Marine Environmental Research[JOURNAL]
Sun
200 papers
Regulated cell death (RCD) in hemocytes: Adaptive mechanisms to BDE-47 stress in marine mussel (Mytilus edulis).
Yang Y, Che Z, Liu Q … +5 more , Xu M, Jiang Y, Wang X, Wang Y, Zhou Z
Mar Environ Res · 2026 May · PMID 42172991 · Publisher ↗
Regulated cell death (RCD) serves as an important protective and adaptive mechanism for organisms under environmental stress. However, knowledge regarding the adaptation of marine mussels to environmental stress through...
Regulated cell death (RCD) serves as an important protective and adaptive mechanism for organisms under environmental stress. However, knowledge regarding the adaptation of marine mussels to environmental stress through RCD remains limited. In the present study, we investigated the types, roles, and mechanisms of regulated cell death (RCD) in hemocytes of the marine mussel Mytilus edulis in response to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a typical polybrominated diphenyl ether (PBDE) and persistent organic pollutant. Transmission electron microscopy observation combined with biochemical detection and transcriptome sequencing revealed that autophagy and apoptosis occurred in hemocytes and were differentially regulated under BDE-47 exposure. Autophagy played a predominant role in the maintenance of hemocyte survival under 0.1 μg/L (environmentally relevant concentration) and 1 μg/L BDE-47 exposure. However, apoptosis was dominant and mitochondrial was damaged with a decrease in ATP production when the exposure concentration increased to 10 μg/L. Combined transcriptomic and metabolomic analyses revealed that the main metabolic mechanism by which hemocytes maintain cell survival involves the release of glycolysis, TCA cycle and fatty acids through autophagy and increased fatty acid β-oxidation. The present study demonstrated the occurrence and role of multiple types of RCD in the hemocytes of Mytilus. edulis exposed to BDE-47, providing new insights into strategies of marine mussels against environmental pollution and the marine biotoxicity of polybrominated diphenyl ethers (PBDEs).
A global analysis of microplastics research: Mapping strategic funding, national research capacity, scientific priorities, and policy frameworks.
Hossain KB, Chen X, Ahammed MF … +12 more , Habib S, Tasnim J, Wang J, Hossain MS, Rani S, Ke H, Chen K, Zou L, Chen P, Charoengpong C, Ahmed MK, Cai M
Mar Environ Res · 2026 May · PMID 42172990 · Publisher ↗
This study examines socioeconomic factors shaping global microplastics research via bibliometric analysis of 18,863 papers (2004-2024), economic data, and a 428-expert survey. It reveals a rapidly growing yet geographica...
This study examines socioeconomic factors shaping global microplastics research via bibliometric analysis of 18,863 papers (2004-2024), economic data, and a 428-expert survey. It reveals a rapidly growing yet geographically and thematically disparate field, where research output correlates not with immediate pollution burden but with sustained national investment. China, with focused funding, leads at 26.73% of publications, while high-pollution, low-capacity regions in Southeast Asia and Africa are underrepresented, their national R&D spending often below the critical 0.5% of GDP threshold. The survey confirms this divides research focus: wealthier nations prioritize human health, cleanup technology, and advanced modeling, while poorer nations are often limited to basic monitoring. Experts collectively identified cleanup technology (28.90%) and human health effects (28.20%) as top future priorities. The study also flags key methodological barriers like absent standard procedures and poor exposure assessments, impeding reliable risk evaluation. In response, we propose a multi-tiered policy framework targeting the full plastic lifespan. Key proposals include sourcecentric rules (e.g., bans on intentionally added microplastics, extended producer responsibility), mandates for advanced wastewater treatment, and support for globally consistent monitoring techniques. The analysis demonstrates the current landscape is a product of deliberate policy and investment choices. Thus, bridging major knowledge and capacity gaps in the world's most affected and vulnerable regions is both an equity imperative and a prerequisite for developing effective, evidence-based, and globally coordinated solutions to the microplastics crisis.
Occurrence, sources, and risk assessment of organophosphate esters in surface water and surrounding seawater of Fildes Peninsula, Antarctica.
Li R, Gao H, Yang J … +3 more , Xu B, Liu X, Yao Z
Mar Environ Res · 2026 Apr · PMID 42172989 · Publisher ↗
Twenty Organophosphate Esters (OPEs) were investigated in seawater and surface water from Fildes Peninsula and its coastal area in Antarctic. In seawater, the concentration range of ΣOPEs was 8.66-97.29 ng/L (mean: 37.96...
