Marine Environmental Research[JOURNAL]
Sun
200 papers
Spatial-temporal distribution differences of nitrogen and phosphorus nutrients and potential eutrophication assessment in the Pearl River Estuary.
Pan Y, Zhao H, Sun L
Mar Environ Res · 2026 Jul · PMID 42402237 · Publisher ↗
Estuaries serve as critical land-sea interfaces with high ecological and socioeconomic value, yet they are increasingly threatened by excessive anthropogenic nutrient inputs due to rapid urbanization and industrializatio...
Estuaries serve as critical land-sea interfaces with high ecological and socioeconomic value, yet they are increasingly threatened by excessive anthropogenic nutrient inputs due to rapid urbanization and industrialization. These inputs have intensified eutrophication, harmful algal blooms, and hypoxia in estuarine systems globally. The Pearl River Estuary (PRE), southern China's largest estuary, receives substantial nutrient loads from both riverine discharge and intense human activities in the highly urbanized Pearl River Delta. Using long-term monitoring data (2017-2024), this study systematically investigated the spatiotemporal distributions of dissolved inorganic nitrogen (DIN), reactive phosphate (PO-P), and dissolved oxygen (DO) in the PRE and assessed the eutrophication status. Results show a persistent nutrient regime characterized by nitrogen enrichment and phosphorus limitation. DIN distribution shows a strong correlation with river discharge, which appears to be an important factor controlling its large-scale land-sea decreasing gradient, with no pronounced east-west differentiation. In contrast, PO-P showed an "east-high, west-low" pattern, linked to coastal anthropogenic inputs and regional hydrodynamics. DO dynamics are regulated by phytoplankton photosynthesis, organic matter mineralization, water temperature, and freshwater runoff, resulting in seasonal and spatial variability. Heterogeneity was observed in nutrient limitation and eutrophication status across seasons and regions, where eutrophication in the inner estuary has been alleviated yet remains severe. This study systematically synthesizes eight years of spatiotemporal dynamics of nutrients and DO across the PRE. The integrated findings provide scientific support for developing regionally differentiated nutrient management frameworks, and have important guiding implications for alleviating eutrophication and seasonal hypoxia in large estuary ecosystems.
The concurrent ecological role of eelgrass beds and on-bottom oyster farms driving community structure in two bays of Atlantic Canada.
Power TJ, Lynn KD, Fernández M … +2 more , Quintanilla-Ahumada D, Quijón PA
Mar Environ Res · 2026 Jul · PMID 42398240 · Publisher ↗
Marine sediments support distinct complements of epifaunal and infaunal assemblages, that often end up associated with the habitats created by ecosystem engineers. While human activity has caused the decline of many of t...
Marine sediments support distinct complements of epifaunal and infaunal assemblages, that often end up associated with the habitats created by ecosystem engineers. While human activity has caused the decline of many of these engineers, like seagrasses, it also accounts for the farming and growth of others, like oysters. This study assessed the contribution of natural eelgrass beds (Zostera marina), on-bottom Eastern oyster aquaculture (Crassostrea virginica), and bare sediments to the abundance and richness of epifaunal and infaunal communities in two bays of Prince Edward Island, Atlantic Canada. Our working hypothesis was that structured habitats (eelgrass and oyster leases) sustain richer or otherwise distinct communities relative to bare sediments. To test it, we sampled epifauna through multiple trapping surveys and then examined infaunal communities in the three habitats. Epifaunal surveys showed that eelgrass beds and oyster leases supported richer and more abundant communities than bare sediments. Multivariate analyses also showed that samples from the first two habitats differed from bare sediments in composition and abundance. Meanwhile, infaunal communities were denser but less diverse in bare sediments, with MDS plots evidencing clear among-habitat differences. These results supported our hypothesis and the notion that structurally complex habitats foster richer epifaunal and infaunal communities, likely by providing diverse shelter and resources. Despite their transitional nature, on-bottom oyster leases contributed to local community structure much like natural eelgrass beds, playing a concurrent ecological role. Hence, they provide services well beyond the economic benefits that they are best known for.
Zooplankton as indicators of coastal water quality: a comparative study of PlanktonScope imaging and DNA metabarcoding of seawater and mesh-screened samples.
Peng Y, How CM, Liu D … +6 more , Deconinck D, Zhao MH, Ip JC, Chan LL, Bi H, Qiu JW
Mar Environ Res · 2026 Jun · PMID 42398239 · Publisher ↗
Zooplankton serve as a vital link between primary producers and higher consumers and act as key indicators of aquatic environmental health. Traditional zooplankton monitoring methods are often time-consuming and labour-i...
