Marine Environmental Research[JOURNAL]
Sun
200 papers
Transport and distribution patterns of floating marine litter: Numerical modeling and AI-empowered solutions.
Yishan W, Junsen Z, Zirui Z … +4 more , Hengxiang L, Honglei J, Kefu Y, Xiangrong X
Mar Environ Res · 2026 Jul · PMID 42143964 · Publisher ↗
Floating marine litter (FML) has emerged as a central priority in global ocean governance. Thoroughly deciphering the spatiotemporal evolutionary mechanisms of its "source-sink" system is fundamental to formulating scien...
Floating marine litter (FML) has emerged as a central priority in global ocean governance. Thoroughly deciphering the spatiotemporal evolutionary mechanisms of its "source-sink" system is fundamental to formulating scientifically robust management strategies, with numerical modeling acting as the core technical tool for quantifying this complex process. This study systematically reviews a decade of research on FML transport simulations, detailing the technical characteristics and applicable scenarios of Eulerian and Lagrangian methods. It clarifies the dynamic drivers and final fate characteristics of FML transport across all scales-from the global ocean and marginal seas to estuarine and coastal zones. It indicates that while phased breakthroughs have been made in existing studies, common bottlenecks persist-including the precise parameterization of complex physical processes, coupled sea-air-particle multiphase interactions, effective assimilation of sparse observational data, and the challenge of defining initial and boundary conditions related to FML sources. In light of these challenges, this study focuses on exploring pathways for the deep integration of artificial intelligence (AI) with traditional numerical models. Drawing on established AI applications in marine environmental forecasting, this study delves into the unique advantages of data-driven methods in capturing nonlinear characteristics of marine debris transport and enhancing computational efficiency. This research aims to provide critical technological guidance for developing a high-precision, intelligent monitoring and early warning system for FML.
How the Mediterranean mussel Mytilus galloprovincialis responds to multiple environmental challenges: Vibrio splendidus and hydrocarbon mixture.
Bertini F, Bisanti L, La Corte C … +8 more , Dara M, Staropoli M, Marcianò LT, Santaluna G, Bouzaiene O, Parrinello D, Cammarata M, Parisi MG
Mar Environ Res · 2026 Jul · PMID 42143963 · Publisher ↗
Marine organisms are exposed to a wide range of environmental stressors and must develop adaptive responses to survive. This study investigated how Mytilus galloprovincialis responds to chemical and biological stress, bo...
Marine organisms are exposed to a wide range of environmental stressors and must develop adaptive responses to survive. This study investigated how Mytilus galloprovincialis responds to chemical and biological stress, both separately and simultaneously. Mussels were exposed for 4 days to a hydrocarbon mixture (diesel + oil engine) and then injected with Vibrio splendidus. Six hours post-injection, responses were assessed by measuring phagocytosis, several immune-related enzymes (lysozyme, phenoloxidase, glutathione peroxidase) and chaperonins (HSP70, HSC70) activities. The contact with the pathogen enhanced phagocytic activity, whereas hydrocarbon mixture inhibited it, confirming hemocytes' sensitivity to environmental stress. Immune-related enzymes measured in plasma, adductor muscle, and digestive gland modulated their activity with particular emphasis on mussels subjected to multiple stress, indicating their involvement in maintaining homeostasis under stressful environmental conditions. Furthermore, chaperonins showed significantly higher values after all treatments. In conclusion, both the pathogen challenge and the hydrocarbon mixture (separately and simultaneously) influenced the parameters considered in the different tissues, suggesting their potential additive effect on M. galloprovincialis. These findings can confirm the importance of M. galloprovincialis as a valuable bioindicator for studying adaptive mechanisms to multiple stressors and assessing marine environmental health.
From juveniles to adults: Ontogenetic and seasonal patterns of loggerhead turtles in oceanic Mediterranean habitats.
Pasanisi E, Maffucci F, Atzori F … +21 more , Azzolin M, Campana I, Carosso L, Castelli A, Costantino M, David L, Di-Méglio N, Farina M, Garcia-Garin O, Gregorietti M, Grossi F, Hochscheid S, Pace DS, Pecoraro M, Roul M, Santini E, Tepsich P, Teti R, Vighi M, Vitale M, Arcangeli A
Mar Environ Res · 2026 Jul · PMID 42143962 · Publisher ↗
The loggerhead turtle (Caretta caretta), one of the most widespread and ecologically significant megafauna species in the Mediterranean, exhibits ontogenetic shifts in spatial distribution and habitat use throughout its...
