic Ocean during 2021 owing to the reversal of the Beaufort Gyre, unlike in previous years. The increased sea ice concentration may restore the marine ecosystem to its previous state; nevertheless, the precise conditions and mechanisms involved remain unclear.MethodsIn this study, the 2008–2017 period was defined as “the sea ice retreat year,” and its zooplankton community distribution representative was estimated using generalized dissimilarity modeling (GDM). Subsequently, we assessed the effect of delayed sea ice melt on the zooplankton community by comparing the zooplankton community of the sea ice retreat year with that in 2021.ResultsIn GDM, numerous satellite parameters significantly affected the zooplankton distribution, with the highest effect during the open-water period and annual primary production (APP) and the lowest in water temperature. The effect of APP and temperature on zooplankton similarity was high around the Bering Strait owing to the advection of Pacific copepods (Eucalanus bungii, Metridia pacifica, and Neocalanus spp.) and synchronized inflow of warm Pacific water. Under significant warming scenarios (Shared Socioeconomic Pathway [SSP]1-2.6 and SSP5-8.5), GDM-based multiple effects predicted that the zooplankton communities in high latitudes will be more affected than those on the southern shelf (northern Bering Sea to southern Chukchi Sea). In 2021, the total abundance across the northern Bering Sea to the Chukchi Sea shelf region was lower than that of the community during the sea ice retreat year. However, certain species (Limacina helicina and Pacific copepods) increased locally (northern Bering Sea and Barrow Canyon) because of the increasing volume of Pacific origin water.DiscussionContrary to the reported increase trend on zooplankton, low primary productivity and phenological mismatch for zooplankton may prevail in the Pacific Arctic Ocean, resulting in a low abundance during autumn 2021.
{"title":"Effect of delayed sea ice retreat on zooplankton communities in the Pacific Arctic Ocean: a generalized dissimilarity modeling approach","authors":"Yuya Hibino, Kohei Matsuno, Amane Fujiwara, Yoshiyuki Abe, Nanami Hosoda, Motoyo Itoh, Atsushi Yamaguchi","doi":"10.3389/fmars.2025.1484609","DOIUrl":"https://doi.org/10.3389/fmars.2025.1484609","url":null,"abstract":"IntroductionSea ice extent increased in the Pacific Arctic Ocean during 2021 owing to the reversal of the Beaufort Gyre, unlike in previous years. The increased sea ice concentration may restore the marine ecosystem to its previous state; nevertheless, the precise conditions and mechanisms involved remain unclear.MethodsIn this study, the 2008–2017 period was defined as “the sea ice retreat year,” and its zooplankton community distribution representative was estimated using generalized dissimilarity modeling (GDM). Subsequently, we assessed the effect of delayed sea ice melt on the zooplankton community by comparing the zooplankton community of the sea ice retreat year with that in 2021.ResultsIn GDM, numerous satellite parameters significantly affected the zooplankton distribution, with the highest effect during the open-water period and annual primary production (APP) and the lowest in water temperature. The effect of APP and temperature on zooplankton similarity was high around the Bering Strait owing to the advection of Pacific copepods (<jats:italic>Eucalanus bungii</jats:italic>, <jats:italic>Metridia pacifica</jats:italic>, and <jats:italic>Neocalanus</jats:italic> spp.) and synchronized inflow of warm Pacific water. Under significant warming scenarios (Shared Socioeconomic Pathway [SSP]1-2.6 and SSP5-8.5), GDM-based multiple effects predicted that the zooplankton communities in high latitudes will be more affected than those on the southern shelf (northern Bering Sea to southern Chukchi Sea). In 2021, the total abundance across the northern Bering Sea to the Chukchi Sea shelf region was lower than that of the community during the sea ice retreat year. However, certain species (<jats:italic>Limacina helicina</jats:italic> and Pacific copepods) increased locally (northern Bering Sea and Barrow Canyon) because of the increasing volume of Pacific origin water.DiscussionContrary to the reported increase trend on zooplankton, low primary productivity and phenological mismatch for zooplankton may prevail in the Pacific Arctic Ocean, resulting in a low abundance during autumn 2021.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"71 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056226","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 : 2025-01-29DOI: 10.3389/fmars.2025.1520497
