Zuhao Zhu , Kazi Belayet Hossain , Huihua Wei , Jie Chen , Renming Jia , Xiaofeng Gao , Haiyan Jin , Minggang Cai
{"title":"Fate and mass budget of microplastic in the Beibu Gulf, the northern South China sea","authors":"Zuhao Zhu , Kazi Belayet Hossain , Huihua Wei , Jie Chen , Renming Jia , Xiaofeng Gao , Haiyan Jin , Minggang Cai","doi":"10.1016/j.marenvres.2024.106797","DOIUrl":"10.1016/j.marenvres.2024.106797","url":null,"abstract":"<div><div>This study investigated the distribution, abundance, and mass budget of microplastics (MPs) in the Beibu Gulf, Northern South China Sea, focusing on their ecological significance and anthropogenic influence. Microplastics were found in all water and sediment samples, with concentrations in surface water ranging from 0.10 to 0.89 items/m³, and in bottom water from 0 to 0.85 items/m³. Sediment samples exhibited higher levels, ranging from 13.12 to 155.59 items/kg. The spatial distribution revealed higher concentrations along the northern Gulf and Guangxi Province, suggesting significant human influence from coastal activities, such as mariculture and industrial discharges. The study utilized both field data and a mass balance box model to estimate the MPs mass budget, revealing that oceanic flow and riverine discharge are major contributors, accounting for 49% and 52% of MPs, while Atmospheric deposition and sedimentation represents 8% and 1%, respectively. The inventory estimation calculated that 0.24 tons of MPs exist in the water column, and 137 tons in the sediment, emphasizing the substantial environmental burden posed by these pollutants. The significance of this research lies in its comprehensive assessment of MPs in a semi-enclosed gulf, providing critical insight into the role of coastal and hydrodynamic processes in MP distribution. This study highlights the urgent need for better waste management practices in coastal regions to mitigate microplastic pollution and its detrimental effects on marine ecosystems.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106797"},"PeriodicalIF":3.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503219","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":"Variability of mesozooplankton, abiotic factors and ecological status of marine environment in the north-eastern part of the Black Sea","authors":"T.A. Shiganova, A.S. Kazmin","doi":"10.1016/j.marenvres.2024.106805","DOIUrl":"10.1016/j.marenvres.2024.106805","url":null,"abstract":"<div><div>Seasonal and interannual dynamics of mesozooplankton abundance, biodiversity, ecological status of the marine environment and concurrent variability of abiotic forcings in the north-eastern part of the Black Sea in 2016–2023 were discussed. Mesozooplankton biomass, total biomass (mesozooplankton plus <em>Noctiluca scintillans</em>), biomass of Copepoda and <em>Parasagitta setosa</em> and harmful heterotrophic dinoflagellate <em>Noctiluca scintillans</em> have been considered along with the water temperature, wind, precipitation and salinity. Natural seasonal dynamic of mesozooplankton, disrupted by the invasion of <em>M. leidyi</em> in 1980s was found to be restored to some extent. General tendencies of interannual variability of mesozooplankton parameters and abiotic factors were documented: biomass exhibited maximums in 2017 and 2022, coincided with negative anomalies of SST and along-coast wind (upwelling conditions) and increased/decreased precipitation/salinity. Steady increase of Shannon index during considered period from 1.5-2 to 2.2–2.6 indicates growing biodiversity in the area. Marine environment had BAD ecological status in 2016–2018 and in 2022–2023 and GOOD one in 2019–2021. Ecological hazard of <em>N</em>. <em>scintillans</em> extensive development have been noticed.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106805"},"PeriodicalIF":3.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503223","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":"Unravelling the metabolomic signatures of migrant and non-migrant glass eels (Anguilla anguilla) and their response to diazepam exposure","authors":"Iker Alvarez-Mora , Valérie Bolliet , Naroa Lopez-Herguedas , Colin Bouchard , Mathilde Monperrus , Nestor Etxebarria","doi":"10.1016/j.marenvres.2024.106801","DOIUrl":"10.1016/j.marenvres.2024.106801","url":null,"abstract":"<div><div>Understanding the migratory cycle of the European eel is crucial for implementing effective conservation measures. The reasons why some glass eels settle in lower estuaries rather