Twenty Organophosphate Esters (OPEs) were investigated in seawater and surface water from Fildes Peninsula and its coastal area in Antarctic. In seawater, the concentration range of ΣOPEs was 8.66-97.29 ng/L (mean: 37.96 ng/L), with TCEP accounting for the highest proportion. In surface water (lake water), the concentration range of ΣOPEs was 9.93-40.16 ng/L (mean: 23.72 ng/L), with tris(1-chloro-2-propyl) phosphate (TCIPP) accounting for the highest proportion. Principal Component Analysis and correlation analysis indicated that OPEs in surface water primarily originated from long-range transport, whereas OPEs in seawater were mainly influenced by human activities, with ship traffic at local docks identified as one of the major sources. Ecological risk assessments revealed that the overall risk of OPEs in surface water was lower than that in seawater. Specifically, the seawater of Maxwell Bay and Great Wall Bay exhibited slightly higher OPEs risks than other regions, with medium-risk areas accounting for 78% and 60% of their respective sampling sites. Among all target OPEs, tris(2-ethylhexyl) phosphate (TEHP) posed the highest risk, generally falling into the low-to-moderate risk category (0.01 < Risk Quotient <1). Given the considerable inventory of OPEs in the waters of Fildes Peninsula, this study indicates that OPEs merit regional risk concern and further scientific evaluation for potential inclusion in the Stockholm Convention on Persistent Organic Pollutants (POPs).
Comparative analysis of the toxicity of fragmented and fibrous microplastics versus natural particles in the sea squirt Ciona intestinalis type A (Ciona robusta).
Saad R, Sekiguchi T, Takai Y … +7 more , Tsuruda Y, Kuroda S, Mizukami-Murata S, Lee S, Qiu X, Shimasaki Y, Oshima Y
Mar Environ Res · 2026 May · PMID 42172988 · Publisher ↗
Microplastics (MPs) are ubiquitous in marine environments and readily ingested by filter-feeding organisms, yet the ecotoxicological effects of irregularly shaped MPs remain poorly understood. This study assessed the acc...
Microplastics (MPs) are ubiquitous in marine environments and readily ingested by filter-feeding organisms, yet the ecotoxicological effects of irregularly shaped MPs remain poorly understood. This study assessed the accumulation and survival effects of aged fragmented polyethylene (afrPE), Nile red-stained afrPE (NR-afrPE), and fibrous polyethylene terephthalate (fiPET) following 168 h of exposure in Ciona intestinalis Type A (C. robusta), with spherical polystyrene (sPS) MPs and inorganic particles (IOPs) included for comparison. Among fragmented MPs, afrPE showed the highest toxicity at 30 and 100-μm (NOEC: 0.099 and < 0.100 mg L), whereas 10-μm afrPE showed no detectable toxicity (NOEC: 1 mg L). NR-afrPE showed a similar pattern (NOEC: 0.24 and < 0.099 mg L at 30 and 100-μm, respectively). FiPET showed intermediate toxicity (NOEC: 0.212 at 20-μm; 0.267 at 50-μm). In contrast, sPS (NOEC: >0.977->0.999 mg L) and IOPs (NOEC: 1 mg L) showed no detectable toxicity. MP accumulation was significantly influenced by concentration and particle size (p < 0.05), whereas survival was affected by concentration and particle shape (p < 0.05), with no significant size effect on toxicity (p > 0.05). These findings indicate that particle size influences accumulation, while toxicity is primarily governed by particle type and exposure concentration.
Trace element profiles in the plastisphere of marine microplastics: A comparison of dry and wet seasons.
Zhang J, Zhao C, Zhang K … +2 more , Xu S, Liu Y
Mar Environ Res · 2026 May · PMID 42172987 · Publisher ↗
Seasonal variations of trace elements in plastisphere are crucial for managing microplastic pollution and preserving marine ecosystems. The plastisphere plays an important role in regulating trace element accumulation on...
Seasonal variations of trace elements in plastisphere are crucial for managing microplastic pollution and preserving marine ecosystems. The plastisphere plays an important role in regulating trace element accumulation on microplastics, yet its seasonal dynamics remain insufficiently understood. This study investigated the variations in trace element concentrations and their sources in the plastisphere from eight sampling sites in coastal waters of Hong Kong during November 2020 and May 2021, representing dry and wet seasons, respectively. Environmental parameters were monitored, and trace elements were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Scanning electron microscopy (SEM) images revealed diverse marine organisms adhering to microplastic surfaces during the wet season. Results showed significant differences in trace element concentrations between internal (microplastic) and external (suspended particulate matter (SPM) and plankton) sources. Negative correlations were observed between plastisphere mass and trace elements, while specific surface area showed positive correlations with certain trace elements. External sources appeared to be the main contributors to trace elements in the plastisphere, although a contribution from the microplastic could not be ruled out for several elements (Cd, Pb, Sb, Zn) in the dry season.
Seasonal variation pattern in the co-occurrence networks and assembly processes of the fish communities in the northwestern Pacific.
Yan H, Li J, Shi W … +2 more , Wang Y, Tian Y
Mar Environ Res · 2026 May · PMID 42167158 · Publisher ↗
The northwestern Pacific (NWP) encompasses diverse oceanographic regimes, with the confluence of the warm Kuroshio and the cold Oyashio forming a seasonally shifting ecotone characterized by strong environmental contrast...