The loggerhead turtle (Caretta caretta), one of the most widespread and ecologically significant megafauna species in the Mediterranean, exhibits ontogenetic shifts in spatial distribution and habitat use throughout its life cycle, which further vary under different seasonal environmental conditions. However, how ontogeny and seasonality jointly shape the large-scale use of oceanic habitats remains poorly understood. Most research has focused on coastal areas, while the oceanic habitats, crucial for development, foraging, and migration have received comparatively limited attention. We investigated the spatial and seasonal patterns of oceanic loggerhead turtles in the Western Mediterranean and Adriatic Seas using standardized ferry-based surveys conducted between 2019 and 2024 within the LIFE CONCEPTU MARIS and FLT Med Net projects. For the first time at this large-scale, individuals were consistently assigned to three life stages (early juveniles, late juveniles, adults), enabling robust ontogenetic comparisons across seasons through multivariate analyses and stage-specific Species Distribution Models. Environmental associations partially overlapped among life stages but varied consistently with ontogeny and season, with differentiation being most pronounced in spring and autumn. Early juveniles were associated with warm, productive, and dynamic waters, whereas adults occurred mainly in deeper and more thermally stable offshore habitats. Late juveniles showed broader and more variable associations, often occupying transitional shelf-oceanic zones influenced by mesoscale activity. Across the basin, the Algerian, Tyrrhenian, and Adriatic regions emerged as recurrent offshore areas used by multiple life stages, although their spatial extent and seasonal importance varied among stages. By integrating ontogeny and seasonal perspectives, this study refines the understanding of loggerhead turtle spatial ecology in the Mediterranean and identifies persistent offshore areas of conservation relevance, supporting the need to extend management beyond coastal ecosystems.
Blue light stimulates the release of humic-like substances in a marine diatom Thalassiosira pseudonana.
Chen B, Liu J, Xu G … +5 more , Chen X, Zhao W, Yang X, Ren H, Li G
Mar Environ Res · 2026 Jul · PMID 42139988 · Publisher ↗
Differential attenuation of various wavebands of solar irradiation makes the blue light spectrum (450-495 nm) to dominate the middle and lower euphotic zones of the oceans, where maximum phytoplankton biomass is often pr...
Differential attenuation of various wavebands of solar irradiation makes the blue light spectrum (450-495 nm) to dominate the middle and lower euphotic zones of the oceans, where maximum phytoplankton biomass is often present. Yet, how these primary producers adjust their cellular composition and the release of dissolved organic matter (DOM) under such light conditions remains unclear, despite potential effects on marine biogeochemical cycles. In this study, we cultivated a model diatom Thalassiosira pseudonana under combinations of light intensity (optimal vs. limited) and light quality (white vs. blue) to investigate the effects of blue light on cellular metabolism and DOM characteristics across growth phases. Results showed that blue light increased the growth rate during the exponential phase by 10% at optimal light and by 12% at limited light, which is related to pigment reprogramming and increased particulate organic carbon (POC) content. Meanwhile, blue light increased dissolved organic carbon (DOC) concentration within the cultures at both optimal and limited light, with maximal enhancements in ΔDOC of 244% and 211% during the exponential phase, respectively. We identified five DOM components using excitation-emission matrix spectroscopy (EEMs) and found that cells under blue light convert a tryptophan-like component into two humic-like substances with lower molecular weight and rich in carboxyl and amino groups, ultimately doubling the humification index (HIX). This may be related to the phenomenon of "photosynthetic overflow" under blue light. Our results indicate that phytoplankton might contribute substantially more to the marine recalcitrant dissolved organic carbon (RDOC) pool than previously recognized.
Relationship between the microplastics in typical marine organisms and the environment: A case study in Bohai Bay, China.
Zheng Y, Zhang Y, Yan ZG … +4 more , Tang C, Wang X, Li Y, Zhang H
Mar Environ Res · 2026 Jul · PMID 42139987 · Publisher ↗
Microplastics are widely distributed in the marine environment, and the impact on organisms is worthy of attention. This study focused on the Bohai Bay as the research area, aiming to gain a deeper understanding of the r...
Microplastics are widely distributed in the marine environment, and the impact on organisms is worthy of attention. This study focused on the Bohai Bay as the research area, aiming to gain a deeper understanding of the relationship between the distribution of microplastics in organisms and the environment as well as their feeding methods. The average abundance of microplastics in the water was 1.83 ± 0.54 items/L at 16 sampling sites in the Bohai Bay. The abundance of microplastics in different organisms and different tissues varied. The abundance of microplastics in the gastrointestinal tracts (4.4 ± 0.7 items/ind., 5.5 ± 0.2 items/g) of predatory fish was higher than that in their gills (2.2 ± 0.8 items/ind., 5.8 ± 1.0 items/g). The polymer types of microplastic in organisms were all present in seawater, including rayon, PET, polyester and PE. Fibrous microplastics were the main shape type in both seawater and organisms, accounting for more than 70.0%. Microplastics smaller than 0.5 mm accounted for the highest proportion, being 43.2% in seawater and 76.5% in organisms. The microplastics size fraction in seawater sample was basically consistent with the microplastics in wild marine organisms. In particular, the abundance, shape, size, color and polymer type distribution patterns of microplastics in filter-feeding mussels was more closely resembled those in seawater. The results revealed that the biological uptake mechanisms suggested by the tissue-specific correlations.
