Marine Environmental Research[JOURNAL]
Sun
200 papers
Microfibres and bivalves: A review of their occurrence and analysis.
Gago J, Villoria-Calvo S, Fajar NM … +4 more , Blanco G, Filgueiras AV, Otero P, Viñas L
Mar Environ Res · 2026 Jun · PMID 42013675 · Publisher ↗
Microfibres represent the most abundant form of microplastics in marine environments and pose potential risks to ecosystems and human health. Bivalves, widely consumed and commonly used as bioindicators, are particularly...
Microfibres represent the most abundant form of microplastics in marine environments and pose potential risks to ecosystems and human health. Bivalves, widely consumed and commonly used as bioindicators, are particularly susceptible to this contamination. This review synthesizes current knowledge on the occurrence and analysis of microfibres in bivalves, based on 107 studies published since 1977. Microfibres were reported in all major bivalve families, with mussels, oysters, and clams being the most frequently investigated groups. Blue fibres were the most common, followed by transparent and black. Polypropylene, polyethylene, and polyester were the predominant polymers, while regenerated cellulose fibres were also frequently detected. Natural fibres, often considered environmentally benign, present risks comparable to those of synthetic polymers. The literature reveals substantial inconsistencies in sampling strategies, digestion protocols, and polymer identification methods, limiting comparability and reliability of reported data. Most studies employed chemical characterization, primarily Fourier-transform infrared spectroscopy, although analytical conditions were often insufficiently documented. Standardization of methodologies is urgently required to improve data quality and enable robust assessment of ecological and human health risks. Recommendations for harmonizing protocols and enhancing monitoring strategies are provided to support future research and inform mitigation measures addressing microfibre pollution in marine ecosystems and seafood safety.
Combining taxonomic and functional traits of marine nematodes to assess benthic environmental quality in the southern Yellow Sea.
Wang Z, Gao S, Song Y … +2 more , Huang M, Liu X
Mar Environ Res · 2026 Jun · PMID 42001784 · Publisher ↗
Marine nematodes, as dominant meiofaunal organisms in benthic ecosystems, play crucial roles in energy flux and serve as sensitive bioindicators of environmental change. This study investigated the spatiotemporal distrib...
Marine nematodes, as dominant meiofaunal organisms in benthic ecosystems, play crucial roles in energy flux and serve as sensitive bioindicators of environmental change. This study investigated the spatiotemporal distribution of nematode assemblages in the southern Yellow Sea during the summer and autumn of 2020 by integrating analyses of taxonomic composition and functional traits. Results identified pronounced spatial heterogeneity driven by the Yellow Sea Cold Water Mass (YSCWM): stations deeper than 60 m exhibited significantly lower abundance, species richness (S), Shannon diversity (H'), and functional richness (FRic), yet showed elevated functional dispersion (FDis) and Rao's quadratic entropy (RaoQ). Bottom water temperature (BWT) and sediment median diameter (Md) were the primary environmental filters, explaining 19.1% of community variation (p < 0.01). Epistratum feeders (2A) predominated across seasons, indicating a relatively stable diatom-based food web. Notably, functional complementarity was enhanced despite taxonomic loss in YSCWM-influenced areas, revealing adaptive trait divergence under intense physical filtering. Integrated environmental assessments using MI, ITD, and H' revealed significant spatial incongruence, as traditional taxonomic indices failed to distinguish thermal suppression from localized environmental stressors. Our findings underscore the critical value of combining both species and functional diversity metrics to accurately characterize ecosystem stability and health in dynamic marine environments.
Predicting sediment ecological state from metagenomes shows equal performance for taxonomic and functional features.
Snipen L, Stoeck T, Angell IL … +7 more , Philip M, Pettersen R, Majaneva S, Ray JL, Stokkan M, Keeley N, Rudi K
Mar Environ Res · 2026 Jun · PMID 42000556 · Publisher ↗
The use of environmental microbial DNA to monitor the ecological state in seafloor sediments has many advantages and efforts are being made to find reliable biomarkers from DNA-based taxonomic profiles. However, the taxo...
