Marine environmental research最新文献

{"title":"Functional specialization of the eelgrass rhizosphere microbiome: Root exudate-mediated assembly and implications for degraded meadow rehabilitation","authors":"Jie Sun ,&nbsp;Xiang Zhao ,&nbsp;Jin-Ji Liu ,&nbsp;Zhen Zhang ,&nbsp;Wen-Jie Yan ,&nbsp;Pei-Dong Zhang","doi":"10.1016/j.marenvres.2025.107577","DOIUrl":"10.1016/j.marenvres.2025.107577","url":null,"abstract":"<div><div>Seagrass meadows provide vital coastal ecosystem services but face accelerated degradation due to anthropogenic stressors. While rhizosphere microbes are recognized for enhancing nutrient cycling and supporting meadow resilience, the mechanisms by which seagrasses recruit functional groups critical for stress mitigation from bulk sediment via root exudates remain poorly understood. This study employed metagenomics and metabolomics to characterize <em>Zostera marina</em> root exudates and compare microbial (bacterial, fungal, archaeal) composition, diversity, and metabolic functions between bulk sediment and rhizosphere. We demonstrate that root exudates--enriched in organic acids and phenolic compounds--act as ecological filters, selectively enriching rhizosphere taxa with specialized functions relevant to habitat recovery, such as nitrogen/sulfur cycling (key processes for mitigating eutrophication impacts). Rhizosphere communities exhibited reduced diversity but heightened functional specialization aligned with host nutrition and stress tolerance, contrasting sharply with bulk sediment communities dominated by methane production and carbon degradation pathways. Critically, bulk sediment serves as a reservoir of pre-adapted genetic potential for environmental adaptation, supplying niche-adaptive genes to the rhizosphere microbiome. Strong metabolite-microbe correlations confirm host exudates as primary drivers of microbial assembly, synchronizing functional traits with host demands. These findings elucidate host-mediated recruitment strategies underpinning seagrass resilience and provide mechanistic insights for designing microbiome-assisted rehabilitation of degraded seagrass habitats. (Images were created with BioRender).</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107577"},"PeriodicalIF":3.2,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118643","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":"Acoustic stress: how biological and anthropogenic noise shape oxidative balance in a coastal crab.","authors":"Solana Morena Snitman, Francesca Maria Mitton, Ceraulo Maria, Liebana Clara, Buscaino Giuseppa, María Paz Sal Moyano","doi":"10.1016/j.marenvres.2025.107572","DOIUrl":"https://doi.org/10.1016/j.marenvres.2025.107572","url":null,"abstract":"<p><p>Environmental sounds, both natural and anthropogenic, are increasingly recognized as relevant stressors for marine and coastal organisms. This study aimed to evaluate the impact of biologically (crustacean and fish) and anthropogenic (motorboat) sound stimuli from a coastal lagoon environment on oxidative stress biomarkers in the crab Cyrtograpsus angulatus, considering different sexes and developmental stages (adult males, adult females and juveniles). Lipid peroxidation (LPO), protein carbonylation (PO), and the activity of the antioxidant enzymes glutathione-S-transferase (GST) and catalase (CAT) were measured in the gills, hepatopancreas, muscle, hemolymph and brain. Sound exposure induced tissue-specific and stage-dependent oxidative responses. These results reveal a complex physiological response to different acoustic cues, suggesting a differential vulnerability to acoustic stress across developmental stages, sexes and specific tissues. Adult males were mainly affected by boat noise, while adult females and juveniles were more vulnerable to natural sounds. LPO increased in most tissues, indicating a potential stress biomarker. This study provides the first report of oxidative stress biomarkers in the brain of a crustacean species, contributing to a better understanding of the neurobiological impact of acoustic stimuli. These findings provide novel insight into how soundscapes shape the oxidative physiology of coastal crustaceans and highlight the need to consider acoustic pollution in the conservation of ecologically relevant habitats.</p>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"107572"},"PeriodicalIF":3.