than migrating upriver remain unclear. This study aims to identify metabolomic signatures that distinguish active (migrant) from inactive (non-migrant) glass eels. Using a combination of target and non-target screening (NTS) approaches, the metabolite profile of glass eels was studied, and a PLS-DA classification model was applied to find differences between behavioural phenotypes. This model highlighted methionine, glutaryl-L-carnitine, and palmitoylcarnitine as key metabolites, with methionine being significantly different between groups. Glutaryl-L-carnitine strongly correlated with activity, suggesting it might be a more sensitive indicator of glass eel activity than previously studied parameters such as weight loss and oxygen consumption. The findings suggest that differences between active and inactive eels result from both swimming activity and intrinsic metabolic differences, with methionine linked to both factors. We also explored potential differences in how diazepam affects active and inactive glass eels. However, our metabolomic approach lacked the sensitivity to detect significant variations. Overall, this study provides valuable insights into the metabolomic distinctions between active and inactive glass eels, establishing a foundation for future research in this field.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106801"},"PeriodicalIF":3.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meihua Lian , Xiangfeng Zeng , Lixia Li , Mingze Sun , Xiaojun Li
{"title":"Fate of arsenic in contaminated coastal soil induced by rising temperature and seawater intrusion","authors":"Meihua Lian , Xiangfeng Zeng , Lixia Li , Mingze Sun , Xiaojun Li","doi":"10.1016/j.marenvres.2024.106799","DOIUrl":"10.1016/j.marenvres.2024.106799","url":null,"abstract":"<div><div>Temperature rising and seawater intrusion are expected to influence the hydrologic regime and redox conditions in coastal soil, and the fate and mechanisms of biogeochemical cycling of Arsenic (As) in the specific environment are poorly understood. This work was carried out in an anaerobic operating chamber by adding sulfate to simulate seawater intrusion under various temperature. Results demonstrated the microbial community diversity was influenced by temperature and the highest Shannon and lowest Simpson index were found at 28 °C. Firmicutes was the dominant bacteria, accounting for 81.16%–93.99%. <em>Desulfosporosinus</em>, with the proportion increasing with temperature, showed a significantly positive correlation with S<sup>2−</sup> for sulfate addition treatments. Actually, transformation of As was meditated by the concentration and valence of sulfur and iron in soil. The dissimilatory reduction of arsenic-bearing Fe oxides occurring in the initial stage, is suspected to be the primary driver of As release. Then, concentration of As declined in aqueous phase due to the reduction of sulfate, and the proportion of residual speciation of As in solid phase increased with temperature, ranging from 6.78% to 27.70%. The results displayed the reducing condition due to seawater intrusion and temperature change could regulate the release and sequestration of As in the coastal soil.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106799"},"PeriodicalIF":3.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469136","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}
Jiaqi Li , Zengjie Jiang , Meng Zhang , Xin Sun , Minghui Jiao , Jiamin Li , Suyan Xue , Ang Li , Longzhen Liu , Ling Zhu , Yuze Mao
{"title":"Large-scale oyster farming accelerates the removal of dissolved inorganic carbon from seawater in Sanggou Bay","authors":"Jiaqi Li , Zengjie Jiang , Meng Zhang , Xin Sun , Minghui Jiao , Jiamin Li , Suyan Xue , Ang Li , Longzhen Liu , Ling Zhu , Yuze Mao","doi":"10.1016/j.marenvres.2024.106798","DOIUrl":"10.1016/j.marenvres.2024.106798","url":null,"abstract":"<div><div>While the direct impact of oyster calcification and respiration on the seawater inorganic carbon system is well-acknowledged, their indirect effect through filter feeding activities remains unclear. Here we studied the impact of large-scale oyster farming on the removal of dissolved inorganic carbon (DIC) from seawater. Field investigations showed that the DIC level in the oyster farming area in Sanggou Bay, China were significantly lower than that in the non-farming area. In-lab incubation showed that regardless of whether incubated in high or low-transparent environments, the DIC removal rate of seawater from the oyster