Zooplankton serve as a vital link between primary producers and higher consumers and act as key indicators of aquatic environmental health. Traditional zooplankton monitoring methods are often time-consuming and labour-intensive, while eDNA metabarcoding and automated imaging systems offer promising alternatives. However, few studies have compared these methods, particularly regarding their sensitivity to small-scale spatial changes in zooplankton communities. Here, we compared the performance of PlanktonScope-an imaging system enabling in situ monitoring and identification of dominant plankton taxa-with eDNA metabarcoding of water and mesh-screened samples along a 20-km pollution gradient in Hong Kong. All three methods consistently detected a spatial gradient in the relative abundance of the dinoflagellate Noctiluca scintillans, jellyfish, and copepods. However, eDNA metabarcoding, especially from net samples, produced very few jellyfish reads, likely due to the fragility of their bodies. Within the eDNA results, Temora sp. And Parvocalanus crassirostris were dominant in the inner harbour, while Centropages typicus and N. scintillans prevailed in the outer harbour. Turbidity and orthophosphate phosphorus significantly influenced the abundance of several key taxa. Overall, our findings show that water- and net-based eDNA approaches provide comparable information on zooplankton diversity, capturing a broader range of taxa at finer taxonomic resolution, while PlanktonScope delivers high-resolution spatial and temporal data. Given the considerably lower workload involved, we recommend using automated imaging for the rapid assessment and monitoring of zooplankton taxa, and water-based eDNA metabarcoding for a deeper understanding of coastal zooplankton community dynamics.
Regulation of short-lived halocarbon distributions and emissions by the Indonesian Throughflow in the Eastern Indian Ocean.
Li J, Zhang S, Zhai X … +1 more , Du L
Mar Environ Res · 2026 Jul · PMID 42398238 · Publisher ↗
Short-lived brominated and iodinated methanes, such as bromoform (CHBr), dibromomethane (CHBr), and methyl iodide (CHI), have significant implications for the halogen cycle, atmospheric chemistry, and climate change. Des...
Short-lived brominated and iodinated methanes, such as bromoform (CHBr), dibromomethane (CHBr), and methyl iodide (CHI), have significant implications for the halogen cycle, atmospheric chemistry, and climate change. Despite their importance, the spatial variability and emission patterns of these halocarbons originating from unique marine environments remain poorly understood. Here, we investigate the response of CHI, CHBr, and CHBr to physical and biological drivers in the Eastern Indian Ocean, a region significantly influenced by the Indonesian Throughflow (ITF). We observe that concentrations of CHI, CHBr, and CHBr are significantly higher in the northern region than in the southern region within the ITF-influenced area, resulting in emission fluxes that are 1.5 to 2.0 times greater than those in the southern region. This enhanced emission is driven by the interaction between nutrients and biological processes. Such interplay is boosted by the warm ITF, with the most pronounced effects observed in the northern ITF-influenced regions. Additionally, we uncover that the nutrient supply at the convergence front of water masses, driven by eddies and upwelling, serves as a key driver for the production of CHI, CHBr, and CHBr. This research highlights the significant contribution of unique marine dynamic processes to atmospheric CHI, CHBr, and CHBr, thereby deepening our understanding of their oceanic releases and atmospheric budgets.
Differential thermal sensitivity among shallow-water octocorals and its association with holobiont composition.
Cheng HY, Wang YC, Meng YZ … +5 more , Wu CY, Liu AC, Lin YC, Hung JH, Yang SH
Mar Environ Res · 2026 Jun · PMID 42391863 · Publisher ↗
Octocorals are increasingly recognized as important structural components of reef ecosystems, yet the mechanisms underlying their responses to thermal stress remain poorly understood. In particular, it remains unclear wh...
Octocorals are increasingly recognized as important structural components of reef ecosystems, yet the mechanisms underlying their responses to thermal stress remain poorly understood. In particular, it remains unclear whether differences in thermal sensitivity among octocorals correspond to variation in their symbiotic algae and associated bacterial communities. Here, we investigated the physiological and microbial responses of four shallow-water octocoral genera (Litophyton, Lobophytum, Sarcophyton, and Sclerophytum) collected from the same region and exposed to experimentally elevated temperatures. Physiological measurements revealed clear genus-specific differences in thermal sensitivity: Litophyton was the most sensitive, showing the most rapid decline in photosynthetic efficiency, the greatest loss of algal symbionts, and the highest mortality. Notably, this pattern did not track symbiont identity: Litophyton was dominated by the thermally tolerant symbiont Durusdinium, whereas the more resilient genera were associated primarily with Cladocopium. Microbiome analyses revealed host-specific bacterial assemblages, with Litophyton harboring a distinct community dominated by Endozoicomonas. Under heat stress, total Endozoicomonas abundance in Litophyton remained relatively stable, but its composition shifted at the ASV level, indicating fine-scale microbial restructuring. Together, these results suggest that thermal sensitivity was not explained by symbiont identity or bacterial community composition among the octocorals examined here. The factors underlying these genus-level differences remain to be identified, but host-level traits, such as morphology and evolutionary history, represent plausible candidates that warrant further investigation. More broadly, our findings caution against directly applying scleractinian-derived holobiont frameworks to octocorals, and highlight the need to better understand how octocoral-dominated reefs respond to continued warming.
