Estuarine Coastal and Shelf Science最新文献

{"title":"Machine learning-based detection of mangrove dynamics in a subtropical bay: reasons and outcomes","authors":"Xiaowen Xie ,&nbsp;Zhijun Dai ,&nbsp;Riming Wang ,&nbsp;Tianliang Wu ,&nbsp;Baoqing Hu ,&nbsp;Xixing Liang","doi":"10.1016/j.ecss.2026.109719","DOIUrl":"10.1016/j.ecss.2026.109719","url":null,"abstract":"<div><div>Mangrove forests constitute one of the most carbon-dense ecosystems in tropical and subtropical intertidal zones, providing significant ecological and economic benefits worldwide. Nevertheless, these vital ecosystems have experienced substantial degradation in recent decades, primarily attributable to escalating anthropogenic pressures and rising sea levels. Here, this study employed remote sensing imagery (1987–2023) and machine learning to examine mangrove forest dynamics in Fangcheng Bay (FCB), a subtropical bay in China's Beibu Gulf. Our analysis demonstrated a remarkable 182.38 % expansion in FCB's mangrove coverage over the 36-year period (1987–2023), with total area increasing from 233.19 ha to 658.49 ha. The West Bay (WB) and East Bay (EB) exhibited respective increases of 52.98 % and 274.47 %. Meanwhile, landward mangroves declined while seaward expansion occurred at an average shoreline progression rate of 1.28 m/yr. Furtherly, our analysis indicates that neither sea level rise nor estuarine declining suspended sediment concentration significantly influenced mangrove expansion. Tidal current-driven sediment deposition created optimal growth conditions by continuously replenishing mangrove tidal flats. These findings elucidate the drivers and patterns of FCB's mangrove dynamics amid rapid urbanization, offering critical implications for global mangrove conservation in comparable bay systems.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"331 ","pages":"Article 109719"},"PeriodicalIF":2.6,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080792","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":"Warming sensitivity limits the proliferation of Undaria pinnatifida (Phaeaophyceae) in the Dutch delta","authors":"Xiaowei Ding ,&nbsp;Klaas Timmermans","doi":"10.1016/j.ecss.2026.109714","DOIUrl":"10.1016/j.ecss.2026.109714","url":null,"abstract":"<div><div>The non-native kelp <em>Undaria pinnatifida</em> has invaded European coastlines for decades, yet its presence in the Dutch Delta remains non-dominant. The mechanisms underlying this limited proliferation are poorly understood, but thermal sensitivity has been proposed as a potential constraint under ongoing ocean warming. To evaluate this, we conducted a controlled 21-day laboratory experiment to assess the effects of temperature on the survival, growth, photosynthetic efficiency, and nutrient (NO₃⁻ and PO₄³⁻) uptake of juvenile <em>U. pinnatifida</em> sporophytes. Survival declined significantly at elevated temperatures, with less than 50 % of individuals surviving after one week, in contrast to &gt;90 % survival at lower temperatures. Growth rates fluctuated around zero across most treatments and became consistently negative at higher temperatures. Nutrient uptake rates remained positive at all temperatures and were significantly enhanced at higher temperatures. Overall, our results indicate that elevated temperatures reduce the survival and growth of <em>U. pinnatifida</em> despite sustained nutrient uptake. This physiological sensitivity suggests that ongoing ocean warming may already be limiting its proliferation in the Dutch Delta and potentially in other regions. These findings offer valuable insight for anticipating future invasion dynamics and refining risk assessments under climate change.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109714"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038339","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":"Highly reworked subtropical mudflat still provides carbon sequestration due to high sedimentation rate","authors":"Man Zhao ,&nbsp;Mandy Wing Kwan So ,&nbsp;Christelle Not ,&nbsp;Benoit Thibodeau ,&nbsp;Juan Diego Gaitán-Espitia","doi":"10.1016/j.ecss.2025.109692","DOIUrl":"10.1016/j.ecss.2025.109692","url":null,"abstract":"<div><div>Tidal flats are typically considered areas with large carbon storage potential over time. Yet such insights are mostly from vegetated areas, the carbon dynamics and long-term sequestration capacity of widespread unvegetated areas remain largely unclear. In this study, we investigated carbon sources, stocks, and sequestration rates over a two-year sampling period at