farming area was significantly higher than that of the non-farming area. These results indicate that cultivated oysters facilitate the removal of seawater DIC in the farming area. To reveal the indirect effect of filter feeding activities on DIC removal, we used 6-m<sup>3</sup> ponds to simulate the oyster-farming environment. Results showed that the average DIC level of the oyster-cultivating groups was 105.83 μmol/kg lower than that of the control groups (without of oyster) after a six-day cultivation. Surprisingly, the average concentration of Chl-a in oyster-cultivating groups was significantly higher than that of the control group at the end of the experiment. Similarly, DIC level declined faster while Chl-a concentration increased faster in seawater that previously experienced 12~20 h of oyster cultivation than that in the control seawater. It was noticed that the transparency of seawater within 6-m<sup>3</sup> ponds increased significantly just after hours of oyster cultivation. This enhanced transparency created a favorable light environment that supported phytoplankton photosynthesis and simultaneously accelerated the DIC removal rate. Overall, oysters not only remove the inorganic carbon in the seawater through calcification but also create a suitable environment for phytoplankton photosynthesis through their filtering activity, and subsequently accelerating the removal of inorganic carbon in the seawater of the oyster farming area.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106798"},"PeriodicalIF":3.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469137","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":"Strong seasonality and unsuspected diversity of haptophytes explored by metabarcoding analysis in the Chinese seas","authors":"Cunchao Wu, Yue Xue, Qingshang Song, Jiehui Yin, Yanying Zhang, Pingping Shen","doi":"10.1016/j.marenvres.2024.106792","DOIUrl":"10.1016/j.marenvres.2024.106792","url":null,"abstract":"<div><div>The haptophytes, are essential components of the marine pico- and nano-plankton but little is known about their diversity and abundance due to the small size. In this study, the taxonomic composition, geographical distribution, and seasonal variation of the haptophytes in the Bohai Sea, the Yellow Sea, and the East China Sea were investigated using DNA metabarcoding in April and October of 2021. A total of 623 and 3756 haptophyte amplicon sequence variants (ASVs) were obtained in spring and autumn, respectively. All currently described or detected haptophyte orders were retrieved, including several deep-branching novel environmental lineages with relative high abundance. The predominant groups were <em>Chrysochromulina</em>, Clade HAP 2-3-4-5, <em>Phaeocystis</em>, and <em>Prymnesium</em> in spring, and <em>Chrysochromulina</em>, <em>Phaeocystis</em>, and <em>Emiliania/Gephyrocapsa</em> compelx in autumn. The richness and diversity showed seasonal variation, with higher alpha diversity occurred in autumn than that of spring. Different haptophyte taxa exhibited unique spatial distribution patterns and water temperature was significantly correlated with the observed community dissimilarities and was the most influential driving factor in both seasons. Our results highlight the high hidden diversity and seasonal variations of haptophytes in the Chinese seas.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106792"},"PeriodicalIF":3.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503222","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}
Di Wu , Kui Wang , Wei Fan , Qicheng Meng , Feng Zhou , Minhui Zheng , Dawei Xu
{"title":"Response of bottom dissolved oxygen reduction to net ecosystem production observed by a wave-driven profiler in the Changjiang River Plume","authors":"Di Wu , Kui Wang , Wei Fan , Qicheng Meng , Feng Zhou , Minhui Zheng , Dawei Xu","doi":"10.1016/j.marenvres.2024.106794","DOIUrl":"10.1016/j.marenvres.2024.106794","url":null,"abstract":"<div><div>Coastal hypoxia, exacerbated by the combined influence of eutrophication and global warming, presents a significant environmental challenge. However, the lag correlation between organic matter (OM) export from the upper layers and bottom dissolved oxygen (DO<sub>BOT</sub>) reduction still lack clear elucidation. This study investigated the coupling between net ecosystem production (NEP, representing the maximum OM export) and DO<sub>BOT</sub> in the Changjiang River plume (CRP), using a wave-driven profiler system. The high-resolution profiles revealed rhythmic fluctuations in water column NEP, with sediment-water exchange (−74.6%) and NEP (−4.0%) dominating DO<sub>BOT</sub> reduction. Notably, surface NEP impacts DO<sub>BOT</sub> with a lag time of 25.65 h, indicating an OM sinking speed of 1.32 mm s<sup>−1</sup>. NEP at a depth of 3.4 m exerted the most significant influence on DO<sub>BOT</sub>, explaining a 12% reduction. These findings elucidate the response mechanism of DO<sub>BOT</sub> reduction to upper OM export and provide insights for hypoxia prediction in coastal and estuarine areas.