The northwestern Pacific (NWP) encompasses diverse oceanographic regimes, with the confluence of the warm Kuroshio and the cold Oyashio forming a seasonally shifting ecotone characterized by strong environmental contrasts that offers a unique natural laboratory to study marine biodiversity. However, the seasonal variation pattern and its drivers in the diversity of fish communities across the basin currently remain poorly understood. This study utilized environmental DNA (eDNA) metabarcoding to investigate seasonal variations in the diversity of fish communities at taxonomic, functional, and phylogenetic levels to assess the ecological processes shaping community assembly. Our findings reveal significant seasonal differences, with higher α diversity in summer, characterized by increased species richness, functional richness, and phylogenetic diversity, indicating increased primary productivity and favorable environmental conditions. β diversity results reveal that species turnover, rather than nestedness, plays the leading role in determining community structure, with greater turnover in summer influenced by dynamic oceanographic processes. Environmental factors, including net primary productivity and dissolved oxygen, show strong correlations with summer fish diversity, whereas geographic factors show a stronger association in autumn. Network analysis reveals stronger species interactions and greater ecological stability in summer, whereas lower connectivity and reduced network stability in autumn indicate increased susceptibility to disturbances. Additionally, stochastic processes, especially drift and dispersal limitation, were found to dominate fish community assembly across both seasons. These findings underscore the ecological importance of seasonal dynamics in the NWP, highlight mechanisms shaping fish biodiversity, and provide insights for season-specific conservation and sustainable fisheries management.
Stable isotope insights into the habitat use of two benthic invertebrates along Antarctic glacier-influenced fjords.
Bardi-Puigdefàbregas P, Bascur M, Barnes DKA … +6 more , Jenkins S, Muñoz-Ramírez CP, Rodríguez E, Brante A, Cardona L, Avila C
Mar Environ Res · 2026 May · PMID 42167157 · Publisher ↗
Retreating glaciers are rapidly transforming fjord ecosystems along the Western Antarctic Peninsula (WAP), yet the trophic responses of benthic fauna remain poorly understood. We analysed δC, δN, δS, and C:N ratios in tw...
Retreating glaciers are rapidly transforming fjord ecosystems along the Western Antarctic Peninsula (WAP), yet the trophic responses of benthic fauna remain poorly understood. We analysed δC, δN, δS, and C:N ratios in two soft-bottom species collected along distance gradients from retreating glaciers in two WAP fjords. The study included the deposit-feeding bivalve Nuculana inaequisculpta from Marian Cove (King George Island) and the opportunistic-feeding sea anemone Edwardsia sp. from Sheldon Cove (Adelaide Island). Near the land-terminating glacier at Marian Cove, bivalves were depleted in C, consistent with reduced phytoplankton growth under surface meltwater influence. Near the marine-terminating glacier at Sheldon Cove, anemones were C-enriched, in line with enhanced phytoplankton blooms driven by deep meltwater inflow. δN, δS, and C:N ratios showed no fjord-scale trends and appeared governed by local factors. Low δS values reflected suboxic sediment inputs in both fjords, possibly linked to denitrification and elevated δN baselines. When associated with blooms, anemones appeared to rely less on sedimentary sources while bivalves showed signs of sediment hypoxia. In both species, reliance on suboxic sediments was potentially related to poor nutritional condition. Environmental factors linked to submarine sills may have improved bivalve nutritional condition and increased anemone trophic level. Overall, benthic δS emerged as an excellent indicator in Antarctic marine habitats, and δC could be a tracer of productivity associated with glacier configuration in Antarctic fjords. Local meltwater conditions may limit organic matter flux to the benthos, nuancing the role of newly ice-free areas as carbon sinks within a negative climate feedback.
Transcriptomic regulatory mechanisms of Zostera caespitosa under different temperatures.
Jiang R, Cai L, Gao X … +7 more , Shen Y, Wu J, Shao L, Wu M, Wu H, Zhang J, He P
Mar Environ Res · 2026 Jul · PMID 42160893 · Publisher ↗
To investigate the molecular mechanisms of the aquatic plant Zostera caespitosa in response to temperature stress, this study analyzed its transcriptomic response characteristics under low and high temperature stresses....