a tidal flat within Mai Po Inner Deep Bay Ramsar Site, Hong Kong. To trace the origins of carbon, monthly measurements of carbon and nitrogen content and their stable isotopes (i.e., δ¹³C and δ¹⁵N) were conducted for surface sediment and suspended matter from adjacent rivers. Our results showed that sediment carbon content fluctuated both temporally and spatially, but the stable isotope analysis revealed a consistently terrestrial signature. The estimated carbon stock in top meter of sediment was approximately 23.5 Mg C ha⁻¹, which was notably lower than the global average for unvegetated tidal flat (86.3 Mg C ha⁻¹). However, sediment accumulation rates determined by ²¹⁰Pb dating, varied from 1.0 to 1.6 with a mean of 1.3 cm yr⁻¹. These rates were comparably higher than most of the rates (&lt;1 cm yr⁻¹) reported worldwide for tidal flats. The historical record of the sediment cores indicated a marked increase in sedimentation rate since late 20th century. While the active and high sedimentation rates drove the lower observed carbon stock, our results still highlight the potential for carbon sequestration in dynamic unvegetated tidal flats. The lower stock underscore the vulnerability of this function to coastal development, which could lead to substantial carbon loss if not well managed.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109692"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886021","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":"Seek in ports and you shall find them: Monitoring marine invasions over time using combined standard assessment methods","authors":"Karen L. Castro ,&nbsp;Clara B. Giachetti ,&nbsp;Nicolás Battini ,&nbsp;Enrique M. Morsan ,&nbsp;Evangelina Schwindt","doi":"10.1016/j.ecss.2026.109711","DOIUrl":"10.1016/j.ecss.2026.109711","url":null,"abstract":"<div><div>Marine biological invasions pose a significant threat to biodiversity. Port areas are sites of major interest, as artificial structures and intense maritime traffic facilitate the arrival and spread of non-native species. Ports act as hotspots for invasions and as stepping-stones for the secondary spread of species into surrounding natural habitats. In this study, we aimed to identify and quantify marine non-native and cryptogenic invertebrate and macroalgae species in the two main Patagonian ports, Puerto Madryn and San Antonio Este, using standardized, replicable assessment methods and comparing communities over time. We conducted field surveys combining two methods previously applied in these ports (fouling samples and recruitment panels) and incorporated sediment sampling to monitor the infaunal benthic invertebrate community. We detected 30 non-native and 7 cryptogenic species, including 15 new records, and others whose status shifted from cryptogenic to non-native based on updated regional revisions. Overall, non-native species richness tripled in Puerto Madryn over eleven years. Few non-native species were shared between ports, suggesting port-specific species pools. Regardless of the port, nearly half of the identified species in this study are non-natives, underscoring the current magnitude of marine invasions in Patagonian ports. Our findings highlight the value of using complementary methods to enhance detection, as some species were recorded by only one approach. Finally, persistent taxonomic challenges, especially in groups like polychaetes and sponges, underscore the need to strengthen taxonomic capacity to improve early detection and effectively monitor temporal and spatial changes in port communities, which is essential for understanding and managing marine invasions.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109711"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978792","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":"Turbidity shapes the spatial diversity of the high-frequency dynamics of bottom layer dissolved oxygen in shallow coastal oceans","authors":"Yishan Wang ,&nbsp;Changyuan Yan ,&nbsp;Yanzhen Gu ,&nbsp;Fangguo Zhai ,&nbsp;Peiliang Li ,&nbsp;Jianying Liu ,&nbsp;Peidong Liu","doi":"10.1016/j.ecss.2025.109684","DOIUrl":"10.1016/j.ecss.2025.109684","url":null,"abstract":"<div><div>High-frequency variations in bottom layer dissolved oxygen (DO) critically influence marine ecosystem metabolism and benthic habitats, yet their controlling mechanisms and spatial heterogeneity in shallow coastal oceans remain poorly understood. Based on four years of in-situ observations and high-resolution numerical simulations, this study systematically investigates