Estuarine Coastal and Shelf Science最新文献

{"title":"Seasonality and local nutrient loading drive changes in organic carbon in seagrass ecosystems in Hong Kong","authors":"Amrit Kumar Mishra ,&nbsp;Katie M. Watson ,&nbsp;Ho Tun Ng ,&nbsp;Man Zhao ,&nbsp;Chanaka Isuranga Premarathne Maha Ranvilage ,&nbsp;Dwi Wai Shan Jaimie ,&nbsp;Tse Cham Man ,&nbsp;Christelle Not ,&nbsp;Benoit Thibodeau ,&nbsp;Juan C. Astudillo ,&nbsp;Juan Diego Gaitán-Espitia","doi":"10.1016/j.ecss.2025.109427","DOIUrl":"10.1016/j.ecss.2025.109427","url":null,"abstract":"<div><div>Natural variation in environmental conditions (e.g., seasonality) modulates the ecological dynamics and functioning of seagrass ecosystems. However, these characteristics can be altered by anthropogenic-driven pressures resulting from coastal urbanization (e.g., nutrient pollution), with significant effects on ecosystem service provision, including carbon sequestration and storage. Understanding these effects is complex as seagrasses exhibit different sensitives to environmental stress and change, generating species-specific responses that vary through temporal and spatial scales. Here, we tested this hypothesis by quantifying the seasonal variation in total carbon (C%; upper sediment layer, 15 cm), total nitrogen (N%), and stable isotopes (δ¹³C and δ¹⁵N) in two seagrass species (i.e., <em>Halophila ovalis</em> and <em>H. beccarii</em>) in Hong Kong, one of the most urbanized coastal areas globally. The C:N ratios and δ¹⁵N values indicated seasonal differences in local nitrogen source and accumulation, resulting in increased total seagrass biomass in the wet season. Isotope results suggested belowground seagrass tissues significantly contributed towards sediment carbon, particularly in the wet season, characterized by increased nitrogen loading.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109427"},"PeriodicalIF":2.6,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of coherent signals for river damming in shallow marine sediments along a 900-km inner shelf mud belt","authors":"Rick J. Yang ,&nbsp;James T. Liu ,&nbsp;Chih-Chieh Su ,&nbsp;Steven C. Chien ,&nbsp;Aijun Wang ,&nbsp;Zhijun Dai","doi":"10.1016/j.ecss.2025.109429","DOIUrl":"10.1016/j.ecss.2025.109429","url":null,"abstract":"<div><div>Continental shelf sediments serve as valuable archives of environmental changes within river basins, providing critical insights into the transfer of terrestrial materials to marine environments. In many major river systems worldwide, large-scale dam constructions have significantly reduced downstream sediment delivery. While previous studies have primarily focused on the impacts of such interventions on river channels and estuaries, highlighting effects such as reduced deltaic sedimentation rates and localized erosion. However, it remains uncertain whether these changes leave detectable stratigraphic signals in more distal regions of the continental shelf. This study investigates whether sedimentary changes associated with the commissioning of the Three Gorges Dam and the Shuikou Hydropower Station are recorded in the 900-km-long Zhejiang–Fujian Mud Belt, located offshore from the Changjiang River mouth. To evaluate the preservation of long-range signals of man-made activities, five dated sediment cores were analyzed using a suite of non-destructive proxies, including grain size, clay mineral assemblages, γ-density, magnetic susceptibility, and color reflectance. A total of 302 downcore measurements were subjected to Empirical Orthogonal Function (EOF) analysis. Distinct shifts in sediment characteristics were observed around the year 2002. The first EOF mode reflected sediment contributions from the Changjiang River, while the second captured inputs from the Minjiang River and other regional sources, indicating that signals of upstream anthropogenic disturbances can be retained even in distal shelf deposits. These findings suggest that continental shelf sedimentary records may preserve not only natural processes but also basin-wide human influences. This underscores the need for caution when using modern shelf records to reconstruct past environmental conditions, as recent anthropogenic imprints may obscure paleoenvironmental signals. By integrating stratigraphic records with multivariate statistical techniques, this study demonstrates here an effectively approach for assessing the influence of land-based activities on offshore sedimentary systems, offering a new perspective on human-induced changes in modern depositional environments.