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106794"},"PeriodicalIF":3.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440885","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}
Bin Wang , Xuelu Gao , Yongliang Liu , Xiyan Sun , Jianmin Zhao , Qianguo Xing , Yuwei Yang
{"title":"Scallop farming impacts on dissolved organic matter cycling in coastal waters: Regulation of the low molecular weight fraction","authors":"Bin Wang , Xuelu Gao , Yongliang Liu , Xiyan Sun , Jianmin Zhao , Qianguo Xing , Yuwei Yang","doi":"10.1016/j.marenvres.2024.106796","DOIUrl":"10.1016/j.marenvres.2024.106796","url":null,"abstract":"<div><div>To elucidate the impacts of scallop farming on the biogeochemical characteristics of low molecular weight (LMW, <1 kDa) dissolved organic matter (DOM), samples collected from a bay scallop mariculture area (MA) and its surrounding areas were determined for absorption and fluorescence spectroscopy after microfiltration and centrifugal ultrafiltration. The values of absorption coefficient <em>a</em><sub>350</sub> showed a spatial variation trend of inshore area (IA) > MA > non-mariculture area (NMA) for both bulk (<0.7 μm) and LMW fractions. Four fluorescent components, namely two protein-like components (tryptophan-like C1 and tyrosine-like C2) and two humic-like components (microbial humic-like C3 and terrestrial humic-like C4), were identified. Scallop farming influenced DOM transformation by altering phytoplankton abundance and promoting microbial degradation. In July, the net contributions of phytoplankton to the spectroscopy parameters of LMW-DOM in the surface seawater were 11.0% for <em>a</em><sub>350</sub>, 4.3% for C1, 0.8% for C2, 0.6% for C3 and 3.0% for C4, respectively; the corresponding values of bulk DOM in the surface seawater were 24.3% for <em>a</em><sub>350</sub>, 20.1% for C1, 5.9% for C2, 2.0% for C3, 2.9% for C4, respectively. Compared with NMA, the contributions of microbial degradation to <em>a</em><sub>350</sub> in MA's surface seawater increased by 9.0% for LMW-DOM and 6.9% for bulk DOM in July; however, the effects on different fluorescent components varied. In August, compared with NMA, the contributions of microbial degradation to spectroscopy parameters in the bottom water of MA decreased by 35.7% for <em>a</em><sub>350</sub>, 6.3% for C2, 1.3% for C3, and 4.4% for C4 for LMW-DOM fraction; for bulk DOM, the corresponding contribution decreased by 10.8% for C1. These variations indicate that protein-like substances from scallop aquaculture are easily degraded into LMW substances, while humic-like substances degradation diminishes over time.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106796"},"PeriodicalIF":3.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440886","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}
Jacopo Fabrello , Maria Ciscato , Davide Asnicar , Jacopo Giorgi , Marco Roverso , Sara Bogialli , Valerio Matozzo
{"title":"Effects of Bisphenol A analogues and their mixture on the crab Carcinus aestuarii: Cytotoxicity, oxidative stress and damage, neurotoxicity, physiological responses, and bioaccumulation","authors":"Jacopo Fabrello , Maria Ciscato , Davide Asnicar , Jacopo Giorgi , Marco Roverso , Sara Bogialli , Valerio Matozzo","doi":"10.1016/j.marenvres.2024.106800","DOIUrl":"10.1016/j.marenvres.2024.106800","url":null,"abstract":"<div><div>Bisphenol A (BPA) analogues are emerging contaminants, whose ecotoxicological profile for aquatic species, particularly marine ones, is little known. In this study, the effects of an environmentally realistic concentration (300 ng/L) of three BPA analogues (BPAF, BPF, and BPS) - alone or as a mixture (MIX) – were evaluated for the first time on the crab <em>Carcinus aestuarii</em>. A multibiomarker approach was adopted to assess the effects of 7 and 14 days of exposure on haemolymph parameters, gill and hepatopancreas biochemical parameters, and physiological responses of crabs. Bioaccumulation