Approaches to the methodological standards in the use of Aurelia Lamarck (1816) (Cnidaria, Scyphozoa) as a model organism in bioassays and experimental applications.
das Neves LO, Morales MLP, Soroldoni S … +2 more , Nagata RM, Pinho GLL
Mar Environ Res · 2026 Jul · PMID 42139986 · Publisher ↗
The use of the jellyfish Aurelia has expanded considerably across marine research, including in ecotoxicology, physiology, biotechnology, and environmental assessment. Despite this growing interest, methodological approa...
The use of the jellyfish Aurelia has expanded considerably across marine research, including in ecotoxicology, physiology, biotechnology, and environmental assessment. Despite this growing interest, methodological approaches vary widely, which can limit the comparability and reproducibility of results. In this review, we compiled and evaluated 46 peer-reviewed articles published between 2015 and 2025 to identify patterns in how Aurelia has been used as a model organism in bioassays and experimental studies. Our synthesis revealed a high degree of methodological heterogeneity, particularly with respect to temperature, photoperiod, feeding regime, life-stage selection, exposure duration, and endpoints. The studies were geographically concentrated in China and Italy, with limited representation from other regions, including tropical and developing countries. Polyps and ephyrae were the life stages most frequently used in ecotoxicological assays, whereas adult medusae were mainly employed in biochemical and biotechnological applications. Overall, our findings highlight the urgent need for clearer reporting practices and standardized experimental approaches to improve reproducibility and support the reliable use of Aurelia as a model organism in marine research.
Paphia undulata enhances sedimentary CH and NO emissions via divergent microbial mechanisms.
Zhong Z, Ruan Y, Qian J … +3 more , Xie M, Tan Q, Chen R
Mar Environ Res · 2026 Jul · PMID 42134209 · Publisher ↗
Global aquaculture expansion has elevated its contribution to greenhouse gas (GHG) emissions, yet shellfish aquaculture's role in methane (CH) and nitrous oxide (NO) fluxes remains poorly understood due to conflicting fi...
Global aquaculture expansion has elevated its contribution to greenhouse gas (GHG) emissions, yet shellfish aquaculture's role in methane (CH) and nitrous oxide (NO) fluxes remains poorly understood due to conflicting findings and unclear mechanistic links between metabolic and bioturbation effects. This study employed a controlled laboratory experiment with Paphia undulata to isolate the impacts of metabolism and bioturbation on sedimentary GHG emissions, combining physicochemical monitoring, microbial community sequencing, and functional gene quantification. Results showed that suspended P. undulata (metabolism-only effect) increased mean NO flux by 60.07% via enrichment of Candidatus Nitrosopumilus, which triggered nitrification stalling at the nitrite stage and subsequent nitrifier denitrification. Buried P. undulata (combined metabolism and bioturbation) elevated mean CH flux by 64.97% by enriching methylotrophic methanogen Methanococcoides and activating the methyl-disproportionation methanogenesis pathway, while ammonium excretion suppressed methanotrophic activity (reduced pmoA gene abundance). These findings demonstrate that P. undulata drives divergent GHG emission pathways through distinct microbial mechanisms, highlighting the necessity of integrating CH and NO emissions into shellfish aquaculture's climate impact assessment and optimizing low-carbon farming practices.
Development of a regional empirical algorithm for estimating biopolymeric carbon from satellite ocean color in the Eastern Yellow Sea.
Jung HM, Joo H, Lee D … +7 more , Park S, Kim J, Kim M, Kim S, Kim JS, Choi H, Lee SH
Mar Environ Res · 2026 Jul · PMID 42128466 · Publisher ↗
The eastern Yellow Sea (EYS) is a semi-enclosed marginal sea characterized by high turbidity from strong tidal mixing and riverine inputs, creating an optically complex environment that challenges satellite remote sensin...