Development of a multiplex PCR-nucleic acid chromatographic strip for rapid detection of representative harmful microalgae in the East China Sea.
Liu F, Zhang M, Ma Y … +5 more , Zhu Y, Wang Y, Guo C, Zhang C, Chen G
Mar Environ Res · 2026 Jul · PMID 42391862 · Publisher ↗
Harmful algal blooms (HABs) are often triggered by the combined effects of multiple phytoplankton species. Therefore, developing an efficient method for simultaneously detecting microalgae is key to providing early warni...
Harmful algal blooms (HABs) are often triggered by the combined effects of multiple phytoplankton species. Therefore, developing an efficient method for simultaneously detecting microalgae is key to providing early warning of HABs. This study developed a technique based on multiplex PCR combined with the nucleic acid chromatographic strip (mPCR-NACS), which can simultaneously detect three representative harmful microalgae in the East China Sea, i.e., Heterosigma akashiwo, Prorocentrum donghaiense, and Karenia mikimotoi. Here, three pairs of specific primers (Ha-FP/Ha-RP, Pd-FP/Pd-RP, and Km-FP/Km-RP) containing specific tags, spacer, and primer sequences were designed based on the ribosomal large subunit rDNA D1-D2 of the target species. The mPCR amplification system was initially established using these specific primers, followed by the optimization of key parameters to increase efficiency, including hybridization temperature (40°C) and detection probe concentration (5.0 μM). Next, a cross-reactivity test with representative control algal species revealed the specificity of the developed mPCR-NACS. A further stability test showed that non-target microalgal species did not interfere with the detection of target microalgae by mPCR-NACS, demonstrating excellent anti-interference ability. In addition, a final evaluation with simulated natural water samples showed that the detection limit of mPCR-NACS could reach 10 cells mL. In summary, the established mPCR-NACS is characterized by simplicity, rapidity, and visualized results, which may provide reliable technical support for the early warning and monitoring of HABs.
Influence of river flow on the catch and biomass of Sakura shrimp in Suruga Bay, Japan.
Nhem V, Siev S, Dwinandha D … +1 more , Yoshimura C
Mar Environ Res · 2026 Jun · PMID 42391861 · Publisher ↗
While coastal ecosystems are strongly influenced by riverine inputs that transport nutrients and stimulate productivity, they can degrade habitats through altered flow regimes. A notable example is Suruga Bay, the deepes...
While coastal ecosystems are strongly influenced by riverine inputs that transport nutrients and stimulate productivity, they can degrade habitats through altered flow regimes. A notable example is Suruga Bay, the deepest bay in Japan, where the economically important Sakura shrimp (Lucensosergia lucens) fishery has substantially declined in recent decades; however, whether river discharge has contributed to this decline remains unclear. This study examines the effect of river discharge on the catch and biomass of Sakura shrimp in this bay. We integrated the statistical analyses of four decades of fishery data (1983-2020) with a three-dimensional ecosystem model (STOC-LT) configured for 2020 under altered river discharge scenarios from four major rivers. The ecosystem model successfully reproduced the observed seasonal patterns of Chl-a and water temperature in Suruga Bay, strengthening the basis for scenario analyses. The scenario analysis revealed fundamentally distinct seasonal pathways. In spring, the increased discharge enhanced the estimated catch through nutrient-driven spatial redistribution near the Fuji River plume, whereas the simulated biomass remained stable, indicating increased catchability rather than population growth. In autumn, both models converged on negative responses; a 20% increase in the river discharge reduced the simulated biomass from 5.22 × 10 to 4.89 × 10 mgC m and estimated catch from 43.5 to 33.1 ton/day, likely as the warmer river water constrains larval survival and reduces catchability. These findings demonstrate that the effects of river discharge on Sakura shrimp fisheries critically depend on the seasonal environmental context, highlighting the need for season-specific management of river discharge.
Energetic scaling mechanisms underlying family growth variation in Ruditapes decussatus.
Ibarrola I, Pérez-Cebrecos M, Antolín C … +6 more , Prieto D, Urrutxurtu I, Urrutia MB, Gairín I, Saavedra C, Navarro E
Mar Environ Res · 2026 Jun · PMID 42385263 · Publisher ↗
The grooved carpet shell (Ruditapes decussatus) is a commercially valuable bivalve species facing declining production due to limited natural recruitment and high inter-individual variability in growth. This study aimed...
