Pub Date : 2026-03-20DOI: 10.3389/fmars.2026.1775690
Wei Yuan, Lei Zhang
The Port State Measures Agreement (PSMA), effective since 2016, the PSMA serves as a legally binding instrument to combat IUU fishing, mandating rigorous inspections of all foreign fishing vessels entering member ports, denying access to known IUU vessels, and conducting thorough investigations of suspicious vessels. Despite its potential, practical enforcement faces challenges, such as limited resources in developing countries, insufficient international cooperation and information sharing, and inconsistencies in legal sanctions across countries. To fully leverage the PSMA’s capacity, key issues such as resource allocation, global cooperation, and harmonization of relevant laws must be addressed.
{"title":"Curbing IUU fishing by enforcing the port state measures agreement","authors":"Wei Yuan, Lei Zhang","doi":"10.3389/fmars.2026.1775690","DOIUrl":"https://doi.org/10.3389/fmars.2026.1775690","url":null,"abstract":"The Port State Measures Agreement (PSMA), effective since 2016, the PSMA serves as a legally binding instrument to combat IUU fishing, mandating rigorous inspections of all foreign fishing vessels entering member ports, denying access to known IUU vessels, and conducting thorough investigations of suspicious vessels. Despite its potential, practical enforcement faces challenges, such as limited resources in developing countries, insufficient international cooperation and information sharing, and inconsistencies in legal sanctions across countries. To fully leverage the PSMA’s capacity, key issues such as resource allocation, global cooperation, and harmonization of relevant laws must be addressed.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"14 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492747","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 : 2026-03-19DOI: 10.3389/fmars.2026.1785301
Nambiyur Boopathymani Komuhi, Amit Ranjan, Mir Ishfaq Nazir, Nathan Felix, Elangovan Prabu, Pushparaj Chidambaram, Venkatachalam Kaliyamurthi, Albin Jemila Thangarani, Arumugam Uma
The aim of the present study was to evaluate the optimal dietary protein level and its effect on the survival rate, observed mortality, cannibalism rate, growth performance, and digestive and metabolic enzyme activity of Channa striata larvae. A total of 4,950 larvae with an average initial weight of 1.5 ± 0.00 mg and an average total length of 0.6 ± 0.01 cm were stocked at 550 larvae in triplicate and fed with isolipidic diets containing graded levels of crude protein 40% (P40), 50% (P50), and 60% (P60) for 26 days. The growth indices, including weight gain, weight gain percentage, average daily growth, protein efficiency ratio, and feed conversion ratio, exhibited a better growth performance in P50, showing a significant difference among treatments ( p < 0.05). A better survival rate was observed in P50, whereas a reduced mortality and cannibalism rate was observed in P50 compared with P40 and P60. Results showed that the optimal dietary protein level of C. striata larvae based on second-order polynomial regression equation was ~51%. Digestive enzymes (amylase, lipase, total protease, trypsin, and chymotrypsin) and metabolic enzymes (alanine aminotransferase and aspartate aminotransferase) showed a similar trend, an elevated peak in P40, followed by P50 and P60. Based on the findings from the present study, it is concluded that crude protein at 51% level is optimal for better growth performance and survival of C. striata larvae.