The eastern Yellow Sea (EYS) is a semi-enclosed marginal sea characterized by high turbidity from strong tidal mixing and riverine inputs, creating an optically complex environment that challenges satellite remote sensing applications. Biopolymeric carbon (BPC), comprising the labile and metabolically active fraction of particulate organic carbon (POC) derived from phytoplankton biochemical components (proteins, carbohydrates, and lipids), serves as a critical indicator of food quality and energy transfer efficiency in marine ecosystems. This study developed a regional empirical algorithm for estimating BPC concentrations from satellite ocean color measurements in the EYS. Using 354 in situ measurements collected from 2017 to 2024, a multiple linear regression (MLR) model was developed with POC and chlorophyll-a (Chl-a) as predictors, achieving moderate yet meaningful validation performance, given the non-optical and composite nature of the target variable. Analysis of a decade of satellite ocean color data (2015-2024) revealed distinct spatial patterns, with higher BPC concentrations in nearshore waters than in offshore regions. These patterns were driven by distinct mechanisms: riverine discharge influencing nearshore dynamics, and seasonal stratification controlling offshore variability. Time-series analysis demonstrated climate-driven phenological shifts in BPC dynamics, consistent with global warming trends. This regional algorithm provides valuable information for monitoring BPC distributions in the EYS, enabling assessment of autochthonous carbon sources and trophic food availability within marine ecosystems under ongoing environmental changes.
Occurrence, seasonal variability, and ecological risk of emerging contaminants in estuarine and nearshore waters around Hainan Island, China.
Niu H, Huang Y, Li S … +3 more , Zhou X, Sun C, Zhao H
Mar Environ Res · 2026 Jul · PMID 42128465 · Publisher ↗
Emerging contaminants (ECs), particularly pharmaceuticals and personal care products (PPCPs), have been increasingly detected in aquatic environments, raising global concerns due to their potential adverse effects on eco...
Emerging contaminants (ECs), particularly pharmaceuticals and personal care products (PPCPs), have been increasingly detected in aquatic environments, raising global concerns due to their potential adverse effects on ecological health. As the ultimate sink for land-based pollutants, the nearshore waters around Hainan Island are particularly vulnerable to PPCPs contamination. The rapid development of the Hainan Free Trade Port has intensified environmental pressures on Hainan Island; however, data regarding PPCPs contamination in its zones remain limited. To address this knowledge gap, this study investigated the occurrence, seasonal variation, and ecological risks of five antifungal agents-climbazole (CLB), fluconazole (FLZ), clotrimazole (CTZ), miconazole (MCZ), and ketoconazole (KTZ)-as well as the insect repellent N,N-diethyl-m-toluamide (DEET) in estuarine and nearshore environments influenced by 12 major rivers around Hainan Island, China. Two sampling campaigns were conducted during the wet and dry seasons. Target compounds were extracted via solid-phase extraction and quantified using HPLC-MS/MS. The results showed that, during the wet season, detection frequencies (DFs) for individual target compounds ranged from non-detection to 62.4%; CTZ was not detected, while MCZ and KTZ were only sporadically present. For the frequently detected compounds (FLZ, CLB, and DEET), mean concentrations ranged from 4.83 to 11.66 ng/L. In the dry season, all target compounds were detected, with DFs ranged from 11.5% to 100% and mean concentrations between 0.59 and 13.27 ng/L. Σ6PPCPs concentrations were significantly higher in the dry season than in the wet season, and were generally higher in estuaries than in adjacent nearshore areas. Ecological risk screening using risk quotients (RQs) indicated predominantly negligible to low risk, with moderate risk identified at a limited number of locations (12% in the dry season, 11% in the wet season); no sites exhibited high risk (RQ ≥ 1) in either season. These findings provide baseline data on the occurrence and risk of six emerging contaminants in a tropical island coastal setting, supporting future monitoring and management of sensitive nearshore ecosystems.
Artificial intelligence for marine oil spill management: Recent advances and future directions.
Wang Z, Huang Y, Zhang G … +8 more , Wang Z, Chen Z, Mulligan CN, Li SS, Elektorowicz M, Li B, Lee K, An C
Mar Environ Res · 2026 Jul · PMID 42119407 · Publisher ↗
Marine oil spills are one of the most severe anthropogenic threats to oceanic ecosystems, coastal communities, and global economic stability. While traditional monitoring and response approaches have played a foundationa...
Marine oil spills are one of the most severe anthropogenic threats to oceanic ecosystems, coastal communities, and global economic stability. While traditional monitoring and response approaches have played a foundational role in oil spill management, their effectiveness is often constrained by limited accuracy, slow response times, and high operational risks. Recent advancements in artificial intelligence (AI), particularly machine learning, computer vision, intelligent sensing, and robotics, have reshaped the landscape of oil spill detection, assessment, and emergency response. This review provides a comprehensive synthesis of AI-driven methodologies currently available for use across the full lifecycle of marine oil spill management. The contents examine AI-enabled risk prediction, failure forecasting, and toxicological and ecological impact assessments; AI applications in oil spill fate and transport modeling, such as physics-informed methods to ensure physical consistency, deep learning architectures for trajectory prediction, and uncertainty quantification techniques that enable probabilistic hazard assessments; integrated remote sensing systems, including autonomous robots; and intelligent manufacturing of remediation materials and the evaluation of AI-based decision support systems. This comprehensive overview of current developments and practical applications, aligned with stakeholder needs, identifies key challenges and provides recommendations for research on data availability, model generalization, interpretability, and system integration to advance AI-enabled, resilient, and environmentally responsible marine oil spill management practices.