Leyuan Feng, Shiyan Zhang, Ming Tao, Ting Sun, Antai Wang
Plagiostomum flatworms are small, free-living organisms frequently found in saltwater or freshwater habitats, but their biological characteristics remain largely unknown. Here, we describe two new species of Plagiostomum collected from the intertidal zone of the South China Sea, based on the integrative studies of morphology, phylogeny, reproduction, and juvenile development. Morphologically, Plagiostomum nanhaiensis sp. nov. can be distinguished from congeneric species by its three dark brown dorsal stripes, pear-shaped vesicula seminalis located ventrally to the intestine, and the testes surrounding the ovaries and bead-like sperm. Additionally, Plagiostomum plagae sp. nov. can be distinguished from P. nanhaiensis sp. nov. and other congeneric species by its two connected dorsal stripes, multiple spherical testes arranged along the ventral midline, a hemispherical vesicula seminalis located on the right ventral side, and grain-shaped sperm. Kimura’s two-parameter distance and phylogenetic analyses further support the recognition of these two new species, showing that the three specimens of P. nanhaiensis sp. nov. and P. plagae sp. nov. form two separate clades within Plagiostomum with solid support. Moreover, these two new species exhibit similar habits and reproductive strategies, adopting hypodermic impregnation. The reproductive studies indicate that in natural environments or larger mating groups, these two new species tend to invest resources in male reproductive functions to enhance fertilization success, while in smaller or single-individual cultures, they shift resources toward complete female reproductive functions. Our results not only enrich the biodiversity data of the family Plagiostomidae in China but also provide new empirical evidence for existing sex allocation theories.
{"title":"Two new species of Plagiostomum (Prolecithophora, Plagiostomidae) from China with its morphology, phylogeny, and reproductive strategy","authors":"Leyuan Feng, Shiyan Zhang, Ming Tao, Ting Sun, Antai Wang","doi":"10.3389/fmars.2025.1520497","DOIUrl":"https://doi.org/10.3389/fmars.2025.1520497","url":null,"abstract":"<jats:italic>Plagiostomum</jats:italic> flatworms are small, free-living organisms frequently found in saltwater or freshwater habitats, but their biological characteristics remain largely unknown. Here, we describe two new species of <jats:italic>Plagiostomum</jats:italic> collected from the intertidal zone of the South China Sea, based on the integrative studies of morphology, phylogeny, reproduction, and juvenile development. Morphologically, <jats:italic>Plagiostomum nanhaiensis</jats:italic> sp. nov. can be distinguished from congeneric species by its three dark brown dorsal stripes, pear-shaped vesicula seminalis located ventrally to the intestine, and the testes surrounding the ovaries and bead-like sperm. Additionally, <jats:italic>Plagiostomum plagae</jats:italic> sp. nov. can be distinguished from <jats:italic>P. nanhaiensis</jats:italic> sp. nov. and other congeneric species by its two connected dorsal stripes, multiple spherical testes arranged along the ventral midline, a hemispherical vesicula seminalis located on the right ventral side, and grain-shaped sperm. Kimura’s two-parameter distance and phylogenetic analyses further support the recognition of these two new species, showing that the three specimens of <jats:italic>P. nanhaiensis</jats:italic> sp. nov. and <jats:italic>P. plagae</jats:italic> sp. nov. form two separate clades within <jats:italic>Plagiostomum</jats:italic> with solid support. Moreover, these two new species exhibit similar habits and reproductive strategies, adopting hypodermic impregnation. The reproductive studies indicate that in natural environments or larger mating groups, these two new species tend to invest resources in male reproductive functions to enhance fertilization success, while in smaller or single-individual cultures, they shift resources toward complete female reproductive functions. Our results not only enrich the biodiversity data of the family Plagiostomidae in China but also provide new empirical evidence for existing sex allocation theories.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"45 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143057133","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 : 2025-01-28DOI: 10.3389/fmars.2024.1494809