{"title":"Optimization of the protein requirement of Channa striata larvae fed graded levels of protein diet","authors":"Nambiyur Boopathymani Komuhi, Amit Ranjan, Mir Ishfaq Nazir, Nathan Felix, Elangovan Prabu, Pushparaj Chidambaram, Venkatachalam Kaliyamurthi, Albin Jemila Thangarani, Arumugam Uma","doi":"10.3389/fmars.2026.1785301","DOIUrl":"https://doi.org/10.3389/fmars.2026.1785301","url":null,"abstract":"The aim of the present study was to evaluate the optimal dietary protein level and its effect on the survival rate, observed mortality, cannibalism rate, growth performance, and digestive and metabolic enzyme activity of <jats:italic>Channa striata</jats:italic> larvae. A total of 4,950 larvae with an average initial weight of 1.5 ± 0.00 mg and an average total length of 0.6 ± 0.01 cm were stocked at 550 larvae in triplicate and fed with isolipidic diets containing graded levels of crude protein 40% (P40), 50% (P50), and 60% (P60) for 26 days. The growth indices, including weight gain, weight gain percentage, average daily growth, protein efficiency ratio, and feed conversion ratio, exhibited a better growth performance in P50, showing a significant difference among treatments ( <jats:italic>p</jats:italic> &lt; 0.05). A better survival rate was observed in P50, whereas a reduced mortality and cannibalism rate was observed in P50 compared with P40 and P60. Results showed that the optimal dietary protein level of <jats:italic>C. striata</jats:italic> larvae based on second-order polynomial regression equation was ~51%. Digestive enzymes (amylase, lipase, total protease, trypsin, and chymotrypsin) and metabolic enzymes (alanine aminotransferase and aspartate aminotransferase) showed a similar trend, an elevated peak in P40, followed by P50 and P60. Based on the findings from the present study, it is concluded that crude protein at 51% level is optimal for better growth performance and survival of <jats:italic>C. striata</jats:italic> larvae.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"3 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492752","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}
Carbonate-associated sulfate (CAS)—trace SO 42- incorporated into carbonate mineral lattices by substituting for CO 32— serves as a valuable geochemical proxy for reconstructing seawater chemistry, redox conditions, microbial sulfate reduction activity, and diagenetic sequences in ancient marine environments, cold seeps, and gas hydrate reservoirs. However, conventional CAS extraction methods, which typically use HCl to digest bulk carbonate samples, yield mixed isotopic and concentration signals from coexisting calcite and dolomite. Therefore, it is difficult to precisely distinguish the sulfur isotopes of CAS in the original sedimentary environment from that resulting from secondary alteration. In order to isolate calcite-hosted CAS (calcite-CAS) from dolomite-hosted CAS (dolomite-CAS), we evaluated six acetic acid leaching conditions in sequence (0.1-0.5 mol/L, 1-2hours). The results indicate that treatment with 0.1 mol/L acetic acid for 1 hour effectively releases calcite-CAS while suppressing dolomite dissolution. When applied to natural carbonate outcrop samples, this approach reveals that the δ³ 4 S values of calcite-CAS are consistently ~8.22‰ higher than those of coexisting dolomite-CAS. Notably, the lowest measured δ³ 4 S Calcite - CAS values are 2-5‰ higher than previously reported bulk CAS data, suggesting that earlier records were biased by the inclusion of dolomite-CAS. We therefore recommend the 0.1 mol/L acetic acid leaching protocol (1 hour) for extracting calcite-CAS from dolomite-bearing carbonate rocks, as this enables more accurate reconstruction of depositional and diagenetic conditions.
{"title":"Sequential extraction of carbonate-associated sulfate from calcite and dolomite in carbonate rocks","authors":"Chenlu Xu, Leqi Liu, Hongxia Li, Chunfang Cai, Hailin Yang, Hongfeng Lu","doi":"10.3389/fmars.2026.1778523","DOIUrl":"https://doi.org/10.3389/fmars.2026.1778523","url":null,"abstract":"Carbonate-associated sulfate (CAS)—trace SO <jats:sub>4</jats:sub> <jats:sup>2-</jats:sup> incorporated into carbonate mineral lattices by substituting for CO <jats:sub>3</jats:sub> <jats:sup>2—</jats:sup> serves as a valuable geochemical proxy for reconstructing seawater chemistry, redox conditions, microbial sulfate reduction activity, and diagenetic sequences in ancient marine environments, cold seeps, and gas hydrate reservoirs. However, conventional CAS extraction methods, which typically use HCl to digest bulk carbonate samples, yield mixed isotopic and concentration signals from coexisting calcite and dolomite. Therefore, it is difficult to precisely distinguish the sulfur isotopes of CAS in the original sedimentary environment from that resulting from secondary alteration. In order to isolate calcite-hosted CAS (calcite-CAS) from dolomite-hosted CAS (dolomite-CAS), we evaluated six acetic acid leaching conditions in sequence (0.1-0.5 mol/L, 1-2hours). The results indicate that treatment with 0.1 mol/L acetic acid for 1 hour effectively releases calcite-CAS while suppressing dolomite dissolution. When applied to natural carbonate outcrop samples, this approach reveals that the δ³ <jats:sup>4</jats:sup> S values of calcite-CAS are consistently ~8.22‰ higher than those of coexisting dolomite-CAS. Notably, the lowest measured δ³ <jats:sup>4</jats:sup> S <jats:sub>Calcite</jats:sub> - <jats:sub>CAS</jats:sub> values are 2-5‰ higher than previously reported bulk CAS data, suggesting that earlier records were biased by the inclusion of dolomite-CAS. We therefore recommend the 0.1 mol/L acetic acid leaching protocol (1 hour) for extracting calcite-CAS from dolomite-bearing carbonate rocks, as this enables more accurate reconstruction of depositional and diagenetic conditions.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"17 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147493003","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 : 2026-03-19DOI: 10.3389/fmars.2026.1790665