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244803","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":"Crab fluids as indicators of ecosystem health and exposure risk: development and validation of a method for bisphenol analogues detection","authors":"Tamyris de A. Gondim ,&nbsp;Gladston R.C. Junior ,&nbsp;Francisco A.D. Filho ,&nbsp;Rivelino M. Cavalcante","doi":"10.1016/j.marenvres.2025.107574","DOIUrl":"10.1016/j.marenvres.2025.107574","url":null,"abstract":"<div><div>This study aimed to develop and validate an analytical method for the simultaneous detection of bisphenol analogues in the hemolymph and urine of two estuarine crab species: <em>Ucides cordatus</em> and <em>Cardisoma guanhumi</em>. The selected matrices are rarely explored in environmental studies, yet they provide valuable insight into internal exposure and contaminant bioaccumulation. Sampling was conducted in 2025 in two estuarine regions along the South Atlantic coast of northeastern Brazil: Fortim (Ceará) and Itapissuma (Pernambuco). The analytical method, based on HPLC-FLD, demonstrated high sensitivity, with LODs as low as 0.004 ng/mL. Bisphenol analogues concentrations were significantly higher in hemolymph than in urine, with BPA, BPF, and BPC frequently exceeding the tolerable daily intake (TDI) of 0.004 μg/kg bw/day. The highest levels were observed in Fortim (Ceará), particularly in <em>C. guanhumi</em>, where bisphenol F reached over 200,000 ng/mL. These concentrations pose potential risks to aquatic organisms and human consumers, given that crab meat and cooking liquid are typically ingested together. HPLC-FLD is a reliable and accessible tool for bisphenol analogues monitoring, especially in low-resource environmental studies. Notably, all bisphenol analogues were detected in hemolymph, while some were absent in urine, reinforcing the former as a more representative matrix for chronic exposure. The presence of highly lipophilic and persistent bisphenol analogues, combined with their bioaccumulation potential, highlights the need for broader regulatory attention beyond BPA. This study demonstrates the relevance of crabs as effective bioindicators and supports the inclusion of alternative biological matrices in environmental risk assessment.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107574"},"PeriodicalIF":3.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227139","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":"Ecotype-specific light intensity responses in Sargassum horneri: bloom-forming vs. benthic forms","authors":"Qi Zhang ,&nbsp;Mingkun Zhuang ,&nbsp;Fang Yan,&nbsp;Shasha Zang,&nbsp;Hongyan Wu,&nbsp;Zhiguang Xu,&nbsp;Menglin Bao","doi":"10.1016/j.marenvres.2025.107571","DOIUrl":"10.1016/j.marenvres.2025.107571","url":null,"abstract":"<div><div>This study compared light-driven physiological adaptations between floating and benthic <em>Sargassum horneri</em> ecotypes using five light intensities (50, 100, 150, 300, and 600 μmol photons m⁻² s⁻¹). Both ecotypes showed bell-shaped relative growth rate (RGR) curves, with floating <em>S. horneri</em> peaking at 6.74 % day⁻¹ at 150 μmol photons m⁻² s⁻¹ and benthic ecotype reached its highest RGR of 6.90 % day⁻¹ at 300 μmol photons m⁻² s⁻¹. At 600 μmol photons m⁻² s⁻¹, both the maximum photochemical efficiency (<em>F</em>_<em>v</em><em>/F</em>_<em>m</em>) and the maximum relative electron transfer rate (rETR_max) of the two ecotypes were observed to be inhibited. Notably, the inhibition was more pronounced in the floating <em>S. horneri.</em> Simultaneously, both ecotypes exhibited resilience to elevated light stress by curtailing pigments synthesis, enhancing the light saturation point (I_k) and tissue carbon storage, and elevating catalase (CAT) and glutathione reductase (GR). The concentrations of soluble proteins and UV-absorbing compounds in benthic <em>S. horneri</em> were significantly greater than those found in floating <em>S. horneri</em> at light intensities of ≥300 μmol photons m⁻² s⁻¹. The results highlight ecotypes-specific physiological adaptations of <em>S. horneri</em> to varying light intensities. In comparison to the floating <em>S. horneri</em>, the benthic <em>S. horneri</em> collected during the same period exhibited a greater resilience and photosynthetic performance under higher light conditions. The study suggests that benthic <em>S. horneri,</em> if dislodged to surface waters, could proliferate rapidly under transient high-light exposure due to its robust photosynthetic plasticity.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107571"},"PeriodicalIF":3.