Ke Pang, Yang Feng, Youchang Zheng, Chao Fang, Xiangrong Xu
The Pearl River delivers a large amount of plastic waste to the Pearl River Estuary (PRE) and adjacent Northern South China Sea (NSCS) region each year. However, the transport of floating litter after release is difficult to predict due to the complex hydrodynamic conditions caused by the climate variability. A regional ocean circulation model coupled with a Lagrangian particle tracking model is utilized in this study to simulate the distribution and fate of floating litter particles in the Pearl River Estuary (PRE) and Northern South China Sea (NSCS) under the influence of El Niño - Southern Oscillation (ENSO) event. Simulations are conducted during all four seasons (spring, summer, fall, and winter) in typical El Niño, La Niña, and ENSO-neutral year. The model reveals that most floating litter remains within Lingding Bay before being transported westward by the counterclockwise circulation over the NSCS and arriving at the Qiongzhou Strait. After crossing the Strait, the debris is carried by the counterclockwise circulation of the Beibu Gulf, and eventually arriving at the coasts of Vietnam and Laos. The ENSO warm (El Niño) and cold (La Niña) phases disrupt circulation patterns and modulate the amount of Pearl River runoff, thereby altering the transport pathways and grounding probabilities of floating litter. During La Niña years, floating litter particles spread over a wider area, travel longer distances, and have lower beaching probabilities. Conversely, during El Niño year, floating litter particles tend to remain within Lingding Bay for longer durations, with some debris entrained towards the Hong Kong region. This study underscores the impact of climate mode of variability in influencing the litter sources, fate and transport and accumulation at estuarine-coastal oceans, which will provide critical scientific insights for plastic pollution management in the PRE - NSCS region, which is a newly identified hotspot for floating litter and microplastic pollution in global oceans.
{"title":"Simulating the ENSO impact on the distribution and fate of floating litter particles in the Northern South China Sea","authors":"Ke Pang, Yang Feng, Youchang Zheng, Chao Fang, Xiangrong Xu","doi":"10.3389/fmars.2024.1494809","DOIUrl":"https://doi.org/10.3389/fmars.2024.1494809","url":null,"abstract":"The Pearl River delivers a large amount of plastic waste to the Pearl River Estuary (PRE) and adjacent Northern South China Sea (NSCS) region each year. However, the transport of floating litter after release is difficult to predict due to the complex hydrodynamic conditions caused by the climate variability. A regional ocean circulation model coupled with a Lagrangian particle tracking model is utilized in this study to simulate the distribution and fate of floating litter particles in the Pearl River Estuary (PRE) and Northern South China Sea (NSCS) under the influence of El Niño - Southern Oscillation (ENSO) event. Simulations are conducted during all four seasons (spring, summer, fall, and winter) in typical El Niño, La Niña, and ENSO-neutral year. The model reveals that most floating litter remains within Lingding Bay before being transported westward by the counterclockwise circulation over the NSCS and arriving at the Qiongzhou Strait. After crossing the Strait, the debris is carried by the counterclockwise circulation of the Beibu Gulf, and eventually arriving at the coasts of Vietnam and Laos. The ENSO warm (El Niño) and cold (La Niña) phases disrupt circulation patterns and modulate the amount of Pearl River runoff, thereby altering the transport pathways and grounding probabilities of floating litter. During La Niña years, floating litter particles spread over a wider area, travel longer distances, and have lower beaching probabilities. Conversely, during El Niño year, floating litter particles tend to remain within Lingding Bay for longer durations, with some debris entrained towards the Hong Kong region. This study underscores the impact of climate mode of variability in influencing the litter sources, fate and transport and accumulation at estuarine-coastal oceans, which will provide critical scientific insights for plastic pollution management in the PRE - NSCS region, which is a newly identified hotspot for floating litter and microplastic pollution in global oceans.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"10 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054928","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 : 2025-01-28DOI: 10.3389/fmars.2024.1523246