To investigate the molecular mechanisms of the aquatic plant Zostera caespitosa in response to temperature stress, this study analyzed its transcriptomic response characteristics under low and high temperature stresses. Through transcriptome sequencing of Z. caespitosa under 5 °C (low temperature) and 25 °C (high temperature) treatments, combined with GO functional annotation and enrichment analysis, KEGG pathway enrichment analysis, and WGCNA gene co-expression network analysis, we systematically dissected the functions of differentially expressed genes (DEGs) and their associations with phenotypic traits. The results showed significant differences in the response strategies of Z. caespitosa to low and high temperatures. At 5 °C, gene expression regulation focused on enhancing membrane stability (e.g., enriched in membrane components and linoleic acid metabolism) and protein processing, while suppressing energy-consuming processes such as ribosome biogenesis and photosynthesis. At 25 °C, the response features involved activation of brassinosteroid biosynthesis, hormone signal transduction, and other growth-related pathways, with photosynthesis-related genes also suppressed. WGCNA analysis further identified MEred and MEturquoise as two key co-expression modules, where the MEred module was significantly positively correlated with biomass and photosynthetic parameters and specifically upregulated under high temperature, revealing the important role of core gene networks in coordinating growth and stress responses. This study systematically revealed the complex transcriptomic regulatory network of Z. caespitosa in response to temperature stress, providing an important molecular basis for a deeper understanding of stress resistance mechanisms in aquatic plants.
Effects of sediment on a rocky intertidal habitat-forming species and its harboured invertebrate assemblages.
Veiga P, Torres AC, Sousa-Pinto I … +1 more , Rubal M
Mar Environ Res · 2026 Jul · PMID 42160892 · Publisher ↗
Sedimentation in rocky shores occurs through natural processes, but it is rising globally due to anthropogenic activities. However, few studies have assessed sediment effects on habitat-forming species and its harboured...
Sedimentation in rocky shores occurs through natural processes, but it is rising globally due to anthropogenic activities. However, few studies have assessed sediment effects on habitat-forming species and its harboured assemblages. To fill this knowledge gap, the mussel Mytilus galloprovincialis was considered as model habitat-forming to evaluate differences associated with varying sediment loads on mussel density and its invertebrate assemblages harboured. Field data were obtained at two non-urban intertidal rocky shores in the Northern Portuguese coast. First, the relationship between sediment load in mussel clumps and the associated invertebrate assemblages was examined in terms of abundance, richness, Pielou and Shannon indexes and multivariate structure. Then, mussel clumps with low and high sediment load were selected at each rocky shore to test differences on density and size of mussels and assemblage descriptors between them. Sediment on mussels was composed by very coarse and coarse sand and showed a patchy distribution, but density and size of mussels were unaffected by sediment. Our results suggest significant effects of sediment on invertebrate assemblage associated with mussels specifically, decreasing evenness and heterogeneity of assemblages by favouring species tolerant to sediment (annelids, copepods and nematodes) and reducing the abundance of grazers and Nucella lapillus. As grazers and N. lapillus are considered keystone species, changes on them may trigger cascading effects on rocky shore ecosystems. Our results highlight that even sedimentation derived from natural processes may impact intertidal biodiversity, which should be considered when managing coastal interventions specially in the current global change framework that probably will exacerbate sedimentation.
Nitrogen limitation enhances Irgarol 1051 toxicity by aggravating PSII photoinhibition in the marine diatom Thalassiosiraweissflogii.
An Y, Zeng S, Li F … +4 more , Wang J, Zhu X, Xu J, Wu Y
Mar Environ Res · 2026 Jul · PMID 42160891 · Publisher ↗
Irgarol 1051, a potent photosystem II (PSII)-inhibiting antifouling biocide, continues to pose significant hazards to marine primary producers as a legacy pollutant. Conventional laboratory toxicity assessments are typic...
Irgarol 1051, a potent photosystem II (PSII)-inhibiting antifouling biocide, continues to pose significant hazards to marine primary producers as a legacy pollutant. Conventional laboratory toxicity assessments are typically conducted under nutrient-replete conditions, which may fail to capture the exacerbated risks in coastal environments where nitrogen availability fluctuates. This study investigated the modulation of Irgarol 1051 phototoxicity by nitrogen availability in the marine diatom Thalassiosira weissflogii. Cells were exposed to factorial combinations of nitrogen (Low: 10 μmol L; High: 100 μmol L) and environmentally relevant Irgarol concentrations (0.2 and 0.4 μg L). Results demonstrated that nitrogen limitation significantly amplified Irgarol-induced inhibition across all physiological endpoints. Low nitrogen availability led to stronger reductions in growth rate, chlorophyll-a content, and effective quantum yield (QY) compared to high-nitrogen conditions. Specifically, relative QY inhibition reached 58% under low nitrogen but only 45% under high nitrogen at the highest concentration. Analysis of rapid light curves (RLCs) further revealed that nitrogen limitation exacerbated the suppression of maximum relative electron transport rate (rETR). Two-way ANOVA confirmed significant synergistic interactions between nitrogen and Irgarol on most parameters. These findings suggest that nitrogen deficiency may weaken the physiological resilience of diatoms to PSII inhibitors, possibly by impairing cellular repair capacity including D1 protein turnover. This study highlights a critical need to incorporate nutrient status into ecological risk assessments to avoid underestimating the hazards of triazine pollutants in nitrogen-limited coastal waters.
Assessing recent anthropogenic carbon dioxide and acidification in the Ross Sea, Antarctica.
