Estuarine Coastal and Shelf Science最新文献

{"title":"Detrital source diversity moderates decomposition and nutrient release in current and future ocean conditions","authors":"Brendan P. Kelaher ,&nbsp;Jamie F. David ,&nbsp;Sebastian Litchfield ,&nbsp;Joanne M. Oakes ,&nbsp;Bradley D. Eyre","doi":"10.1016/j.ecss.2025.109259","DOIUrl":"10.1016/j.ecss.2025.109259","url":null,"abstract":"<div><div>The complex interactions between detrital diversity and ocean climate change are not well understood. Here, we used sixteen outdoor raceways to test the hypothesis that ocean warming, and acidification would increase rates of decomposition and nutrient release from detritus of common macroalgae, but the magnitude of change would vary for single detrital sources compared to mixed sources. Our litter-bag experiment to test this hypothesis had six types of macroalgal detritus: (i) <em>Ecklonia radiata,</em> (ii) <em>Sargassum vestitum</em>, (iii) <em>Caulerpa filiformis</em>, (iv) <em>Ecklonia</em> and <em>Sargassum</em> mix, (v) <em>Ecklonia and Caulerpa</em> mix, and (vi) <em>Sargassum</em> and <em>Caulerpa</em> mix. The experimental design also had an orthogonal set of treatments testing effects of ocean warming and acidification, individually and combined, based on the RCP 8.5 climate model for 2081–2100. The identity of detrital sources significantly influenced decomposition rates, carbon liberation and nutrient release. The treatments with two detrital sources did not have increased rates of decomposition and nutrient release compared to single sources. However, detrital source mixing significantly moderated variation in decomposition and nutrient release rates. While ocean acidification had little effect on the decomposition of macroalgal detritus, ocean warming tended to increase rates of decomposition. Given that excessive decomposition can lead to severe anoxia, the results suggest the risk of this occurring will be greater in the warmer oceans of coming decades. In such circumstances, the moderating force of detrital diversity may become increasingly important in maintaining benthic oxygen concentrations and detritus-based production.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"319 ","pages":"Article 109259"},"PeriodicalIF":2.6,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Importance of the microphytobenthos in the foodweb of tropical mudflats","authors":"Alexandre Carpentier ,&nbsp;Anne Lizé ,&nbsp;Hien Nguyen Thanh ,&nbsp;Pierrick Bocher ,&nbsp;Christel Lefrançois ,&nbsp;Antoine Gardel ,&nbsp;Pierre-Yves Pascal ,&nbsp;Christine Dupuy","doi":"10.1016/j.ecss.2025.109257","DOIUrl":"10.1016/j.ecss.2025.109257","url":null,"abstract":"<div><div>Mudflats are peculiar dynamic ecosystems, at the interface of terrestrial and aquatic ecosystems, known for their large carbon storage ability. Mudflats also provide food source and constitute important habitats for photosynthetic organisms and consumer communities. Tropical mudflats are highly unstable and only temporarily accessible to either aquatic or aerial consumers because of tides, which raises the question of the trophic functioning of these habitats. Their importance in terms of trophic resources for species that temporarily feed there as well as the carbon origin of mudflat foodweb deserve to be explored. This was assessed, over a year in a tropical mudflat (French Guiana) at two sites (Sinnamary and Awala-Yalimapo), from primary producers to predators, using stable isotope ratios (δ¹³C and δ¹⁵N) as a proxy of their diet. The results showed that trophic interactions were similar in each site and only a few influences of the seasons were detected for the meiofauna (<em>Halomonhystera</em> sp.), and fish (<em>Gobionellus oceanicus</em> only in Sinnamary). The microphytobenthos constituted the dominant primary source incorporated by the meiofauna, which in turn was an important one for the fish. The three shorebird species depended mainly on the microphytobenthos, green algae and Tanaidacea and secondarily on the meiofauna. The two resident fishes relied on the same sources as the birds but incorporating higher proportions of the meiofauna taxa (Copepoda, Nematoda, and Ostracoda). The analyses of species niche overlaps between the three shorebirds and the two resident fish demonstrated that they might compete for resources. The results are discussed in relation to the central place of the MPB as a direct or indirect source of carbon for the vast majority of organisms present on these tropical mudflats, whether transient or resident species.