Lili Li, Xiaochen Zhang
Blue carbon policy is a strategic priority for mitigating climate change and advancing marine conservation. Quantifying the attributes of these policies is essential for their scientific formulation and for driving sustainable innovation. Grounded in policy instrument theory, this study constructs a three-dimensional “Instrument-Theme-Stage” framework to evaluate the blue carbon policy documents issued in China since 2015. Through quantitative text analysis, the research examines the evolutionary process and distribution of policy instruments. Findings reveal that China has established a preliminary policy system which is heavily reliant on capacity-building instruments, whereas supply-oriented, regulatory, and demand-based instruments see limited use. Moreover, the analysis identifies structural imbalances, including disproportionate instrument allocation, uneven thematic coverage, and weak alignment between policy instruments and specific themes. To address these issues, this study recommends rebalancing the instrument mix, strengthening thematic coordination, and ensuring precise matching of instruments to policy goals. Doing so will improve the adaptability and strategic configuration of China’s blue carbon governance.
{"title":"Allocation and adaptation in China’s blue carbon policy: a quantitative textual analysis based on a “theme-instrument-stage” framework","authors":"Lili Li, Xiaochen Zhang","doi":"10.3389/fmars.2026.1790665","DOIUrl":"https://doi.org/10.3389/fmars.2026.1790665","url":null,"abstract":"Blue carbon policy is a strategic priority for mitigating climate change and advancing marine conservation. Quantifying the attributes of these policies is essential for their scientific formulation and for driving sustainable innovation. Grounded in policy instrument theory, this study constructs a three-dimensional “Instrument-Theme-Stage” framework to evaluate the blue carbon policy documents issued in China since 2015. Through quantitative text analysis, the research examines the evolutionary process and distribution of policy instruments. Findings reveal that China has established a preliminary policy system which is heavily reliant on capacity-building instruments, whereas supply-oriented, regulatory, and demand-based instruments see limited use. Moreover, the analysis identifies structural imbalances, including disproportionate instrument allocation, uneven thematic coverage, and weak alignment between policy instruments and specific themes. To address these issues, this study recommends rebalancing the instrument mix, strengthening thematic coordination, and ensuring precise matching of instruments to policy goals. Doing so will improve the adaptability and strategic configuration of China’s blue carbon governance.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"15 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147493002","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 : 2026-03-19DOI: 10.3389/fmars.2026.1631769
Carolin Paul, Jan Dierking, Anke Kremp
The trophic mode is one of the most important functional traits of organisms, determining their position in the food web and their role in the ecosystem. Under the classical concept, phytoplankton was considered to consist exclusively of phototrophic and microzooplankton exclusively of heterotrophic organisms. However, it is now increasingly recognized that mixotrophy (e.g. combining photo- and phagotrophy) occurs among both photo- and microzooplankton species, and that in extension, trophic diversity and relationships among plankton are expected to be more extensive and complex than previously thought. To enhance understanding of plankton trophic modes, diversity and relationships during spring bloom period in Bornholm Basin, central Baltic Sea, we categorized here the temporal succession in (1) the aquatic protist community by trophic modes, and (2) the community composition in terms of taxonomic groups and feeding mode, and its correlation with environmental factors and available prey-size. Our results show that the trophic mode composition of the community changed drastically over the course of the spring season, representing a high trophic complexity and more complex dynamics than previously suggested. The heterotrophic community was characterized by a high diversity of species and groups, with heterotrophic ciliates showing a clear seasonal succession in body size-classes, switching from the smallest sized-fraction (10-20 µm) in winter to an increasingly amount of larger-sized species of 30-55 µm and >55 µm with progression of the spring period. Changes in ciliate community composition were correlated with sea surface temperature, shifting from a cold-associated to a warm-associated community over the course of the spring season. Results further suggest that in communities including a larger mixotrophic component, size trait-based trophic relations between heterotrophic groups and their prey are complex, potentially due to similar prey-size preferences among heterotrophic and mixotrophic species. Overall, our findings emphasize the importance of accounting for the trophic modes of species to enhance the understanding of trophic relations and dynamics within bloom events.
