High Production Volume Chemicals (HPVCs) are contaminants that pose serious threats to aquatic environments and species that inhabit them, given their massive production and ubiquitous distribution across biological compartments. Among them, organophosphate esters (OPEs) are of particular concern, as they are widely used as plasticizers and flame-retardants, and linked to various forms of toxicity in marine organisms. In this study, we investigated the ecotoxicological response of juvenile gilthead seabream Sparus aurata to the OPE tris (2-chloroisopropyl) phosphate (TCPP) following chronic dietary exposure to three different concentrations (low, D1: 0.2 mg kg^-1; ecologically relevant, D2: 2 mg kg^-1; and high, D3: 10 mg kg^-1). Different biomarkers indicative of antioxidant defence mechanisms (catalase, CAT, glutathione S-transferase, GST, activities), metabolism (citrate synthase, CS, lactate dehydrogenase, LDH, activities) and endocrine disruption (vitellogenin content, VTG), as well as cell (lipid peroxidation levels, LPO) and protein damage (ubiquitin content, UBI) were analyzed in liver and muscle to assess TCPP toxicity. High concentrations of TCPP affected S. aurata growth, but not overall fitness condition. Furthermore, metabolic disruption and severe oxidative damages were observed, regardless of exposure dose. VTG content significantly decreased after exposure to all TCPP dosages, indicating a possible masculinization effect. These findings provide new insights to the scientific knowledge on TCPP ecotoxicological attributes and impacts on marine ichthyofauna. In addition, our results confirm the relevance of conducting integrated multi-biomarker approaches to disclose the ecotoxicological effects of poorly studied chemical contaminants and, ultimately, implement wastewater treatment strategies and legislation to protect marine ecosystems from pollution.

Extreme weather events, particularly marine heatwaves (MHWs), increasingly threaten aquaculture systems worldwide by impairing animal physiology and economical sustainability. This showcases the need to develop nutritional approaches that enhance animal performance under sub-optimal conditions. This study evaluated the effects of dietary supplementation with the brown macroalga Laminaria digitata (whole dried powder or extract) on the antioxidant status, digestive activity, and lipid metabolism of juvenile Sparus aurata exposed to a simulated MHW. Fish were fed four diets (control, 0.3% extract, and 0.3% or 1.5% powder) for 30 days before being exposed to a category III Mediterranean MHW. Under optimal temperature, macroalgae supplementation reduced oxidative status (lower catalase activity). The powder-feeds decreased lipid peroxidation, while the extract-feed elicited the opposite. All supplemented diets reduced proteolytic activity, and the extract-feed also decreased amylase activity. The MHW impaired gastrointestinal antioxidant defenses and liver lipid metabolism, decreasing catalase and glutathione S-transferase activities, as well as ΣPUFA n-6, 16:1 n-7, and 18:2 n-6 levels. The 0.3% powder-feed mitigated MHW-induced reductions in antioxidant activity, while both 0.3%-diets prevented thermal stress-related alterations on fatty acid profile. Overall, L. digitata powder at 0.3% was most effective at enhancing thermal stress resilience, supporting its value as a functional aquafeed ingredient.

This study focused on the diet and feeding habits of the invasive pufferfish Lagocephalus sceleratus in the coastal waters of Crete (Cretan and Libyan Sea, eastern Mediterranean). The diet was composed of a wide variety of organisms, while the number of specimens with empty gastrointestinal tracts was low (14.41%). In total we were able to identify 38 different species of fish and invertebrates within the tracts analysed. Fish were the main diet component, followed by crustaceans and mollusks (mostly gastropods and cephalopods). At family level, the most significant preys were Sparidae and Mullidae teleosts, along with Cavoliniidae gastropods. The trophic level of L. sceleratus was estimated to be 4.13. The trophic niche breadth was intermediate, whereas the L. sceleratus population exhibits a mixed feeding strategy. Spatiotemporal differences in diet composition were also identified. The application of generalized additive models (GAMs) revealed that depth at which the fish were captured, season, region and total length, were significant predictors of the probability of occurrence of its most frequent prey groups. Fish prey occurrence was more probable in autumn and summer and at circa 20-25 m depth. In contrast, the probability of consuming crustaceans was higher in spring and winter and in specimens measuring 450-500 mm in length, and lower at 20-25 m, whilst increasing until a maximum at 40 m. The probability of non-cephalopod mollusks consumption was higher in winter and in the Libyan Sea, as well as at greater depths. Fish size had a significant effect on the likelihood of consuming photosynthetic organisms (algae and seagrass) and cephalopods, which was higher in larger fish. This study presents further evidence of the negative impact of L. sceleratus on the fisheries sector, revealing both predation on commercial species and the ingestion of various fishing gear parts.

Plastic pollution is a major environmental concern. In humans, ingestion through contaminated seafood is a recognized exposure route to microplastics, which may impact gut health. However, the extent to which microplastics interfere with digestion and nutrient absorption remains unclear. To this end, the present work aimed to assess, for the first time, the influence of microplastic particles (polyethylene terephthalate, PET, and polylactic acid, PLA) on the digestibility of three selected seafood species (gilthead seabream, Sparus aurata; Atlantic salmon, Salmo salar; and hard clam, Mercenaria mercenaria) using an in vitro human digestion model. Furthermore, this study evaluated the potential degradability of microplastics along the gastrointestinal tract and examined how particle type and exposure level (10 or 20 particles) may influence seafood digestibility. Protein digestibility in S. aurata and S. salar filets was ~86%, while in M. mercenaria it was ~73%, regardless of microplastic presence or quantity. PET and PLA integrity was affected differently by digestion, with PLA showing greater surface degradation. These findings provide preliminary insight into the mutual interactions between microplastics and the human digestive process, highlighting the importance for further research into how the leaching of plastics additives may or may not influence the bioaccessibility of essential nutrients.