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"319 ","pages":"Article 109257"},"PeriodicalIF":2.6,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cellular Responses of Ruditapes philippinarum Clams to Global Changes: Assessing the Risks of Rising Temperatures and E-Waste","authors":"Julieta Sturla Lompré ,&nbsp;Marta Cunha ,&nbsp;Joao Pinto ,&nbsp;Amadeu M.V.M. Soares ,&nbsp;Eduarda Pereira ,&nbsp;Rosa Freitas","doi":"10.1016/j.ecss.2025.109262","DOIUrl":"10.1016/j.ecss.2025.109262","url":null,"abstract":"<div><div>Electronic waste (E-waste) has become a significant environmental challenge in recent decades due to the rapid increase in electronic device production and the subsequent disposal of obsolete products. E-waste contains hazardous materials, including metals like chromium (Cr) and rare earth elements (REEs) such as terbium (Tb), which can leach into aquatic ecosystems and cause severe ecological damage. With global temperatures projected to rise due to climate change, the interaction between these contaminants and increasing temperatures could heighten risks to aquatic life. This study examines the combined effects of Cr and Tb on the biochemical and physiological responses of the Manila clam (<em>Ruditapes philippinarum</em>), a species commonly used as a bioindicator of environmental stress. Clams were exposed to Cr, Tb, and their mixture at two temperatures (18 and 21 ºC) over 28 days to assess how warming influences metal toxicity. The overall biochemical response of the clams was evaluated using Principal Coordinate Ordination (PCO). The results showed that at 21 ºC, the biochemical effects were significantly exacerbated, particularly with the inhibition of antioxidant and biotransformation enzymes compared to those exposed at 18 ºC. This suggests that oxidative stress impaired the enzymatic activity of the clams, especially under simultaneous exposure to both metals. These findings highlight the increased risk of metal toxicity in a warming world, emphasizing the need for integrated management strategies that address both e-waste and climate change. By providing critical insights into the combined effects of contaminants and temperature, this research aims to inform more effective regulatory policies to protect aquatic ecosystems.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"319 ","pages":"Article 109262"},"PeriodicalIF":2.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental factors governing spatio-temporal series of aquatic vegetation in the Bagnas lagoon","authors":"A. Bernard ,&nbsp;S. Alleaume ,&nbsp;X. Fortuny ,&nbsp;F. Munoz ,&nbsp;E. Pitard","doi":"10.1016/j.ecss.2025.109261","DOIUrl":"10.1016/j.ecss.2025.109261","url":null,"abstract":"<div><div>Macrophytes are a key component of lagoon ecosystems, and the spatio-temporal variation of their biomass reflects the effect of environmental drivers. Understanding these dynamics is essential for managing, preserving and anticipating the fate of such fragile ecosystems. First, using both satellite data and field observations, we showcase here a machine learning approach to accurately detect submerged vegetation in a preserved lagoon in South France, the Bagnas lagoon. Second, we investigate the statistical relationship between the surface area of <em>Stuckenia pectinata</em> and abiotic factors known to influence the life history of this aquatic plant. We thus identify and evaluate the factors that most impact <em>Stuckenia pectinata</em> population dynamics within the lagoon. We find that water temperature, salinity, and depth are significantly related to submerged aquatic vegetation (SAV) coverage. We show that the SAV surface area reaches a peak during summer, which can vary across years. Furthermore, we examine the lifetime distribution of SAV during each year cycle across the pond. We show that the average annual lifespan differs significantly from one year to the next, which can be explained by annual differences in exposure time to sufficiently high water levels.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"319 ","pages":"Article 109261"},"PeriodicalIF":2.