Menglei Shi, Sisi Chen, Yutong Feng, Shiyuan Wang, Yuyu Xia, Jianlin He
With an estimated global prevalence of 32.4%, non-alcoholic fatty liver disease (NAFLD) is currently the most prevalent chronic liver condition. The marine ecosystem, distinguished by its distinctive environmental characteristics, is a treasure trove of novel lead compounds possessing unique chemical structures, offering promising avenues for the development of new therapeutic agents or dietary supplement targeting NAFLD. Marine bioactive substances from natural products, such as polysaccharides, polyphenols, polyunsaturated fatty acids, and peptides, have been shown to benefit liver health by alleviating metabolic dysfunction through multiple mechanisms. This paper reviews the effects of marine bioactive substances from various marine entities, including marine fauna, flora, and microorganisms, on the regulation of NAFLD. A brief overview of the predominant pathogenic mechanisms underlying the disease is also provided, thereby establishing a critical link between the therapeutic potential of marine bioactive substances and the management of NAFLD.
{"title":"Marine natural products as an important source of bioactive substances for non-alcoholic fatty liver disease management","authors":"Menglei Shi, Sisi Chen, Yutong Feng, Shiyuan Wang, Yuyu Xia, Jianlin He","doi":"10.3389/fmars.2024.1523246","DOIUrl":"https://doi.org/10.3389/fmars.2024.1523246","url":null,"abstract":"With an estimated global prevalence of 32.4%, non-alcoholic fatty liver disease (NAFLD) is currently the most prevalent chronic liver condition. The marine ecosystem, distinguished by its distinctive environmental characteristics, is a treasure trove of novel lead compounds possessing unique chemical structures, offering promising avenues for the development of new therapeutic agents or dietary supplement targeting NAFLD. Marine bioactive substances from natural products, such as polysaccharides, polyphenols, polyunsaturated fatty acids, and peptides, have been shown to benefit liver health by alleviating metabolic dysfunction through multiple mechanisms. This paper reviews the effects of marine bioactive substances from various marine entities, including marine fauna, flora, and microorganisms, on the regulation of NAFLD. A brief overview of the predominant pathogenic mechanisms underlying the disease is also provided, thereby establishing a critical link between the therapeutic potential of marine bioactive substances and the management of NAFLD.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"115 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054922","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 : 2025-01-28DOI: 10.3389/fmars.2025.1546289
Xiaomeng Geng, Huiru Li, Le Wang, Weidong Sun, Yize Li
In recent years, Ulva prolifera green tide, as a large-scale marine ecological phenomenon, has occurred frequently in coastal areas such as the Yellow Sea and the East China Sea, significantly affecting marine ecosystems and fishery resources. With the continuous advancement of remote sensing technologies, these technologies have become indispensable tools for monitoring Ulva prolifera green tides. This review provides a comprehensive overview of the advances in remote sensing band indices for detecting green tides, including spatiotemporal distribution analysis, area and biomass estimation, drift trajectory modeling, and investigations of their driving mechanisms. Additionally, it identifies the limitations and unresolved challenges in current approaches, such as constraints on data resolution, algorithmic biases, and environmental variability. The potential for integrating multi-source remote sensing data with marine environmental parameters and deep learning techniques is discussed, emphasizing their roles in improving the accuracy and reliability of monitoring and predicting Ulva prolifera green tides. This review aims to guide future research efforts and technological innovations in this field.
