Search Results (412)

Marine biofouling is a major global concern affecting the marine industry, the environment, and public health. The accumulation of organisms on submerged surfaces causes significant economic losses, including increased fuel consumption, higher pollutant emissions, and accelerated corrosion. Antifouling (AF) coatings with biocides are widely used to prevent this problem. However, many conventional biocides have been banned due to toxicity, creating an urgent need for environmentally friendly alternatives. In previous studies, we synthesized a gallic acid derivative and three flavonoids that showed AF activity against the settlement of mussel larvae (Mytilus galloprovincialis) together with low ecotoxicity. In the present work, to further assess their potential in marine coatings and exploit the advantages of nanocarriers in protecting and prolonging bioactive effects, these compounds were loaded into halloysite nanotubes (HNTs) and incorporated into epoxy coatings. Coatings containing the same AF compounds in free form were also prepared for comparison. HNTs were characterized by scanning electron microscopy (SEM), and compound loading was quantified by thermogravimetric (TG) analysis. The resulting composites were analyzed by SEM and dynamic water contact angle measurements. Laboratory bioassays with M. galloprovincialis larvae showed that coatings containing HNT-loaded synthetic compounds generally reduced larval settlement more effectively than the corresponding coatings containing the same compounds directly dispersed in the epoxy matrix, with values below 20% after both 15 and 40 h of exposure for the best-performing formulation. These findings highlight the novelty of the proposed HNT-based delivery strategy for nature-inspired synthetic antifoulants and support its potential for the development of effective and environmentally safer AF coatings. Full article

Marine heatwaves and invasive tunicate fouling increasingly co-occur in mussel aquaculture, yet their combined effects on rope-level performance and plankton dynamics remain unclear. A 9-day field-based mesocosm experiment in Georgetown Harbour (Prince Edward Island, Canada) examined the independent and interactive effects of heatwaves (~4.5 °C above ambient) and tunicates on 50 cm sections of Mytilus edulis culture rope. Oxygen consumption rate (OCR), clearance rate (CR), capture efficiency (CE), absorption efficiency (AE), scope for growth (SFG), and condition index (CI) were quantified to assess rope-level performance, and net primary productivity (NPP) was examined to evaluate ecosystem-level effects. OCR increased with rope biomass and exhibited a biomass-temperature interaction, with a stronger increase observed under heatwave conditions. CR also increased with biomass and decreased with temperature. These shifts in metabolism and feeding resulted in near-zero SFG and reduced CI under heatwave conditions, independent of biomass. Both grazer biomass and temperature significantly influenced NPP under high-light conditions, with increasing biomass reducing NPP. Tunicate presence enhanced the retention of smaller particles, highlighting species-specific differences in particle retention within the mussel rope community. The findings suggest that warming can reduce the performance of mussel rope communities, while fouling-associated shifts in community composition may amplify grazing pressure and alter particle removal dynamics, with potential consequences for ecosystem functioning. Full article

Marine mucilage events are intensifying in semi-enclosed seas under accelerating climate- and nutrient-driven pressures, yet their ecosystem-level consequences for aquaculture-linked coastal habitats remain insufficiently documented. This study provides an integrated spatiotemporal assessment of water quality, phytoplankton community structure, and biometric responses of Mytilus galloprovincialis during and after the 2025 mucilage outbreak in the Gulf of Erdek (Sea of Marmara, Türkiye). Mucilage accumulation was associated with sharp increases in turbidity, total suspended solids, and particulate organic matter, alongside declines in dissolved oxygen and pH. Phytoplankton assemblages exhibited marked seasonal restructuring: the mucilage period was characterized by the coexistence of mucilage-forming taxa, non-toxic bloomers, and multiple harmful algal bloom (HAB) groups, including DSP- and ASP-related species, whereas post-mucilage conditions were dominated by non-toxic diatoms with substantially reduced HAB representation. The dinoflagellate species representing the May period in terms of abundance were Noctiluca scintillans and Prorocentrum micans; the diatom species were Chaetoceros radiatus, Cylindrotheca closterium, Pseudo-nitzschia pseudodelicatissima, and Thalassiosira rotula; and the coccolithophore was Phaeocystis pouchetii. Mussel biometric analyses revealed biometric indices and condition values markedly below regional historical baselines during the mucilage event, alongside reduced meat yield, followed by pronounced compensatory growth during the post-mucilage period. Our findings demonstrate that mucilage acts as both a physical and biological stressor, driving short-term ecological shifts in phytoplankton diversity and imposing substantial but reversible physiological impacts on mussel stocks. These results underscore the need for continuous biodiversity monitoring frameworks that integrate mucilage dynamics, HAB occurrence, and aquaculture resilience in regions vulnerable to climate-enhanced organic aggregate formation. Full article

