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Mass strandings of sperm whales (Physeter macrocephalus) are rare in the Mediterranean Sea. Nevertheless, in 2014 a pod of 7 specimens stranded alive along the Italian coast of the Central Adriatic Sea: 3 individuals died on the beach after a few hours due to internal damages induced by prolonged recumbency; the remaining 4 whales were refloated after great efforts. All the dead animals were genetically related females; one was pregnant. All the animals were infected by dolphin morbillivirus (DMV) and the pregnant whale was also affected by a severe nephropathy due to a large kidney stone. Other analyses ruled out other possible relevant factors related to weather conditions or human activities. The results of multidisciplinary post-mortem analyses revealed that the 7 sperm whales entered the Adriatic Sea encountering adverse weather conditions and then kept heading northward following the pregnant but sick leader of the pod, thereby reaching the stranding site. DMV infection most likely played a crucial role in impairing the health condition and orientation abilities of the whales. They did not steer back towards deeper waters, but eventually stranded along the Central Adriatic Sea coastline, a real trap for sperm whales. [ABSTRACT FROM AUTHOR]

The northern Gulf of Mexico has a long history of polycyclic aromatic hydrocarbon (PAH) contamination from anthropogenic activities, natural oil seepages, and the 2010 Deepwater Horizon explosion and oil spill. The continental shelf of the same area is a known breeding ground for sperm whales (Physeter macrocephalus). To evaluate PAH-DNA damage, a biomarker for potential cancer risk, we compared skin biopsies collected from Gulf of Mexico sperm whales in 2012 with skin biopsies collected from sperm whales in areas of the Pacific Ocean in 1999–2001. All samples were obtained by crossbow and comprised both epidermis and subcutaneous blubber. To evaluate exposure, 7 carcinogenic PAHs were analyzed in lipids extracted from Pacific Ocean sperm whale blubber, pooled by sex, and location. To evaluate PAH-DNA damage, portions of all tissue samples were formalin-fixed, paraffin-embedded, sectioned, and examined for PAH-DNA adducts by immunohistochemistry (IHC) using an antiserum elicited against benzo[ a ]pyrene-modified DNA, which crossreacts with several high molecular weight carcinogenic PAHs bound to DNA. The IHC showed widespread epidermal nuclear localization of PAH-DNA adducts in the Gulf of Mexico whales (n  = 15) but not in the Pacific Ocean whales (n  = 4). A standard semiquantitative scoring system revealed significantly higher PAH-DNA adducts in the Gulf of Mexico whales compared to the whales from the Pacific Ocean study (p  =  .0002). [ABSTRACT FROM AUTHOR]

The Cuvier's beaked whale (Ziphius cavirostris) is one of the least known cetacean species worldwide. The decreasing population trend and associated threats has led to the IUCN categorising the Mediterranean subpopulation as Vulnerable on the Red List of Threatened Species. This study aimed to investigate for the first time the ecotoxicological status of Cuvier's beaked whale in the NW Mediterranean Sea. The study sampled around the 20% of the individuals belonging to the Ligurian subpopulation, collecting skin biopsies from free-ranging specimens. The levels of polychlorinated biphenyl (PCBs), polybrominated diphenyl ethers (PBDEs) and induction of cytochrome's P450 (CYP1A1 and CYP2B isoforms) were evaluated. Results highlighted that the pattern of concentration for the target contaminants was PCBs > PBDEs and the accumulation values were linked to age and sex, with adult males showing significantly higher levels than juvenile. Concerns raised by the fact that 80% of the individuals had PCB levels above the toxicity threshold for negative physiological effects in marine mammals. Therefore, these findings shed light on this silent and serious threat never assessed in the Mediterranean Cuvier's beaked whale population, indicating that anthropogenic pressures, including chemical pollution, may represent menaces for the conservation of this species in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Biodegradable polymers have been proposed as an alternative to conventional plastics to mitigate the impact of marine litter, but the research investigating their toxicity is still in its infancy. This study evaluates the potential ecotoxicological effects of both virgin and marine-incubated microparticles (MPs), at environmentally relevant concentration (0.1 mg/l), made of different biodegradable polymers (Polycaprolactone, Mater-Bi, cellulose) and conventional polymers (Polyethylene) on Mytilus galloprovincialis by using transcriptomics. This approach is increasingly being used to assess the effects of pollutants on organisms, obtaining data on numerous biological pathways simultaneously. Whole hepatopancreas de novo transcriptome sequencing was performed, individuating 972 genes differentially expressed across experimental groups compared to the control. Through the comparative transcriptomic profiling emerges that the preponderant effect is attributable to the marine incubation of MPs, especially for incubated polycaprolactone (731 DEGs). Mater-Bi and cellulose alter the smallest number of genes and biological processes in the mussel hepatopancreas. All microparticles, regardless of their polymeric composition, dysregulated innate immunity, and fatty acid metabolism biological processes. These findings highlight the necessity of considering the interactions of MPs with the environmental factors in the marine ecosystem when performing ecotoxicological evaluations. The results obtained contribute to fill current knowledge gaps regarding the potential environmental impacts of biodegradable polymers. [Display omitted] • M. galloprovincialis hepatopancreas de novo transcriptome sequencing was performed. • All microparticle (MPs) treatments significantly alter the mussel transcriptome profile. • The marine incubation of MPs increases the transcriptional effects of all polymers. • Biopolymers (cellulose and Mater-Bi) exposure causes lower transcriptional alteration. • Innate immunity and lipid metabolisms processes are the most affected by MPs exposure. [ABSTRACT FROM AUTHOR]