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109429"},"PeriodicalIF":2.6,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maritime and lagoon beaches sediments mineral phases and potentially toxic elements characterization and evaluation of microplastics retention","authors":"Joana Fortunato ,&nbsp;Fernando Rocha ,&nbsp;Sara Fateixa ,&nbsp;Carla Candeias","doi":"10.1016/j.ecss.2025.109428","DOIUrl":"10.1016/j.ecss.2025.109428","url":null,"abstract":"<div><div>The present study aimed to characterize the texture, mineral phases, and geochemical composition of sixteen sediment samples of beaches in Portugal, from maritime and Ria de Aveiro lagoon environments. Additionally, the presence of Microplastics (MPs) in these sediments was estimated. Sediments from both environments were classified as sands, with a quartz content ranging ∼70–90 %. The physicochemical parameters showed neutral conditions, with pH between 6.16 and 7.05, typically of this type of setting. The concentration of As, Cr, and Zn was above sediment guidelines, suggesting anthropogenic contamination, particularly in one location, posing a risk to beach users. Contamination indices and toxicological assessment confirmed anthropogenic contamination, particularly by Cr on the maritime beaches, highlighting pollution and toxicity risk. This may be linked to industrial, domestic, and agricultural activities, population density, traffic, as well as traditional fishing practices. MPs were identified in both sediments and water samples from maritime and Ria de Aveiro beaches, ranging 38 to 958 MP/kg. The more abundant identified MPs were PUR, ABS, and PE, mainly in the form of fibers, with different colors.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109428"},"PeriodicalIF":2.6,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic changes in soil organic carbon and influencing factors in typical coastal reclaimed wetlands of China","authors":"Panlong Zhao ,&nbsp;Gaoru Zhu ,&nbsp;Chao Yu ,&nbsp;Min Xu ,&nbsp;Wenbin Yi ,&nbsp;Huiying Yu ,&nbsp;Yinghui Jiang ,&nbsp;Zhenglei Xie","doi":"10.1016/j.ecss.2025.109426","DOIUrl":"10.1016/j.ecss.2025.109426","url":null,"abstract":"<div><div>Coastal tidal wetlands are key blue carbon ecosystems with significant carbon sequestration capacity. Understanding the effects of tidal flat reclamation on soil organic carbon (SOC) and its components is essential for informing effective wetland management and policy. This study collected 96 surface soil and sediment samples from Dongtai City, Jiangsu Province, across various land use types, including un-reclaimed tidal flats (0 years) and reclamation sites with 10, 15, 25, 40, and 50 years of reclamation history. Results showed that SOC content generally increased with reclamation age, peaking at 8.92 g/kg after 25 years. While SOC content differences among post-reclamation land use types were not statistically significant, woodland exhibited the highest SOC levels (8.71 g/kg), highlighting its superior carbon sink potential. Additionally, contents of soil dissolved organic carbon (DOC), easily oxidizable organic carbon (EOC), and microbial biomass carbon (MBC) also increased over time. Among these, EOC exhibited the highest average content (1.59 g/kg) across the Dongtai reclamation area. Woodland consistently showed the highest active carbon component content levels (DOC: 4.14 mg/kg, EOC: 2.27 g/kg, MBC: 50.16 mg/kg). Land use type significantly influenced DOC and EOC contents but had no substantial effect on MBC. Environmental factors such as soil moisture, pH, and nitrogen input also impacted SOC dynamics. Notably, nitrogen addition significantly affected SOC and EOC levels in tidal flats and paddy fields, with less pronounced effects on DOC and MBC. These findings provide valuable insight into the long-term impacts of coastal land reclamation on soil carbon pools, with implications for sustainable land management. The study emphasizes the importance of prioritizing land uses with high carbon sink potential, such as woodland, and optimizing soil moisture, pH, and nutrient inputs to enhance carbon pool stability.