{"title":"Unravelling protist trophic complexity and prey-size dynamics in Central Baltic spring blooms","authors":"Carolin Paul, Jan Dierking, Anke Kremp","doi":"10.3389/fmars.2026.1631769","DOIUrl":"https://doi.org/10.3389/fmars.2026.1631769","url":null,"abstract":"The trophic mode is one of the most important functional traits of organisms, determining their position in the food web and their role in the ecosystem. Under the classical concept, phytoplankton was considered to consist exclusively of phototrophic and microzooplankton exclusively of heterotrophic organisms. However, it is now increasingly recognized that mixotrophy (e.g. combining photo- and phagotrophy) occurs among both photo- and microzooplankton species, and that in extension, trophic diversity and relationships among plankton are expected to be more extensive and complex than previously thought. To enhance understanding of plankton trophic modes, diversity and relationships during spring bloom period in Bornholm Basin, central Baltic Sea, we categorized here the temporal succession in (1) the aquatic protist community by trophic modes, and (2) the community composition in terms of taxonomic groups and feeding mode, and its correlation with environmental factors and available prey-size. Our results show that the trophic mode composition of the community changed drastically over the course of the spring season, representing a high trophic complexity and more complex dynamics than previously suggested. The heterotrophic community was characterized by a high diversity of species and groups, with heterotrophic ciliates showing a clear seasonal succession in body size-classes, switching from the smallest sized-fraction (10-20 µm) in winter to an increasingly amount of larger-sized species of 30-55 µm and &gt;55 µm with progression of the spring period. Changes in ciliate community composition were correlated with sea surface temperature, shifting from a cold-associated to a warm-associated community over the course of the spring season. Results further suggest that in communities including a larger mixotrophic component, size trait-based trophic relations between heterotrophic groups and their prey are complex, potentially due to similar prey-size preferences among heterotrophic and mixotrophic species. Overall, our findings emphasize the importance of accounting for the trophic modes of species to enhance the understanding of trophic relations and dynamics within bloom events.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"13 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492750","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 : 2026-03-19DOI: 10.3389/fmars.2026.1765872
Anthony W. J. Bicknell, Samuel Gierhart, Mario Lambrette, Matthew J. Witt
Offshore wind turbine fixed-bottom foundations provide artificial hard substrate through the water column that encourages marine flora and fauna to colonise and aggregate around the introduced structures, a well-documented phenomenon known as the ‘artificial reef effect’. The cumulative impact thousands of turbine foundations at multiple offshore sites have on local and regional marine species populations and communities is not fully understood. Knowledge of the extent and magnitude of the reefing effect at a fine scale (single turbines) is a prerequisite to making broader-scale (single or multiple wind farms) predictions of population level and ecosystem changes caused by presence of offshore wind farms. The influence of fine-scale distance (<250 m) to turbine jacket foundations on abundance, biomass and size of demersal fishes was assessed at a northern latitude wind farm. Abundance and biomass of all demersal fishes, flatfish Pleuronectiformes spp. and haddock Melanogrammus aeglefinus were found to have a significant negative relationship with increasing distance from foundations. Haddock were found to aggregate closer to the structures, yet all statistical models predicted a similar magnitude of increase for each group of between ~1.5 and 1.6 times more individuals and biomass at 30 m from the foundations compared to 240 m. The results illustrate that fine-scale proximity to offshore wind fixed foundations has considerable effects on the presence of some demersal fish species. The cumulative or wider ecosystem consequences of these effects are not known, but the further evidence for localised reefing effects can be of strategic interest for optimizing future wind farm project design, included implementation of nature-inclusive measures that could help meet future marine net gain aspirations.
