Marine environmental research最新文献

{"title":"Environmental concentrations of fluoxetine antidepressant affect early development of sea urchin Paracentrotus lividus","authors":"Roberta Miroglio,&nbsp;Roberta Nugnes,&nbsp;Lisa Zanetti,&nbsp;Marco Faimali,&nbsp;Chiara Gambardella","doi":"10.1016/j.marenvres.2025.107080","DOIUrl":"10.1016/j.marenvres.2025.107080","url":null,"abstract":"<div><div>Fluoxetine (FLX), one of the most widely prescribed selective serotonin reuptake inhibitors, is frequently detected in the aquatic environment. In this study we assessed the ecotoxicological effects of FLX on the early life-stages of the sea urchin <em>Paracentrotus lividus,</em> a key species in the Mediterranean Sea. Fertilization rate, developmental anomalies and behavioural alterations were evaluated up to 72 h by exposing gametes, zygotes, and embryos (gastrula) to environmental (0.001, 0.01 mg/L) and high concentrations (0.1, 1, 10 mg/L). Further, the different types and frequency of morphological anomalies at larval level were classified to estimate the Index of Contaminant Impact (ICI) at relevant and high concentrations. The ICI was applied to predict which FLX concentrations may pose a risk to sea urchins. Although FLX did not affect fertilization, significant skeletal anomalies and behavioural alterations were found in plutei from each exposed stage. Based on EC50 values, the sensitivity level ranks as follows: zygote &gt; gastrula &gt; sperm. The ICI values indicated high and moderate impacts only at high concentrations. However, a slight impact was also found in plutei from zygote exposure at relevant environmental concentrations, highlighting a potential risk for sea urchin early development. Considering increasing FLX consumption, we suggest to include this PC in monitoring plans, to not exceed levels that may impair and severely affect the early developmental stages of echinoderms. In addition, our findings promote the use of ICI as a novel tool for FLX impact assessment.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107080"},"PeriodicalIF":3.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628891","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}

{"title":"Between shells and seas: Effects of ocean acidification on calcification and osmoregulation in yellow clam (Amarilladesma mactroides)","authors":"Isadora Porto Martins Medeiros ,&nbsp;Fernanda Chaves Lopes ,&nbsp;Marta Marques Souza","doi":"10.1016/j.marenvres.2025.107083","DOIUrl":"10.1016/j.marenvres.2025.107083","url":null,"abstract":"<div><div>The decline in ocean pH due to rising CO₂ levels is a critical factor impacting marine ecosystems. Ocean acidification (OA) is expected to negatively affect various organisms, particularly those with mineralized structures. While the effects of OA on the calcification of shells and exoskeletons are documented, the impact on homeostatic processes, such as osmoregulation, is less understood. Osmoregulation is vital for maintaining water and salt balance within marine organisms, crucial for their survival and physiological functions. Acidification may alter ion exchange mechanisms, affecting the regulation of ions. In this study, we evaluated the effects of intermediate OA (pH 7.6) with or without hypersaline stress (35‰) on calcification and osmotic balance biomarkers in the bivalve <em>Amarilladesma mactroides</em> after 96h of acute exposure. We found that pH did not affect hemolymph osmolality or extracellular Ca²⁺ concentration. However, OA impaired the bivalve's ability to maintain its mineralized structures by decreasing Ca²⁺-ATPase enzyme activity in the mantle. The increase in carbonic anhydrase activity indicated a specific response to maintain acid-base balance in the tissue, i.e., compensating for the effects of acidification by neutralizing CO₂ accumulation and stabilizing internal pH. In the gills, both enzymes showed increased performance under higher salinity and reduced pH. Exposure to less alkaline pH inhibited carbonic anhydrase and Na⁺/K⁺-ATPase activity, potentially affecting the regulation of essential inorganic osmolytes.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107083"},"PeriodicalIF":3.