Mo A, Kim TW, Jung J … +7 more , Kim TW, Choi JO, Kim Y, La HS, Park J, Kim KH, Park K
Mar Environ Res · 2026 Jul · PMID 42160890 · Publisher ↗
Over the past decade, the East Ross Sea has experienced a significant decline in sea ice, enabling direct observational studies of regional carbon dynamics. The accumulation rate of anthropogenic CO in the East Ross Sea...
Over the past decade, the East Ross Sea has experienced a significant decline in sea ice, enabling direct observational studies of regional carbon dynamics. The accumulation rate of anthropogenic CO in the East Ross Sea is up to six times higher than the long-term Industrial Era mean due to the inflow of seawater from the Amundsen Sea by accelerated glacial melting. In contrast, the West Ross Sea exhibited comparatively smaller changes. Measurements of dissolved inorganic carbon and stable carbon isotope indicate that, over the period 2011-2020, changes in δC (Suess effect) and anthropogenic CO were 0.20 ± 0.06‰ and -5 ± 2 μmol kg in the West Ross Sea, and -0.15 ± 0.01‰ and 9 ± 1 μmol kg in the East Ross Sea. These findings suggest rapid acidification in the East Ross Sea, with aragonite undersaturation likely to occur by the mid-2030s, accompanied by an expected pH decrease of ∼0.2 units by the end of the century.
Testing a new approach to quantify intracellular trace metal contents in microphytoplankton using sequential selective extraction.
Layglon N, Izard P, Del Amo Y … +4 more , Dutour C, Gorse-Labadie L, Schäfer J, Coynel A
Mar Environ Res · 2026 Jul · PMID 42160889 · Publisher ↗
Current methodologies used to quantify intracellular trace metal (TM) contents in microphytoplankton rely on the assumption that samples consist exclusively of phytoplankton cells, with no contribution from inorganic par...
Current methodologies used to quantify intracellular trace metal (TM) contents in microphytoplankton rely on the assumption that samples consist exclusively of phytoplankton cells, with no contribution from inorganic particles. Therefore, the present study aimed to propose a sequential selective extraction protocol for suspended particulate matter that preserve the cellular integrity of phytoplankton until the final Aqua Regia extraction. Seawater was collected in the Arcachon Bay and filtered through polycarbonate membranes (PC; Isopore™, 2 μm pore size). These membranes were put in contact with various extractants to isolate specific TM fractions. A subset of membranes was used for observation with scanning electron microscope (SEM) to assess the impact of the extractants on phytoplankton integrity. Among the tested solutions (i.e. ascorbate, 0.1 M NaOH, hydrogen peroxide, EDTA, 1 M HCl), only hydrogen peroxide was found to be destructive for the phytoplankton cells. Accordingly, a four-step sequential extraction was established: (1) ascorbate solution, (2) 0.1 M NaOH, (3) EDTA, (4) 1 M HCl, in order to selectively remove TM associated with inorganic phases or organic matter. Subsequently, PC membranes were digested by Aqua Regia to break down the phytoplankton cells and quantify the intracellular TM contents. The established protocol proves to be robust and effective to quantification the minimal TM content in diatoms and silicoflagellates cells. Results showed that Al, V, Mn, Fe, Cu, As, Pb, and Th were present in low proportion in the Aqua Regia solution (less than 20 % of the total content), suggesting limited internalization. In contrast, Cr (93 ± 3 %), Co (74 ± 23 %), and Ni (79 ± 17 %) fractions were dominantly present in the intracellular fraction suggesting they play major roles in TM biogeochemical cycles involving phytoplankton.
Phytoplankton responses to marine heatwaves in the Kuroshio-Oyashio Extension region: Seasonal variations and potential drivers.
Zhang H, Wang N, Chen Y … +3 more , Lian P, Hao Z, Li X
Mar Environ Res · 2026 Jul · PMID 42160888 · Publisher ↗
In the Kuroshio-Oyashio Extension (KOE) region, increasing marine heatwaves (MHWs) are significantly impacting marine ecosystems and socio-economic systems. Based on satellite and Argo data, this study employs composite...
In the Kuroshio-Oyashio Extension (KOE) region, increasing marine heatwaves (MHWs) are significantly impacting marine ecosystems and socio-economic systems. Based on satellite and Argo data, this study employs composite analysis to assess MHW characteristics and their influence on phytoplankton biomass. MHWs are more intense and prolonged in the upstream KOE than the downstream, with long-term events showing a marked rise since 2017 at a rate of 13 days/year. Overall, MHWs inhibit phytoplankton growth, with long-term MHWs suppressing biomass by 28% more than short-term events. Spatially, the most pronounced reduction occurs upstream (up to -40%), where warming reinforces the northern oceanic front, limiting southward nutrient transport from subarctic waters and promoting the intrusion of nutrient-poor Kuroshio water. Downstream responses exhibit distinct seasonal patterns: spring biomass can increase by more than 20% under sufficient light, temperature, and nutrients. In contrast, other seasons exhibit reductions due to nutrient limitation, most sharply in autumn (reaching -37%) owing to northward Ekman transport anomalies. Summer responses are moderated by weaker upwelling and stronger stratification, whereas winter responses remain weak but are strengthening, influenced by background nutrients, Ekman transport, and upwelling. These findings advance understanding of MHW ecological impacts in western boundary current regions and support fisheries management under ongoing ocean warming.