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145149793","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":"Effects of heat stress on the pectoral skeletal muscle of the Antarctic icefish Chionodraco hamatus and the red-blooded Trematomus bernacchii","authors":"Filippo Garofalo ,&nbsp;Gianfranco Santovito ,&nbsp;Daniela Amelio","doi":"10.1016/j.marenvres.2025.107573","DOIUrl":"10.1016/j.marenvres.2025.107573","url":null,"abstract":"<div><div>Antarctic teleosts are extreme stenotherm species living at temperatures near to sea water freezing point (−1.9 °C), with annual fluctuations of less than 1 °C. Increasing ocean warming exposes all species to stressful conditions, including decreased oxygen availability. Therefore, the impact of heat stress on morpho-functional traits of Antarctic fishes is receiving intense attention, particularly concerning species without haemoglobin (Hb). In this study, were analyzed the effects of acute heat stress on the pectoral muscle of two Antarctic teleosts, the red-blooded <em>Trematomus bernacchii</em> and the Hb-less <em>Chionodraco hamatus</em>, on morphology, apoptosis and expression of molecules involved in vascular motility and heat shock response. After heat stress, we observed structural changes in the pectoral muscle of both species. In particular, those of icefish appear more vascularised with larger vessels. By immunolocalisation we evidenced species-specific differences in expression and localisation of endothelial nitric oxide synthase (eNOS), serotonin (5HT), vesicular acetylcholine transporter (VAch) and Heat Shock Protein 90 (HSP90) that, after exposure to 4 °C, in icefish seem to be up-regulated. Moreover, using the TUNEL technique, we found more apoptotic nuclei in the icefish after heat stress. Besides showing species-specific responses of pectoral muscle to heat stress in the two Antarctic teleosts, our results suggest a greater vulnerability to warming of Hb-less fish species.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107573"},"PeriodicalIF":3.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145213109","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":"Sargassum fusiforme improves the growth conditions of prawn by means of nutrient utilization and improvement of the microbial environment","authors":"Yuhuan Li ,&nbsp;Chen Chen ,&nbsp;Hongyan Xiang ,&nbsp;Congquan Gao ,&nbsp;Yubao Li ,&nbsp;Mingjiang Wu ,&nbsp;Binbin Chen","doi":"10.1016/j.marenvres.2025.107575","DOIUrl":"10.1016/j.marenvres.2025.107575","url":null,"abstract":"<div><div>The enrichment of inorganic nitrogen in the aquaculture water can contribute to aquatilia diseases and lead to seawater pollution. In this study, we explored the alleviating effect and mechanism of <em>Sargassum fusiforme</em> on ammonia poisoning in seawater during shrimp farming. The results revealed that in the early cultivation period, there was a 88.14 % elimination of NH₄⁺-N, an inhibition of the exponential proliferation of microalgae. However, after 10 days of cultivation, there were increases in the richness and diversity of the bacterial communities in the water. Although there were initial increases in the photosynthesis of <em>S. fusiforme</em>, along with significant increases in the contents of soluble proteins and the activity of antioxidant enzymes, there were corresponding reductions in the nitrogen absorption capacity and relative growth rate. During the later stage of cultivation, <em>P. vannamei</em> was subjected to NH₄⁺-N stress, which promoted the activities of antioxidant and immune-related enzymes; however, the period during which <em>P. vannamei</em> was subjected to NH₄⁺-N stress was short, and the RGR of <em>P. vannamei</em> was 1.35 %, which was significantly higher than other aquaculture systems. This indicated that <em>S. fusiforme</em> can efficiently utilize ammonia, improve the growth environment of <em>P. vannamei</em>, and enhance its survival capacity by optimizing the microbial community relationship in the water. These findings provided reference and data support for the construction of high-density breeding and the ecological treatment of aquaculture wastewater for aquatic animals.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107575"},"PeriodicalIF":3.