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610836","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":"CO2 dynamics and sequestration potential in high-nutrient, low-chlorophyll bays: A case study of Yueqing Bay","authors":"Yixing Zhang ,&nbsp;Bin Wang ,&nbsp;Qian Li ,&nbsp;Dewang Li ,&nbsp;Chen Zeng ,&nbsp;Mingyao Xing ,&nbsp;Xuan Zhang ,&nbsp;Zhao Zhang ,&nbsp;Jinkun Qiu ,&nbsp;Yahui Chen ,&nbsp;Hongliang Li ,&nbsp;Zhenhao Sun ,&nbsp;Yanbing Xu ,&nbsp;Jianfang Chen","doi":"10.1016/j.marenvres.2025.107061","DOIUrl":"10.1016/j.marenvres.2025.107061","url":null,"abstract":"<div><div>Bays, as transitional zones in the land-sea continuum, exhibit fluctuating sea-air CO₂ fluxes influenced by climate change and human activities. The role of eutrophic bays as CO₂ sinks is debated, highlighting the need to understand CO₂ dynamics and controlling factors. This research employs the subtropical semi-enclosed Yueqing Bay as a case to investigate the dynamics of <em>p</em>CO₂ and sea-air CO₂ flux, as well as the carbon sink potential in high-nutrient, low-chlorophyll (HNLC) bays through high-resolution underway surveys. Although eutrophic bays worldwide typically function as atmospheric CO₂ sinks on an annual scale, the high concentration of suspended particulate matter (SPM) from the Oujiang River, combined with sediment resuspension and other processes, inhibits primary production, thereby reducing CO₂ sequestration. As a result, Yueqing Bay acts as a net atmospheric CO₂ source in August and November, with fluxes of 6.22 ± 8.79 mmol m⁻² d⁻¹ and 0.53 ± 0.19 mmol m⁻² d⁻¹, respectively, and an average flux of 1.23 ± 1.04 mol m⁻² yr⁻¹. However, acting as nutrient reservoirs, the underutilized nutrients in Yueqing Bay partially contribute to algal blooms, which in turn enhance CO₂ absorption at the Bay Mouth through seawater exchange. Therefore, HNLC bays like Yueqing Bay demonstrate spatial redistribution of CO₂ sink function due to hydrodynamic and biogeochemical processes, offering new insights into the role of bay ecosystems in the carbon cycle.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107061"},"PeriodicalIF":3.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610834","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":"Lasting impacts of rapid salinity change on physiological energetics of estuarine oysters (Crassostrea hongkongensis)","authors":"Tuo Yao ,&nbsp;Fortunatus Masanja ,&nbsp;Jie Lu ,&nbsp;Shengli Fu ,&nbsp;Wenfan Luo ,&nbsp;Vicent Michael Shija ,&nbsp;Lingtong Ye ,&nbsp;Liqiang Zhao","doi":"10.1016/j.marenvres.2025.107076","DOIUrl":"10.1016/j.marenvres.2025.107076","url":null,"abstract":"<div><div>The duration of rapid salinity change (RSC) prevailing in estuarine and coastal regions is increasing due to extreme climate and weather events, posing significant challenges to marine bivalves. The Hong Kong oyster <em>(Crassostrea hongkongensis)</em>, an ecologically and economically important species in tropical estuarine ecosystems, has experienced increasing mass mortality during prolonged periods of RSC, yet little is known about underlying physiological processes. Here, we investigated how physiological energetics of <em>C. hongkongensis</em> were affected by longer-lasting scenarios and four-week episodes of RSC. Compared with ambient conditions with seawater salinity ranging from 15 to 20, rapid salinity change by ± 10 units significantly decreased the survival of oysters, with RSC-induced hyposaline stress (−10) resulting in more serious consequences than that of hypersaline regime (+10). Continuing exposure of oysters to both RSC scenarios significantly affected their feeding activities, but the food absorption efficiency were still virtually unchanged. Significantly depressed respiration and increased excretion activities were observed in RSC-stressed oysters, resulting in significantly lowered O:N ratio. Overall, when exposed to RSC, oysters showed significantly decreased scope for growth, due to shifts in energy budget toward maintenance of essential physiological processes. Our results demonstrate the vulnerability of estuarine oysters to prolonged RSC events, and underscore the pressing need to develop strategies to enhance oyster tolerance under intensifying RSC conditions and safeguard oyster aquaculture in this era of unprecedented climate change.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107076"},"PeriodicalIF":3.