The use of environmental microbial DNA to monitor the ecological state in seafloor sediments has many advantages and efforts are being made to find reliable biomarkers from DNA-based taxonomic profiles. However, the taxonomic composition of microbial communities can vary over time and space, while their functional characteristics typically remain consistent. Furthermore, functionality may better capture the breadth of biological complexity. Therefore, we here tested whether functional attributes of microbial communities serve as more reliable indicators of environmental quality than their taxonomic composition. To test this, we analyzed a set of Metagenome-Assembled-Genomes (MAGs) from 41 different coastal locations in Norway and Iceland, characterized by environmental impact gradients resulting from salmon aquaculture. Functional and taxonomic features extracted from these MAGs were then used to predict the ecological state of the corresponding sample sites using several supervised machine learning models and stratified feature selection. Our findings indicate that both taxonomic and functional features demonstrated comparable effectiveness in predicting environmental quality. This outcome has direct relevance for eDNA-based regulatory compliance monitoring. However, the functional insights derived from the most significant functional features identified by machine learning models remain essential for deepening our understanding of the ecological processes underpinning practical biomonitoring tools.
Biotic carbon stocks across trophic levels in the shallow littoral zone - the role of biodiversity and environmental drivers.
Pykäri J, Sumelius H, Ollus V … +3 more , Wennhage H, Norkko A, Villnäs A
Mar Environ Res · 2026 Jun · PMID 41996967 · Publisher ↗
Carbon storage is an important ecosystem service that marine ecosystems provide. Shallow vegetated habitats are a hotspot for carbon cycling, having high benthic productivity due to high solar irradiation and nutrient in...
Carbon storage is an important ecosystem service that marine ecosystems provide. Shallow vegetated habitats are a hotspot for carbon cycling, having high benthic productivity due to high solar irradiation and nutrient inputs from land. Quantification of the carbon stocks on an ecosystem level has rarely been done in the very shallow littoral (∼1 m) zone. In this study, we quantified biotic carbon stocks of primary producers to predators at 20 relatively exposed coastal sites in the northern Baltic Sea, where the dominant seafloor habitats were submerged mixed vegetation and bare sediment. There was high spatial variability in the total biotic carbon stock, ranging from 0.13 to 45.95 g C m. Most of the carbon in the studied soft-sediment habitats was bound in vegetation (on average 5.14 g C m), followed by infauna (on average 4.96 g C m), while the carbon stocks of epifauna and fish were much smaller. Biodiversity, here represented by taxon richness, and sediment properties (i.e., fine sediment and organic matter content) were the most important drivers of variation in the different compartments of the biotic carbon stock. Our study shows that shallow, littoral ecosystems are important in capturing carbon and sustaining biodiversity, which should be considered in management and conservation strategies.
Macrofaunal diversity and secondary production in kelp holdfasts (Phaeophyceae) within a climatic transition zone.
Reis B, Franco JN, Costa DA … +6 more , Casalís-Cantallo H, van der Linden P, Sousa-Pinto I, Arenas F, Antunes C, Rodil IF
Mar Environ Res · 2026 Jun · PMID 41996966 · Publisher ↗
Despite substantial research on kelp holdfast biodiversity, the drivers of macrofaunal diversity, abundance, and biomass across holdfast types and different climatic regions remain unresolved. This uncertainty extends to...
Despite substantial research on kelp holdfast biodiversity, the drivers of macrofaunal diversity, abundance, and biomass across holdfast types and different climatic regions remain unresolved. This uncertainty extends to ecosystem functioning, where empirical estimates of secondary production are rare. We quantified the relative influence of regional environmental context and holdfast morphology on macrofaunal assemblages inhabiting holdfasts of Laminaria ochroleuca and Saccorhiza polyschides in two contrasting regions along the western Iberian coast climatic gradient: the northern A Coruña, Spain (COR; cooler, lower wave exposure) and the southern Peniche, Portugal (PEN; warmer, higher wave exposure). We also investigated ecological functioning by estimating secondary production. Macrofauna diversity, abundance, biomass (ash-free dry mass; AFDM), and secondary production were assessed at the holdfast level in samples collected from both regions in summer 2021. Holdfast structural complexity was quantified as surface-to-volume ratio (SA/V). Underwater Visual Census (UVC) surveys were conducted to provide reef-scale context for regional differences. Secondary production (consumer incorporation of organic matter per time) was estimated with Edgar's empirical model to infer energy-transfer dynamics. The cooler region, COR, exhibited significantly higher overall diversity and production than PEN. While S. polyschides supported lower taxonomic diversity than L. ochroleuca, it exhibited higher secondary production. These findings highlight the importance of regional climatic context in shaping kelp holdfast biodiversity and functioning. Differences between cooler and warmer regions suggest that variation in thermal regimes can be associated with changes in holdfast community structure and secondary production.
Potential of the bivalve Perna perna as bioindicator of eutrophication in tropical coastal ecosystems: carbon and nitrogen stable isotopes, fatty acids and shell morphometry.