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109426"},"PeriodicalIF":2.6,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144569974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decadal analysis of chlorophyll fluorescence, algal blooms and driving factors from a fixed-point observing system in the Northern Adriatic Sea","authors":"Simone Toller ,&nbsp;Francesco Riminucci ,&nbsp;Emanuele Böhm ,&nbsp;Lucilla Capotondi ,&nbsp;Annamaria Correggiari ,&nbsp;Chiara Lapucci ,&nbsp;Emanuele Organelli ,&nbsp;Mariangela Ravaioli ,&nbsp;Rosalia Santoleri ,&nbsp;Giuseppe Stanghellini ,&nbsp;Caterina Bergami","doi":"10.1016/j.ecss.2025.109423","DOIUrl":"10.1016/j.ecss.2025.109423","url":null,"abstract":"<div><div>From August 2012 to December 2022, continuous optical measurements of Chlorophyll Fluorescence (ChlF) were conducted at the E1 meteo-oceanographic buoy, a fixed-point observing system located off the Emilia-Romagna coast in the Northern Adriatic Sea (Italy, Mediterranean Sea). Using a WET Labs® ECO Triplet fluorescence sensor, a total of 69,705 hourly ChlF observations revealed significant seasonal and interannual variations in chlorophyll concentrations at the sea surface. ChlF concentrations ranged from below detection limits to a maximum daily average of 41 μg/L, with seasonal peaks during spring (April–June) and winter (January–March). Thanks to an automated detection procedure for algal bloom based on net growth rates and other parameters, it was possible to identify 40 bloom events over the ten years period. Principal Component Analysis (PCA) highlighted the influence of key environmental factors such as temperature, dissolved oxygen, turbidity, salinity, wind speed, as well as processes like nutrient transport and freshwater inputs, on Chl variability. Seasonal patterns emerged as primary drivers: spring blooms were dominated by temperature, salinity, and dissolved oxygen, summer typically featuresstratified conditions with sporadic bloom events, while autumn and winter blooms are more influenced by wind speed and turbidity, which promote nutrient redistribution and mixing. Moreover, the analysis of algal blooms identified two distinct seasonal patterns: Single – Peak blooms, predominant in spring, and Multi – Peak blooms, typical of autumn and winter, each defined by characteristic environmental conditions shaping onset, progression, and duration. These findings highlight the essential role of long-term data series in understanding coastal marine ecosystems and assessing the environmental factors driving algal bloom events.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109423"},"PeriodicalIF":2.6,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144597113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Different populations of the Antarctic notothen fish Trematomus scotti differ in key life history traits","authors":"Thomas Desvignes ,&nbsp;Alejandro Valdivieso ,&nbsp;Luca Schiavon ,&nbsp;Camilla Sguotti ,&nbsp;Federico Calì ,&nbsp;Emilio Riginella ,&nbsp;Margaret Streeter ,&nbsp;Jacob Grondin ,&nbsp;Nathalie R. Le François ,&nbsp;Magnus Lucassen ,&nbsp;Felix C. Mark ,&nbsp;H. William Detrich III ,&nbsp;Chiara Papetti ,&nbsp;John H. Postlethwait ,&nbsp;Mario La Mesa","doi":"10.1016/j.ecss.2025.109425","DOIUrl":"10.1016/j.ecss.2025.109425","url":null,"abstract":"<div><div>Antarctic notothenioid fish form an adaptive radiation that diversified in the Southern Ocean over the past 10 million years. The biology and life history of about a third of notothenioids have been studied, however, most frequently from a single location. Because species distributions can be discontinuous and depend on environmental conditions, local populations might differ substantially both genetically and phenotypically from distant conspecifics. Among notothenioids, the 15 <em>Trematomus</em> species diversified to occupy environments ranging from subsurface cryopelagic habitats to the deep sea and many <em>Trematomus</em> species likely have circumpolar distributions. Here, we analyzed life history traits of the notothen <em>Trematomus scotti</em> from two distinct geographic areas: Andvord Bay, a fjord on the Western Antarctic Peninsula, and the Weddell Sea at the edge of pack