{"title":"A comprehensive review of remote sensing techniques for monitoring Ulva prolifera green tides","authors":"Xiaomeng Geng, Huiru Li, Le Wang, Weidong Sun, Yize Li","doi":"10.3389/fmars.2025.1546289","DOIUrl":"https://doi.org/10.3389/fmars.2025.1546289","url":null,"abstract":"In recent years, <jats:italic>Ulva prolifera</jats:italic> green tide, as a large-scale marine ecological phenomenon, has occurred frequently in coastal areas such as the Yellow Sea and the East China Sea, significantly affecting marine ecosystems and fishery resources. With the continuous advancement of remote sensing technologies, these technologies have become indispensable tools for monitoring <jats:italic>Ulva prolifera</jats:italic> green tides. This review provides a comprehensive overview of the advances in remote sensing band indices for detecting green tides, including spatiotemporal distribution analysis, area and biomass estimation, drift trajectory modeling, and investigations of their driving mechanisms. Additionally, it identifies the limitations and unresolved challenges in current approaches, such as constraints on data resolution, algorithmic biases, and environmental variability. The potential for integrating multi-source remote sensing data with marine environmental parameters and deep learning techniques is discussed, emphasizing their roles in improving the accuracy and reliability of monitoring and predicting <jats:italic>Ulva prolifera</jats:italic> green tides. This review aims to guide future research efforts and technological innovations in this field.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"78 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054923","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 : 2025-01-28DOI: 10.3389/fmars.2025.1539865
Adi Khen, Maggie D. Johnson, Michael D. Fox, Jennifer E. Smith
Coral reef algae serve many important ecological functions, from primary production to nutrient uptake and reef stabilization, but our knowledge of longer-term effects of thermal stress on algae in situ is limited. While ocean warming can facilitate proliferation of algae and potential phase shifts from coral to macroalgal-dominated states, algal responses may vary by species, genus, functional group, or type (e.g., calcareous vs. fleshy). We used 11 years of annual monitoring data (2009-2019) that spans two El Niño-associated heatwaves to examine benthic algal community dynamics on Palmyra Atoll in the central Pacific Ocean. We quantified the percent cover of algal taxa via image analysis of permanent benthic photoquadrats from two habitats on Palmyra: the deeper, wave-exposed fore reef (10 m depth) and the shallower, wave-sheltered reef terrace (5 m depth). Each habitat was characterized by distinct algal communities: predominantly calcareous taxa on the fore reef and predominantly fleshy taxa on the reef terrace. Patterns in abundance fluctuated over time and/or in response to thermal anomalies in 2009 and 2015. Fleshy algae generally increased in cover post-warming, which coincided with large declines of the calcified macroalgae, Halimeda spp. Long-term monitoring of coral reef algal communities is critical for understanding their differential responses to thermal stress and can improve projections of ecosystem functioning in the context of global change.
{"title":"Benthic algal community dynamics on Palmyra Atoll throughout a decade with two thermal anomalies","authors":"Adi Khen, Maggie D. Johnson, Michael D. Fox, Jennifer E. Smith","doi":"10.3389/fmars.2025.1539865","DOIUrl":"https://doi.org/10.3389/fmars.2025.1539865","url":null,"abstract":"Coral reef algae serve many important ecological functions, from primary production to nutrient uptake and reef stabilization, but our knowledge of longer-term effects of thermal stress on algae <jats:italic>in situ</jats:italic> is limited. While ocean warming can facilitate proliferation of algae and potential phase shifts from coral to macroalgal-dominated states, algal responses may vary by species, genus, functional group, or type (e.g., calcareous vs. fleshy). We used 11 years of annual monitoring data (2009-2019) that spans two El Niño-associated heatwaves to examine benthic algal community dynamics on Palmyra Atoll in the central Pacific Ocean. We quantified the percent cover of algal taxa via image analysis of permanent benthic photoquadrats from two habitats on Palmyra: the deeper, wave-exposed fore reef (10 m depth) and the shallower, wave-sheltered reef terrace (5 m depth). Each habitat was characterized by distinct algal communities: predominantly calcareous taxa on the fore reef and predominantly fleshy taxa on the reef terrace. Patterns in abundance fluctuated over time and/or in response to thermal anomalies in 2009 and 2015. Fleshy algae generally increased in cover post-warming, which coincided with large declines of the calcified macroalgae, <jats:italic>Halimeda</jats:italic> spp. Long-term monitoring of coral reef algal communities is critical for understanding their differential responses to thermal stress and can improve projections of ecosystem functioning in the context of global change.