Erbas T, Meziane T, Nepomuceno A … +11 more , Pereira E, Duarte M, Brandini N, Cerda M, Le Moal P, Nascimento LS, Abreu M, Machado W, Bernardes M, Moser GAO, Abril G
Mar Environ Res · 2026 Jun · PMID 41990592 · Publisher ↗
Stable isotopes, fatty acids (FAs), and morphometric data are used to describe how eutrophication influences the mussel Perna perna along the coast of Rio de Janeiro (Brazil). Three sites were selected according to their...
Stable isotopes, fatty acids (FAs), and morphometric data are used to describe how eutrophication influences the mussel Perna perna along the coast of Rio de Janeiro (Brazil). Three sites were selected according to their nutrients and chlorophyll a concentration: MAM oligotrophic, ITA mesotrophic to eutrophic and BV, eutrophic. Particulate organic matter (POM) was a mixture of few amounts of cyanobacteria and a predominant source composed in recycled terrigenous OM and bacteria in MAM, of phytoplankton in ITA and BV with a higher contribution of bacterioplankton and a lower food quality in BV. POM was more abundant at ITA and BV but with a lower content of essential poli-unsaturated fatty acids compared to MAM. In the digestive gland, isotopic enrichment factors and FAs profiles reflected intense feeding selectivity. Mussels in the eutrophic sites were able to maintain higher FA concentrations in their muscles and selectively retain essential PUFAs (20:5ω3, 22:6ω3), causing a stronger isotopic fractionation, consistent with long-term integration of assimilated resources and physiological adjustments. In contrast, mussels at the oligotrophic site were apparently starved with a reduced metabolism to maintain essential FAs threshold in their tissues. Shell morphometric traits also differed among sites, with greater morphological heterogeneity observed under eutrophic conditions, particularly in larger individuals (≥7.5 cm). Overall, the combined biochemical and morphometric responses of P. perna reflect trophic differences among sites, suggesting that this species can provide useful information on eutrophication gradients in tropical coastal ecosystems.
From hatchling to adult: multi-stressor effects of zinc toxicity and salinity in a benthic marine annelid.
Fox JA, Rodríguez-Romero A, Massamba-N'Siala G
Mar Environ Res · 2026 Jun · PMID 41980509 · Publisher ↗
Coastal ecosystems are increasingly affected by the combined pressures of climate change and anthropogenic pollution, exposing marine organisms to multiple interacting stressors. Shifts in temperature and precipitation a...
Coastal ecosystems are increasingly affected by the combined pressures of climate change and anthropogenic pollution, exposing marine organisms to multiple interacting stressors. Shifts in temperature and precipitation are altering the physicochemical balance of coastal waters, including salinity changes that can modulate metal toxicity. Understanding how these factors interact under environmentally realistic conditions is essential for assessing organismal vulnerability in changing environments. Using the benthic marine annelid Ophryotrocha labronica, a model species in eco-toxicological studies, we examined the combined effects of salinity (22, 27, 32 psu) and zinc (0, 50, 100 μg/L) on the survival, growth, and fecundity of individuals across three life stages: hatchling, juvenile, and adult females and males. All stages experienced a 3-day exposure to each salinity-zinc combination, while adults were further exposed for 4 days to assess sex-specific responses. No significant interactive effects of salinity and zinc were detected except for the 3-day growth rate, and early life stages were not more sensitive than adults. Survival probabilities and growth rates were significantly reduced at the highest zinc concentration regardless of life stages and sex, while fecundity remained unaffected. These results demonstrate that zinc toxicity can dominate organismal responses under optimal salinities and at zinc concentrations that are environmentally realistic in urbanized bays, while also providing evidence that earlier stages are not necessarily more vulnerable to metal toxicity. Overall, this work emphasizes the need for more species-specific, life-stage integrated assessments within a multi-stressor framework to improve predictions of organismal tolerance and vulnerability under changing coastal conditions.
Physiological and molecular effects of wind turbine blade erosion particles on the Pacific oyster (Magallana gigas).
Song S, Su C, Shan X … +2 more , Zhang H, Zhao Y
Mar Environ Res · 2026 Jun · PMID 41967218 · Publisher ↗
The rapid expansion of offshore wind energy, driven by the global demand for clean energy, has raised concerns about the release of erosion particles (EPs) from turbine blade erosion and their potential impacts on marine...