The grooved carpet shell (Ruditapes decussatus) is a commercially valuable bivalve species facing declining production due to limited natural recruitment and high inter-individual variability in growth. This study aimed to identify the growth variation at both inter-family and intra-family levels over short- and long-term periods. Four full-sibling families (i.e., offspring from one female × one male) were produced and reared under identical hatchery conditions. Individuals covering the full range of growth rate variation were sampled during the juvenile and adult stages (experiments initiated at 4 and 18 months post-fertilization) to assess physiological parameters related to energy acquisition and metabolism. Intra-family differences in growth were more pronounced than inter-family differences, with full siblings displaying over two orders of magnitude in live weight after only 4 months, a pattern that persisted over time. Allometric analysis revealed that faster-growing individuals displayed equal or higher feeding and routine metabolic activity per unit mass compared to their slower-growing siblings, after accounting for differences in body size. These results suggest that intrinsic differences in filtering capacity are the main physiological contributor of intra-family variation in growth performance. Limited but significant inter-family differences were also observed in physiological scaling parameters, supporting the role of genetic background in influencing growth. Overall, our findings highlight endogenous filtering capacity as the primary physiological mechanism underlying growth variability in R. decussatus, providing mechanistic insight into energetic regulation of growth in marine bivalves.
Associations of nutrient and heavy metal gradients with the diversity, functional traits, and community assembly of marine planktonic ciliates.
Zhang E, Chen J, Zhang W
Mar Environ Res · 2026 Jun · PMID 42385262 · Publisher ↗
Planktonic ciliates are key components of marine microbial food webs and sensitive responders to environmental variation. Seasonal surveys at 12 stations in Xiamen Bay were conducted to examine associations between nutri...
Planktonic ciliates are key components of marine microbial food webs and sensitive responders to environmental variation. Seasonal surveys at 12 stations in Xiamen Bay were conducted to examine associations between nutrient and heavy metal gradients and ciliate productivity, diversity, functional traits, and community assembly. A total of 94 species were identified. Abundance and biomass peaked in spring, whereas tintinnids dominated in autumn. Ciliate abundance and diversity were generally higher near the Jiulong River estuary and industrial areas, where nutrient and heavy metal concentrations were elevated. Functional traits showed clear seasonality, with medium-sized forms dominating from spring to autumn and loricate forms reaching their highest CWM score in autumn. RLQ and fourth-corner analyses showed that tintinnids were positively associated with Cr but negatively associated with Cu, Cd, TP, and PO-P, whereas aloricate ciliates showed the opposite pattern. Co-occurrence networks were dominated by positive associations and showed higher connectivity in surface waters. Neutral community models indicated that stochastic processes explained 32 to 40% of community variation, suggesting a moderate neutral component in community assembly. These results show that nutrient and heavy metal gradients were associated with planktonic ciliate community variation in Xiamen Bay, including changes in species and trait composition, network structure, and community assembly, thereby providing an ecological basis for assessing environmental change in eutrophic and contaminated coastal waters.
LIMPET: Grazer, sculptor, facilitator, food. Perhaps the most overlooked ecosystem engineer and service provider of our time.
Firth LB
Mar Environ Res · 2026 Jun · PMID 42385261 · Publisher ↗
Limpets are abundant and recognisable inhabitants of shorelines globally, yet their ecological and societal roles remain underappreciated. Through persistent grazing, bioerosion, and the provision of mobile biogenic surf...
Limpets are abundant and recognisable inhabitants of shorelines globally, yet their ecological and societal roles remain underappreciated. Through persistent grazing, bioerosion, and the provision of mobile biogenic surfaces through their shells, many limpets modify habitat structure, regulate algal assemblages with cascading effects on biodiversity. Their grazing activity can regulate disturbance-mediated mosaics and grazer-dominated bare patches, while shells can support diverse epibiotic and cryptic associated communities which under certain circumstances, can act as localised reservoirs of propagules and genetic diversity. The strength and direction of these effects are highly context dependent and vary with species traits, density and environmental conditions, with the strongest engineering impacts often associated with large-bodied or territorially dominant species. Together, these processes position some limpets as ecosystem engineers whose influence extends beyond trophic interactions to include habitat modification and formation. Beyond their ecological functions, limpets have long provided provisioning and cultural services, including use as food, bait, tools and shell products. Human exploitation can therefore represent not only biomass extraction, but also the selective removal of dominant habitat-modifying grazers with potential consequences for ecosystem functioning and resilience. Emerging research further indicates that the functional traits of some limpet species could be harnessed in nature-based solutions including biofouling control, eco-engineering on coastal infrastructure and support for habitat recovery. Recognising limpets as ecosystem engineers, ecosystem service providers, and components of ecological resilience provides a broader framework for integrating biodiversity conservation, restoration, and adaptive coastal management.
Presuming pathways of sea turtles using stable isotopes from shells of epibiont barnacles.
Jo K, Kim J, Kim BY … +1 more , Kim T
Mar Environ Res · 2026 Jun · PMID 42379031 · Publisher ↗
Understanding the migratory pathways of sea turtles is critical for effective conservation efforts, however, direct tracking in vast oceanic habitats remains challenging. This study explores the use of stable isotope ana...