{"title":"Fine-scale proximity to offshore wind turbine foundations increases biomass of demersal fish species","authors":"Anthony W. J. Bicknell, Samuel Gierhart, Mario Lambrette, Matthew J. Witt","doi":"10.3389/fmars.2026.1765872","DOIUrl":"https://doi.org/10.3389/fmars.2026.1765872","url":null,"abstract":"Offshore wind turbine fixed-bottom foundations provide artificial hard substrate through the water column that encourages marine flora and fauna to colonise and aggregate around the introduced structures, a well-documented phenomenon known as the ‘artificial reef effect’. The cumulative impact thousands of turbine foundations at multiple offshore sites have on local and regional marine species populations and communities is not fully understood. Knowledge of the extent and magnitude of the reefing effect at a fine scale (single turbines) is a prerequisite to making broader-scale (single or multiple wind farms) predictions of population level and ecosystem changes caused by presence of offshore wind farms. The influence of fine-scale distance (&lt;250 m) to turbine jacket foundations on abundance, biomass and size of demersal fishes was assessed at a northern latitude wind farm. Abundance and biomass of all demersal fishes, flatfish Pleuronectiformes spp. and haddock <jats:italic>Melanogrammus aeglefinus</jats:italic> were found to have a significant negative relationship with increasing distance from foundations. Haddock were found to aggregate closer to the structures, yet all statistical models predicted a similar magnitude of increase for each group of between ~1.5 and 1.6 times more individuals and biomass at 30 m from the foundations compared to 240 m. The results illustrate that fine-scale proximity to offshore wind fixed foundations has considerable effects on the presence of some demersal fish species. The cumulative or wider ecosystem consequences of these effects are not known, but the further evidence for localised reefing effects can be of strategic interest for optimizing future wind farm project design, included implementation of nature-inclusive measures that could help meet future marine net gain aspirations.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492753","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 : 2026-03-19DOI: 10.3389/fmars.2026.1720284
Alena Wachmann, Alejandra Mora-Soto, Jennifer Yakimishyn, Krista Bohlen, Emily Fulton, Maycira Costa
Canopy-forming kelps, bull kelp ( Nereocystis luetkeana ) and giant kelp ( Macrocystis tenuifolia ), form dynamic underwater forests that underpin coastal biodiversity, fisheries, and human well-being. Yet, their persistence under accelerating ocean warming and intensifying marine heatwaves remains poorly understood, particularly at regional scales. We integrate nearly 170 years of evidence, including data from British Admiralty charts (1858–1956) and 10-m Sentinel-2 imagery (2020–2023) to map modern kelp distribution and centennial persistence across 5,600 km of the West Coast of Vancouver Island (WCVI), British Columbia, Canada, partitioned into four ecoregions. Kelp forests in cooler, high-energy ecoregions, containing 97.5% of modern canopy area, remained highly persistent (~88%) over the past century, suggesting the presence of climatic refugia. By contrast, the warmer and more sheltered ecoregion exhibited markedly lower persistence (52%), which was associated with elevated spring and summer sea surface temperatures. These results demonstrate the importance of century-scale baselines for distinguishing natural variability from climate-driven change and identify spatial refugia as priority areas for conservation and restoration within British Columbia’s and First Nations’ marine protection and climate adaptation strategies.
{"title":"Centennial persistence of kelp forests on the West Coast of Vancouver Island, Canada","authors":"Alena Wachmann, Alejandra Mora-Soto, Jennifer Yakimishyn, Krista Bohlen, Emily Fulton, Maycira Costa","doi":"10.3389/fmars.2026.1720284","DOIUrl":"https://doi.org/10.3389/fmars.2026.1720284","url":null,"abstract":"Canopy-forming kelps, bull kelp ( <jats:italic>Nereocystis luetkeana</jats:italic> ) and giant kelp ( <jats:italic>Macrocystis tenuifolia</jats:italic> ), form dynamic underwater forests that underpin coastal biodiversity, fisheries, and human well-being. Yet, their persistence under accelerating ocean warming and intensifying marine heatwaves remains poorly understood, particularly at regional scales. We integrate nearly 170 years of evidence, including data from British Admiralty charts (1858–1956) and 10-m Sentinel-2 imagery (2020–2023) to map modern kelp distribution and centennial persistence across 5,600 km of the West Coast of Vancouver Island (WCVI), British