Zooplankton community structure and environmental responses revealed by in situ observations in the Ningyuan River estuary, Hainan Island.
Guo Z, Wang W, Guo B … +3 more , Wang J, Li P, Xiao Y
Mar Environ Res · 2026 Jul · PMID 42119406 · Publisher ↗
Traditional zooplankton net sampling provides well-established approaches for species identification and density estimation; however, it is often subject to physical filtration, sample compression, and behavioral avoidan...
Traditional zooplankton net sampling provides well-established approaches for species identification and density estimation; however, it is often subject to physical filtration, sample compression, and behavioral avoidance, which can lead to underestimation of small-sized or fragile taxa. Moreover, such methods have limited capacity to resolve fine-scale spatial distributions and aggregation patterns of zooplankton under in situ conditions. In recent years, underwater in situ imaging has emerged as a promising tool for zooplankton investigations owing to its ability to provide non-invasive, real-time observations in the natural environment. In this study, underwater in situ zooplankton imaging data collected during winter 2023 and spring 2024 in the Ningyuan River estuary, Hainan Island, were used to examine seasonal variations in community structure, niche differentiation, and environmental responses of zooplankton in this tropical estuary. The results revealed pronounced seasonal differences in zooplankton communities. Winter assemblages were characterized by higher overall abundance and were dominated by Chaetognatha and Copepods, whereas spring assemblages exhibited lower abundance but a more diverse taxonomic composition, with Copepods and tunicates as the dominant groups. Chaetognatha and Copepods displayed relatively broad niche breadths, while most other taxa exhibited intermediate to narrow niches. Niche overlap and variance-ratio results suggested that overall interspecific association was weak and non-significant in both seasons, with a slight segregation tendency in winter (VR = 0.76) and a slight co-occurrence tendency in spring (VR = 1.79). Multivariate analyses further indicated that water temperature, salinity, dissolved oxygen (DO), and pH were the primary environmental factors associated with the spatial patterns of zooplankton communities. These findings improve our understanding of zooplankton responses to environmental gradients in tropical estuarine systems and highlight the value of integrating in situ imaging into multi-source monitoring frameworks.
Bacillus thuringiensis contamination as a biological hazard to embryogenesis of Carcinoscorpius rotundicauda in Malaysian tropical coasts.
Ghaleb RAM, Wei SS, Raj Kumar HC … +7 more , Kadir NHA, Sheikh HI, Meilana L, Sidique SNM, Parimannan S, Kumaran JV, Nelson BR
Mar Environ Res · 2026 Jul · PMID 42119405 · Publisher ↗
Several marine arthropods rely on external fertilization and beach-based egg incubation. This includes Carcinoscorpius rotundicauda, a horseshoe crab species with embryogenesis of 40 days. During this period, C. rotundic...
Several marine arthropods rely on external fertilization and beach-based egg incubation. This includes Carcinoscorpius rotundicauda, a horseshoe crab species with embryogenesis of 40 days. During this period, C. rotundicauda eggs were exposed to thermal stress and fluctuating tidal conditions, potentially increasing vulnerability to biological contaminants. In this study, abnormal eggs, indicated with red embryonic envelop were sampled from a nesting site potentially impacted by perturbation through anthropogenic activities. Microbial analysis was conducted to investigate biological contamination as an ecotoxicological stressor. Bacterial isolates were obtained from symptomatic eggs and characterized using Gram staining, 16 S-rRNA sequencing, virulence gene profiling, and biochemical assays. All isolates were identified as Bacillus thuringiensis, a known bioinsecticide with documented use in terrestrial agriculture and potential marine dispersal. Phenotypic assays confirmed the production of protease, gelatinase, and lipase which were factors associated with pathogenicity. Mechanistically, Bacillus thuringiensis infection was found to compromise embryonic development by depleting yolk-derived lipid and protein reserves, especially during the first 15 post-fertilization days. This early-stage infection delayed or arrested embryogenesis, likely due to metabolic competition and enzyme-mediated degradation of essential nutrients. The findings suggest a novel biological hazard to early life stages of C. rotundicauda and demonstrate a mechanistic link between microbial contamination and developmental failure in a species with a prolonged incubation window. This study provides new evidence of environmental hazard from virulent B. thuringiensis contamination, potentially introduced or enriched by anthropogenic activities. It underscores the need to evaluate microbial contaminants as ecotoxicological agents in coastal ecosystems, especially under climate- and pollution-driven stress scenarios.
Thermal limits of estuarine amphipods and their implications for aquaculture production.
