Marine environmental research最新文献

{"title":"River inflow and seawater intrusion shape distinct phytoplankton communities in jinghai bay, a coastal bay of the Yellow Sea","authors":"Jinchang Sui ,&nbsp;Dongsheng Ding ,&nbsp;Yan Zhang ,&nbsp;Lin Zhu ,&nbsp;Zhengguo Cui ,&nbsp;Jun Sun ,&nbsp;Yuqiu Wei","doi":"10.1016/j.marenvres.2025.107309","DOIUrl":"10.1016/j.marenvres.2025.107309","url":null,"abstract":"<div><div>Phytoplankton are key primary producers that shape the structure and function of estuarine ecosystems. However, the distinct effects of riverine inputs and seawater intrusion on phytoplankton communities remain unclear. This study investigated the seasonal dynamics of phytoplankton in Jinghai Bay during spring and summer 2023, focusing on the contrasting influences of river inflow and seawater intrusion. Our data revealed two distinct zones: a river-influenced zone (RIZ) with low salinity and high nutrients, and a seawater-intrusion zone (SIZ) with high salinity and low nutrients. In spring, the SIZ exhibited higher phytoplankton abundance and evenness, while the RIZ showed greater species richness. During summer, the RIZ had higher abundance and simplified dominant species, whereas the SIZ maintained higher diversity and evenness. Environmental drivers also differed between the two zones: phytoplankton dynamics in the RIZ were mainly shaped by DIN, DIP, and temperature, while those in the SIZ were governed by salinity gradients. Redundancy analysis further revealed that salinity positively correlated with phytoplankton diversity in the SIZ but negatively with dominant species in the RIZ. These findings suggest that river inflow promotes phytoplankton growth by altering community composition, while seawater intrusion imposes salinity-driven selection. Overall, our results highlight the contrasting mechanisms through which river inflow and seawater intrusion regulate phytoplankton traits in estuarine ecosystems.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107309"},"PeriodicalIF":3.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral characteristics of organic matter from algae and its complexation with copper: a case study of Ulva prolifera","authors":"Tian-Zi Zhang ,&nbsp;Li-Min Zhou ,&nbsp;Yu-Yuan Wang ,&nbsp;Lu Han ,&nbsp;Xiao-Yan Cao ,&nbsp;Gui-Peng Yang","doi":"10.1016/j.marenvres.2025.107305","DOIUrl":"10.1016/j.marenvres.2025.107305","url":null,"abstract":"<div><div>The changes in dissolved organic matter (DOM) during algal decay play a crucial role in the biochemical processes in nearshore ecosystems. The decay processes of <em>Ulva prolifera</em> under dark and light conditions were simulated in laboratory to investigate the characteristics of the DOM released during its settlement. The spectral characteristics of <em>Ulva prolifera</em>-DOM were analyzed using ultraviolet–visible spectra (UV–Vis) and fluorescence excitation-emission matrix spectroscopy combined with parallel factor analysis (EEMs-PARAFAC), and the copper complexation characteristics were evaluated by anodic stripping voltammetry (ASV). It was found that the DOM derived from <em>Ulva prolifera</em> decay contained labile substances and was sensitive to light, which had significant metal complexation abilities. In dark, relatively high molecular weight DOM was released and then transformed into humic-like substances with a high degree of humification and aromaticity. DOM with stronger copper complexation ability and more copper complexing sites gradually became the dominant. EEMs-PARAFAC showed the DOM was composed of humic-like components C1, C3, tryptophan-like component C2, fulvic acid-like component C4, and tyrosine-like component C6 in the dark degradation, while under light, the DOM was composed of C1, C2, C3, C6 and fulvic acid-like component C5. Lower levels of DOM were released under light. Fulvic acid was the main component with a relatively low degree of humification. The copper complexation capacity (CuCC) and conditional stability constants (log <em>K</em>) increased first and then declined rapidly, with the data significantly lower than those of the degradation in dark at the end of the experiment.