This study highlights for the first time the presence of plastic debris in the stomachs of Mediterranean lanternfishes (Myctophidae): Electrona risso, Diaphus metopoclampus, Hygophum benoiti and Myctophum punctatum. Samples were collected in the central Mediterranean Sea between 2010 and 2014. Plastics ingested belonged to small microplastics (0.2 - 2 mm), large microplastics (2 - 5 mm) and mesoplastics (5 - 25 mm), having mainly clear colors. Their frequency of occurrence in stomachs was equal to 2.7%, but it increases to 5.8% if only migratory species are considered. The higher number of plastics was found in E. risso and H. benoiti (5 in both species). The plastic ingestion may represent a risk for vertical migrant lanternfishes due to the increase in buoyancy. Ecotoxicological aspects linked to the potential effects of contaminants on lanternfish biology and to the transfer of pollutants throughout the marine trophic web up to top predators should be deepened. [ABSTRACT FROM AUTHOR]

Fungi are an essential component of marine ecosystems, although little is known about their global distribution and underwater diversity, especially in sediments. Microplastics (MPs) are widespread contaminants worldwide and threaten the organisms present in the oceans. In this study, we investigated the fungal abundance and diversity in sediments, as well as the MPs, of three sites with different anthropogenic impacts in the Mediterranean Sea: the harbor of Livorno, the marine protected area "Secche della Meloria"; and an intermediate point, respectively. A total of 1526 isolates were cultured and identified using a polyphasic approach. For many of the fungal species this is the first record in a marine environment. A comparison with the mycobiota associated with the sediments and MPs underlined a "substrate specificity", highlighting the complexity of MP-associated fungal assemblages, potentially leading to altered microbial activities and hence changes in ecosystem functions. A further driving force that acts on the fungal communities associated with sediments and MPs is sampling sites with different anthropogenic impacts. [ABSTRACT FROM AUTHOR]

• Simultaneous detection method for of PCBs, PBDEs, NBFRs and PAEs in fish was developed. • The developed method's analytical performance was compared to traditional methods. • The method proved to be accurate, precise and reproducible. • Method sustainable in terms of handling and solvent and time consuming. • The method was successfully applied to edible fish species from the Mediterranean Sea. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), phthalate esters (PAEs) are pervasive environmental pollutants, posing threats to both ecosystems and human health. Although several analytical methods were developed for these compounds, they are not performed simultaneously. This study addresses the need for a sustainable, novel, analytical approach capable of simultaneously determining these diverse chemical classes in edible fish muscles. Employing ultrasound extraction coupled with dispersive solid-phase extraction (d-SPE) as a cleanup procedure, the method was compared to conventional techniques, revealing significant improvements. Analytical parameters were thoroughly assessed, and the innovative method demonstrated notable advantages, reducing extraction and purification times by approximately 74–80 % and solvent consumption by around 94–97 %. Applied to Mediterranean Sea fish samples, the results underscore the method's potential as a viable, sustainable alternative to traditional approaches, promising enhanced efficiency and reduced environmental impact. [ABSTRACT FROM AUTHOR]