Rodrigues DP, Marques L, Teixeira J … +4 more , Ferreira J, Sousa JP, Duarte RC, Calado R
Mar Environ Res · 2026 Jul · PMID 42114244 · Publisher ↗
Estuarine systems are characterised by strong seasonal fluctuations in temperature and salinity, exposing species to physiological challenges that can limit their survival. Amphipods are naturally abundant in estuaries a...
Estuarine systems are characterised by strong seasonal fluctuations in temperature and salinity, exposing species to physiological challenges that can limit their survival. Amphipods are naturally abundant in estuaries and have gained attention in aquaculture for their high nutritional value and suitability to large scale production. Their commercially feasible production will only be achieved if these are cultured in open or semi-open earthen pond systems, where temperature and salinity naturally fluctuate. As such, the physiological resilience of amphipods to such fluctuating environmental conditions is key for their production. The present study investigated the thermal limits of the amphipod species Melita palmata, Marinogammarus marinus, and Gammarus locusta under habitat-specific salinity regimes to assess their resilience to environmental variability relevant to aquaculture production using earthen ponds. Thermal limits, assessed via critical thermal maximum (CTmax), revealed species-specific patterns: M. palmata and M. marinus exhibited similarly high CTmax values (>33.5 °C), indicating a stronger thermal tolerance; G. locusta showed a lower CTmax (31-32 °C), but the highest thermal safety margin. Based on its biological traits and biochemical profile, G. locusta was selected for an experiment testing the influence of salinity on its thermal limits. Specimens reared under a salinity gradient (15-35) displayed significantly higher CTmax at higher salinities, regardless of sex. Amphipods maintained at the lowest salinity tested (15) displayed a lower mass-to-length ratio and lower CTmax values, indicating energetic costs associated with osmotic stress. Understanding how thermal and osmotic gradients modulate amphipod physiology is paramount to develop climate-resilient production strategies.
Boosting anaerobic reductive dehalogenation with natural protein amendments to unlock cryptic organohalide-reducing bacteria.
Tan T, Hu T, Chen B … +7 more , Kuang W, Yu H, Xie Y, Zhang Z, Wang H, Deng Z, Zhang C
Mar Environ Res · 2026 Jul · PMID 42107247 · Publisher ↗
Deep-sea sediments host a rich yet largely unexplored reservoir of microorganisms capable of reductive dehalogenation. However, the activity of dehalogenating consortia is often limited even under carbon-rich conditions,...
Deep-sea sediments host a rich yet largely unexplored reservoir of microorganisms capable of reductive dehalogenation. However, the activity of dehalogenating consortia is often limited even under carbon-rich conditions, impeding the identification of key functional players. In this study, we report that the addition of natural protein materials can dramatically stimulate reductive dehalogenation in an enrichment culture derived from deep-sea cold seep sediments. This stimulatory effect was clearly demonstrated by supplementation with bovine serum albumin (BSA), which significantly enhanced the degradation rates of 2,4,6-tribromophenol (2,4,6-TBP) and tetrachloroethene (PCE). Integrated metagenomic and metatranscriptomic analyses revealed that two candidate novel clostridial lineages-Romboutsia and Oxobacteraceae-present in BSA-amended cultures harbored distinct reductive dehalogenase (RDase) genes. Romboutsia harbored three RDase genes, with one being upregulated during the degradation of 2,4,6-TBP intermediates and another specifically responding to PCE, suggesting a substrate-dependent regulatory strategy. Oxobacteraceae encoded a cytosolic RDase that was highly expressed during 2,4,6-TBP transformation. Metabolic reconstruction further indicated that both lineages could utilize BSA-derived amino acids for growth. This work establishes an effective biostimulation strategy to activate dehalogenation in deep-sea microbial communities and expands the known diversity and functional versatility of candidate organohalide-reducing bacteria.
A multi-taxon evaluation of tropical-subtropical boundary using tree-of-life eDNA across Taiwanese waters.
Peiris MAK, Liu SV
Mar Environ Res · 2026 Jul · PMID 42105424 · Publisher ↗
Understanding whether biogeographic boundaries are consistent across different marine taxa is essential for effective biodiversity monitoring and ecosystem management. In Taiwan, a boundary between tropical and subtropic...
Understanding whether biogeographic boundaries are consistent across different marine taxa is essential for effective biodiversity monitoring and ecosystem management. In Taiwan, a boundary between tropical and subtropical marine communities has been described primarily based on hard coral and fish assemblages, yet it remains unclear whether this boundary is detectable across broader components of the marine metazoan taxa. Here, we use multi-marker eDNA metabarcoding across 10 coastal locations spanning a latitudinal gradient from northern to southern Taiwanese waters to evaluate whether the previously-defined biogeographic break is reflected in other taxonomic groups. Phylum-specific analyses revealed distinct tropical assemblages for multiple taxa, including cnidaria (hard corals), mollusca, arthropoda (copepods), chordata (tunicates), echinodermata and bryozoa with putative transitional communities at Penghu Islands. ZOTU richness showed clear latitudinal gradients for many metazoan phyla: hard corals (scleractinia) and several benthic groups increased towards the south, whereas copepod richness was highest in northern waters. Indicator species analyses identified that copepods dominate in the north and scleractinian corals in the south. Collectively, our results demonstrate that the tropical-subtropical boundary in Taiwanese waters exerts a potential structuring effect on multiple marine taxa. This study highlights the value of broad-scale eDNA metabarcoding for detecting biogeographic transitions. It provides a multi-taxon baseline for long-term monitoring across one of the most dynamic marine boundaries in the Western Pacific.