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785594","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":"Fisheries bycatch threatens sessile communities of the Great Amazon Reef System","authors":"Afonso Luiz José Oliveira Silva ,&nbsp;Alexandre Pires Marceniuk ,&nbsp;George Joaquim Garcia Santos ,&nbsp;Felipe Ferreira Campos ,&nbsp;Anne Isabelley Gondim ,&nbsp;Alex Garcia Cavalleiro de Macedo Klautau ,&nbsp;Wagner Cesar Rosa Santos ,&nbsp;Bruno Eleres Soares ,&nbsp;Ronaldo Bastos Francini-Filho ,&nbsp;Ralf Tarciso Silva Cordeiro","doi":"10.1016/j.ecss.2025.109256","DOIUrl":"10.1016/j.ecss.2025.109256","url":null,"abstract":"<div><div>The Great Amazon Reef System (GARS) is an ecosystem amid major economic and environmental disagreements. Besides the eminent threats from oil and gas exploration in its surroundings, the reefs are also exposed to intense fishing pressure, including destructive practices such as bottom gillnetting and trawling. We assessed the richness of benthic sessile invertebrates (Cnidaria and Porifera) and associated taxa (Echinodermata) to report the impacts from fisheries bycatch on the GARS. A taxonomic survey was carried out based on photographic records and notes (dates and geographic coordinates) made by onboard observers at more than 200 stations sampled over approximately 42.000 km². The photographic records were made from invertebrates incidentally collected through four fishing gears: bottom trawling, shrimp trawling, bottom gillnet (“rede de caçoeira”), and pit trap (“manzuá”). These gears were used to sample 209 fishing stations, including benthic invertebrates as bycatch. We also assessed literature records on the distribution of benthic invertebrates to check for overlaps between reef benthic communities and fishing effort. A total of 54 species were recorded as bycatch. Richness was highest for the Phylum Echinodermata. Among the structuring taxa, Cnidaria was the richest, with the Class Anthozoa represented mainly by scleractinian corals (seven species, 24 stations) and gorgonians (seven species, 26 stations), whereas hydrozoans were more frequent (five species, 50 stations). The distribution of the hydrocoral <em>Stylaster roseus</em> was extended to the north. Porifera had 16 species and were dominated by the class Demospongiae in 8 Orders. We show here that gillnet and trawling fisheries pose significant threats to reef integrity by removing sessile key species as bycatch. Fishery pressures on GARS are mainly concentrated in the areas where habitat-forming species occur, thus threatening a broad diversity of benthic reef organisms. Corals and sponges are selectively impacted by traps and gillnets. In the long term, fisheries bycatch may impose profound disturbances to benthic reef communities and decline fishery yields. Our results reinforce the urgent need for a systematic conservation approach to reconcile extractive activities with conservation goals.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"319 ","pages":"Article 109256"},"PeriodicalIF":2.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685955","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":"Habitat use by juvenile fish in macroalgae and seagrass beds in a temperate South African seascape","authors":"Thembani Mkhize ,&nbsp;Janine Adams ,&nbsp;Shirley Parker-Nance ,&nbsp;Nicola James","doi":"10.1016/j.ecss.2025.109258","DOIUrl":"10.1016/j.ecss.2025.109258","url":null,"abstract":"<div><div>Structurally complex habitats such as seagrass, mangroves and macroalgae are important as nurseries in estuaries and nearshore marine environments. While numerous studies have focussed on structurally complex vegetated habitats in estuaries, fewer studies have focussed on vegetated nursery habitats (particularly macroalgae) in nearshore areas and their importance. In this study, stereo remote underwater video systems (sRUV) were used to examine the nature of shallow water vegetated habitat (<em>Zostera capensis</em> and <em>Plocamium corallorhiz</em>a) usage by juvenile fish in the Algoa Bay shallow water seascape (Swartkops Estuary and nearshore). The two macrophytes habitats are different in structural complexity, with <em>P. corallorhiza</em> having more structural complexity indices higher than <em>Z. capensis</em>. <em>Plocamium corallorhiz</em>a had a higher juvenile total abundance, dominated by young-of-the year sparids. Although total juvenile abundance was lower in <em>Z. capensis</em> seagrass, the abundance of the estuarine-dependent sparid <em>Rhabdosargus holubi</em> (all young-of-the-year recruits) was higher in <em>Z. capensis</em>. <em>Plocamium corallorhiz</em>a had a higher species richness compared to <em>Z. capensis</em>. Differences in species composition (abundance and richness) may be associated with high habitat heterogeneity in macroalgal sampling sites. Exhibited behaviours by juveniles in both habitats were dominated by slow meandering and feeding, behaviours associated with a high level of habitat use. In terms of fish community composition, both macrophyte habitats grouped broadly together but were statistically distinct from fish communities in unstructured sand.