The rapid expansion of offshore wind energy, driven by the global demand for clean energy, has raised concerns about the release of erosion particles (EPs) from turbine blade erosion and their potential impacts on marine benthic organisms. In this study, the Pacific oyster (Magallana gigas) was used as a model organism to investigate the toxicological mechanisms of EPs. Organisms were subjected to exposure experiments at different concentrations, combined with analyses of superoxide dismutase (SOD), catalase (CAT), and acid phosphatase (ACP) activities, malondialdehyde (MDA) content, transcriptomics, and metabolomics. Results showed that EP exposure induced significant oxidative stress, as evidenced by elevated lipid peroxidation and activation of the antioxidant enzyme defense system. Additionally, based on transcriptomic and metabolomic data, EPs may disrupt cytoskeletal integrity and endocytic function, thereby impairing membrane structural stability and substance transport capacity. Furthermore, EPs may disrupt the energy metabolism network: low-concentration exposure primarily suppresses the tricarboxylic acid (TCA) cycle and glycolysis, potentially leading to insufficient energy production, while high-concentration exposure may further diminish lipid reserves and inhibit gluconeogenesis, exacerbating metabolic imbalance. Moreover, EPs exposure activates the cGAS-STING and NF-κB signaling pathways, triggering innate immune responses and interfering with apoptosis. This study demonstrates that EPs are biologically active; they not only elicit antioxidant defense responses at the physiological and biochemical levels but also disrupt key metabolic and immune pathways at the molecular level. This research provides novel insights into the ecological risk assessment of this emerging pollutant from offshore wind farms and highlights the importance of incorporating EPs in marine ecological safety evaluations.
Acute toxicity and ecological risk assessment of arsenic and bisphenol A in the Bohai Sea.
Li S, Wang X, Qi R … +2 more , Li Y, Miao J
Mar Environ Res · 2026 Jun · PMID 41967217 · Publisher ↗
Arsenic (As) and bisphenol A (BPA), representing conventional inorganic and emerging organic pollutants respectively, are ubiquitous in coastal environments and pose potential ecological threats. Given the semi-enclosed...
Arsenic (As) and bisphenol A (BPA), representing conventional inorganic and emerging organic pollutants respectively, are ubiquitous in coastal environments and pose potential ecological threats. Given the semi-enclosed nature and intense anthropogenic pressures of the Bohai Sea, region-specific ecological risk assessments (ERA) are imperative for effective management. This study prioritized 24 representative native aquatic species from the Bohai Sea and curated a robust acute toxicity database for As and BPA through integrated literature mining and acute toxicity experiments. Based on species sensitivity distribution (SSD) models, hazardous concentrations for 5% of species (HC) were derived, resulting in acute predicted no-effect concentrations (PNEC) of 1.69 μg/L for As and 100.7 μg/L for BPA. The Risk Quotient (RQ) analysis revealed that As poses a moderate ecological risk in the three major semi-enclosed bays, while BPA currently exhibits low risk levels. These findings underscore the necessity of utilizing locally-derived toxicity data for accurate ERA and provide a scientific foundation for site-specific pollution control strategies in the Bohai Sea.
A multidomain lens on the temporal dynamics of surface microbial communities in the Southern Ocean (2013-2019).
Faria LC, Raut Y, McNichol J … +3 more , Williams NLR, Fuhrman JA, Signori CN
Mar Environ Res · 2026 Jun · PMID 41967216 · Publisher ↗
Marine microorganisms are vital to biogeochemical cycles and food web dynamics, with their community structure shaped by environmental factors such as temperature, light, and salinity. While microbial dynamics in the wes...
Marine microorganisms are vital to biogeochemical cycles and food web dynamics, with their community structure shaped by environmental factors such as temperature, light, and salinity. While microbial dynamics in the western Antarctic Peninsula are relatively well-studied, the northwestern region remains underexplored, particularly in long-term, multidomain analyses. To fill this gap, we investigated microbial communities encompassing all three domains of life (Bacteria, Archaea, and Eukarya) in the Northwestern Antarctic Peninsula. Using the universal primer set 515Y/926R, we sequenced unfractionated seawater from ten sites over a six-year period (2013-2019). Environmental parameters, temperature and salinity, showed minimal variation across the study. However, microbial diversity and composition, especially among eukaryotic phytoplankton, displayed significant temporal changes among seasons and years. The prokaryotic community, by contrast, was relatively stable, with Gammaproteobacteria-particularly the Nitrincolaceae family-maintaining high relative abundance throughout all sampling periods, but a few distinct ASVs. In contrast, no eukaryotic group exhibited consistently high relative abundance across sampling periods. The summer of 2016, marked by a strong El Niño event, presented the most distinct microbial community structure, underscoring the sensitivity of these communities to extreme climatic conditions. These results highlight the importance of integrated, long-term studies to better understand the dynamics, interactions, and resilience of microbial ecosystems in the rapidly changing Antarctic environment.