Monitoring microplastics (MPs) in the marine environment is an ongoing process, and our understanding of their impact on marine organisms is limited. The present study evaluates the effects of ingested MPs on the marine MP pollution bioindicator fish species Mullus surmuletus. The study follows a three-fold approach to assess the impact of MPs on marine organisms by investigating: 1) the ingestion of MPs, 2) the bioaccumulation of phthalate compounds as plastic additives, and 3) the evaluation of toxicological biochemical and cellular biomarkers. Striped red mullets were sampled in the marine protected area (MPA) of the National Marine Park of Zakynthos and coastal sites with high touristic pressure in Zakynthos Island in the Ionian Sea, Greece. Fewer ingested MPs and lower phthalate concentrations were found in fish inside the MPA compared to those sampled outside the marine park. However, no relationship was found between either phthalate concentrations or biomarker levels with the ingested MPs in the red striped mullets. Biomarker levels were influenced by season and site, but no effect could be attributed to the ingested MPs. The lack of association of biomarker responses and plasticizer bioaccumulation to MP ingestion can be explained by the low number of ingested MPs in the fish from Zakynthos coastal area as MP abundance ranged from 0.15 to 0.55 items per individual fish. [Display omitted] • Fewer ingested MPs observed in fish inside the marine protected area (MPA). • Lower phthalate accumulation measured in fish inside the MPA. • No responses of ecotoxicological biomarkers to MPs were observed. • No relationship found between either phthalate accumulation or biomarkers with MPs. • The low MP ingestion can account for the lack of ecotoxicological effects. [ABSTRACT FROM AUTHOR]

Highlights • Values measured in free-ranging specimens are lowest for all parameters, permitting to consider them as baseline data. • After 1 year of rehabilitation immune responses were similar to free-ranging ones. • During rehabilitation chronic inflammation (monocytes) and parasitism (eosinophils) decrease. Abstract The sea turtles maintaining in rescue centres can cause physiological stress to the animals with subsequent effects, such as the imbalance of immune system components. It is therefore crucial to investigate how innate immune responses are influenced by stress within recovery centers with the aim to use them as primary tools for the evaluation of the rescued specimens' health status and for developing more effective conservative strategies. In this study we monitored for the first time different immune responses in hospitalized Mediterranean loggerhead sea turtles (Caretta caretta) (n = 88), comparing them with free-ranging animals (n = 11). The final scope was to identify sensitive tools based on immune responses parameters that rescue centers operators could use to verify the stress condition of hospitalized specimens. Blood samples were obtained from loggerhead sea turtles hospidalized for different periods (≤2 months; >2 months and ≤1 year; >1 year) in various Italian rescue centers. Free-ranging turtles were captured in the South of Spain during a shipboard survey with a minimal invasive technique. Samples were analyzed for different stress-associated parameters (white cells count, heterophils:lymphocytes (H:L) ratio, respiratory burst, total antioxidant status (TAS), lysozyme). Free-ranging specimens showed lower values for most of the measured parameters. The highest values of TAS, lysozyme activity, respiratory burst and leukocytes profile were detected during the first 2 months of hospitalization, that resulted as the most critical period for the rehabilitation of turtles. After more than 1 year, immune values were similar to the values of free-ranging, indicating an acclimatization to captivity and health conditions amelioration. Moreover, monocytes low levels and eosinophils significant decrease in hospitalized animals indicated the absence of chronic inflammations and reduction of parasitic load during rehabilitation. Statistical analysis pointed out that lysozyme activity and eosinophyls count represent valid methods to diagnose physiological stress and inflammation in hospitalized loggerhead sea turtles. [ABSTRACT FROM AUTHOR]