the spatial diversity of high-frequency dynamics of bottom layer DO concentrations in the coastal oceans of China. The results show that the high-frequency fluctuations of bottom layer DO concentrations are most pronounced in summer and have two dominant frequency bands at diurnal and semi-diurnal periods. Further analyses indicate that bottom-layer DO concentrations are primarily influenced by diurnal variations in shallow waters with low turbidity, whereas semi-diurnal variations exert the strongest influence in high-turbidity environments. Model experiments further confirm turbidity as the key factor shaping the spatial diversity of high-frequency bottom DO dynamics by regulating underwater light availability and the relative importance of biogeochemical and physical processes. Under low-turbidity conditions, sufficient light penetration enhances near-bottom photosynthesis, leading to diurnal dominance. In contrast, under high-turbidity conditions, strong light limitation suppresses biological regulation, allowing semi-diurnal tidal mixing to become the dominant driver of bottom-layer DO variability. Overall, this study underscores the pivotal role of turbidity in mediating the balance between tidal dynamics and biogeochemical processes, offering new insights into high-frequency oxygen variability in shallow coastal oceans.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109684"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038474","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 occurrence and spread of Terpios hoshinota on coral reefs: impact on coral cover and reef recovery in Palk Bay, India","authors":"Thinesh Thangadurai ,&nbsp;Riana Peter ,&nbsp;Ramu Meenatchi ,&nbsp;Uma Chinnaiyan ,&nbsp;Subburaman Selvaraj ,&nbsp;Sivagurunathan Paramasivam ,&nbsp;Joseph Selvin","doi":"10.1016/j.ecss.2025.109685","DOIUrl":"10.1016/j.ecss.2025.109685","url":null,"abstract":"<div><div><em>Terpios hoshinota</em>, an encrusting sponge known to impact coral communities, is rapidly expanding its geographic range. However, its long-term effects on coral cover and persistence remain poorly understood. To address this, We surveyed reef across Palk Bay in 2021, including the outbreak epicentre at Mandapam Jetty, where <em>T. hoshinota</em> caused a 60 % decline in coral cover between 2009 and 2015. We also evaluated other threats from 2009 to 2021, as well as current coral recruitment, to assess the reef's resilience. We found that <em>T. hoshinota</em> had spread from a single site in 2009 to all sites in Palk Bay by 2021. However, <em>T.hoshinota</em> current cover is lower (2.6–9 %) than in earlier outbreaks, indicating a late stage outbreak phase. Despite the decline, <em>T. hoshinota</em> persists at the original site, continuing to affect multiple coral genera including coralline algae, confirming its long-term establishment. At the epicentre, coral cover declined and became spacillay fragmented, leaving a few isolated patches and massive colonies. Recruitment is notably lower than other sites, with algal overgrowth and coral rubble dominating the benthos. Our analysis revealed a negative correlation between algal cover and coral recruit density, suggesting that post-outbreak conditions favor algal proliferation and hinder coral recovery. While two bleaching events between 2009 and 2021 also contributed to partial coral mortality, the sponge's persistence, combined with algal dominance and reduced recruitment, indicates a continuing risk of reef degradation and impaired recovery.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109685"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886022","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":"Analysis of fisheries impact on the Vietnamese marine ecosystem based on a linear inverse model","authors":"Trang Phuc-Hong Hoang ,&nbsp;Samuel Guéret ,&nbsp;Philippe Bogaerts","doi":"10.1016/j.ecss.2025.109676","DOIUrl":"10.1016/j.ecss.2025.109676","url":null,"abstract":"<div><div>A model of the Vietnamese marine ecosystem is proposed to analyze the ecological development level in the decades 2000s and 2010s, the related causes and, especially, the fisheries impact. The ecosystem model consists of Linear Inverse Models (LIMs) that allow reconstructing carbon flows across five different trophic levels, computing four functional attributes, and estimating the fate of organic matter as well as the total system throughput of the ecosystem. The LIMs were solved to determine, on the one hand, the range of admissible solutions of each flux and, on