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107305"},"PeriodicalIF":3.0,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wind-tide modulated net ecosystem metabolism in a Changjiang River Estuary aquaculture zone during mid-autumn","authors":"Di Wu ,&nbsp;Kui Wang ,&nbsp;Guoquan Wang ,&nbsp;Qinglin Mu ,&nbsp;Wei Fan ,&nbsp;Dawei Xu","doi":"10.1016/j.marenvres.2025.107302","DOIUrl":"10.1016/j.marenvres.2025.107302","url":null,"abstract":"<div><div>The Changjiang River Estuary (CRE) supports critical fisheries and aquaculture industries. Net Ecosystem Metabolism (NEM) serves as a key indicator for assessing aquaculture ecosystem health, providing early warning of hypoxia risks, determining environmental carrying capacity, and guiding scientific aquaculture management. However, the hydrologic regime of the CRE, influenced by monsoons and strong tides, makes the combined effects of high-frequency wind and tidal variations on NEM dynamics poorly understood. In this study, we deployed a high-resolution <em>in-situ</em> profiler at a mussel aquaculture site in the CRE during September–October 2022 to continuously measure parameters, including dissolved oxygen (DO), at 1-min intervals. We then applied a one-dimensional DO mass balance model to quantify NEM variations and elucidate the driving mechanisms under contrasting wind and tidal conditions. Results indicated a predominantly heterotrophic ecosystem, with a mean NEM value of −6.0 ± 27.4 mmol m⁻² h⁻¹. Mechanistic analysis revealed that wind and tidal forces regulate NEM by modulating the frontal dynamics between the Changjiang River Diluted Water (CDW) and the Taiwan Warm Current (TWC). Northerly winds enhanced heterotrophy by intensifying CDW dominance and terrestrial organic matter inputs. In contrast, easterly winds coupled with spring tides promoted autotrophy through the onshore advection of shelf surface waters (SSW). Tidal cycles further regulated NEM through vertical mixing-mediated benthic nutrient output, resulting in higher autotrophy during spring tides. These findings, derived from high-frequency observations, highlight the acute sensitivity of estuarine metabolism to shifts in dominant water masses. They provide essential insights for adaptive management strategies, such as implementing real-time environmental monitoring and selecting species aligned with water mass dynamics, to enhance aquaculture sustainability amidst climate variability. Nevertheless, limitations in the temporal scope (mid-autumn period) and localized geography necessitate future investigations into seasonal/interannual NEM variations across broader spatial scales. Integrating wider drivers, including river discharge and climate change, will yield more robust data support and mechanistic analysis for developing predictive models.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107302"},"PeriodicalIF":3.0,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cold stress disrupts gill homeostasis in juvenile yellowfin tuna (Thunnus albacares) by altering oxidative, metabolic, and immune responses","authors":"Junhua Huang ,&nbsp;Zhengyi Fu ,&nbsp;Jing Bai ,&nbsp;Zhenhua Ma","doi":"10.1016/j.marenvres.2025.107300","DOIUrl":"10.1016/j.marenvres.2025.107300","url":null,"abstract":"<div><div>Acute cold stress can disrupt physiological homeostasis in marine fish and may induce pronounced metabolic and immune responses in pelagic species such as yellowfin tuna (<em>Thunnus albacares</em>), which possess regional endothermic capabilities. As a key tissue interfacing with the environment, the gill plays essential roles in gas exchange, ion regulation, immune defense, and energy metabolism, making it highly susceptible to thermal fluctuations. This study investigated the physiological responses of gill tissue in juvenile yellowfin tuna under acute cold stress, using two treatment groups—LT (24 °C) and ULT (18 °C)—with a control group (CG, 30 °C). Sampling was conducted at 0, 12, 24, and 36 h to assess antioxidant and metabolic enzyme activities, histopathological alterations, and the expression of immune- and metabolism-related genes. Results showed time-dependent changes in antioxidant enzymes (SOD, CAT, POD, GSH-Px), with significantly elevated MDA and LPO levels at 12 h and 24 h (<em>p</em> &lt; 0.05), especially under 18 °C, indicating intensified oxidative stress. Significant alterations in AST, LDH, ACP, and AKP suggested metabolic reprogramming and membrane function changes. Variations in Na⁺/K⁺-ATPase and Ca²⁺/Mg²⁺-ATPase activity reflected ion regulation under thermal stress. Gene expression of hspa8b, heat shock cognate 71 kDa protein, irf3, lpl, and pck2 demonstrated temperature- and time-dependent adaptive responses. Histological analysis revealed progressive edema, necrosis, and lamellar disruption with decreasing temperature. Collectively, these findings highlight a multilayered stress response in yellowfin tuna gill tissue under cold exposure and provide new insights into thermal adaptation and cold-tolerant aquaculture strategies for pelagic species.