The loggerhead sea turtle ( Caretta caretta ) is a long-lived carnivorous reptile included in the IUCN Red List. The IUCN assessment for this species underlines the lack of information regarding pollution and pathogens and indicates as a priority effort to investigate and reduce the impacts of these threats. In this contest, the aim of our study was to conduct the first ecotoxicological assessment of this species in the Mediterranean Sea using a nondestructive integrated methodology. We set up and applied a monitoring protocol which includes endpoints, such as CYP1A, LPO, ENA assay, B esterases, never investigated before in this species. Seventy-five loggerhead turtles were sampled in a nondestructive way in Italian Sea Turtle Rescue Centers or free-ranging along the Spanish coasts. Blood, skin and carapace samples were used to test biomarker responses (CYP1A, VTG, LPO, Comet and ENA assay, BChE, GGT) and contaminant (OCs, PAHs, Pb, Cd, Hg) levels. Elaboration of experimental results was carried out taking also into consideration different age classes of the specimens. Among the main results obtained we should underline the statistically significant correlation between carcinogenic PAHs in blood and DNA fragmentation as well as between Cd in carapace and GGT in plasma. We also evidenced as youngest animals showed significantly higher DNA fragmentations, BChE inhibition and increase of GGT. Older specimens showed the highest levels of erythrocyte nuclear abnormalities which may indicate a long term toxicological stress. This study contributed to expand the knowledge about the ecotoxicology of C . caretta in the Mediterranean. The nondestructive protocol could also be applied to other marine ecosystems and other sea turtle species. [ABSTRACT FROM AUTHOR]

Microplastic pollution can impact filter-feeding marine megafauna, namely mobulid rays, filter-feeding sharks, and baleen whales. Emerging research on these flagship species highlights potential exposure to microplastic contamination and plastic-associated toxins. Research and its wide communication are needed to understand the magnitude of the issue and improve marine stewardship. [ABSTRACT FROM AUTHOR]

The olive oil extraction process produces large amounts of olive mill waste (OMW) that can be re-used in agriculture by land spreading. OMW has a low pH, high salinity and high levels of polyphenols and is potentially dangerous for the environment. It is therefore mandatory to develop procedures able to produce OMW with lower environmental impact. The first aim of the present study was to evaluate the toxicological effects of two different typologies of OMW: raw Two-Phase Olive Mill Waste (TPOMW) and raw Olive Mill Waste Waters (OMWW), on a soil bioindicator, the earthworm Eisenia fetida, using neurotoxicity (AChE), oxidative stress (LPO, CAT) and genotoxicity (comet assay) biomarkers. The second aim was to test the efficacy of a composting/bioaugmentation process by investigating the toxicological effects of the bioremediated OMW. E. fetida was exposed for 72 h to increasing concentrations (12.5, 25, 50%) of raw and bioremediated TPOMW and OMWW in an artificial soil (50% potting soil + 50% quartz sand). Raw OMW caused earthworm mortality at high doses and measurable biochemical and cellular effects at lower doses. The main cause of these effects is probably the high level of polyphenols present in the OMW. Neurotoxic effects, induction of oxidative stress and genotoxic effects were highlighted. The most evident toxicological effects were produced by the TPMW. The evaluation of the bioremediation process efficacy revealed that a high decrease in acidity and polyphenol content corresponds to a decrease of toxicological effects. This study contributed to assess the environmental sustainability of the bioremediated OMWs, to be used as fertilizers in agriculture. [ABSTRACT FROM AUTHOR]

This is the first survey to investigate the occurrence and extent of microplastic (MPs) contamination in sub surface waters collected near-shore and off-shore the coastal area of the Ross Sea (Antarctica). Moreover, a non-invasive method to analyze MPs, consisting in filtration after water sampling and analysis of the dried filter through Fourier Transform Infrared Spectroscopy (FTIR) 2D Imaging, using an FPA detector, was proposed. The non-invasiveness of analytical set-up reduces potential bias and allows subsequent analysis of the filter sample for determination of other classes of contaminants. MPs ranged from 0.0032 to 1.18 particle per m 3 of seawater, with a mean value of 0.17 ± 0.34 particle m −3 , showing concentrations lower than those found in the oceans worldwide. MPs included fragments (mean 71.9 ± 21.6%), fibers (mean 12.7 ± 14.3%), and others (mean 15.4 ± 12.8%). The presence of different types of MPs was confirmed by FTIR spectroscopy, with predominant abundance of polyethylene and polypropylene. The potential environmental impact arising from scientific activities, such as marine activities for scientific purposes, and from the sewage treatment plant, was also evidenced. [ABSTRACT FROM AUTHOR]