Phytoplankton community composition in a subtropical semi-enclosed bay: Influence of the river discharge and oyster farming.
Chen D, Zhao K, Shi Z … +3 more , Li X, Jiang Z, Xu J
Mar Environ Res · 2026 Jul · PMID 42156207 · Publisher ↗
The Pinglu Canal Waterway construction, one of the largest river-sea canal projects in China, will be fully operational by the end of 2026, which is expected to increase the river discharge to the Maowei Sea. Two field i...
The Pinglu Canal Waterway construction, one of the largest river-sea canal projects in China, will be fully operational by the end of 2026, which is expected to increase the river discharge to the Maowei Sea. Two field investigations were conducted in winter 2021 and summer 2022 to explore effect of the river discharge and oyster farming on phytoplankton community composition and diversity in the Maowei Sea with intensive oyster farming. Our results showed that seasonal river discharge and oyster farming mediated remarkably the phytoplankton community composition. Oyster farming reduced the biomass of micro-sized phytoplankton, and mediated the phytoplankton community composition by selectively feeding on micro-sized Bacillariophyta. In winter, micro-sized Bacillariophyta was the predominant phytoplankton species and oyster feeding enhanced phytoplankton diversity, while freshwater nano-sized Cyanophyta dominated due to high flow of river discharge and oyster feeding reduced the phytoplankton diversity in summer. Our results revealed the links between phytoplankton community composition, seasonal river discharge and intensive oyster farming and provide baseline data on phytoplankton community and environmental variables to assess the ecological impact of the Pinglu Canal Waterway in the future, which was useful for formulating effective environmental management strategies.
Unlocking fine-scale temporal dynamics of coral reef health: a multi-kingdom microbial fingerprinting approach across seawater and sediment.
Stenger PL, Tribollet A, Cuet P … +6 more , Guilhaumon F, Mangion P, Bureau S, Ferreira S, Pennober G, Jourand P
Mar Environ Res · 2026 Jul · PMID 42156206 · Publisher ↗
Coral reefs are rapidly degrading worldwide, creating a need for sensitive biomonitoring tools to detect early ecological shifts before visible collapse. Traditional monitoring often misses these incipient changes. We hy...
Coral reefs are rapidly degrading worldwide, creating a need for sensitive biomonitoring tools to detect early ecological shifts before visible collapse. Traditional monitoring often misses these incipient changes. We hypothesized that multi-kingdom microbial fingerprinting could reveal fine-scale temporal dynamics and early bioindicators of reef environmental change. The study was conducted on the fringing reef of Réunion Island (south-west Indian Ocean), a system exposed to local anthropogenic pressures. Seawater and sediment samples were collected bimonthly from April to October 2022 at three reef sites. Bacterial (16S rRNA), fungal (ITS2), microalgal (TufA), and protistal (18S rRNA) communities were characterized using metabarcoding. Physicochemical parameters were integrated via multivariate analyses. Time emerged as a stronger structuring factor than space. Bayesian analyses identified 368 temporally associated ASVs (Amplicon Sequence Variant), revealing microbial succession patterns. Bacterial communities shifted from Pseudomonadota-dominated assemblages (April) to Bacteroidota-dominated communities later in the year, with recurring ASVs (e.g., Pseudohongiella, Neptuniibacter caesariensis, Mycobacterium). Fungal communities showed marked temporal fluctuations, including recurrent peaks of potentially pathogenic genera (Aspergillus, Candida, Ramichloridium). Microalgal assemblages were habitat-structured (Chlorophyta in seawater, Rhodophyta in sediments), while protists communities exhibited pronounced late-season shifts, including dinoflagellate enrichment in October. Measured physicochemical parameters explained only a limited fraction of community variability, suggesting a strong role for biological interactions and unmeasured drivers. These findings highlight the sensitivity of high-resolution, multi-kingdom microbial fingerprinting for detecting early-warning bioindicators, outperforming traditional low-frequency monitoring. This study provides a robust, transferable framework for proactive coral reef biomonitoring and ecosystem management under increasing anthropogenic pressure.
Allometric shell scaling drives body size-dependent shifts in preference and performance in a hermit crab.
Alcaraz G, Burciaga LM
Mar Environ Res · 2026 Jul · PMID 42156205 · Publisher ↗
As animals develop and increase in body size, they often shift the value they place on specific resources. Such shifts can also arise because resource traits change allometrically with size. With increasing body size, th...