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"52 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054924","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 : 2025-01-28DOI: 10.3389/fmars.2025.1461723
Katherine Baker, Svenja Halfter, Ben Scoulding, Kerrie M. Swadling, Shane A. Richards, Matthieu Bressac, Caroline A. Sutton, Philip W. Boyd
The passive sinking flux of particles, termed the biological gravitational pump (BGP), is an important component of the ocean’s biological carbon pump. In addition, carbon-rich particles are actively injected to depth through the diel vertical migration (DVM) of micronekton and mesozooplankton from the surface to the oceans’ twilight zone (200 m – 1000 m depth). This is known as the mesopelagic-migrant pump (MMP). We investigated the magnitude of the MMP at one subantarctic and two polar sites in summer by assessing particulate and dissolved carbon export below 200 m depth based on DVM and the composition of the mesopelagic community. Carbon injection potential (CIP) for the dominant taxa at each site was estimated through four pathways, i.e., excretion, respiration, fecal pellets, and carcass production. Blooms of two migratory tunicate species, the pyrosome Pyrosoma atlanticum (subantarctic) and the salp Salpa thompsoni (polar) dominated the micronekton biomass and MMP export ranged from 5.0 to 9.4 mg C m-2 d-1 across the three Southern Ocean sites. Mesozooplankton abundance was dominated by copepods, which contributed an additional 0.7 to 32.2 mg C m-2 d-1 to the MMP. Results from this summertime study suggest an increase in the relative importance of the MMP compared to the BGP south of the Polar Front, however, future work should target the seasonality of the MMP, which necessitates linking environmental drivers to micronekton and mesozooplankton community composition, life history, and DVM.
{"title":"Carbon injection potential of the mesopelagic-migrant pump in the Southern Ocean during summer","authors":"Katherine Baker, Svenja Halfter, Ben Scoulding, Kerrie M. Swadling, Shane A. Richards, Matthieu Bressac, Caroline A. Sutton, Philip W. Boyd","doi":"10.3389/fmars.2025.1461723","DOIUrl":"https://doi.org/10.3389/fmars.2025.1461723","url":null,"abstract":"The passive sinking flux of particles, termed the biological gravitational pump (BGP), is an important component of the ocean’s biological carbon pump. In addition, carbon-rich particles are actively injected to depth through the diel vertical migration (DVM) of micronekton and mesozooplankton from the surface to the oceans’ twilight zone (200 m – 1000 m depth). This is known as the mesopelagic-migrant pump (MMP). We investigated the magnitude of the MMP at one subantarctic and two polar sites in summer by assessing particulate and dissolved carbon export below 200 m depth based on DVM and the composition of the mesopelagic community. Carbon injection potential (CIP) for the dominant taxa at each site was estimated through four pathways, i.e., excretion, respiration, fecal pellets, and carcass production. Blooms of two migratory tunicate species, the pyrosome <jats:italic>Pyrosoma atlanticum</jats:italic> (subantarctic) and the salp <jats:italic>Salpa thompsoni</jats:italic> (polar) dominated the micronekton biomass and MMP export ranged from 5.0 to 9.4 mg C m<jats:sup>-2</jats:sup> d<jats:sup>-1</jats:sup> across the three Southern Ocean sites. Mesozooplankton abundance was dominated by copepods, which contributed an additional 0.7 to 32.2 mg C m<jats:sup>-2</jats:sup> d<jats:sup>-1</jats:sup> to the MMP. Results from this summertime study suggest an increase in the relative importance of the MMP compared to the BGP south of the Polar Front, however, future work should target the seasonality of the MMP, which necessitates linking environmental drivers to micronekton and mesozooplankton community composition, life history, and DVM.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"59 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054921","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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