ice zones. These two populations inhabit drastically different areas with important differences in environmental conditions driven by latitude, temperature and ice cover, thus enabling the study of the effects of the environment on life history traits. We first found no evidence for substantial genetic heterogeneity based on the mitochondrial marker <em>mt-co1</em>. Fish in Andvord Bay, however, grew faster and reached longer sizes than congeners in the Weddell Sea. Furthermore, females in Andvord Bay had higher fecundity but produced smaller eggs compared to females in the Weddell Sea. Thus, these two populations of <em>T. scotti</em> displayed distinct life histories likely in response to local environmental conditions. Local life history traits such as these are crucial to consider to evaluate the vulnerability of a species to environmental change.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109425"},"PeriodicalIF":2.6,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the coral habitability status of marine ecosystems along the eastern coast of the Andaman Islands, India","authors":"Debaleena Majumdar ,&nbsp;Barnali Das ,&nbsp;Asit Kumar Roy ,&nbsp;Subha Chakraborty ,&nbsp;Debajit Datta","doi":"10.1016/j.ecss.2025.109421","DOIUrl":"10.1016/j.ecss.2025.109421","url":null,"abstract":"<div><div>The Andaman Islands, hosting one of the most enriched marine ecosystems globally, have faced significant ecological threats due to various physico-climatic changes over recent decades, adversely impacting approximately 25 mangrove species and 135 coral species. To evaluate these impacts systematically on regional marine ecology, this study develops and applies a coral habitat quality index (CHI) along the eastern Andaman coast using an integrated approach combining key physico-climatic indicators, participatory coastal community appraisals, and geospatial analysis. A total of 187 georeferenced sampling points within a 5 km offshore buffer were analysed for the years 2008, 2013, and 2018. The Analytic Hierarchy Process (AHP) was employed to prioritise factors influencing coral habitat conditions, with stakeholder-based pairwise comparisons from four distinct coastal community groups forming the basis for CHI computation. Results reveal that the southern zone of the eastern coast has progressively developed into a relatively healthier marine habitat than its northern and central counterparts, with CHI values averaging 1.24 (2013–2018), compared to 1.01 and 1.08, respectively. Notably, offshore zones south of Rangat exhibit the most ecologically resilient characteristics, evidenced by a consistent rise in CHI scores across the study period. The methodological framework presented here enables replication across comparable island and coastal ecosystems, offering a scalable decision-support tool for marine conservation planning, impact monitoring, and adaptive coastal resource governance. Overall, this study advances technical insight into spatio-temporal coral habitat dynamics while supporting evidence-based policy and sustainable marine ecosystem management strategies.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109421"},"PeriodicalIF":2.6,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sediment-induced lateral circulation in tidal channels with high turbidity: A cross-sectional modeling study","authors":"Jian Zhou,&nbsp;Hongwu Tang","doi":"10.1016/j.ecss.2025.109409","DOIUrl":"10.1016/j.ecss.2025.109409","url":null,"abstract":"<div><div>Despite extensive research on salinity-induced lateral circulation (SalLC) in tidal systems, the dynamics of sediment-induced lateral circulations (SedLC) remain largely unexplored. This study employs idealized cross-sectional modeling to investigate SedLC in a highly turbid tidal channel with lateral bathymetric variations. Lateral bathymetric gradients trigger sequential lateral gradients in tidal velocity, turbulence, suspended sediment concentration, sediment-induced density anomalies, and ultimately internal pressure. This sediment-induced lateral baroclinic forcing, combined with periodic tidal mixing, governs the onset, development, and dissipation of SedLC, exhibiting a clear flood-ebb symmetry. SedLC is characterized by a bottom turbidity current, surface countercurrent and center upwelling/downwelling