Understanding the migratory pathways of sea turtles is critical for effective conservation efforts, however, direct tracking in vast oceanic habitats remains challenging. This study explores the use of stable isotope analysis (SIA) of epibiont barnacle shells as a method to infer the migration history of a sea turtle. Oxygen (δO) and carbon (δC) isotopic compositions were analyzed along the growth axes of barnacle shells collected from five barnacles attached to a loggerhead sea turtle (Caretta caretta) stranded in Jeju Island, Korea. Using Secondary Ion Mass Spectrometry (SIMS), high-resolution isotopic measurements were obtained, and regionally calibrated growth curve coefficients were derived to reconstruct the turtle's migratory pathway. The isotopic values ranged from -6.56‰ to 2.17‰ for δO and from -5.06‰ to 2.98‰ for δC. The regional growth curve coefficients indicated larger and faster growth in the study area compared with previously reported regions. The analysis suggested that the turtle migrated through the Taiwan Strait, the Philippines, the Ryukyu Islands, and waters near Jeju Island before stranding. The same approach was subsequently applied to infer the migratory pathways of two other sea turtles: a loggerhead specimen, that was inferred to have moved between the Philippines and Jeju Island via Taiwan Strait and the Ryukyu Islands, and a hawksbill turtle, that might have migrated north toward Jeju Island through the Ryukyu Islands. These findings demonstrate the potential of barnacle-based SIA to provide valuable insights into sea turtle movements, particularly in regions where traditional tracking methods are impractical.
Development of salinity-zone-specific water quality criteria for total nitrogen and total phosphorus in Guangdong coastal waters, China.
Yang Y, Li Y, Zhang P … +3 more , Xu F, Ye S, Zhang J
Mar Environ Res · 2026 Jun · PMID 42379030 · Publisher ↗
Human activities and climate change have degraded coastal ecosystems by elevating nutrient concentrations, thereby exacerbating eutrophication in the coastal waters in the past decades. Increased nutrient levels lead to...
Human activities and climate change have degraded coastal ecosystems by elevating nutrient concentrations, thereby exacerbating eutrophication in the coastal waters in the past decades. Increased nutrient levels lead to hypoxia, eutrophication, and frequent harmful algal blooms. However, current estuarine and marine assessments rely on Dissolved Inorganic Nitrogen (DIN) and Dissolved Inorganic Phosphorus (DIP), disconnecting them from land-based total nitrogen (TN) and total phosphorus (TP) indicator controls. To address this, we established site-specific TN and TP criteria based on salinity zonation to support integrated land-sea management. Using 9697 monitoring datasets (2012-2022), the study area was classified into four zones: tidal freshwater zone (salinity ≤2), low brackish mixed water area (2 < salinity ≤15), moderately brackish mixed water area (15 < salinity ≤25), and seawater area (salinity >25). Numeric nutrient criteria were derived using frequency distribution statistics and Classification and Regression Tree (CART) analyses to identify ecological response thresholds. The recommended TN criteria for the four respective zones were 1.80, 1.50, 0.50, and 0.40 mg/L, while TP criteria were 0.10, 0.06, 0.05, and 0.04 mg/L. Moreover, the derived reference values were compared and analyzed with those from other coastal waters, both domestically and internationally, to verify their rationality and applicability. Validation using independent data (2021-2024) indicated that TN-based assessment increased the compliance rate of "good quality" water compared to the traditional DIN criteria, effectively mitigating false negatives in water quality evaluation. These results demonstrate that the proposed criteria effectively bridge the gap between riverine discharge limits and marine quality objectives. This study provides a robust scientific foundation for the development of zoning-based nutrient management strategies, offering solutions for different ecological zones. It presents a systematic framework that integrates land-sea nutrient control, which can be applied to manage and mitigate eutrophication in complex estuarine and coastal environments.
Plasticity of marine ecosystem dynamics as a condition for its stability: modeling seasonal and vertical dynamics of the Arctic shelf ecosystem.
Solovjova NV
Mar Environ Res · 2026 Jun · PMID 42372395 · Publisher ↗
Ecosystem stability is a central concept in systems ecology, yet its manifestation in marine ecosystems, particularly in low-productivity Arctic shelf ecosystems under climate-driven variability, remains insufficiently u...