As animals develop and increase in body size, they often shift the value they place on specific resources. Such shifts can also arise because resource traits change allometrically with size. With increasing body size, the hermit crab Calcinus californiensis shifts from assigning similar value to several shell species to exhibiting a strong preference for conical shells. In this study, we evaluated how allometric changes in shell mass and internal volume influence the functional costs of using a conical versus a globose shell species, and how these costs relate to shifts in shell preference. We found that key shell traits differ as they increase in size; conical shells gain mass at a higher rate than globose shells relative to their internal volume. As such, small hermit crabs carry similar shell mass in both shell types, while larger individuals must carry much heavier conical shells to obtain the same internal volume as globose shells. Consequently, metabolic rate and muscular strength show shallower scaling with body size in hermit crabs occupying conical shells than in those using globose shells. Therefore, the costs and benefits of using each shell type are similar at small sizes but progressively diverge as hermit crabs grow, leading to size-dependent shifts in shell preference. Our findings suggest that preference for shell species can be a potentially adaptive plastic process shaped by the allometric scaling of both hermit crab physiology and gastropod shell morphology.
Elevated suspended particulate matter reorganises carbon fraction in mangrove ecosystems.
Cheng D, Li D, Yang S … +6 more , Zhang X, Zhang Q, Li J, Liu J, Mao Y, Xiao Y
Mar Environ Res · 2026 Jul · PMID 42156204 · Publisher ↗
Mangrove wetlands are a core component of blue carbon ecosystems worldwide. Elevated suspended particulate matter (SPM) in natural waters is a ubiquitous environmental stressor, yet its effects on the carbon cycling of m...
Mangrove wetlands are a core component of blue carbon ecosystems worldwide. Elevated suspended particulate matter (SPM) in natural waters is a ubiquitous environmental stressor, yet its effects on the carbon cycling of mangroves remain poorly unelucidated. Here, we conducted a 90-day microcosm experiment using Kandelia obovata and integrated high-resolution chemical and biological profiling to systematically elucidate how SPM loading affects mangrove carbon-cycling processes. As SPM increased from 0 to 30 mg/L, the photosynthetic activity of phytoplankton declined, accompanied by suppressed Calvin-Benson-Bassham-cycle signatures and a relative enrichment of glycolysis- and TCA-related signatures, resulting in a 0.71 mg/L increase in dissolved inorganic carbon (DIC) and a 1.12 mg/L decrease in dissolved organic carbon (DOC) on day 90. Concurrently, suppressed sediment β-glucosidase activity contributed to a 1.76 mg/g increase in sediment organic carbon (SOC). As SPM further increased from 30 to 70 mg/L, strengthened autotrophic carbon fixation and attenuated heterotrophic carbon oxidation in the water column contributed to a 2.45 mg/L decrease in DIC and a 0.30 mg/L increase in DOC. Excessive SPM load compromised the antioxidant defence system of mangroves, leading to oxidative damage in mangrove plants, thereby reducing photosynthetic activity, while sediment β-glucosidase activity increased, collectively resulted in a 1.20 mg/g decrease in SOC. Our results indicate that elevated SPM reorganises carbon composition within mangrove wetlands, with potential implications for global-scale carbon cycling, underscoring the importance of incorporating SPM as a key agent forcing in the management of blue carbon ecosystems.
PFAS contaminants in surface waters, effluents, sediments and coastal food webs off the Solent coastline UK.
Obanya HE, Ginley F, Payne MR … +1 more , Ford AT
Mar Environ Res · 2026 Jul · PMID 42151005 · Publisher ↗
Per- and polyfluoroalkyl substances (PFAS) are persistent coastal contaminants. Their distribution across environmental compartments and food webs remains poorly understood. The Solent is a densely urbanised tidal strait...
Per- and polyfluoroalkyl substances (PFAS) are persistent coastal contaminants. Their distribution across environmental compartments and food webs remains poorly understood. The Solent is a densely urbanised tidal strait representative of industrialised coastal systems. Inputs from wastewater treatment plants, combined sewer overflows, and historic landfills create multiple PFAS pathways to the marine environment. We integrated our collected field samples (including surface waters, n = 3; and multiple biota species collected in triplicate) with regulatory monitoring datasets (sediment and archived biota) and wastewater effluent records to quantify PFAS across surface waters, sediments, treated wastewater effluent, and marine biota from the Solent. In sediments, ΣPFOS was present at the highest mean concentrations, at 0.5 μg kg dry weight. Surface waters and effluents contained a broader mixture of short- and long-chain PFAS. Mean ΣPFOS concentrations in surface water reached 8.5 ng L, exceeding the UK/EU environmental quality standard for coastal waters (0.65 ng L). Treated effluent contained several short-chain PFAS, including PFHxA, PFBA, and PFBS, at mean concentrations of 1.3-5.9 ng L. PFOA (3.1-4.0 ng L) and PFOS (5.7-7.2 ng L) were also consistently detected. In biota, ΣPFOS exceeded the biota EQS (9.1 μg kg wet weight) only in harbour porpoise liver, with a mean concentration of 341.39 μg kg. However, when expressed as PFOA-equivalents using EU relative potency factors (RPFs), most of the biota samples exceeded the EFSA benchmark of 77 ng/kg. However, twenty-three samples from Langstone harbour had no detectable PFAS. Multivariate analyses showed that PFAS composition varied among species but was not associated with literature-based trophic grouping (PERMANOVA R = 0.058, p > 0.05). Although ecological EQS exceedance was limited to PFOS in specific matrices, application of RPFs revealed widespread exceedance of mixture-based health benchmarks. These findings demonstrate that reliance on single-compound regulatory thresholds may underestimate cumulative PFAS risk in UK coastal systems. A mixture-based toxic equivalency approach exposes potential regulatory blind spots in current PFAS assessment frameworks.