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"319 ","pages":"Article 109258"},"PeriodicalIF":2.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ichthyoplankton temporal and spatial patterns in sub-Antarctic coastal and oceanic waters of the Southwestern Atlantic","authors":"Daniel O. Bruno ,&nbsp;Luciana Riccialdelli ,&nbsp;Yamila Becker ,&nbsp;Jacobo Martin ,&nbsp;Mariela F. Victorio ,&nbsp;Eduardo M. Acha ,&nbsp;Daniel A. Fernández","doi":"10.1016/j.ecss.2025.109260","DOIUrl":"10.1016/j.ecss.2025.109260","url":null,"abstract":"<div><div>The southernmost region of the Southwestern Atlantic (SW Atlantic) has a complex environmental structure with different oceanographic conditions that aid the survival of early life stages of sub-Antarctic fish. This study evaluated the spatial and temporal variations in ichthyoplankton composition of SW Atlantic's sub-Antarctic coastal and oceanic waters and the relationship with environmental variables (water temperature and salinity). Six multidisciplinary oceanographic surveys (austral spring of 2014, 2015, 2016, summer of 2015, and autumn of 2016, 2017) were conducted in two coastal and three oceanic zones of the southern SW Atlantic. A total of 425 fish eggs and 871 fish larvae at the yolk sac (N = 37), preflexion (N = 513), flexion (N = 13), and postflexion (N = 308) stages were collected. Eleven fish taxa in the larval stage were identified. The highest abundance of eggs and larvae in the preflexion stage occurred in spring, dominated by the Fuegian sprat (<em>Sprattus fuegensis</em>) in all zones. However, the abundance of fish larvae in the postflexion stage was higher in autumn at the southern slope of the Burdwood Bank, with a dominance of Patagonian cods (<em>Patagonotothen</em> spp.). Water temperature played a significant role in explaining the abundance of larvae in the preflexion stage, whereas water salinity was significant for eggs and larvae in the postflexion stage. Our results allow us to infer the role of this complex oceanographic system in the early life history of fish. Thus, a conceptual framework for the ichthyoplankton distribution patterns in the area is proposed.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"318 ","pages":"Article 109260"},"PeriodicalIF":2.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680951","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":"Predator-prey interaction between a native octopus and an invasive crab: Habitat and size dependent effects on consumption and behaviour","authors":"Juan P. Livore ,&nbsp;María M. Mendez ,&nbsp;Silvina Van der Molen ,&nbsp;María E. Segade ,&nbsp;Nicolás Ortiz","doi":"10.1016/j.ecss.2025.109253","DOIUrl":"10.1016/j.ecss.2025.109253","url":null,"abstract":"<div><div>The potential benefits of invasive species on native predators have received little attention. We propose that <em>Octopus tehuelchus</em>, a native predator on Patagonian coasts, may find a novel food source in the invasive <em>Carcinus maenas</em>. Thus, we assess ecological and behavioural aspects of the predator-prey interactions under controlled conditions. Two sizes of octopus and crab, and two substrate types were used to determine their effects on consumption of <em>Carcinus</em> by <em>Octopus</em>. Large octopuses consumed more crabs irrespective of substrate type, and more crabs were consumed on hard than sandy substrate. Both small and large octopuses consumed a larger proportion of small crabs. A size refuge for crabs from large octopuses was found at 70 mm carapace width. Octopuses’ time to first attack, number of approaches and number of attacks did not differ with prey size. Defensive responses by prey were greater in smaller sized crabs and the largest tested crabs (80–85 mm) were the only ones to attempt attacks on octopuses. Together, our results suggest less vulnerability of <em>C. maenas</em> to octopus predation on sandy substrates where crabs bury themselves. However, it may be a novel food resource for <em>O. tehuelchus</em> particularly on hard substrates. <em>Octopus</em> predation may result in a reduction of green crab populations in areas of high octopus density with cascading effects on the diverse invertebrate community affected by <em>C. maenas</em>. Our study is a valuable contribution to the ecology of biological invasions, showing that exotic species can become an abundant food resource potentially benefiting predator populations.