Ecosystem stability is a central concept in systems ecology, yet its manifestation in marine ecosystems, particularly in low-productivity Arctic shelf ecosystems under climate-driven variability, remains insufficiently understood. These systems face heightened vulnerability from anthropogenic impacts and have scarce field observations. The restructuring of functional regimes in sensitive Arctic ecosystems and community reorganization necessitates modeling studies to identify stability boundaries. Here, we apply a calibrated hierarchical model to investigate the seasonal and vertical dynamics of phytoplankton, zooplankton, nitrates, and organic matter in a low-productivity Arctic shelf ecosystem. The model accounts for matter transfer along the food chain in accordance with conservation laws. For phytoplankton, it incorporates nitrate consumption, zooplankton grazing, photoinhibition, and organotrophy. The equations include phytoplankton consumption by zooplankton and zooplankton consumption by fish. External forcings comprise surface heat fluxes, seasonal variation, and vertically nonuniform temperature and illumination. Numerical experiments varying key parameters, such as maximum growth rates and half-saturation constants, reveal stable dynamical regimes and the restructuring boundaries of the dynamics. Nonlinear transitions from single-peak low-productivity dynamics (Kara Sea-like) to dual-peak high-productivity regimes (Barents Sea-like) occur without loss of stability. Zooplankton responses lag behind of phytoplankton but remain stable across trophic cascades. Spatially resolved simulations reproduce realistic surface and subsurface phytoplankton maxima (SMPs), with their timing and depth governed by physiological traits and hydrophysical conditions. The wide-range parameter variations explored in the model simulations support the hypothesis that under-ice phytoplankton blooms may occur in low-productivity Arctic seas - events that remain beyond the reach of both field surveys and satellite monitoring. The model's results are consistent with available Arctic shelf observations. These results demonstrate robust ecosystem plasticity amid parameter shifts that mirror Arctic warming, linking microscale physiological traits to macroscale functional stability and thereby informing projections for climate-stressed shelves.
Wildfire ash impacts the early development of the sea urchin Paracentrotus lividus.
Miroglio R, Soro P, Ferrando S … +6 more , Rosa G, Oneto M, Bianchini P, Faimali M, Farina S, Gambardella C
Mar Environ Res · 2026 Jun · PMID 42365837 · Publisher ↗
The Mediterranean Basin is facing an increasing frequency and intensity of wildfires driven by climate change, raising concern about their off-site impacts on marine ecosystems. This study provides for the first time the...
The Mediterranean Basin is facing an increasing frequency and intensity of wildfires driven by climate change, raising concern about their off-site impacts on marine ecosystems. This study provides for the first time the effects of wildfire ash on the early developmental stages of the sea urchin Paracentrotus lividus, a keystone Mediterranean species. Environmentally relevant aqueous ash extracts (AEAs; 5 g/L) and their dilutions were tested through spermio- and embryotoxicity assays, assessing responses across multiple levels of biological organization. Fertilization success, larval development and morphology, apoptosis and enzymatic activity were evaluated up to 72 h of exposure. In addition, the Index of Contaminant Impact (ICI) was estimated by classifying the type and frequency of larval morphological anomalies, allowing the prediction of ash concentrations that may pose an ecotoxicological risk to sea urchins. Although fertilization was not affected, early development was significantly impaired, revealing a higher sensitivity of fertilized egg exposure rather than sperm. Choline acetyltransferase (ChAT) inhibition, increased acetylcholinesterase (AChE) activity, and enhanced apoptosis were observed, indicating the activation of inflammatory and stress-related pathways. Alterations in larval morphology and development were found from 25% AEA dilution upwards, being responsible from slight to moderate impact. Overall, these results suggest that wildfire ash represents an emerging threat to the early life stages of coastal marine species such as echinoderms. Furthermore, they support the use of sea urchins as sensitive bioindicators of wildfire-related marine pollution.
Otolith elemental fingerprints indicate the importance of estuarine nursery areas for European anchovy in the Gulf of Cadiz.
Miró JM, Tanner SE, Megina C … +6 more , Donázar-Aramendía I, Dawson J, Trueman CN, Cameron TC, García-Gómez JC, Sturrock AM
Mar Environ Res · 2026 Jun · PMID 42364605 · Publisher ↗
Understanding which habitats function as nurseries is essential for assessing population connectivity and managing exploited marine fishes. Early life stages often concentrate in estuarine and coastal environments, yet h...
Understanding which habitats function as nurseries is essential for assessing population connectivity and managing exploited marine fishes. Early life stages often concentrate in estuarine and coastal environments, yet high larval abundance does not necessarily translate into recruitment to adult stocks. Here, we compared otolith chemistry and field-based abundance data to evaluate the nursery role of major estuarine systems (Guadiana, Odiel-Tinto, Guadalquivir, Cadiz Bay) and adjacent coastal areas for European anchovy (Engraulis encrasicolus) in the Gulf of Cadiz during 2016-2018. Using LA-ICPMS, we obtained elemental fingerprints from postlarvae as young as ∼20 days old, representing the first application of this technique at such an early developmental stage for this species. Despite some interannual variability, otolith elemental signatures differed consistently among locations, allowing accurate classification (80.1%) using Random Forest models. Zn, Ba, Cu, P and Pb were the most important predictors and showed positive relationships with ambient water concentrations. Adult anchovies sampled offshore in 2018 were assigned to their most probable nursery origins, revealing that ∼20% of the adult stock had used estuarine habitats, mainly the Guadiana estuary and Cadiz Bay. Importantly, the estuarine contribution did not correlate with postlarval density, particularly in the Guadalquivir estuary, highlighting the role of hydrodynamic processes in decoupling abundance from recruitment success. The heavily mining-impacted Odiel-Tinto system showed elevated metal concentrations in water and otoliths, negligible contribution to the adult stock, and evidence that Ba-based salinity marker can be confounded by contamination. Overall, this approach improves understanding of anchovy dynamics in ICES Division 9a-South.