Columbia, Canada, partitioned into four ecoregions. Kelp forests in cooler, high-energy ecoregions, containing 97.5% of modern canopy area, remained highly persistent (~88%) over the past century, suggesting the presence of climatic refugia. By contrast, the warmer and more sheltered ecoregion exhibited markedly lower persistence (52%), which was associated with elevated spring and summer sea surface temperatures. These results demonstrate the importance of century-scale baselines for distinguishing natural variability from climate-driven change and identify spatial refugia as priority areas for conservation and restoration within British Columbia’s and First Nations’ marine protection and climate adaptation strategies.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"94 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492749","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 : 2026-03-19DOI: 10.3389/fmars.2026.1797207
Cristina Munari, Michele Mistri
This review synthesizes current knowledge on the sea walnut Mnemiopsis leidyi , focusing on its potential as an emerging source of bioactive compounds rather than solely as a marine invader. The Ponto–Mediterranean expansion of the species and its ecological impacts are briefly outlined to provide context on the origin and magnitude of available biomass. Particular emphasis is placed on biological traits, physiological plasticity, and environmental tolerance that enable recurrent production of large gelatinous stocks. Recent evidence indicates substantial biochemical diversity, including antibiofilm and antimicrobial peptides, photoproteins, and a largely unexplored immune-associated molecular space with potential biotechnological and pharmaceutical relevance. These characteristics position M. leidyi as a promising candidate for biorefinery approaches aimed at extracting high-value molecules from low-cost marine biomass. However, pronounced spatial and temporal variability, together with the inherent unpredictability of natural blooms, represents a major bottleneck for reliable biomass supply and industrial exploitation. Addressing this constraint will require complementary strategies to stabilize production and improve process scalability. By integrating ecological context with biochemical and applied perspectives, this review identifies key challenges, knowledge gaps, and future directions for the sustainable valorization of gelatinous marine biomass and its derived biomolecular resources.
{"title":"The sea walnut Mnemiopsis leidyi: from ecological nuisance to potential biological resource","authors":"Cristina Munari, Michele Mistri","doi":"10.3389/fmars.2026.1797207","DOIUrl":"https://doi.org/10.3389/fmars.2026.1797207","url":null,"abstract":"This review synthesizes current knowledge on the sea walnut <jats:italic>Mnemiopsis leidyi</jats:italic> , focusing on its potential as an emerging source of bioactive compounds rather than solely as a marine invader. The Ponto–Mediterranean expansion of the species and its ecological impacts are briefly outlined to provide context on the origin and magnitude of available biomass. Particular emphasis is placed on biological traits, physiological plasticity, and environmental tolerance that enable recurrent production of large gelatinous stocks. Recent evidence indicates substantial biochemical diversity, including antibiofilm and antimicrobial peptides, photoproteins, and a largely unexplored immune-associated molecular space with potential biotechnological and pharmaceutical relevance. These characteristics position <jats:italic>M. leidyi</jats:italic> as a promising candidate for biorefinery approaches aimed at extracting high-value molecules from low-cost marine biomass. However, pronounced spatial and temporal variability, together with the inherent unpredictability of natural blooms, represents a major bottleneck for reliable biomass supply and industrial exploitation. Addressing this constraint will require complementary strategies to stabilize production and improve process scalability. By integrating ecological context with biochemical and applied perspectives, this review identifies key challenges, knowledge gaps, and future directions for the sustainable valorization of gelatinous marine biomass and its derived biomolecular resources.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"14 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492751","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 : 2026-03-18DOI: 10.3389/fmars.2026.1725777
Douglas M. Scheidt, Jane A. Provancha, Eric D. Stolen, David R. Breininger, Resa A. Cancro, Russell H. Lowers, Eric A. Reyier, Bonnie J. Ahr