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619950","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":"Spatial and temporal patterns in pelagic fish egg assemblages in spring and late autumn–winter in eastern Beibu Gulf","authors":"Jinrun Wang ,&nbsp;Haiyan Zhang ,&nbsp;Chuanhao Pan,&nbsp;Bo Feng,&nbsp;Gang Hou","doi":"10.1016/j.marenvres.2025.107066","DOIUrl":"10.1016/j.marenvres.2025.107066","url":null,"abstract":"<div><div>Semi-enclosed gulfs play important roles in global marine ecosystems, but they are vulnerable to anthropogenic disturbance and the effects of climate change. Beibu Gulf, the largest semi-enclosed gulf in China, is characterized by complex oceanographical conditions and high fish diversity, and it is an important fishing and spawning ground for many fish species. However, little is known about where these fishes spawn. We examine spatial and temporal distributions of fish eggs and their assemblages in the eastern Beibu Gulf in spring and late autumn–winter of 2020. A total of 75 taxa of fish eggs were identified, belonging to 9 orders, 33 families and 52 genera. In spring, the taxa are dominated by species in the families Clupeidae, Leiognathidae, and Carangidae (43.62%, 19.84%, and 12.51% of the total catch, respectively); from late autumn–winter, dominant families are the Engraulidae (27.52%), Sparidae (15.08%), and Clupeidae (13.32%). Five egg assemblages are recognized in spring, and four in late autumn–winter. Of available environmental variables, the sea surface temperature anomaly, water depth, and chlorophyll-a concentrations most affect fish egg assemblages. These results provide information to inform protection of fish spawning grounds and to aid fisheries management in Beibu Gulf.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107066"},"PeriodicalIF":3.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610835","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}

{"title":"Phosphorus addition mitigates the combined negative effects of high temperature and nitrogen stress on corals","authors":"Zhuojing Zhou ,&nbsp;Huidan Yang ,&nbsp;Sichen Li ,&nbsp;Haochen Niu ,&nbsp;Dongdan Yuan ,&nbsp;Hongwei Zhao","doi":"10.1016/j.marenvres.2025.107075","DOIUrl":"10.1016/j.marenvres.2025.107075","url":null,"abstract":"<div><div>Global warming and imbalances in nitrogen (N)-phosphorus (P) ratios due to increased human activity have had significant impacts on coral reef ecosystems. However, the underlying mechanisms of these impacts remain poorly understood. In this study, a controlled experiment was conducted on <em>Acropora hyacinthus</em> treated with different P concentrations at high temperature (30 °C) and high N level (9 μM nitrate), which was analyzed in terms of physical observations and physiological indices, as well as photosynthetic activity and fatty acid composition. The results indicated that nitrate enrichment significantly reduced Symbiodiniaceae density, total chlorophyll content, and photosynthetic efficiency, as well as notable coral bleaching. P addition alleviated some of these detrimental effects, enhancing symbiotic relationship and maintaining photosynthetic activity. Additionally, changes in fatty acid composition suggest that P supplementation may improve coral tolerance to the combined stress of heat stress and nitrate enrichment by enhancing coral heterotrophy. These findings underscore the importance of balanced nutrient ratio for corals and propose P supplementation as a potential strategy to mitigate the combined stress on coral reefs.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107075"},"PeriodicalIF":3.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610833","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":"Assessing the contribution of Tidal Flats to climate change and carbon neutrality through modeling approaches","authors":"Sukyeong Yang ,&nbsp;Heung-Sik Park ,&nbsp;Bong-Oh Kwon ,&nbsp;Jong Seong Khim ,&nbsp;Jongmin Lee ,&nbsp;Gopika Sharesh ,&nbsp;Nhi Yen Thi Dang ,&nbsp;Seungdo Kim","doi":"10.1016/j.marenvres.2025.107067","DOIUrl":"10.1016/j.marenvres.2025.107067","url":null,"abstract":"<div><div>Tidal coastal ecosystems show promising potential as natural carbon sinks in mitigating climate change. Under the combined effect of carbon deposition, capturing, converting, and storing