Trophodynamics of dominant crustaceans in a permanently open lagoon system during summer: insights from stable isotopic composition and fatty acid profiles.
Kim D, Ju J, Lee DY … +1 more , Park HJ
Mar Environ Res · 2026 Jun · PMID 42364604 · Publisher ↗
A coastal lagoon is a shallow inland water body connected to the ocean with restricted inlets that receives organic matter from various sources as a land-sea transitional zone. To determine the factors driving resource u...
A coastal lagoon is a shallow inland water body connected to the ocean with restricted inlets that receives organic matter from various sources as a land-sea transitional zone. To determine the factors driving resource utilization by crustaceans in response to the East Asian summer monsoon, we compared the stable isotopic (SI) ratios and fatty acids (FAs) of three dominant crustaceans in a coastal lagoon in Korea during the pre-monsoon, monsoon, and post-monsoon periods in 2021. Bayesian mixing models were used to evaluate the relative contributions of the five potential food sources to consumer diets. The isotopic signature displayed a significant difference in interspecific and temporal comparisons, characterized by a diet shift from phytoplankton-feeding mysid shrimp to macroalgal consumption during the monsoon period. In contrast, Palaemonidae shrimps consumed macroalgae throughout summer, and selectivity was enhanced during the monsoon period. FA profiles revealed that dinoflagellates were the dominant basal food source in crustacean feeding patterns, and macroalgal consumption by crustaceans was primarily derived from freshwater discharge when the summer monsoon event influenced the physically warm and disturbed conditions in the shallow lagoon. Additionally, we confirmed that trophic plasticity in crustaceans occurred concurrently with dinoflagellate availability during the monsoon period, as revealed by chemotaxonomic analysis of the phytoplankton community structure. The complementarity of the biomarkers allowed for a better understanding of food-web dynamics in temperate lagoons linked with East Asian monsoon events by providing qualitative and quantitative information on bottom-up processes.
Estimating local-scale patch size of seafloor litter from bottom trawling experiments.
Yang Z, Shiode D, Tokai T
Mar Environ Res · 2026 Jun · PMID 42364603 · Publisher ↗
Seafloor litter has become a growing environmental concern to marine ecosystems and coastal economies. To better understand the environmental behavior of seafloor litter, it is important to characterize its spatial patch...
Seafloor litter has become a growing environmental concern to marine ecosystems and coastal economies. To better understand the environmental behavior of seafloor litter, it is important to characterize its spatial patchiness at local scales. However, the local-scale patch size of seafloor litter has rarely been quantified. Thus, a patch size spectrum method was developed to estimate local-scale patch size from bottom-trawling survey data. The method utilized geostatistical simulations to relate observed area-normalized catches with simulated area-normalized catches under varying potential patch sizes. Cross-validation demonstrated predictive accuracy with a typical relative error of ∼20% and 31% in worst-performing cases. Application to experimental bottom-tow data collected from Tokyo Bay showed the local-scale patch size of 134 m, substantially smaller than the trawling transect length (∼2.8 km). Moreover, the local-scale patch size remained temporally stable between two survey periods. This method provides a novel framework for quantifying local-scale heterogeneity in seafloor litter distribution, and it is broadly applicable to other forms of integrated line transect sampling, such as benthic organism surveys and environmental monitoring where within-transect spatial resolution is limited.
Investigating the risk mechanisms underlying community diversity in the offshore wind farm through nonlinear threshold responses of zooplankton indicator species.
Jia S, Han W, Huang S … +3 more , Liu H, Wang X, Han Q
Mar Environ Res · 2026 Jun · PMID 42364602 · Publisher ↗
Against the backdrop of increasing human activities such as offshore wind farms, understanding changes in zooplankton diversity and the threshold mechanisms underlying species responses is of considerable theoretical and...