currents, creating complex cross-sectional flows of water and sediment. A schematic of tidally influenced SedLC dynamics reveals three primary stages: strong SedLC with surface convergence during slack tides, moderate SedLC with surface divergence during accelerating tides, and weak SedLC with surface convergence during decelerating tides. Strong interactions occur between tidally symmetric SedLC and tidally asymmetric SalLC, with the circulations adding during flood and counteracting during ebb. This study enhances our understanding of baroclinically-driven lateral hydrodynamics in tidal systems, with potential implications for three-dimensional substance transport.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109409"},"PeriodicalIF":2.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-energy systems are underrepresented in global porewater studies of sandy beach aquifers","authors":"Gudrun Massmann ,&nbsp;Janek Greskowiak ,&nbsp;Julius Degenhardt ,&nbsp;Bert Engelen ,&nbsp;Moritz Holtappels ,&nbsp;Rena Meyer ,&nbsp;Mike Müller-Petke ,&nbsp;Nils Moosdorf ,&nbsp;Jutta Niggemann ,&nbsp;Katharina Pahnke ,&nbsp;Vincent Post ,&nbsp;Anja Reckhardt ,&nbsp;Kai Schwalfenberg ,&nbsp;Stephan Seibert ,&nbsp;Hannelore Waska ,&nbsp;Christian Winter","doi":"10.1016/j.ecss.2025.109424","DOIUrl":"10.1016/j.ecss.2025.109424","url":null,"abstract":"<div><div>Aquifers beneath sandy beaches act as land-ocean conduits for groundwater and are active biogeochemical reactors modifying chemical fluxes across the land-sea interface. Subterranean estuaries of high-energy beaches with large tidal and wave amplitudes could be particularly reactive due to the exchange of large seawater volumes and transport of marine derived constituents deep into the subsurface. In this study, we first present a new classification for coastal energy regimes as a function of mean tidal range and mean significant wave height and define the term “high-energy”. We establish a global distribution map of coastal energy regimes and classify porewater study sites in sandy beach aquifers related to their prevalent energy regime. Despite their extensive contribution to the global shoreline, the porewater biogeochemistry of high-energy environments is largely unknown. Through a summary of the few existing porewater studies at high-energy beaches we reveal patterns in morphology, hydrology, and biogeochemistry, describe promising research strategies, and highlight future research avenues in these challenging environments.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109424"},"PeriodicalIF":2.6,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mollusc epifaunal assemblages are simplified due to habitat shifts under ocean acidification","authors":"Gustavo M. Martins ,&nbsp;Javier Herrero ,&nbsp;Cristina Canella ,&nbsp;Sérgio P. Ávila ,&nbsp;Afonso Prestes ,&nbsp;Joana Barcelos e Ramos ,&nbsp;Jason M. Hall-Spencer ,&nbsp;João Faria","doi":"10.1016/j.ecss.2025.109422","DOIUrl":"10.1016/j.ecss.2025.109422","url":null,"abstract":"<div><div>Ocean acidification can have profound effects on marine organisms, particularly those that rely on calcium carbonate for shell and skeleton formation, resulting in structural changes to marine ecosystems. Here, we contrast the structure of marine mollusc communities (epifauna) associated with an abundant shallow-water macroalga, <em>Halopteris scoparia,</em> in an area with seawater carbonated by natural CO₂ seeps and three reference sites, off the Azores archipelago. Epifaunal mollusc abundance and diversity were significantly lower at the CO₂ seep compared to reference sites whilst species accumulation curves and Jaccard multivariate analyses showed that the mollusc assemblage was consistently less diverse at the CO₂ seep. Most of the abundant epifaunal species that were present at the CO₂ seep were also found at reference sites, but less common or rare species were generally absent from the former. We conclude that while some molluscs are likely to cope with ocean acidification, the overall biodiversity of epifaunal molluscs will be simplified under these conditions in a future ocean.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"323 ","pages":"Article 109422"},"PeriodicalIF":2.6,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}