A novel three-step biologically informed ocean partitioning strategy: insights from toxigenic phytoplankton in a coastal upwelling system.
Lima MJ, Caballero I, Barbosa AB
Mar Environ Res · 2026 Jul · PMID 42105423 · Publisher ↗
Ocean partitions are often based on readily accessible variables, such as abiotic factors and chlorophyll-a concentration, but provide limited insight into biological patterns. This study developed a three-step partition...
Ocean partitions are often based on readily accessible variables, such as abiotic factors and chlorophyll-a concentration, but provide limited insight into biological patterns. This study developed a three-step partitioning strategy prioritizing environmental factors that best described the variability patterns of harmful algal bloom (HAB)-forming taxa off SW Iberia. These included the producers of amnesic shellfish poisoning (ASP), diarrhetic shellfish poisoning (DSP), and paralytic shellfish poisoning (PSP). First, dimensionality reduction and unsupervised classification were applied to three environmental datasets, derived from remote sensing and model outputs, covering a 19-year period. Second, different empirical-statistical models were used to determine which datasets best explained the abundance of HAB-producers, available for an 8-year period in different classified coastal production areas. Finally, the best datasets were used to derive partitions prioritizing the variability of different HAB groups, at a pixel level. The first classifications identified up to 12 regions, with four to five located in the coastal-slope domain, with a variable configuration depending on the dataset. The best predictor datasets and models identified five regions (two inner-shelf, two outer-shelf/slope, and one transitional coastal-ocean region), representative of HAB groups. No clear distinctive partitions were identified for different groups, namely for ASP- and DSP-producers, likely due to the combined influence of upwelling and freshwater discharges, along with submarine topographic features. Our partitioning strategy can be applied to other marine systems and taxonomic groups. Future improvements, including more complete environmental and biological datasets, could enhance the value of biologically informed environmental partitions as proxies for species abundance.
Field performance of innovative wood protection treatments on early successional macrofouling communities.
Iannucci S, Kaidi S, Camisa F … +3 more , Auriemma R, Nasi F, Cibic T
Mar Environ Res · 2026 Jul · PMID 42096875 · Publisher ↗
Marine biofouling has long threatened the integrity of wooden structures commonly used in coastal and sensitive lagoon areas. To improve softwood durability while minimising environmental impacts, innovative antifouling...
Marine biofouling has long threatened the integrity of wooden structures commonly used in coastal and sensitive lagoon areas. To improve softwood durability while minimising environmental impacts, innovative antifouling treatments (i.e. Silvanolin® and thermal modification (TM)) have been developed as alternatives to traditional copper-based products. In this study, we assessed and compared the in-situ performance of these innovative treatments with the commercially available copper-based chromated copper borate (CCB) on the early stages of macrofouling community development. A total of 72 Picea abies panels, divided into four groups (12 samples per treatment: CCB, Silvanolin, TM, and controls), were immersed for 20 and 40 days at two sites in the Grado Lagoon, characterised by diverse hydrodynamic conditions. Overall, 36 macrofouling species were found. According to PERMANOVA test, communities differed significantly between the two sites, highlighting the key role of local hydrodynamics in influencing both treatment effectiveness and fouling settlement dynamics. The high-flow site showed greater macrofouling colonisation and recruitment, indicating reduced performance of treatments. In contrast, the enclosed site exhibited lower overall colonisation and dominance of copper-tolerant species such as cirripeds and tubeworms indicating a longer but still limited treatment efficacy. Taxonomic composition also varied among treatments, with TM having a major effect in selecting certain species over others. This study highlights the multifaceted role of local hydrodynamics in affecting wood treatment performance and structuring macrofouling communities. It also provides valuable field-based insights and a practical methodological framework for testing innovative, environmentally compatible antifouling solutions in highly sensitive coastal areas.
Effects of elevated temperature and chitosan on hemocyte immune competence in the Mediterranean clam Ruditapes decussatus: Implications for aquaculture resilience under climate change.