Coastal ecosystems are increasingly threatened by climate change, especially the rising frequency of marine heatwaves (MHWs), which often co-occur with emerging nanomaterials such as graphene oxide (GO), whose ecological risks are still being evaluated. While the effects of GO have been studied in isolation, little is known about its interaction with thermal stress events. This research studied the combined effects of temperature (18 °C and 23 °C, simulating control and MHW conditions) and GO nanosheets exposure (0.01 mg/L) on two key estuarine bivalves: the clam Scrobicularia plana and the mussel Mytilus galloprovincialis. After 7 days of exposure (duration of many MHWs), energy metabolism, antioxidant defenses, oxidative damage, and neurotransmission were assessed. The results revealed that clams exhibited lower ETS and SOD activity when exposed to MHWs and lower SOD and AChE activities at MHW + GO, compared to the control treatment. Mussels relied primarily on SOD activity across treatments but showed increased susceptibility to GO nanosheets, with higher LPO levels and a significant reduction in AChE activity when exposed to GO at both temperatures. Overall, our findings suggest that S. plana shows a stronger response to the environmental alterations tested than M. galloprovincialis. Combined exposure to GO + MHW triggers species-specific biochemical responses in estuarine bivalves, highlighting how physiological traits shape the assessment of ecological risks posed by nanomaterial pollution under climate change. Full article

Marine biofouling remains a major challenge for maritime industries, affecting submerged structures and vessels worldwide. The long-standing reliance on biocidal coatings, together with their documented environmental impacts, has led to increasingly restrictive regulations and an urgent demand for environmentally compatible antifouling (AF) solutions. This study evaluates the AF potential and toxicological profile of two nucleoside analogues, hypoxanthine arabinoside (1′) and 2′-deoxyinosine (2′), selected based on the previously reported non-lethal AF activity of the naturally occurring nucleosides adenosine and 2′-deoxyadenosine from cyanobacteria. Both analogues inhibited the growth of Navicula sp. by approximately 60% without inducing mortality and significantly reduced settlement of Mytilus galloprovincialis plantigrades, with EC₅₀ values of 5.50 µM (1′) and 8.54 µM (2′), and no lethality detected (LC₅₀ > 200 µM). At near-EC₅₀ concentrations, both compounds increased acetylcholinesterase and tyrosinase activities, supported by molecular docking results, suggesting involvement of neurotransmission- and byssal formation-related pathways. Proteomic analysis revealed compound-specific molecular responses. No lethal effects were observed in non-target organisms (LC₅₀ > 32 µM for A. amphitrite and LC₅₀ > 50 µM for A. salina), and environmental fate modelling predicted low bioaccumulation and rapid degradation. Overall, substitution of the amino group by a carbonyl group preserved AF efficacy without increasing toxicity, highlighting nucleosides as promising low-toxicity AF agents. Full article

Mytilus galloprovincialis is a significant indicator species due to its ability to bioaccumulate environmental pollutants, such as lead (Pb), which can hinder essential reproductive molecular processes. This study aimed to examine the effect of exposure to lead (0.5, 1.5 and 5 μg/L PbCl₂) on the state of protamine-like (PL) proteins—the primary components of sperm nuclear basic proteins—and their interaction with DNA. PL proteins were analysed using acetic acid–urea PAGE and SDS-PAGE, after which their ability to bind and protect DNA from oxidative damage was also assessed. Exposure to lead resulted in SDS-PAGE-detectable alterations of the PL, particularly at levels of 1.5 µg/L and 5 µg/L of PbCl₂ and modified their capacity for DNA-binding at all doses of PbCl₂. Experiments testing the release of PLs from sperm nuclei further confirmed this, revealing a reduced release. In addition, the ability of PL proteins to protect DNA from oxidative damage was reduced at the highest exposure dose, suggesting improper condensation of sperm chromatin. Computational analyses of human protamines in the presence of lead indicated the formation of coordination complexes with Pb²⁺ in PLI-II and PL-III, potentially impairing DNA binding. Overall, our study demonstrates that exposure to lead alters the function of PL proteins and potentially destabilises the sperm chromatin of M. galloprovincialis. This provides valuable insights into the reproductive toxicity of this metal. Full article