Seawater acidification accelerates growth but hastens decline in batch cultures of the marine diatom Thalassiosira pseudonana.
Zong H, Sun Z, Lv D … +4 more , Shang Y, Wu Y, Xu J, Li F
Mar Environ Res · 2026 Jun · PMID 41967215 · Publisher ↗
Diatoms are characterized by rapid cell division and a high capacity to adapt to environmental variability, and some species can form blooms when environmental conditions are favorable. Previous studies have largely focu...
Diatoms are characterized by rapid cell division and a high capacity to adapt to environmental variability, and some species can form blooms when environmental conditions are favorable. Previous studies have largely focused on the bloom development phase, during which biomass accumulates rapidly, whereas the decline phase-despite its critical role in carbon export and microbial loop dynamics-has received far less attention. Here, we tracked changes in cell density and inorganic carbon utilization characteristics throughout the entire course of a simulated Thalassiosira pseudonana bloom under ambient (420 μatm) and elevated pCO (1000 μatm) conditions. Inhibitors of carbonic anhydrase and direct bicarbonate transporters were applied to investigate the characteristics of inorganic carbon utilization. The relationship between photosynthetic rate and inorganic carbon concentration was measured to assess inorganic carbon affinity. The simulated T. pseudonana bloom was characterized by rapid cell density accumulation, reaching a peak within 10 days, followed by a rapid decline without a distinct stationary phase. As the bloom progressed, photosynthetic rate and the maximum quantum yield of photosystem II declined, whereas the inorganic carbon affinity increased. Elevated CO enhanced growth and maximum quantum yield during the acceleration phase but resulted in an 86% higher fitted death rate during the decline phase. Regarding the relationship between photosynthetic rate and dissolved inorganic carbon concentration, elevated CO increased the maximum photosynthetic rate and half-saturation constant only during the acceleration phase. Collectively, these results indicate that seawater acidification can influence both biomass accumulation and decline intensity in diatom blooms, with potential consequences for carbon sequestration and its redistribution among biogeochemical pools.
A "Seesaw Effect" resolving the paradox in microzooplanktonic ciliate-environment interactions in the tropical Qinzhou Bay estuary-offshore continuum.
Wang C, Zhang T, Li B … +6 more , Yang W, Du H, Huang S, Wang J, Jiang H, Wang X
Mar Environ Res · 2026 Jun · PMID 41967214 · Publisher ↗
Microzooplanktonic ciliates are critical to marine biogeochemical cycles, yet the linkages between their community structure, carbon storage, size spectrum, and environmental drivers remain poorly understood in tropical...
Microzooplanktonic ciliates are critical to marine biogeochemical cycles, yet the linkages between their community structure, carbon storage, size spectrum, and environmental drivers remain poorly understood in tropical estuarine ecosystems. Here, we conducted field surveys along the estuary-offshore continuum of Qinzhou Bay (South China Sea) in summer 2024, dividing the area into Inner Bay (IB), Bay Neck (BN), and Outer Bay (OB) based on salinity and nutrient gradients to clarify ciliate assemblage characteristics and governing factors. Our results indicate substantial river-derived nutrient inputs, with peak ciliate abundance and biomass observed in the IB, whereas the BN exhibited the highest tintinnid densities. The estimated ciliate-mediated carbon stock in Qinzhou Bay was approximately 1.6 ± 1.1 × 10 t C day. Moreover, size-spectrum analysis revealed a consistent decline in ciliate abundance from small to large size-fraction across all zones. However, slopes of size spectra varied between surface and bottom layers, indicating a transition from bottom-stability at IB to surface-stability at OB. Multivariate biota-environment analyses further identified salinity, nutrients, and Chl a as driving factors in shaping ciliate assemblage. To resolve this paradox (high nutrient‒low Chl a‒high ciliate abundance in the IB and the inverse pattern in the OB), we propose a "Seesaw Effect" conceptual framework. This framework illustrates a bet-hedging adaptive strategy of microzooplankton in response to strong environmental gradients across the estuary-offshore continuum. Collectively, these findings highlight the spatiotemporal variability of ciliate communities in Qinzhou Bay and provide a conceptual framework for assessing microzooplankton responses to environmental change in tropical land-sea interface ecosystems.
Corrigendum to "Comparative nekton habitat assessment of eroded-forest, marsh, and beach estuarine shorelines".
Lupton C, Drymon M, Woodrey M … +3 more , Temple N, Scyphers S, Sparks E
Mar Environ Res · 2026 Jun · PMID 41966882 · Publisher ↗
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Saint Peter and Saint Paul Archipelago as a key stopover for yellowfin tunas from the Gulf of Guinea.