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154996","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":"Influence of the strong 2015/16 El Niño and extreme rainfall events on micro- and mesozooplankton in a coastal pelagic ecosystem of the western tropical Atlantic","authors":"Morgana Brito-Lolaia ,&nbsp;Simone Maria de Albuquerque Lira ,&nbsp;Nathália Lins-Silva ,&nbsp;Humberto Lázaro Varona ,&nbsp;Ralf Schwamborn","doi":"10.1016/j.marenvres.2025.107576","DOIUrl":"10.1016/j.marenvres.2025.107576","url":null,"abstract":"<div><div>In this study, we analyzed the effects of the record-strength 2015/16 “Godzilla” El Niño (EN), and subsequent extreme rainfall events (in 2017 and 2019) on local zooplankton communities in Tamandaré Bay, Brazil. Micro- and mesozooplankton (&gt;64 μm) samples and abiotic data were obtained in, approximately, four campaigns per year, from June 2013 to August 2019. Micro- and mesozooplankton abundance, composition, and environmental conditions (chlorophyll <em>a,</em> salinity, temperature, winds, river discharge, and water transparency), and the Tropical Southern Atlantic SST index (TSA) were analyzed in a seven-year time series study. Local rainfall in the rainy seasons of 2015 and 2016 was far below the seasonal average, leading to lower Una River discharge and more transparent water in Tamandaré Bay during the EN period. Conversely, there were extreme rainfall events in 2017 and 2019, which had conspicuous effects on several abiotic factors. The copepod <em>Euterpina acutifrons</em>, the ciliate <em>Favella ehrenbergii</em> and “other ciliates” displayed high abundances in the rainy season. The 2015/16 EN led to a community change in the study area. We observed high abundances during the Post-EN period for many zooplankton taxa. The abundance of ciliate <em>F. ehrenbergii</em> was high in the Post-EN period and showed strong positive correlations with Una River discharge and chlorophyll <em>a</em>, showing that this species was strongly affected by nutrient inputs due to the peak in Una River discharge. This approach permitted new insights into processes and drivers that shape the pelagic ecosystem in a tropical coastal pelagic ecosystem.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107576"},"PeriodicalIF":3.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155060","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":"Photosynthesis and photoprotection dynamics in cultured dinoflagellate Lingulaulax polyedra (formerly Lingulodinium polyedra)","authors":"Córdoba-Mena Noris ,&nbsp;López-Calderón Jorge ,&nbsp;Torres-Beltrán Mónica ,&nbsp;Ruíz-de-la-Torre Mary Carmen ,&nbsp;Camacho-Ibar Victor ,&nbsp;Olivos-Ortiz Aramis ,&nbsp;Montes-González Omar ,&nbsp;Ferreira-Arrieta Alejandra ,&nbsp;Gonzalez-Silvera Adriana","doi":"10.1016/j.marenvres.2025.107569","DOIUrl":"10.1016/j.marenvres.2025.107569","url":null,"abstract":"<div><div>The study of photosynthesis and the growth of phytoplankton organisms is important for a better understanding of primary productivity, especially in precursors of harmful algal blooms (HABs), such as the dinoflagellate <em>Lingulaulax polyedra</em> (formerly <em>Lingulodinium polyedra</em>)<em>.</em> The effect of nutrient availability (low concentration: 200.3/10.3 μM, medium: 280.5/14.8 μM, and high: 479.7/26.3 μM NaNO₃/NaH₂PO₄) and irradiance (50, 150, 300, and 750 μmol quanta m⁻² s⁻¹) on the growth rate (μ), photosynthetic efficiency (α), relative electron transport rate (rETR), pigment concentration and absorption coefficient in <em>in vitro</em> cultures of <em>L. polyedra</em> was analyzed. It was observed that μ did not vary with nutrient concentration or irradiance (p &gt; 0.05, AN), and the stationary growth phase was observed in all treatments on day 9 of cultivation. As irradiance increased, significant increase in photoprotective carotenoid pigments and a reduction in photosynthetic pigments were observed among treatments. <em>L. polyedra</em> showed the highest α during the stationary phase in treatments under 50 μmol quanta m⁻² s⁻¹ irradiance, with a value of 0.259 ± 0.005. Cultures did not show differences between nutrients, suggesting that the species-specific response to light availability depends on the growth phase. This study suggests <em>L. polyedra</em> adjusts its energy use based on irradiance, prioritizing growth in the exponential phase and optimizing photosynthesis for nutrient distribution in the stationary phase. This study contributes to understanding the species’ resilience at different irradiances and nutrient concentrations, which can help to understand the adaptations that allow it to potentially form harmful algal blooms (HABs).