Eukaryotic microorganisms, including microalgae, protists, fungi, and micro-metazoans, act as drivers of energy flow and nutrient cycling, collectively forming the microbial food loop, and also serve as important indicators of environmental health. To investigate the seasonal variation in eukaryotic microorganisms in a mussel farming area, a total of 96 seawater samples were collected from surface and bottom layers of water across different seasons. High-throughput sequencing of the 18S rRNA gene was employed to characterize shifts in microbial community structure and identify key influencing factors. Our results indicated significant seasonal differences in eukaryotic microbial communities between surface and bottom waters. Redundancy Analysis (RDA) revealed that seasonal variations in community structure were primarily driven by environmental factors such as temperature, dissolved oxygen (DO), and salinity. Co-occurrence network analysis indicated that surface water networks exhibited higher numbers of nodes and edges, as well as greater modularity, suggesting more distinct niche differentiation and higher natural connectivity within the community. These findings provide fundamental data for understanding the response mechanisms of eukaryotic microbial communities to seasonal changes in the mussel cultivation area of Gouqi Island. Full article

The Mediterranean mussel, Mytilus galloprovincialis, is currently facing unprecedented mass mortality events (MMEs) that threaten the economic and ecological stability of Mediterranean aquaculture. The present review gathered and analyzed current knowledge on climate change and environmental disorders that may cause MMEs in Mediterranean mussels, compromising mussel physiology and immune competence. Biological agents, which proliferate under stress conditions, can either trigger direct disease or act as co-factors in mortality. The impact of the economic loss following MMEs in mussel production in the Mediterranean Sea is also described. The main key drivers used in the analysis of the literature were “M. galloprovincialis”, “MMEs”, “environmental stressors”, “climate change”, “pathogens”, “pollutants”, “economical losses”. The One Health–One Welfare framework recognizes the inextricable interconnection between the health of human, mussel, and marine ecosystems. This approach is essential for developing holistic monitoring programs, robust risk assessment strategies, and adaptive management policies capable of ensuring the long-term sustainability of Mediterranean mussel production and the ecological stability of coastal systems. In the future, the development of integrated water monitoring systems where mussels are both farmed species and active biological sentinels is possible. The implementation of a digital monitoring system will offer a transformative strategy for mitigating MMEs in Mediterranean mussel populations. Full article

Apostichopus japonicus undergoes evisceration in response to adverse environmental stimuli, and its coelomocytes undergo rapid regeneration within 6–24 h to restore innate immune function. FOS, an immediate early gene, regulates cell proliferation and cycle, but its role in A. japonicus coelomocyte regeneration after evisceration is unclear. In this study, AjFOSL from A. japonicus was cloned, which harbors a 609 bp open reading frame (ORF) encoding 202 amino acids (aa) with a conserved bZIP domain and is localized on chromosome 14. It shares 58% homology with FOS from Holothuria leucospilota and Lytechinus pictus. Phylogenetic analysis revealed that AjFOSL clusters closely with FOS from Magallana gigas and Mytilus edulis. Tissue distribution analysis showed that AjFOSL was widely expressed in various tissues, with the highest expression level detected in the tentacles. Temporal expression profiling demonstrated that AjFOSL was significantly upregulated by 1.75-fold at 6 h after evisceration. After AjFOSL knockdown, the peak expression of Cyclin A, Cyclin B, and E2F was delayed and the coelomocyte number was consistently reduced compared with that in the evisceration-only group. The AjFOSL acted as an immediate early response gene and was associated with the regulation of coelomocyte regeneration by modulating the expression of cell cycle-related genes. This study provides novel insights into the molecular associations underlying coelomocyte regeneration and the evolutionary adaptation of FOS genes in echinoderms. Full article