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107300"},"PeriodicalIF":3.0,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144288668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling hidden Flows: Tracing submarine groundwater discharge in Punnakayal Estuary coastal region, Tamil Nadu, India, through radon (222Rn) and GIS topology","authors":"Selvam Sekar ,&nbsp;Muthukumar Perumal","doi":"10.1016/j.marenvres.2025.107301","DOIUrl":"10.1016/j.marenvres.2025.107301","url":null,"abstract":"<div><div>The precise quantification and understanding of submarine groundwater discharge (SGD) pose significant challenges, despite its critical role in the dynamics of coastal ecosystems. The present study conducted in the Punnakayal Estuary, Tamil Nadu, India presents an innovative approach to unveil hidden flows of groundwater discharge using a combination of radon (²²²Rn) tracing and Geographic Information Systems (GIS) Topology. Radon (²²²Rn), a radioactive gas that occurs naturally acts as a unique tracer for SGD due to its ability to partition between groundwater and surface water. In the present study, radon concentrations were measured systematically across the estuarine environment to identify areas of SGD influence. The data were then integrated into a GIS framework, where spatial topology was employed to analyze the intricate connectivity between surface water bodies, subsurface groundwater and SGD pathways. The results reveal a comprehensive view of SGD dynamics within the Punnakayal Estuary with the fresh SGD of 4.52 × 10⁻⁷ m³/s through GIS modelling approach. Notably, the combination of radon tracing and GIS topology unveils previously concealed pathways of groundwater discharge. High-flow accumulation zones indicative of SGD was identified, shedding light on the spatial distribution of this vital hydrological process. SST of the region was also calculated to validate this approach. This research contributes to our understanding of coastal hydrogeology and ecosystem health in the Punnakayal region, with implications for sustainable coastal management and resource conservation. The integrated approach of radon tracing and GIS topology offers a robust methodology applicable to similar coastal environments globally, addressing the challenges associated with the hidden flows of submarine groundwater discharge. By uncovering the intricate subsurface interactions between groundwater and estuarine systems, was not only advances scientific knowledge but also provides valuable understandings to protect and preserve the delicate balance of coastal ecosystems.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107301"},"PeriodicalIF":3.0,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determining dominant phytoplankton assemblages and their controlling factors in the winter sea-ice-covered southern sea of okhotsk and the spring open water through a multiple analytical approach","authors":"Yanxu Sun ,&nbsp;Jun Nishioka ,&nbsp;Takenobu Toyota ,&nbsp;Koji Suzuki","doi":"10.1016/j.marenvres.2025.107297","DOIUrl":"10.1016/j.marenvres.2025.107297","url":null,"abstract":"<div><div>The southern Sea of Okhotsk (SSO) is a semi-enclosed marginal sea of the North Pacific. Winter sea ice strongly influences the physical, biogeochemical, and ecosystem processes in the SSO. However, the succession of phytoplankton assemblages from winter to spring and their relationships with controlling factors remain unclear. Here, we used microscopy, algal pigment signatures, and 18S rRNA gene (rDNA)-based metabarcoding to identify predominant phytoplankton assemblages in the SSO from winter to spring during 2022 and compared these data with environmental factors. As a result, diatoms were the consistently dominant group in the SSO, although about half of the winter phytoplankton were other phytoplankton groups as estimated by pigment signatures. In winter, diatom communities were associated with the presence of ice-covered regions. Co-occurrence network analysis using 18S rDNA sequences showed that the centric diatoms <em>Thalassiosira</em> and <em>Chaetoceros</em> had higher co-occurrence relationships with ice-melted coastal waters in winter, contributing to the spring bloom with higher chlorophyll <em>a</em>. The ice or ice-related diatoms represented by <em>Porosira</em>, <em>Bacterosira</em>, and <em>Fragilariopsis</em> in the under-ice seawater more likely influenced the algal assemblages in the coastal seawater. We found that not only sea ice diatoms but also winter phytoplankton in East Sakhalin Current (ECS)-affected coastal waters can contribute to the large spring bloom in the study area, and that could be more prevalent in less sea ice conditions due to warming. The findings of this study highlight the importance of an integrated approach to comprehensively understand predominant phytoplankton communities and their ecological traits in the changing environment.