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"319 ","pages":"Article 109253"},"PeriodicalIF":2.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685901","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":"Vertebral elemental composition reveals ontogenetic changes in habitat use in a Northeast Atlantic mesopredator shark","authors":"Neil D. Cook ,&nbsp;Ana Samperiz ,&nbsp;Morten Andersen ,&nbsp;Edward Inglis ,&nbsp;Marc-Alban Millet ,&nbsp;Jo Cable ,&nbsp;Sarah E. Perkins","doi":"10.1016/j.ecss.2025.109255","DOIUrl":"10.1016/j.ecss.2025.109255","url":null,"abstract":"<div><div>Sharks are increasingly threatened with extinction due to overexploitation. Research priorities to mitigate these trends include identifying ontogenetic variations in spatial and temporal habitat use, as well as critical habitat areas to protect key life stages and processes. Here we demonstrate the regional applicability of laser ablation inductively coupled plasma mass spectrometry with natural tags (barium, magnesium, manganese, strontium) for investigating broad-scale habitat use patterns amongst at risk elasmobranchs in the Northeast Atlantic. We assess vertebral elemental composition in smallspotted catsharks <em>Scyliorhinus canicula</em> as a model species in the Bristol Channel and English Channel, UK, and identify ontogenetic variations throughout the sampling area, with shared habitat use by young-of-year and sub-adults distinct from adult life stages. We find sex segregation only amongst adults, which appears to be driven by male dispersal. Finally, we suggest that distinct adult populations appear to use multiple birthing grounds which therefore are potentially critical habitats for population recruitment, but with differential importance according to usage. Together these findings present an opportunity to integrate precautionary management into current conservation planning in the UK; <em>S. canicula</em> is centrally important to marine food webs, therefore strengthening population robustness against emerging fisheries and environmental perturbations should be a key objective.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"319 ","pages":"Article 109255"},"PeriodicalIF":2.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Marine heatwaves effects on quantity, composition, and turnover of sedimentary organic matter in a Mediterranean coastal lagoon: A benthocosm study","authors":"Francesco Palmas ,&nbsp;Francesca Cariccia ,&nbsp;Viviana Pasquini ,&nbsp;Serenella Cabiddu ,&nbsp;Pierantonio Addis ,&nbsp;Antonio Pusceddu","doi":"10.1016/j.ecss.2025.109252","DOIUrl":"10.1016/j.ecss.2025.109252","url":null,"abstract":"<div><div>Marine heatwaves (MHWs), caused by climate change, are becoming increasingly frequent and more intense, impacting benthic marine ecosystems. Nonetheless, knowledge about MHWs effects on the sediment biogeochemistry of coastal lagoons are almost unknown. We show that MHWs of different intensity (+4, +8 °C) simulated in benthocosm altered quantity, biochemical composition and nutritional quality of sedimentary organic matter obtained from a Mediterranean coastal lagoon. Sedimentary contents of carbohydrates, chlorophyll-a, and total phytopigments and biopolymeric C decreased significantly (by ca. −25, −37, −34, −15 %, respectively) already at +4 °C; at +8 °C those changes were accentuated for almost all variables (by −34, −48, −50, −14 %, respectively), including lipids (by −16 %), ultimately causing a drop in the nutritional quality of food for the benthos. This was plausibly the result of interacting (possibly synergistic) factors including the decay of labile molecules exposed to warmer conditions, an increased consumption due to the stimulation of heterotrophic activity by warmer temperatures, and an increased degradation (up to 31 % at +4 °C) due to the stimulation of extracellular enzymes. We can anticipate that more frequent, intense and long-lasting MHWs will influence at large sedimentary biogeochemistry in coastal lagoons and their ability to store blue C. However, since our experiments did not control for other factors possibly interacting at the microscale (e.g. microbial communities’ responses to warming and hypoxia), we foster the need of further studies to disentangle the effects of MHWs from those of other climatic stressors.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"318 ","pages":"Article 109252"},"PeriodicalIF":2.6,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}