Taxonomic and functional diversity patterns of nematode assemblages in a semi-enclosed coastal system (Pagasitikos gulf, Central Aegean Sea).
Voulgaris K, Varkoulis A, Vafidis D
Mar Environ Res · 2026 Jul · PMID 42150322 · Publisher ↗
Taxonomic and functional diversity patterns of nematode assemblages were examined in a trawl-restricted gulf (Pagasitikos Gulf, Central Aegean Sea). The goal was to determine the drivers that structure nematode communiti...
Taxonomic and functional diversity patterns of nematode assemblages were examined in a trawl-restricted gulf (Pagasitikos Gulf, Central Aegean Sea). The goal was to determine the drivers that structure nematode communities and examine whether functional approaches add information beyond taxonomic patterns. Samples were taken from 36 stations across three nutrient zones and genus-level abundances were combined with categorical traits to calculate taxonomic and functional indices. Environmental drivers were examined using multivariate analyses, including RLQ ordination, variance partitioning, null models, and generalized additive models of functional groups. Genus richness, Shannon diversity, Rao's Q, functional dispersion, functional richness and maturity index differed among zones and these differences remained significant after accounting for depth. The lower external zone contained 76.71% of the total genus pool and 82.69% of the total functional entity pool, whereas the upper external zone showed the lowest representation (27.4% of genera and 30.77% of functional entities). Functional space occupancy was high in both the inner gulf (92.89%) and lower external zone (90.63%), but lower in the upper external zone (70.74%). RLQ showed poor fit between single traits and abiotic variables, whereas trait complexes were better responses to environmental gradients. The upper external zone exhibited the worst ecosystemic condition, associated with nematode genera that belonged to trophic group 2A, heavily annulated cuticle, capsulated head and very complex amphids. These findings show that ecological zonation captures community structure better than depth alone and that functional patterns largely mirror taxonomic structure, while providing additional context on redundancy, vulnerability, and the distribution of ecological strategies. The combination of moderate functional redundancy and localized functional vulnerability suggests uneven resilience across zones, with lower-quality areas showing reduced functional representation and increased sensitivity to disturbance. This combined taxonomic-functional approach strengthens benthic assessment in coastal systems.
Reductions of dry atmospheric inorganic nitrogen deposition and carbon uptake in the Yellow Sea of the Northwestern Pacific Ocean for the COVID-19 period.
Park CU, Bae S, Kim HS … +7 more , Yang D, Kim TW, Ko YH, Lee MH, Kim Y, Khondaker S, Kim H
Mar Environ Res · 2026 Jul · PMID 42150321 · Publisher ↗
Rapid population growth and industrialization in Northeast Asian countries have led to excessive atmospheric nitrogen (N) inputs into the Yellow Sea and the Northwestern Pacific Ocean. Given its location between China an...
Rapid population growth and industrialization in Northeast Asian countries have led to excessive atmospheric nitrogen (N) inputs into the Yellow Sea and the Northwestern Pacific Ocean. Given its location between China and the Korean Peninsula, the Yellow Sea is influenced by anthropogenic emissions from both regions and receives substantial N deposition, which may enhance primary productivity. We monitored dry inorganic N (nitrate; NO and ammonium; NH) deposition and analyzed the isotopic compositions of δN- and δO-NO, δC-total carbon (TC), and δN-total nitrogen (TN) in total suspended particle (TSP) samples collected before the COVID-19 (2018) and during the COVID-19 (2021-2022). Reduced human activities such as vehicle exhaust and coal combustion led to a decrease in dry inorganic N deposition from 2.6 mmol N m month in 2018 to 1.4 mmol N m month in 2021-2022. Based on the estimated conversion of deposited N to C, C uptake by phytoplankton in the Yellow Sea decreased by 21.2 to 34.0 Gg C month during 2021-2022 compared to 2018. Our findings indicate that future reductions in N emissions and deposition may affect the ocean's capacity to absorb C.
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