• Zebrafish were treated with microplastics (MPs) and sorbed environmental contaminants. • Gastrointestinal (GIT) mucosa and gill epithelium were severely altered. • The composition of the GIT-associated microbiome was modified. • Complex behavioral alterations were observed. • MPs with sorbed contaminants produced more harmful effects than MPs alone. Aquatic animals ingest Microplastics (MPs) which have the potential to affect the uptake and bioavailability of sorbed co-contaminants. However, the effects on living organisms still need to be properly understood. The present study was designed to assess the combined effects of MPs and environmental contaminants on zebrafish (Danio rerio) health and behavior. Adult specimens were fed according to three different protocols: 1) untreated food (Control group); 2) food supplemented with 0.4 mg/L pristine polyethylene-MPs (PE-MPs; 0.1–0.3 mm diameter) (PEv group); 3) food supplemented with 0.4 mg/L PE-MPs previously incubated (PEi group) for 2 months in seawater. Analysis of contaminants in PEi detected trace elements, such as lead and copper. After 15 days of exposure, zebrafish underwent behavioral analysis and were then dissected to sample gills and intestine for histology, and the latter also for microbiome analysis. Occurrence of PEv and PEi in the intestine and contaminants in the fish carcass were analyzed. Both PEv- and PEi-administered fish differed from controls in the assays performed, but PEi produced more harmful effects in most instances. Overall, MPs after environmental exposure revealed higher potential to alter fish health through combined effects (e.g. proportion of microplastics, pollutants and/or microorganisms). [ABSTRACT FROM AUTHOR]

Transitional water ecosystems have low water exchanges and can trap chemicals and microplastics (MPs). In this study, MPs, trace elements, polycyclic aromatic hydrocarbon-PHAs levels and the oxidative stress response were assessed in Mytilus galloprovincialis from two Italian lagoon ecosystems (Orbetello and Varano). In addition, the ecotoxicological effects induced by the exposure of M. galloprovincialis to high-density polyethylene-HDPE MPs were also determined. Levels of trace elements were almost always comparable among the sites, whereas MPs were found only in mussels from Orbetello. PAHs were always under the limit of quantification. Glutathione peroxidase and malondialdehyde levels were significantly higher in mussels from Varano. As regard the exposure test, it was found a significant effect of treatment, site and their interaction on mortality and biochemical biomarkers in both fed and unfed mussels. However, principal component analysis suggests similar effects of both color and nourishment condition on biochemical biomarkers. These findings warrant further investigation. [Display omitted] • Mussels from the two lagoons differed in contaminants and oxidative stress levels. • Site of mussel collection influence the oxidative stress biomarkers. • Exposure of mussels to 0.05 g/L HDPE microplastics caused biochemical effects. • HDPE color and feeding condition did not influence biomarkers of oxidative stress. [ABSTRACT FROM AUTHOR]

The establishment of marine protected areas is considered the main global strategy to halt the loss of marine biodiversity. Since most of marine areas are open systems, this form of habitat protection cannot prevent their contamination due to human activities performed outside of their borders. Innovative approaches to assess the health status of protected marine habitats are therefore needed. Here we developed a multidisciplinary approach that combines ecological characteristics, bioaccumulation of inorganic and organic pollutants, cell damage (micronuclei frequency, nuclear alterations and LPO) and enzymatic (AChE, CAT, IDH, LDH, GST and CAT) markers focused on an intertidal brachyuran crab, Pachygrapsus marmoratus , to assess the impacts of contaminant exposure on Mediterranean coastal habitats. As study sites we selected two protected areas and two sites within industrial ports of the Ligurian Sea. Our results showed that the selected crab species is an excellent bioindicator. Individuals collected in sites with the highest levels of heavy metal pollution showed the highest signals of stress responses at both cellular and enzymatic levels, coupled with a high incidence of the parasite Sacculina carcini , a signal of impairment of their standard development and reproduction cycle. We could also prove that one of the selected marine protected areas showed the same intensity of impact as its adjacent port site. Our multidisciplinary approach proved to be a valuable tool to assess the environmental quality and health of protected and disturbed Mediterranean coastal environments and to inform efficient management and protection schemes for such habitats. [Display omitted] • Ecological, chemical and biomarker data were recorded in an intertidal crab. • Populations from two marine protected areas and two adjacent ports were selected. • Oxidative stress and genotoxicity biomarkers were higher in crabs from polluted sites. • One protected population showed stress related responses similar to adjacent port one. • Our integrated approach showed to be reliable for efficient management for coastal habitats. [ABSTRACT FROM AUTHOR]