Menezes R, Duponchelle F, Panfili J … +4 more , Queiroz APN, Diaha CN, Santana FM, Lessa RPT
Mar Environ Res · 2026 Jun · PMID 41962519 · Publisher ↗
The yellowfin tuna (Thunnus albacares) is a widely distributed species performing long-distance migrations. Along the migratory route, individuals may use critical habitats for feeding and energy replenishment to continu...
The yellowfin tuna (Thunnus albacares) is a widely distributed species performing long-distance migrations. Along the migratory route, individuals may use critical habitats for feeding and energy replenishment to continue their journeys; these habitats are denominated stopover sites. Such areas are poorly documented for large-bodied migratory pelagic fishes globally and remain unreported in the Atlantic. The objective of this pilot study was to identify the potential role of the Saint Peter and Saint Paul Archipelago (SPSPA) as a stopover site for yellowfin tunas caught off western Africa, using otolith chemistry. Ten pre-adult/adult yellowfin tunas were caught by purse seine fisheries along the Gulf of Guinea. Otoliths from these specimens were chemically analyzed through a core-edge transect. The SPSPA signature - characterized by high concentrations of Zn, Sr, and Ba - was examined along the otoliths. Eight out of ten yellowfin tunas exhibited coinciding peaks of these three elements in their multi-elemental profiles, suggesting passage through the SPSPA. Multivariate statistical approaches supported the hypothesis that yellowfin tunas from the Gulf of Guinea temporarily inhabited the SPSPA. Individuals arrived at the SPSPA at around 0.8 years of age and remained for roughly 5.3 months, thus categorizing the SPSPA as a 'full-service hotel' stopover. These findings suggest that the SPSPA plays a key role in the migration of the species and underscore the need for stronger enforcement to safeguard yellowfin tunas at this small, remote, geologically unique archipelago in the Atlantic Ocean.
Physiological tolerance and predator-mediated resistance as critical factors influencing the invasion success in two solitary ascidians.
Pinochet J, Barrios-Figueroa R, Jorquera E … +4 more , Molina-Valdivia V, Lagos-Oróstica M, Urbina MA, Brante A
Mar Environ Res · 2026 Jun · PMID 41955794 · Publisher ↗
Understanding the mechanisms that determine invasion success requires evaluating both abiotic constraints and biotic interactions acting on introduced species. In this study we analyzed the role of environmental filterin...
Understanding the mechanisms that determine invasion success requires evaluating both abiotic constraints and biotic interactions acting on introduced species. In this study we analyzed the role of environmental filtering, understood as the capacity of organisms to tolerate physical conditions such as temperature and oxygen availability, and biotic resistance, defined as the effects of native consumers in limiting establishment. These processes were evaluated in two solitary ascidians, Corella eumyota (Phlebobranchia: Corellidae) and Asterocarpa humilis (Stolidobranchia: Styelidae), collected from settlement plates deployed at approximately 1 m depth in Coliumo Bay (36°32'S, 72°56'W), central Chile. Both species exhibited broad thermal tolerance, maintaining survival between 12 and 20 °C, tolerating cooling to 4 °C, and showing mortality at 24 °C. They also displayed high resistance to hypoxic conditions, with critical oxygen tension (Pcrit) values of 0.64 ± 0.35 kPa for Corella eumyota and 2.01 ± 0.74 kPa for Asterocarpa humilis, indicating physiological capacity to persist in low oxygen environments. Predation assays conducted with native consumers observed in the plates revealed contrasting effects, as the crab Romaleon setosum consumed a high proportion of individuals, whereas the fish Hypsoblennius sordidus showed limited consumption. Adult ascidians were used in the experiments, allowing the assessment of local consumers to prey on settled organisms rather than early life stages. Overall, the results indicate that invasion success in these ascidians emerges from the combined action of broad physiological tolerance that enables persistence under broad environmental conditions and context dependent biotic resistance that may limit their expansion into adjacent natural habitats.
Evaluation of the combined toxicity of copper and benzo[a]pyrene to phytoplankton in the Jiaozhou Bay based on mesocosm experiment.
Zhang S, Li Y
Mar Environ Res · 2026 Jun · PMID 41955793 · Publisher ↗
Coastal ecosystems are frequently subjected to complex mixtures of pollutants. However, the combined ecological effects of different pollutant types, such as heavy metals and persistent organic compounds, remain poorly u...