of the three bisphenols was also investigated in crabs by UHPLC-HRMS. A significant reduction in total haemocyte counts was recorded in crabs exposed for 7 days to BPAF and MIX and for 14 days to the MIX, whereas an increase was found in crabs treated for 14 days with BPAF. Cell proliferation increased significantly in crabs exposed for 14 days to BPS and MIX. An imbalance of the antioxidant system, as well as oxidative damage, was recorded in gills and hepatopancreas. No neurotoxic effects were observed in crabs. At the physiological level, exposure to MIX increased the respiration rate of crabs. As for bioaccumulation, only bisphenol AF was detected in crabs. Overall, the present study demonstrated that BPA analogues can affect some important cellular parameters, induce oxidative stress and alter physiological responses in crabs.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106800"},"PeriodicalIF":3.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qiaofeng Ma , Shuxiu Liang , Jiawen Sun , Shahid Ahmad , Zhenhua Wang , Wenhao Hou , Zhaochen Sun , Bijin Liu , Wenguo Huang
{"title":"Quantitatively unveiling the role of coastal wetlands in regulating eutrophication and enhancing water environmental capacity","authors":"Qiaofeng Ma , Shuxiu Liang , Jiawen Sun , Shahid Ahmad , Zhenhua Wang , Wenhao Hou , Zhaochen Sun , Bijin Liu , Wenguo Huang","doi":"10.1016/j.marenvres.2024.106787","DOIUrl":"10.1016/j.marenvres.2024.106787","url":null,"abstract":"<div><div>Human activities have intensified the global challenge of coastal eutrophication. Recently, water resource managers have encountered difficulties in formulating precise pollutant reduction strategies to mitigate coastal eutrophication. Despite the recognized importance of coastal wetlands and pollution sources in influencing coastal nutrient levels, accurately quantifying their impact remains difficult. To address this challenge, this study introduces a novel approach for optimizing water environmental capacity. A coupled model integrating hydrodynamics, water quality, and wetland nutrient mechanisms was developed to simulate the spatio-seasonal distribution of water, sediment, and vegetation nutrients in a semi-enclosed bay (Liaodong Bay, China) and a large-scale coastal wetland (Liaohe estuary wetland, China). Model parameters and simulation results were calibrated and validated using extensive long-term field investigations and laboratory experiments. The average root mean square errors between simulated and observed values for all validation points were as follows: 0.80 mg L<sup>−1</sup>, 0.53 mg L<sup>−1</sup>, 0.08 mg L<sup>−1</sup>, 6.70 μg L<sup>−1</sup>, and 0.50 μg L<sup>−1</sup> for dissolved oxygen, chemical oxygen demand, dissolved inorganic nitrogen, dissolved inorganic phosphorus, and chlorophyll-a, respectively. The total nitrogen (TN) and total phosphorus (TP) in the sediment were 0.10 g kg<sup>−1</sup> and 0.05 g kg<sup>−1</sup>, respectively. For <em>Suaeda salsa</em>, the TN and TP were 2.91 g kg <sup>−1</sup> and 0.08 g kg <sup>−1</sup>, respectively. For <em>Phragmites australis</em>, the TN and TP were 114.22 g kg <sup>−1</sup> and 6.21 g kg <sup>−1</sup>, respectively. The results suggest that excessive river discharge and a stable residual circulation structure contribute to the persistent eutrophication in Liaodong Bay. The Liaohe estuary wetland enhances the environmental capacity of dissolved inorganic nitrogen and dissolved inorganic phosphorus in Liaodong Bay to 271 ± 31 t yr<sup>−1</sup> and 8 ± 1 t yr<sup>−1</sup>, respectively, accounting for 1.8 ± 0.2% and 1.3 ± 0.2% of their respective environmental capacities. The reduction in dissolved inorganic nitrogen concentration is significant, with a maximum decrease of 0.17 mg L<sup>−1</sup>. The maximum contributions of atmospheric deposition and aquaculture wastewater to dissolved inorganic nitrogen concentration are 0.08 mg L<sup>−1</sup> and 0.03 mg L<sup>−1</sup>, respectively, with higher contributions in spring and summer than in fall and winter. These findings highlight the critical role of coastal wetlands in mitigating eutrophication and underscore the need for spatio-seasonal water management programs. This work serves as a model for effectively reducing global coastal pollution emissions.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"202 ","pages":"Article 106787"},"PeriodicalIF":3.0,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433530","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}