Chemicals discovered in water at levels that may be significantly different than expected are referred to as contaminants of emerging concern (CECs) because the risk to environmental health posed by their occurrence/frequency is still unknown. The worldwide distributed compounds perfluorooctanoic acid (PFOA) and bisphenol A (BPA) may fall into this category due to effects on endocrine receptors. We applied an ex vivo assay using small slices of bioptic skin from the bottlenose dolphin, Tursiops truncatus , cultured and treated for 24 h with different PFOA or BPA concentrations to analyze global gene expression. RNA was labeled and hybridized to a species-specific oligomicroarray. The skin transcriptome held information on the contaminant exposure, potentially predictive about long-term effects on health, being the genes affected involved in immunity modulation, response to stress, lipid homeostasis, and development. The transcriptomic signature of dolphin skin could be therefore relevant as classifier for a specific contaminant. [ABSTRACT FROM AUTHOR]

A plethora of different sampling methodologies has been used to document the presence of micro-plastic fragments in sea water. European Marine Strategy suggests to improve standard techniques to make future data comparable. We use Manta Trawl sampling technique to quantify abundance and distribution of micro-plastic fragments in Sardinian Sea (Western Mediterranean), and their relation with phthalates and organoclorine in the neustonic habitat. Our results highlight a quite high average plastic abundance value (0.15 items/m 3 ), comparable to the levels detected in other areas of the Mediterranean. “Site” is the only factor that significantly explains the differences observed in micro-plastic densities. Contaminant levels show high spatial and temporal variation. In every station, HCB is the contaminant with the lowest concentration while PCBs shows the highest levels. This work, in line with Marine Strategy directives, represents a preliminary study for the analysis of plastic impact on marine environment of Sardinia. [ABSTRACT FROM AUTHOR]

In the present study, the genotoxic potential of nanosized TiO 2 anatase and micro-sized rutile on bottlenose dolphin ( Tursiops truncatus ) fibroblasts and leukocytes was investigated. Human and mouse cells were also studied in order to compare susceptibility to TiO 2 in different mammalian species. Cell lines were exposed for 4, 24, and 48 h to different concentrations of TiO 2 (20, 50, 100, 150 μg/ml) and DNA damage was investigated by single cell gel electrophoresis (Comet assay). Both anatase and rutile induced increased DNA damage, even though statistically significant effects were scattered according to species and cell lines. Bottlenose dolphin leukocytes and murine fibroblasts exhibited increased DNA damage after rutile exposure at some doses/times, while human fibroblasts showed a significant dose–response effect after a 4 h exposure to anatase. Human leukocytes were tolerant to both anatase and rutile. Ultrastructural investigation showed that TiO 2 particles entered the cell and were compartmentalized within membrane-bound vesicles. [ABSTRACT FROM AUTHOR]