Florida manatees ( Trichechus manatus latirostris ) are challenged by human alteration of landscapes and waterways. Coastal eutrophication has increased the frequency and intensity of Indian River Lagoon (IRL) algal blooms, promoting seagrass die-offs in areas that once consistently provided manatee forage. For decades the densest aggregations of manatees in Florida, outside of warm-water sites in winter, occurred in the northern Banana River (NBR) at Kennedy Space Center. Historically, the nearby Mosquito Lagoon (ML) had low numbers. Beginning in 2011, several catastrophic algal blooms caused the die-off of nearly 60% of the areal extent of all IRL seagrasses. Most severe impacts were in the Indian River and Banana River with lesser impacts in ML. This study evaluated several decades of manatee aerial survey data using statistical models to identify the environmental and temporal factors influencing manatee abundance, behavior and habitat use in the NBR (1990–2024) and ML (2016–2024). Using a Bayesian hierarchical model, we evaluated how manatee counts were affected by season, water clarity, and coastwide trends in manatee population size. Manatee abundance was evaluated across four distinct IRL seagrass Die-Off periods: Pre-Die-Off, Initial Die-Off (2011-2015), Secondary Die-Off (2016-2022), and Post-Die-Off (2023-2024). NBR manatee abundance increased well into the Initial Die-Off and then declined sharply until reaching historic lows in 2019. Beginning in 2016, only the ML maintained high seagrass coverage and a notable surge in manatee counts indicated aggregations shifted to ML. The Boosted Regression Tree Analysis top two predictors of abundance were seagrass Die-Offs periods and season. Optimized Hotspot Analysis of NBR manatee spatial distribution was compared to seagrass distribution and revealed that during the Pre-Die-Off, manatee hotspots occurred along deep-water resting areas adjacent to seagrass. Starting in the Initial Die-Off, manatee hotspots shifted toward ever shallower waters presumably to access the receding seagrass beds. The proportion of calves observed also declined dramatically after the Initial Die-Off period. These findings demonstrate that manatees aggregate in traditional areas with extreme fidelity but need to shift to “other pastures” during localized seagrass die-offs. Future shifts from habitat degradation will require best practices and adaptive management to safeguard manatees.
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Pub Date : 2026-03-17DOI: 10.3389/fmars.2026.1743589
Taavi Liblik, Fred Buschmann
The Baltic Sea observing system combines ship-based, autonomous, and remote-sensing components, yet major observational gaps persist in the shallow and dynamic coastal zone. Here, we present the first evaluation of a micro-autonomous underwater vehicle (micro-AUV) for high-resolution mapping of the Baltic Sea water column and assess its potential integration into regional coastal observing systems. Eleven missions were conducted in 2025 across three contrasting environments—the shallow estuarine Bay of Matsalu, the Suur Strait, and the coastal slope of the Baltic Proper—covering depths from 1 to over 100 m. The micro-AUV operated reliably under diverse hydrographic conditions, capturing fine-scale frontal, submesoscale, and benthic-layer structures, as well as a dual upwelling cell. Comparisons with reference profiles confirmed the high accuracy of temperature and salinity measurements, and strong correlations for chlorophyll-a fluorescence and turbidity. The vehicle’s endurance (up to 40 km or ~7 h at 1.5 m s −1 ) enables efficient mesoscale surveys, while its maneuverability allows operation in very shallow or complex coastal areas where gliders and floats cannot be used. The results demonstrate that micro-AUVs can fill a critical observational gap between ship-based surveys, gliders, FerryBoxes, and coastal stations by extending coastal observations offshore and resolving vertical structures inaccessible to remote sensing. Despite limitations in endurance and communication range, micro-AUVs represent a promising, cost-efficient addition to integrated coastal observing systems, supporting targeted process studies and rapid-response missions in dynamic environments such as the Baltic Sea.
波罗的海观测系统结合了船基、自主和遥感组件，但主要的观测空白仍然存在于浅海和动态沿海区。在这里，我们首次对用于波罗的海水柱高分辨率测绘的微型自主水下航行器（micro-AUV）进行了评估，并评估了其整合到区域沿海观测系统的潜力。2025年，在三个截然不同的环境中进行了11次任务——马萨卢浅水河口湾、苏尔海峡和波罗的海沿岸斜坡——覆盖深度从1米到100多米。该微型auv在不同的水文条件下可靠地工作，捕获了精细尺度的锋面、亚中尺度和底层结构，以及双上升流单元。与参考剖面的比较证实了温度和盐度测量的高准确性，以及叶绿素-a荧光和浊度的强相关性。车辆的续航力（在1.5 m s - 1下可达40公里或~7小时）能够进行有效的中尺度调查，同时其机动性允许在非常浅或复杂的沿海地区操作，这些地区不能使用滑翔机和浮子。结果表明，微型auv可以通过将沿海观测扩展到近海并解析遥感无法获得的垂直结构，填补船载调查、滑翔机、FerryBoxes和海岸站之间的关键观测空白。尽管在续航能力和通信范围方面存在局限性，但微型auv代表了综合海岸观测系统的一个有前途的、经济高效的补充，支持波罗的海等动态环境中有针对性的过程研究和快速响应任务。
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