Against the backdrop of increasing human activities such as offshore wind farms, understanding changes in zooplankton diversity and the threshold mechanisms underlying species responses is of considerable theoretical and practical significance. To investigate variations in zooplankton community diversity under wind farm disturbance, as well as the responses of indicator species to environmental factors, this study eight surveys were conducted over four years (2021-2024). The results showed that, in terms of static community pattern description, both the wind farm area and the control area exhibited relatively high community diversity, and community dissimilarity was dominated by species turnover. From the perspective of dynamic processes, six significant environmental factors were first screened using Mantel tests, followed by TITAN analysis, which successfully identified 64 indicator species. Under the pressure of the dissolved inorganic nitrogen gradient, indicator species were dominated by negative responses, whereas responses to salinity were predominantly positive. Overall, due to wind farm disturbance, the control area exhibited more responsive zooplankton indicator species than the wind farm area. This study identified indicator species that contributed positively to increasing community diversity along the diversity gradient, providing insights into the species-level mechanisms underlying diversity change. Notably, Calanus sinicus was identified as a negatively responding indicator species in the control area, with a threshold at H' = 2.166. The positively contributing species identified here offer a new perspective for the restoration of community diversity in offshore wind farm areas. These positively contributing species provide a new perspective for the restoration of community diversity in offshore wind farm areas. This study fills a gap in understanding offshore wind farm effects on zooplankton communities and species responses, and provides a scientific basis for future ecological assessment, species conservation, and wind farm planning.
Environmental variables driving spatial variation in fatty acid composition of brackish-water zooplankton communities.
von Weissenberg E, Ruhanen H, Holopainen M … +2 more , Käkelä R, Engström-Öst J
Mar Environ Res · 2026 Jun · PMID 42361489 · Publisher ↗
Eutrophication, warming, and salinity fluctuations are altering the fatty acid composition of marine plankton communities and the quality of available food to consumers. The planktonic content of essential fatty acids 22...
Eutrophication, warming, and salinity fluctuations are altering the fatty acid composition of marine plankton communities and the quality of available food to consumers. The planktonic content of essential fatty acids 22:6n-3 and 20:5n-3 is prone to changes due to the warming of seas, with cascading effects on the food webs, and zooplankton transfers these fatty acids from phytoplankton to fish. We studied the effect of temperature, salinity and eutrophication on zooplankton community samples collected during two weeks in August on R/V Aranda. The study area has high spatial representativeness and covers six basins of the Baltic Sea. The zooplankton lipids were converted to fatty acid methyl esters, which were identified by GC-MSD and analysed for quantitative composition by GC-FID. The fatty acid compositions of the zooplankton community differed between the sea areas. Temperature and eutrophication together were responsible for higher share of the fatty acid markers of heterotrophic bacteria in the zooplankton community, whereas salinity correlated with low EPA/DHA and high n-3/n-6 polyunsaturated fatty acid ratios. Salinity likely affected the fatty acid compositions indirectly by shaping the species composition: the low-salinity areas were dominated by cladocerans typically rich in EPA. This study showed that the Baltic zooplankton communities have significant spatial variation in terms of fatty acid nutritional quality, and this variation is driven by multiple environmental variables reflecting climate change. Our results help to understand how phytoplankton fatty acids mediate the effects of climate change to organisms at higher trophic levels by altering their supply of essential fatty acids.
Targeted substrate design is required to improve post-settlement survival of shellfish.
Lanham BS, Morris RL
Mar Environ Res · 2026 Jun · PMID 42361488 · Publisher ↗
The strength of biotic stressors (i.e., predation) can determine the success of shellfish reef restoration projects. In recruitment limited systems where seeding is a common restoration strategy, ensuring the survival of...
The strength of biotic stressors (i.e., predation) can determine the success of shellfish reef restoration projects. In recruitment limited systems where seeding is a common restoration strategy, ensuring the survival of seeded individuals is an ongoing challenge. Testing of novel materials that provide refuges is becoming increasingly common to combat the issue. Although this addition of complexity to restoration substrates can improve the settlement of pediveliger larvae, increasing the density of seeded individuals, how this complexity then alters post-settlement survival has been less studied. The aim of this study was to investigate post-settlement survival of juvenile oysters on concrete surfaces with added surface roughness and complexity in contrast to control tiles. Concrete tiles that had either a rough surface (via sandblasting) or a complex surface (via the addition of grooves and ridges) were seeded with Australian flat oysters (Ostrea angasi) and placed into the field for 15 months. Predator access was tested by measuring the consumption of dried mussel baits (Mytilus galloprovincialis) on complex tiles. The addition of sandblasting or complexity to concrete tiles did not alter the survival of Australian flat oysters and the consumption of blue mussel baits did not differ among complex tiles. Sandblasting and adding complexity to concrete surfaces has previously been shown to improve the settlement of shellfish but in this study, the type of complexity was not sufficient to improve post-settlement survival of oysters or reduce consumption. To create restoration substrates for shellfish or other sessile invertebrates, understanding the mechanisms that drive their settlement and post-settlement survival is vital. Here, substrates with rough or complex surfaces that encouraged larval settlement were not sufficient to increase post-settlement survival, highlighting the importance of designing substrates that can achieve positive outcomes for target species at multiple life-stages.
About
- Frequency
- Sun
- Papers found
- 200
- RSS feed
- Subscribe