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107297"},"PeriodicalIF":3.0,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of aged microplastics on the abundance of antibiotic resistance genes in oysters and their excreta","authors":"Yifang Yu,&nbsp;Jing Qian,&nbsp;Weichao Wang,&nbsp;Minwei Xie,&nbsp;Qiao-Guo Tan,&nbsp;Rong Chen","doi":"10.1016/j.marenvres.2025.107284","DOIUrl":"10.1016/j.marenvres.2025.107284","url":null,"abstract":"<div><div>The widespread use of plastics in global aquaculture raises concerns about their environmental impact, particularly due to their degradation into microplastics (MPs). These MPs not only pose risks to aquatic organisms and ecosystems but also serve as carriers for emerging pollutants such as antibiotic resistance genes (ARGs). By facilitating the enrichment and transport of ARGs in aquatic environments, MPs may exacerbate the spread of antibiotic resistance, particularly in filter-feeding organisms. The underlying effects of MPs on ARGs in oysters and the further risks have not been clearly elucidated. Here, we explored the effects of aged polyethylene (PE) and polyethylene terephthalate (PET) MPs on ARGs abundance in oysters (<em>Magallana angulata</em>). Our results showed that MPs significantly enriched ARGs after three months of aging in the aquaculture environment with variations depending on polymer type. After two weeks of MPs exposure, the absolute abundance of ARGs in oyster tissues fluctuated, with <em>tetA</em> (PE MPs exposure), <em>tetG</em> (PET MPs exposure), and <em>oqxB</em> significantly increasing, while <em>fexA</em> was suppressed. However, despite being 1.16 to 5.46 × 10⁹ times higher than in oyster tissues (excluding <em>tetC</em>), ARGs in excreta showed no significant trend. Additionally, significant positive correlations were observed between <em>intI1</em> and <em>sul2</em>/<em>tetG</em> in tissues and between <em>intI1</em> and <em>sul1</em> in excreta, suggesting potential ARGs transmission through the food chain or excretion. This study advances our understanding of the complex interactions between MPs and ARGs, underscoring the need for effective management strategies to mitigate their ecological and public health risks.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107284"},"PeriodicalIF":3.0,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144307361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Classifying the seascape of eastern tropical pacific based on physicochemical variables","authors":"Erick Bolaños-Durán ,&nbsp;Aarón Israel Muñiz-Castillo ,&nbsp;Fausto Valenzuela-Quiñonez ,&nbsp;David Arturo Paz-García","doi":"10.1016/j.marenvres.2025.107294","DOIUrl":"10.1016/j.marenvres.2025.107294","url":null,"abstract":"<div><div>The Eastern Tropical Pacific (ETP) is a highly environmentally heterogeneous ocean with high biological richness and endemism. Capturing and structuring this variability through a classification into seascapes is essential to support ecological research and ecosystem-based marine management. Here, we present an objective seascape classification for the ETP based on 20 years of satellite- and model-derived data using seven Essential Climate Variables (ECVs), including sea surface temperature, salinity, pH, turbidity, and current velocity. We compared four unsupervised clustering methods, three Fuzzy c-means (FCM) algorithms and Self-Organizing Maps combined with Partitioning Around Medoids (SOM-PAM) to classify the ETP seascape. As a result, the ETP was divided into thirteen and fifteen seascapes, respectively. The SOM-PAM approach provided finer spatial resolution and more ecologically interpretable patterns and was thus selected for the final classification. The fifteen seascapes (SS) delineated consistent environmental structures, including those with high salinity and thermal variability (SS-1–SS-3); peripheral ones influenced by subtropical water masses (SS-4, SS-14); dominated by strong current velocities (SS-12, SS-13); characterized by thermal stability (SS-7–SS-10); transitional conditions (SS-5, SS-6, SS-11); and low salinity associated with freshwater input (SS-15). The classification reflects key oceanographic features with several seascapes showing spatial congruence with existing biogeographic frameworks. Additionally, the analysis revealed previously unrecognized seascapes that represent important oceanographic processes within the ETP. This classification offers a step forward for the understanding of the spatially explicit environmental framework to inform marine spatial planning, biodiversity studies, and assessments of eco-evolutionary processes in the ETP.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107294"},"PeriodicalIF":3.