the other hand, a Monte Carlo sampling of the polytope of flux solutions. From that sampling, the investigated functional attributes were consumption, egestion (flow to detritus), respiration and export. Based on the comparison of the total system throughput, fate of organic matter, and functional indices over the temporal periods, five conclusions are highlighted: (1) the flow of ecosystem energy in the 2010s period has increased by 32 % with respect to the previous decade; (2) catches of tunas, small pelagic fishes and cephalopods in the 2010s have significantly increased due to the La Niña phenomena, while other fisheries declined due to an increase of ocean temperature; (3) sea turtles in Vietnam are on the edge of extinction caused by tuna catches regardless of the recent raising awareness programs on protection and conservation; (4) the population of marine mammals on the coast of Vietnam up to the 2010s has decreased due to climate change, habitat destruction, overfishing, pollution and bycatch; (5) a contrasting sensitivity analysis between the 2000s and 2010s revealed reduced ecological resilience, calling for priority protection of vulnerable trophic groups.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109676"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928465","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":"Century-long coral evidence of climate and anthropogenic influences on tropical coastal phosphorus cycling in the northern South China Sea","authors":"Ning Guo ,&nbsp;Wei Jiang ,&nbsp;Kefu Yu ,&nbsp;Jian-xin Zhao ,&nbsp;Yinxian Song ,&nbsp;Yue-xing Feng ,&nbsp;Chunmei Feng","doi":"10.1016/j.ecss.2026.109720","DOIUrl":"10.1016/j.ecss.2026.109720","url":null,"abstract":"<div><div>Phosphorus (P) is a critical and scarce nutrient in marine ecosystems, playing a vital role in sustaining primary productivity. Its dynamic variations are closely linked to coastal anthropogenic activities and climate change. However, due to the lack of long-term continuous observational data, our understanding of the evolution patterns of coastal nutrients at interannual to centennial scales remains limited. Coral skeletal phosphorus-to-calcium ratio (P/Ca) has been demonstrated to be a robust proxy for reconstructing long-term phosphate variations in seawater. This study utilized P/Ca ratios in <em>Porites lutea</em> coral from the Luhuitou fringing reef of Hainan Island to reconstruct the historical variations of dissolved inorganic phosphorus (DIP) in surface seawater since 1870. The results reveal that coral P/Ca ratios in the Sanya coastal waters are jointly regulated by terrestrial inputs and upwelling processes. Specifically, P fertilizer application in agricultural activities has significantly increased terrestrial P loading, which is subsequently transported to coastal waters via submarine groundwater discharge (SGD). Crucially, El Niño-Southern Oscillation (ENSO)-driven regional hydrothermal conditions play a pivotal regulatory role in this process. Precipitation provides the transport momentum, while the anomalous high temperatures during El Niño years significantly accelerate chemical weathering, thereby greatly enhancing the P transport flux. Furthermore, against the background of long-term climate warming, this temperature-dominated weathering and transport mechanism is intensifying. The ENSO-modulated upwelling transports P-enriched deep water to the surface, creating a cumulative effect with anthropogenic P sources that collectively enhances marine primary productivity. Notably, the decline in live coral coverage of the Luhuitou fringing reef occurred prior to the marked rise in the coral P/Ca ratio, indicating that elevated DIP concentrations in seawater are not the primary driver of ecological degradation in this reef. This study not only confirms the unique value of coral geochemical proxies in deciphering long-term nutrient dynamics, but also highlights that the ongoing intensification of soil P weathering-transport processes in tropical regions under anthropogenic climate warming may pose potential ecological risks. These findings provide critical scientific supports for integrated coastal zone management.