</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107569"},"PeriodicalIF":3.2,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118723","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":"Earlier onset of phytoplankton bloom in the Southern Bight of the North Sea in response to climate variability","authors":"Zixia Liu ,&nbsp;Ilias Semmouri ,&nbsp;Yunmeng Li ,&nbsp;Maarten De Rijcke ,&nbsp;Emmanuel Van Acker ,&nbsp;Colin R. Janssen ,&nbsp;Jana Asselman","doi":"10.1016/j.marenvres.2025.107570","DOIUrl":"10.1016/j.marenvres.2025.107570","url":null,"abstract":"<div><div>Phytoplankton are essential to marine ecosystems, driving biogeochemical cycles and supporting diverse marine species and systems. Shifts in bloom timing of these species can disrupt food webs and carbon cycling. This study investigates changes in the timing and composition of phytoplankton blooms in the Belgian Part of the North Sea (BPNS) and examines the environmental drivers behind these shifts. We analyzed data from 2018, 2019, and 2021, combining remote sensing, <em>in situ</em> measurements, flow imaging microscopy, and DNA metabarcoding to assess phytoplankton community structure and bloom phenology. Typically, two major annual blooms occur in this region: a mid-spring bloom dominated by <em>Phaeocystis globosa</em> and an early-summer diatom bloom primarily consisting of <em>Thalassiosira</em> species. In 2021, both blooms occurred approximately one month earlier than in 2018 and 2019. Contrary to expectations, this advance in blooming was not associated with higher sea temperatures or increased light availability (quantified by photosynthetically active radiation). Instead, we observed increases in phosphate concentrations and reductions in salinity preceding the blooms. These changes suggest that alterations in nutrient dynamics and salinity acted as bottom-up controls, triggering the earlier onset of phytoplankton blooms and supporting the Disturbance Recovery Hypothesis.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107570"},"PeriodicalIF":3.2,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105995","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":"Application of satellite and bio-argo float-based estimation of particulate organic carbon for ecosystem monitoring in the Arabian sea","authors":"S.R. Shahimol ,&nbsp;Rupam Kalita ,&nbsp;Aneesh Anandrao Lotliker","doi":"10.1016/j.marenvres.2025.107568","DOIUrl":"10.1016/j.marenvres.2025.107568","url":null,"abstract":"<div><div>Particulate organic carbon (POC) is an essential environmental parameter playing a crucial role in the biogeochemical carbon cycle. The present study estimates POC concentration, in the Arabian Sea, using satellite and bio-Argo float, providing time and three-dimensional space coverage. The satellite-derived POC concentration, using remote sensing reflectance, showed a good correlation (R² = 0.79) with the in-situ derived using backscattering coefficient, giving the confidence to combine these data for further analysis. Strong seasonality was observed in the surface and sub-surface distribution of POC concentration. During the southwest monsoon season, high POC concentration was observed along the coast primarily due to increased productivity by upwelling-induced nutrients. In contrast, during the northeast monsoon, higher POC concentration was observed in the northern Arabian Sea due to a boost in productivity due to nutrient influx through convective mixing. Although the POC concentration distribution was similar to chlorophyll-<em>a</em> (chl-<em>a</em>), their rate varied, as evident from the POC to chl-<em>a</em> ratio. The vertical distribution of POC concentration showed a remarkable Intermediate Nepheloid Layer (INL) between ∼200 and ∼400m, where suspended particle concentrations are higher than those in adjacent ocean layers. The INL was associated with high POC, low oxygen, and lower nitrate. The increase in subsurface POC may likely be due to the export flux and the associated low nitrate and high nitrite, below the thermocline and within the INL, under low oxygen, indicated the denitrification process. The significant findings from the study have enhanced the understanding of POC dynamics for effective monitoring of the ecosystem.</div></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":"212 ","pages":"Article 107568"},"PeriodicalIF":3.2,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155061","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}