Human activities have driven habitat degradation and biodiversity loss in marine ecosystems, highlighting the need for strategies that reconcile food production with ecosystem restoration. Restorative aquaculture has emerged as a potential tool to enhance habitat complexity, nutrient cycling, and biodiversity. The review highlighted a global imbalance between mussel production and research on its ecological benefits, with most studies emphasizing environmental impacts rather than positive ecosystem effects. Mussel farms enhance habitat complexity and provide trophic subsidies through mussel fall-off, supporting higher abundances of crustaceans and echinoderms, including commercial species such as lobsters. Ecological effects vary with spatial scale, production type (inshore vs. offshore), substrate characteristics, and farm structure. This review highlights both the ecological benefits and potential risks, including ecological traps. Research gaps include the need for quantitative assessments and long-term monitoring. Mussel farms act as both trophic and structural facilitators, demonstrating how low-trophic aquaculture can synergistically support marine biodiversity and ecosystem resilience. Properly managed, mussel farming could transition from a food production activity to a regenerative ecological tool. Full article

Synthetic or plastic microfibers (MFs) are an emerging form of microplastic pollution in marine ecosystems, derived from textile degradation and weathering of fishing and aquaculture gear. Despite extensive evidence of MFs in marine organisms, the effects of MFs exposure on mussels remain poorly understood. This study investigated the impact of synthetic MFs on the mussel Mytilus galloprovincialis (Lamarck, 1819) over a semi-chronic time scale of 14 days, using MFs produced by grinding a microfiber cloth. Adult mussels were exposed to three MFs treatments: 8, 40, and 100 MFs/L, reflecting current and future scenarios in the Black Sea. Biomarkers assessed included lysosomal membrane stability (LMS), catalase (CAT), glutathione-S-transferase (GST), and acetylcholinesterase (AChE) activities. Significant lysosomal membrane destabilization (p < 0.05) occurred across all treatments. CAT activity in the digestive gland significantly decreased by 31.2%, 53.3%, and 62.1% at 8, 40, and 100 MFs/L, respectively. GST activity showed inhibition at 8 and 100 MFs/L and stimulation at 40 MFs/L. AChE activity decreased at 8 MFs/L but increased at higher concentrations. These results indicate that even environmentally relevant levels of synthetic MFs can alter cellular stability and enzymatic responses in mussels, suggesting potential ecological risks for marine bivalves. Full article

Better understanding the fate and transport of estuarine per- and polyfluoroalkyl substances (PFASs) requires coupling multiple matrix-specific biogeochemical roles, rather than relying on a single-matrix approach. We therefore evaluated sediment and biological matrices (blue mussels (BMs), Mytilus edulis; and hardshell clams (HSCs), Mercenaria mercenaria) as complementary indicators of PFAS contamination across three locations over a 240-day period following a spill event. A three-tiered analytical approach was applied: Tier 1 used non-parametric statistics to assess the broad-spectrum detection patterns for a total of 40 PFASs (n = 47 samples); Tier 2 employed generalized regression (adaptive Elastic Net), random forest, and artificial neural networks to model the concentrations of the most frequently detected PFASs (PFOS, PFOA, PFHxA, and PFOSA) (n = 188 observations); and Tier 3 implemented a system dynamics model to mechanistically couple the PFOS and 5:3 FTCA fate. The results suggest that the sediment acted as a long-term sink for legacy long-chain compounds (99.3%, primarily PFOS), while the biota, particularly BMs, acted as sensitive recorders of acute pulses and hydrophilic precursors, uniquely accumulating 5:3 FTCA during spring pulses (p < 0.001). All the models identified the matrix type as the dominant driver of the most prevalent PFAS concentrations. A reliance on sediment monitoring alone may fail to capture the majority of the active contamination burden sequestered in the biota, suggesting that effective risk assessment necessitates an integrated view. Full article