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluctuations in sediment blue carbon density associated with land use changes and mangrove distribution along the semiarid, rapidly industrializing coastline of India","authors":"Rupak Dey ,&nbsp;Khayali Vaidya ,&nbsp;Manish Solanki ,&nbsp;Aliya Naz ,&nbsp;Mayurdhvajsinh Jadeja ,&nbsp;Vandanaba Jadeja ,&nbsp;Seema B. Sharma ,&nbsp;Abhiroop Chowdhury","doi":"10.1016/j.marenvres.2025.107295","DOIUrl":"10.1016/j.marenvres.2025.107295","url":null,"abstract":"<div><div>Mangrove ecosystems can sequester blue carbon, yet anthropogenic activities increasingly threaten it's habitat and carbon storage capacity. The blue carbon sequestration potential of mangroves is an underexplored avenue in climate change science. The sustainable development goal (SDG)13 strongly emphasizes the need to reduce carbon emissions, whereas SDG 14 focuses on conserving coastal and marine ecosystems Understanding mangroves' essential ecosystem services, primarily ‘blue carbon’, distributed in different climatic zones is being prioritized by academics and policymakers. The Indian subcontinent is endowed with mangroves along its different coasts; however, the semiarid mangrove patches only exist in the western Indian district of Kachchh and are largely, unexplored. In our present study, we conducted a comprehensive assessment of sediment carbon stocks across multiple sites subjected to varying degrees of industrialization, urbanization, and agricultural encroachment along the coastline of Kachchh mangroves. Sediment cores were obtained from mangrove areas categorized as pristine, moderately impacted, and heavily industrialized to measure organic carbon content and assess its relationship with Normalized Difference Vegetation Index (NDVI). The approach aimed to evaluate variations in the blue carbon pool concerning different land use patterns. Seasonal sampling of mangrove sediments was conducted in both anthropogenically impacted and unaffected zones, with the resulting data analyzed using a three-way ANOVA (analysis of variance) within GLM (general linear model). A relationship was observed between anthropogenic activities and values of organic carbon density (OCD) and blue carbon pool. Respite of Mangrove restoration activities, the human intervention led to lower OCD values (1.2 % and 1.4 %, S.E. = ±.56) near industrial activity zones. This calls for combined efforts from all sectors to restore these fragile ecosystems in the region. The contributing role of mangroves as blue carbon sink is important in the fight against climate change.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107295"},"PeriodicalIF":3.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144288669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term response to light after the polar night in the Arctic kelps Alaria esculenta and Saccharina latissima","authors":"Pablo Cobos ,&nbsp;Francisco JL. Gordillo ,&nbsp;Patricia Roza ,&nbsp;Angela Wulff ,&nbsp;Carlos Smerdou","doi":"10.1016/j.marenvres.2025.107298","DOIUrl":"10.1016/j.marenvres.2025.107298","url":null,"abstract":"<div><div>The current absence of ice in early spring in a number of Arctic fjords allows sunlight to penetrate the water column about two months earlier than it used to be when a thick ice cover was present. This can potentially change the growth dynamics of permanent seaweed forests. To elucidate the ability of seaweeds to take advantage of this early available light, growth, photosynthetic performance, and biochemical composition has been analyzed in two major forest-forming algal species, <em>Alaria esculenta</em> and <em>Saccharina latissima</em>, from Kongsfjorden (Svalbard) collected in early February, and incubated in dim light and dark conditions. For <em>A. esculenta</em>, new tissue appeared during the last weeks of the polar night, so that the new and old tissues coexisted in the same individuals and were compared. Dim light triggered positive growth rates. The onset of light led to rapid (1 h) increase in the optimum quantum yield (F_v/F_m) in the new tissue of <em>A. esculenta</em>, while the old tissue and <em>S. latissima</em> increased their maximum photosynthetic electron transport rate (ETR_m). The new tissue accumulated 3 to 5 times more internal nitrate than the old tissue, but it showed lower content of photosynthetic pigments. Dim light promoted changes in stored carbohydrates in <em>A. esculenta</em> while the total C:N:P ratios remained stable in both species. Furthermore, <em>S. latissima</em> responded to light by decreasing its ∂¹³C values, indicating some activation of its carbon concentrating mechanism. Overall, dim light showed the potential to trigger photosynthetic metabolism and growth as early as February.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"210 ","pages":"Article 107298"},"PeriodicalIF":3.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}