Ladhar-Chaabouni R, Dammak F, Dhaffouli F … +3 more , Hachicha H, Ayadi W, Makdad-Gargouri R
Mar Environ Res · 2026 Jul · PMID 42096874 · Publisher ↗
This study evaluates how chitosan and temperature shape the thermal tolerance and immune status of the Mediterranean clam Ruditapes decussatus. Hemocytes were exposed in vitro to chitosan at 5, 15 and 45 μg mL under thre...
This study evaluates how chitosan and temperature shape the thermal tolerance and immune status of the Mediterranean clam Ruditapes decussatus. Hemocytes were exposed in vitro to chitosan at 5, 15 and 45 μg mL under three thermal regimes (room temperature, 30 °C and 37 °C), while intact clams were exposed in vivo to 45 mg L chitosan in natural seawater at 20, 27 and 32 °C. Hemocyte responses were assessed through cell metabolic and lysosomal integrity (MTT and neutral red assays), phagocytic activity, and apoptosis (flow cytometry). In vitro, both chitosan concentration and temperature significantly shaped hemocyte behaviour, with higher doses and warmer conditions associated with reduced mitochondrial activity, marked shifts in phagocytic profiles between granulocytes and hyalinocytes, and increased apoptosis, highlighting a strong dependence on cell type and endpoint. In vivo, by contrast, temperature emerged as the dominant factor: chitosan was associated with enhanced hemocyte viability only under benign thermal conditions, whereas warming primarily drove lysosomal destabilization and selectively reduced granulocyte-mediated phagocytosis, while apoptosis remained largely unchanged. Together, these results depict chitosan as a conditional modulator of bivalve immunity whose apparent benefits or risks depend on temperature, exposure level and biological context (in vitro versus in vivo).
Effects of ocean acidification on radular tooth material properties in Littorina littorea (Gastropoda, Mollusca).
Krings W, Schreiber HKC, Gorb SN
Mar Environ Res · 2026 Jul · PMID 42092269 · Publisher ↗
Ocean acidification is known to affect calcified structures in marine organisms, yet its impact on non-calcified but functionally essential feeding tools remains poorly understood. The radula is a defining molluscan apom...
Ocean acidification is known to affect calcified structures in marine organisms, yet its impact on non-calcified but functionally essential feeding tools remains poorly understood. The radula is a defining molluscan apomorphy, whose mechanical performance is critical for feeding and survival. Here we investigated the effects of reduced seawater pH on the radular teeth of the intertidal gastropod Littorina littorea. Individuals were maintained for seven weeks under acidified conditions (pH 7.5) or near-present-day conditions (pH 8.1) and compared with a field-collected control group. Radulae were analysed using scanning electron microscopy, confocal laser scanning microscopy, energy-dispersive X-ray spectroscopy, and nanoindentation. Radulae from acid-treated individuals exhibited markedly increased tooth wear in the working zone despite largely preserved gross morphology. Wear was most pronounced at the cusps of central and lateral teeth and showed rounded profiles indicative of progressive abrasive wear. Acidic conditions caused pronounced changes in the outer tooth coating, including reduced silicon enrichment and substantial decreases in stiffness and hardness, while the inner tooth structure was only weakly affected. Confocal microscopy revealed treatment-specific autofluorescence patterns, suggesting pH-dependent alterations of the organic matrix. Differences between laboratory-maintained and field-collected individuals further indicate that feeding conditions influence radular tooth properties. These results demonstrate that ocean acidification can impair radular function through material-level degradation of composite feeding structures, potentially reducing grazing efficiency and imposing sublethal fitness costs.
Coupling effect of phytoplankton community structure and nitrogen factors in estuary of Bohai Bay and its adjacent coastal waters.
Qiao L, Wang W, Li X … +3 more , Zhang Y, Su R, Huang R
Mar Environ Res · 2026 Jul · PMID 42085837 · Publisher ↗
Over the past 22 years, the phytoplankton species richness in the Bohai Bay decreased continuously and the diatom-to-dinoflagellate succession became prominent, due to the intensive terrestrial nitrogen input. To explore...
Over the past 22 years, the phytoplankton species richness in the Bohai Bay decreased continuously and the diatom-to-dinoflagellate succession became prominent, due to the intensive terrestrial nitrogen input. To explore the regional coupling mechanism between nitrogen factors and phytoplankton, we investigated 41 stations in the estuary of Bohai Bay and its adjacent coastal waters in August 2023. Results showed that phytoplankton abundance was higher in nearshore waters and lower in offshore waters. In terms of phytoplankton species, estuaries were dominated by cyanobacteria and green algae while coastal waters were dominated by diatoms and dinoflagellates. The N/P molar ratio far exceeded the canonical Redfield ratio of 16:1, confirming a persistent phosphorus limitation status. Pearson correlation analysis showed that nitrogen, reactive phosphate, and suspended solids were core drivers regulating diatom communities. This study clarifies the coupling characteristics and provides a theoretical basis for eutrophication management in Bohai Bay.
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