Biofouling communities are usually managed as pests in aquaculture, yet their natural proliferation in fish farms makes them also promising IMTA extractive components. The growth and biomass production of four dominant macrofoulers, Mytilus galloprovincialis (mussels), Sabella spallanzanii (polychaete worms), Phallusia mammillata and Styela plicata (ascidians), were evaluated under a novel IMTA system in the Ionian Sea (southern Italy). Coconut-fiber ropes (10 m) were deployed around fish cages in October 2022 and monitored over a 1-year cycle. Monthly density, length-frequency and cohort analyses combined with species-specific length-weight relationships were used to estimate target species’ growth and biomass. Mytilus and Sabella showed single-cohort dynamics, with densities steadily declining over time, whereas ascidians displayed continuous recruitment allowing for additional rope-deployment windows. Specific growth rates in length were significantly higher in Phallusia and Sabella (≈25% month⁻¹) than in Mytilus and Styela (≈17 and 22% month⁻¹). Total macrofouling biomass (live weight) increased from ≈350 kg in May to a peak of ≈2500 kg in August, remaining as high in October. Mytilus and Sabella accounted for 60–80% of total biomass while ascidians contributed 20–40%. Beyond environmental restoration, this multispecies biomass offers several potential commercial opportunities and could be further valorized through biorefinery-based cascading extraction, including final conversion into bioenergy. Overall, IMTA could leverage traditionally undesired fouling organisms as multifunctional crops, enhancing bioremediation while supporting circular blue-bioeconomy principles. Future research should focus on optimizing rope deployment timing, harvesting strategies, and biomass valorization pathways to fully exploit the emerging potential of integrating multispecies fouling biomass within IMTA systems. Full article

To address the inefficiency and high labor intensity associated with traditional manual mussel seedling unloading, this study proposes an automated traction-rope mussel unloading machine. This study focuses on the thick-shelled mussel (Mytilus coruscus) as the research subject. Furthermore, the key mussel unloading processes were simulated using the EDEM software to analyze mechanical interactions during detachment. A breakable mussel discrete element model was developed, and its Bonding V2 model parameters were systematically calibrated. Using the ultimate crushing displacement (2.25 mm) and ultimate crushing load (552 N) as response variables, the model was optimized through a sequential experimental design comprising Plackett–Burman screening, the steepest ascent method, and the Box–Behnken response surface methodology. The results demonstrate that the optimal parameter combination consists of unit area normal stiffness (2.48 × 10¹¹ N/m³), unit area tangential stiffness (3.80 × 10⁸ N/m³), critical normal stress (3.15 × 10⁶ Pa), critical tangential stress (2.90 × 10⁷ Pa), and the contact radius (1.60 mm). The model’s accuracy was validated through integrated discrete element simulations and prototype testing. The equipment achieves an exceptionally low mussel damage rate of only 1.2%, effectively meeting the operational requirements for mussel unloading. This study provides both theoretical foundations and practical insights for the design of mechanized mussel unloading systems in China. Full article

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovitis. The prevalence of RA is estimated to be 0.5–1% worldwide. Methods: This work investigated the therapeutic effects and underlying mechanisms of blue mussel (Mytilus galloprovincialis) oil (BMO) on RA in rats, using green-lipped mussel oil (GMO) and Antarctic krill oil (KO) as controls. Results: The results suggested that BMO, GMO, and KO all alleviated paw swelling in rats and reduced serum levels of rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibody, and pro-inflammatory cytokines such as TNF-$\alpha$ and IL-17. Histopathological assessment further revealed that BMO, GMO, and KO prevented synovial fibroplasia, mitigated inflammatory cell infiltration, and improved cartilage damage in ankle joints. Overall, BMO exhibited slightly superior alleviating effects compared with GMO and KO. Plasma lipidomics analysis revealed that the lipid metabolites altered by BMO showed significant correlations with RA-related indicators, particularly pro-inflammatory cytokines. Functional enrichment analysis suggested the involvement of inflammation-related pathways, particularly the NF-$\kappa$B signaling pathway. Further validation demonstrated that BMO effectively suppressed the production of inflammatory cytokines (TNF-$\alpha$, IL-17) and the expression of NF-$\kappa$B p65, JAK2, and STAT3 proteins in synovial tissue. And IL-17 production in footpad tissues is closely associated with CD3-positive T cells. Similar effects were also observed for GMO and KO. Conclusions: Collectively, BMO might ameliorate RA by inhibiting NF-$\kappa$B and JAK2/STAT3 signaling pathways. Full article