atmospheric CO₂ into coastal sediments over a long period, tidal flats are of great significance to the ecology. In addition to preventing coastal erosion, the organic carbon buried in tidal flats should play an important role in mitigating climate change and achieving the carbon neutrality target. However, although the growing interest in tidal flat carbon has prompted studies to estimate carbon stocks at the global level in general and Korea in particular, comprehensive assessments of the role of carbon stocks in climate change have yet to be made. Therefore, the present study aims to quantify and simulate organic carbon stocks in tidal flats habitats of the Korean coast through a carbon balance model, thereby assessing their role in climate change and carbon neutrality. Biomass vegetation, meteorological, and sedimentary data up to 70 cm depth were sampled from 37 sites representing tidal flats along the Korean coast and then applied to the model to simulate the carbon sequestration rate as well as to provide predictions of sediment carbon stocks until 2050. The study revealed that the average total organic carbon (TOC) storage in vegetated and non-vegetated tidal flats reach 53.41 Mg C ha⁻¹ and 45.48 Mg C ha⁻¹ up to a depth of 70 cm in 2050, respectively, of which vegetation on the ground accounts for 3.06 ± 3.01 MgC.ha⁻¹. Carbon mass is found to increase linearly over time in nearly all areas studied, with carbon sequestration rates ranging from 0.037 to 0.71 (MgC ha^{− 1} yr^{− 1}). The Korean tidal flats contain 11,200,000 MgC (∼4.13 × 10⁷ tCO₂ eq) of organic carbon (70 cm depth). This clearly reflects their potential for inclusion in the Nationally Determined Contribution (NDC) under the Paris Agreement. Model simulation result indicated that the topsoil carbon mass of Tidal Flats in the year 2050 could contribute 7.64 × 10⁶ tons CO₂eq towards the “2050 carbon neutral strategy of the Republic of Korea”. The findings of this study shall strengthen the knowledge base regarding Korea's Tidal flat carbon stocks as well as their potential role in mitigating climate change and contributing to future carbon neutrality goals.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107067"},"PeriodicalIF":3.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580656","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":"Selective herbivory on necrotic tissue can promote tolerance to abiotic disturbances in the seagrass Cymodocea nodosa","authors":"Luis G. Egea,&nbsp;Rocío Jiménez-Ramos","doi":"10.1016/j.marenvres.2025.107064","DOIUrl":"10.1016/j.marenvres.2025.107064","url":null,"abstract":"<div><div>Herbivores play an important role in shaping seagrass community structure, but local stressors can change the ecological significance of herbivory by altering seagrass physiology in ways that affect herbivore preferences. However, few studies have assessed the cumulative influence of diverse local stressors on seagrass ecosystem function in relation to herbivory pressure. Here, we performed a four-month <em>in situ</em> experiment and laboratory feeding trials to examine the effects of two abiotic stressors (light reduction and nutrient enrichment) and simulated herbivory on the physiology of <em>Cymodocea nodosa</em> meadows and associated plant-mesograzer interactions, with the goal of understanding seagrass resilience to multiple disturbances. We found that light reduction primarily affected leaf morphology, resulting in lower shoot surface area, plant biomass and leaf growth rate. Simulated herbivory stimulated the production of phenolic compounds with a potential antimicrobial effect. Nutrient enrichment significantly reduced the C:N ratio and increased seagrass necrosis tissues and growth of opportunistic algae. Further, while higher macroalgal biomass was negatively correlated with <em>C. nodosa</em> performance, epiphyte biomass was positively correlated. Furthermore, our findings evidenced that <em>C. nodosa</em> leaves not only had high nutritional quality under nutrient enrichment, but also the presence of necrotic areas could be a significant driver modulating isopod consumption. We discuss the potential ecological impact of the natural mesograzer preference for necrotic tissue, which may promote the recovery of seagrass communities under local stressors.