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109720"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038337","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":"Patterns of trophic niche overlap of diadromous and marine Arctic fishes in Beaufort Sea coastal lagoons","authors":"Sydney Wilkinson ,&nbsp;Lara Horstmann ,&nbsp;Benjamin D. Barst ,&nbsp;Todd Sformo ,&nbsp;Trent Sutton ,&nbsp;Kenneth Dunton ,&nbsp;Katrin Iken","doi":"10.1016/j.ecss.2025.109657","DOIUrl":"10.1016/j.ecss.2025.109657","url":null,"abstract":"<div><div>Ongoing climatic changes in the coastal Arctic can influence the food webs that support a variety of fish species and subsistence fisheries in coastal lagoons. Along the Beaufort Sea coast, lagoons provide productive summer feeding habitats for both diadromous fishes migrating from freshwater and marine fishes migrating from the shelf. We compared trophic niche size and niche overlap between diadromous species, Arctic Cisco (<em>Coregonus autumnalis</em>), Least Cisco (<em>Coregonus sardinella</em>), and Dolly Varden (<em>Salvelinus malma</em>), and marine species, Polar Cod (<em>Boreogadus saida</em>), Fourhorn Sculpin (<em>Myoxocephalus quadricornis</em>), and Saffron Cod (<em>Eleginus gracilis</em>), across lagoon systems differing in freshwater input and oceanic exchange. Using complementary biomarkers (stomach contents, bulk δ¹³C and δ¹⁵N, compound-specific amino acid δ¹³C, and fatty acid profiles), we found that diadromous fishes consistently exhibited broader trophic niches than marine fishes, reflecting their ability to exploit both freshwater and offshore pelagic resources. Trophic overlap occurred across the two life histories in both lagoon types, but was greater in high-exchange lagoons, primarily due to shared reliance on amphipods, mysids, and marine carbon sources. Considering the different biomarker turnover times, this overlap likely extends from late winter ice cover into open water periods. These results suggest that competition for prey is probable among species with contrasting life histories, particularly during periods of low prey abundance. By resolving seasonal and spatial patterns of trophic overlap, our findings provide important baseline knowledge for modeling future scenarios of lagoon connectivity and for informing subsistence fisheries management under ongoing changes in the Arctic.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109657"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928463","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":"Contrasting sediment and aquatic CO2 and CH4 effluxes across Australian tropical salt flat, saltmarsh, mangrove and tidally restricted wetlands","authors":"Sigit D. Sasmito ,&nbsp;Amrit K. Mishra ,&nbsp;Clément Duvert ,&nbsp;Lamberto Montagna ,&nbsp;Alexander S. Barkley ,&nbsp;Dzaki S. Widanto ,&nbsp;Rory Mulloy ,&nbsp;Paula Cartwright ,&nbsp;Nathan J. Waltham","doi":"10.1016/j.ecss.2025.109693","DOIUrl":"10.1016/j.ecss.2025.109693","url":null,"abstract":"<div><div>Coastal wetlands are globally important natural carbon sinks but can also act as sources of greenhouse gas emissions. Despite recent progress in quantifying carbon sources and sinks in these ecosystems, uncertainties remain over the climate benefits of restoration, particularly where greenhouse gas emissions may offset carbon gains. Here, we present paired measurements of sediment and aquatic CO₂ and CH₄ effluxes comparing vegetated (mangrove and saltmarsh) and unvegetated (salt flat) wetlands, as well as tidally connected and tidally restricted wetlands, in tropical monsoonal northern Australia during the cool dry season of 2025. Sediment CO₂ and CH₄ effluxes were significantly higher in saltmarshes and mangroves than in salt flats, which likely reflects greater organic matter inputs, root-associated processes, and higher sediment moisture in vegetated habitats. In addition, tidally restricted wetlands exhibited substantially higher aquatic CH₄ effluxes than tidally connected systems, consistent with the observed salinity gradient. Sediment CH₄ efflux data from salt flats in this study (median: 0.013, range: 0.007–0.015 nmol CH₄ m⁻² s⁻¹) provide one of the first measurements of salt flat methane rates in Australia. These results fill emission factor gaps for tropical monsoonal coastal wetlands and reinforce the need to quantify both sediment- and water-air CO₂ and CH₄ fluxes in blue carbon assessments. More broadly, accounting for aquatic fluxes alongside sediment fluxes is essential for quantifying mitigation potential from restoring coastal wetlands and informing blue carbon management relevant to Australia's Nationally Determined Contributions implementation.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"330 ","pages":"Article 109693"},"PeriodicalIF":2.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928464","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}