Coastal ecosystems are frequently subjected to complex mixtures of pollutants. However, the combined ecological effects of different pollutant types, such as heavy metals and persistent organic compounds, remain poorly understood in natural environments. To investigate the combined ecological effects of copper (Cu) and benzo[a]pyrene (BaP) on phytoplankton in natural marine environments, a mesocosm experiment was conducted in the Jiaozhou Bay in autumn 2024. Changes in phytoplankton biomass (chlorophyll a, Chl-a), community structure, and nutrients were monitored in response to exposure to Cu and BaP, both individually and in combination. The results showed that Cu exhibited a strong dose-dependent inhibition effect: at low concentration level, the highly tolerant phytoplankton species Amphora sp. became dominant (Y = 1.000, where Y represents the dominance index) while at high concentration, the growth of phytoplankton was completely suppressed. In comparison to Cu, BaP showed relatively weaker inhibition effect on total biomass but markedly altered the community composition of phytoplankton, with Leptocylindrus danicus becoming dominant at high concentration (Y = 0.636). Cu and BaP showed joint toxic effects at both the low-concentration and high-concentration treatments. An antagonistic interaction was observed at the low-concentration treatment, with the measured inhibition rate (82.37 ± 1.40%) lower than the predicted value from the independent action model (92.19 ± 0.84%). In contrast, an additive effect was observed at the high-concentration treatment, implied by the consistency between the measured (98.78 ± 0.88%) and predicted (99.84 ± 0.02%) inhibition rates. This study demonstrated that in natural marine environments, combined Cu and BaP pollution can influence phytoplankton communities through either antagonistic or additive interactions, depending on their concentrations. These findings offer critical empirical evidence and a framework for developing more accurate risk assessment models for multi-pollutant scenarios in coastal ecosystems.
Effects of the nutritional quality of food on the reproduction of copepods in the vicinity of Daya Bay nuclear power plant.
Li H, Si Y, Chen M … +1 more , Shen A
Mar Environ Res · 2026 Jun · PMID 41950657 · Publisher ↗
This study investigated the regulatory mechanisms of polyunsaturated fatty acids (PUFAs) and environmental factors on copepods reproductive success in thermally influenced waters of Daya Bay through seasonal in-situ expe...
This study investigated the regulatory mechanisms of polyunsaturated fatty acids (PUFAs) and environmental factors on copepods reproductive success in thermally influenced waters of Daya Bay through seasonal in-situ experiments (2022-2023). Generalized additive models revealed that fatty acid composition was the strongest predictor of reproductive variability, explaining 75.7-91.7% of variance in weight-specific egg production, in-situ egg production (IEP), and egg hatching rate (EHR). Temperature (18.15-29.63 °C) was positively correlated with IEP but exhibited a unimodal relationship with EHR, peaking at 24 °C. Salinity (31.33-33.72) suppressed IEP linearly, while particulate organic nitrogen (3.67-57.03 μg L) enhanced both IEP and EHR; Chlorophyll a showed no significant effect. Among PUFAs, eicosapentaenoic acid (EPA) was strongly positively correlated with all reproductive metrics, whereas docosahexaenoic acid (DHA) showed consistent negative correlations, likely due to competitive prey interactions or dinoflagellate toxin exposure. The ω-6 PUFA Linoleic acid (LA) displayed metabolic antagonism with ω-3 PUFAs, showing a unimodal relationship with IEP and negative correlation with EHR. Stations proximal to the power plant exhibited elevated summer temperatures but reduced fatty acid concentrations, highlighting that PUFAs-driven food quality, rather than phytoplankton biomass, critically governs copepods population dynamics in anthropogenically pressured ecosystems.
Ciliate Uronema marinum feeding influences the production of dimethyl sulfur compounds.
Yu J, Zhang Q, Tian JY … +5 more , Liu SQ, Liu LF, Meng CX, Lu DL, Yang GP
Mar Environ Res · 2026 Jun · PMID 41946088 · Publisher ↗
Dimethyl sulfide (DMS), a climatically important biogenic gas, is produced from the transformation of dimethylsulfoniopropionate (DMSP) and dimethyl sulfoxide (DMSO). While zooplankton grazing is known to promote DMS rel...