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107064"},"PeriodicalIF":3.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580655","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":"Geochemical behavior of iron-sulfur coupling in coastal wetland sediments and its impact on heavy metal speciation and migration","authors":"Jiaojiao Xia ,&nbsp;Xue Fan ,&nbsp;Yanyan Lu ,&nbsp;Yan Li ,&nbsp;Zhiquan Wang ,&nbsp;Shengbing He ,&nbsp;Huihua Lyu ,&nbsp;Jian Li","doi":"10.1016/j.marenvres.2025.107065","DOIUrl":"10.1016/j.marenvres.2025.107065","url":null,"abstract":"<div><div>Coastal wetlands play a vital role in energy flow and material cycling, holding irreplaceable significance for global ecological security. This paper provides a comprehensive review of the geochemical behaviors of key elements, particularly iron and sulfur, in coastal wetland sediments, as well as their influence on the speciation and mobility of heavy metals. The findings indicate that the redox processes of iron, driven by both biotic and abiotic factors, are tightly coupled with sulfur redox reactions, thereby continuously regulating the speciation and mobility of heavy metals. This interplay serves as a critical determinant in the “source-sink” dynamics of heavy metals within coastal wetland sediments. A deeper understanding of these intricate mechanisms is essential for elucidating the operational principles of wetland ecosystems, assessing their ecological and environmental quality, and developing effective protection and management strategies. Future research should prioritize a deeper exploration of iron-sulfur cycling mechanisms, enhance the monitoring and evaluation of heavy metal transformation and migration processes, and investigate the environmental effects of secondary iron-sulfur minerals on the behavior and storage of heavy metals. These efforts will provide robust theoretical support for the restoration and sustainable management of coastal wetland ecosystems.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107065"},"PeriodicalIF":3.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling active nitrate and nitrite cycling in a eutrophic coastal bay, southern China from a dual isotope perspective","authors":"Zixuan Li,&nbsp;Hantao Zhou,&nbsp;Minfang Zheng,&nbsp;Mengya Chen,&nbsp;Run Zhang,&nbsp;Min Chen","doi":"10.1016/j.marenvres.2025.107060","DOIUrl":"10.1016/j.marenvres.2025.107060","url":null,"abstract":"<div><div>Increased nutrient loading in coastal waters poses a threat to marine ecosystems. To develop effective management strategies, a clearer understanding of nitrogen cycle dynamics for the main species is crucial for understudied urbanized areas. By employing stable isotopes of nitrate (δ¹⁵N and δ¹⁸O) and the rarely reported nitrite isotopes, we found a decoupling between physical mixing and microbial transformative processes in the Xiamen Bay. During the dry season, dominated by endmember mixing, the SIAR (Stable Isotope Analysis in R) model identifies manure (50%) as the primary nitrate source, followed by fertilizer, sewage, and rainfall. Microbial processes govern nitrogen cycling during the wet season, as evidenced by the relatively low ε value (∼2.4‰) using the Rayleigh fractionation model. This likely reflects distinct environmental conditions in coastal waters compared to the open ocean, such as limited light and iron availability. Nitrite isotope ratios implicate ammonia oxidation and nitrite oxidation as the primary drivers of nitrite variability during the wet season. This suggests that seasonal nitrite accumulation in summer may result from a decoupling of these processes in response to temperature fluctuations. Theoretical calculations of the nitrite reservoir, based on key parameters like temperature and substrate concentration, further support this argument. Our findings highlight the highly dynamic nature of nitrate and nitrite cycling in coastal environments. This underscores the need for further research in these understudied coastal systems, particularly in the context of intensifying human activities and climate change.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"207 ","pages":"Article 107060"},"PeriodicalIF":3.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610831","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}