Dimethyl sulfide (DMS), a climatically important biogenic gas, is produced from the transformation of dimethylsulfoniopropionate (DMSP) and dimethyl sulfoxide (DMSO). While zooplankton grazing is known to promote DMS release, the impacts of ciliated protozoa remain less understood. Here, we studied the effects of feeding behavior of ciliates Uronema marinum on DMS, DMSP, and DMSO generation. The diet, diet concentration, temperature, and salinity experiments showed that the presence of U. marinum increased DMS concentrations by a factor of 2 to 16 while simultaneously decreasing dissolved and particulate DMSP (DMSP) concentrations. The mean conversion efficiency of grazed DMSP to DMS(P) was 56%. However, the effect of grazing activity on dissolved and particulate DMSO (DMSO) concentrations was minor, which may be due to non-activation of DMSO reductase. Furthermore, the diet, temperature, and salinity controlled the ciliate ingestion rates (IRs), and thereby affected DMS production. The increase in DMS concentration was positively correlated with the ciliate IRs. Specifically, the optimal conditions for IRs and growth rates (GRs) of U. marinum were feeding on Isochrysis galbana at 20 °C and salinity 30-32. DMS production was highest (48.48 nmol/L) when fed Prorocentrum donghaiense and lowest (28.4 nmol/L) when fed Phaeodactylum tricornutum. Rising temperatures increased DMS but decreased DMSP. Rising salinity (peaking at 30-32) also increased DMS, while DMSP and DMSO increased with salinity in controls as osmolytes. These findings show that temperature, salinity, and prey characteristics regulate grazing-driven sulfur transformations by modulating algal DMSP/DMSO pools, ciliate physiology, and enzyme activities-key processes determining DMSP and DMSO fate within the microbial food web.
A comparative study of body proportions in Euphausiids. Relationships with the physical environment.
Färber Lorda J
Mar Environ Res · 2026 Jun · PMID 41946087 · Publisher ↗
Dominant euphausiid species inhabiting the Tropical Mexican Pacific, the California Current, and the Antarctic regions were studied to understand differences in their development patterns. Body proportions were analyzed...
Dominant euphausiid species inhabiting the Tropical Mexican Pacific, the California Current, and the Antarctic regions were studied to understand differences in their development patterns. Body proportions were analyzed in each species using four measurements and the Differentiation Index (DI, after Färber-Lorda, 1990). The genus Euphausia showed a smaller DI in warmer waters. Differences in regression slopes between sexes within each species showed distinct morphological patterns across genera. The exponent b of the asymptotic regression between Abdominal Length (AL) and Carapace Length (CL) (AL = aCL) by sex was higher for males in all Euphausia species and lower in Nyctiphanes simplex (an egg-carrying species) and the genus Thysanoessa. Differences in the mean Differentiation Index (ΔDI) between males and females were calculated for all species in each area. Mean seawater density in the upper 400 m layer, also calculated for each sampled area, showed a similar trend to ΔDI, while mean temperature showed the opposite trend. The Antarctic Euphausia superba showed the highest ΔDI. A trend towards larger Abdominal Length and Eye Diameter, but smaller Carapace Length and lower lipid levels, was found in a group of mature males (Males II) of E. superba. Higher lipid content likely contributes to buoyancy, allowing distinct morphological differentiation patterns within the genus Thysanoessa; Nyctiphanes simplex, a sac-spawning species, also exhibits a different growth pattern. Physical environmental conditions and lipid content are assumed to regulate the morphological differences between sexes in these species.
Into new depths: climate-driven habitat expansion of the endangered skate Dipturus chilensis (Chondrichthyes, Rajiformes).
Villafaña JA, Almendras D, González-Aragón D … +14 more , Torres FI, Concha FJ, Guzmán-Castellanos AB, Contreras I, Buldrini KE, Oyanadel-Urbina P, Sandoval CA, Miranda B, Mazo G, Cárdenas F, Valdivia M, Pequeño G, Lara C, Rivadeneira MM
Mar Environ Res · 2026 Jun · PMID 41941848 · Publisher ↗
The yellownose skate (Dipturus chilensis) is an endangered skate with a narrow distribution in the southeastern Pacific, facing intense fishing pressure and potential climate threats. Using a species distribution model,...
The yellownose skate (Dipturus chilensis) is an endangered skate with a narrow distribution in the southeastern Pacific, facing intense fishing pressure and potential climate threats. Using a species distribution model, we projected the current and future distribution of D. chilensis under contrasting climate change scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5) for mid-century (2050) and end-of-century (2100). Our models, which demonstrated robust predictive performance significantly better than random expectations, identified maximum temperature and minimum oxygen as the primary environmental drivers of habitat suitability. Projections revealed a consistent poleward range shift towards the Channels and Fjords of Southern Chile ecoregion across all scenarios. While localized habitat loss was projected in Central Chile and Araucanian ecoregions, particularly under high emissions (SSP5-8.5), these losses were outweighed by southern expansions, leading to a net increase in total suitable habitat by 2100. These findings underscore the critical need for climate-adaptive management strategies, including the protection of emerging southern refugia and dynamic fisheries regulations, to ensure the long-term persistence of D. chilensis.
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