Few studies evaluated long-term effects of polyvinyl chloride (PVC) microplastics (MPs) ingestion in fish. The present study aimed to investigate the integrated biomarker responses in the liver and blood of 162 European seabass, Dicentrarchus labrax , exposed for 90 days to control, virgin and marine incubated PVC enriched diets (0.1 % w/w) under controlled laboratory condition. Enzymatic and tissue alterations, oxidative stress, gene expression alterations and genotoxicity were examined. Additives and environmental contaminants levels in PVC-MPs, control feed matrices and in seabass muscles were also detected. The results showed that the chronic exposure at environmentally realistic PVC-MPs concentrations in seabass, cause early warning signs of toxicological harm in liver by induction of oxidative stress, the histopathological alterations and also by the modulation of the Peroxisome proliferator-activated receptors (PPARs) and Estrogen receptor alpha (ER-α) genes expression. A trend of increase of DNA alterations and the observation of some neoformations attributable to lipomas suggest also genotoxic and cancerogenic effects of PVC. This investigation provides important data to understand the regulatory biological processes affected by PVC-MPs ingestion in marine organisms and may also support the interpretation of results provided by studies on wild species. [Display omitted] • Exposure to PVC-MPs cause early warning signs of toxicological harm in liver. • Exposure to PVC-MPs cause genotoxic and cancerogenic effects. • Development of neoplasm tissues could be related to the PVC chronic exposure. • Additives and POPs levels in PVC-MPs, control feed and muscles were detected. • Chronic exposure studies are an important tool to clarify the MPs impact in fish. [ABSTRACT FROM AUTHOR]

Due to massive production, improper use, and disposal of plastics, microplastics have become global environmental pollutants affecting both freshwater and marine ecosystems. Several studies have documented the uptake of microplastics in wild species and the correlated biological effects, such as epithelial damage, inflammation, metabolic alterations, and neurotoxicity. However, the effects of microplastics are not fully understood yet. In this study, adult zebrafish have been exposed for twenty days to two concentrations of a mix of polystyrene and high-density polyethylene microplastics. The biological effects were investigated through the expression levels of a set of selected genes in head kidney samples and two enzymatic biomarkers, acetylcholinesterase and lactate dehydrogenase, in head and body homogenates respectively. The lowest microplastic concentration up-regulated genes involved in xenobiotics catabolic processes (cyp2p8), and adaptive immunity (tcra). Acetylcholinesterase activity was inhibited by the highest microplastics exposure, while a weaker and no significant inhibition was induced by the lowest concentration. No significant effects on lactate dehydrogenase activity were observed. The results presented in this study support the hypothesis that MPs exposure could induce the activation of an immune response and the xenobiotic metabolism, suggesting also that the cytochrome P450 enzyme cyp2p8 and acetylcholinesterase may be sensitive to MPs contamination. [Display omitted] • Microplastics can up-regulate genes involved in the xenobiotic metabolism. • Microplastics can modulate the expression of immune genes in the head kidney. • Acetylcholinesterase activity was inhibited after MPs exposure. [ABSTRACT FROM AUTHOR]

The Mediterranean basin is the second largest global biodiversity hotspot in the world, which coexists with a plethora of anthropogenic stress. This study examines the risks that marine litter poses to Mediterranean biodiversity, using the Special Protection Area of Mediterranean Importance (SPAMI) "Pelagos Sanctuary" as a case study. In this paper, a new survey method and data analysis strategies to assess the impact of marine litter, including microplastics, on Mediterranean organisms, is proposed. A total of 23 species, from invertebrates to cetaceans, were analysed using two main monitoring approaches. In the first approach, the core density distribution areas of 11 megafauna species (elasmobranchs, sea turtles, seabirds, and cetaceans) and 4 invertebrate species were evaluated through an extended field survey. Simultaneously, monitoring of floating macro- and micro-litter was performed to be overlapped with the species distribution and abundance. The second monitoring approach assessed the ingestion of marine litter, microplastics and the levels of plastic additives in 10 stranded megafauna species and in 7 invertebrate and fish species. The final data processing, merging the data on biodiversity and marine litter abundance and distribution in the environment, with the data of ingested marine litter, microplastics, and plastic additives in sentinel species, allowed to: a) create risk maps for the species inhabiting the Pelagos Sanctuary, identifying critical areas for biodiversity conservation; b) identify the most exposed species to the risk of marine litter by an "exposure score"; c) to select sentinel species for pelagic environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier B.V. All rights reserved.)

Marine litter, particularly microplastics, is a growing threat to the Mediterranean Sea, impacting biodiversity and ecosystem health. However, most studies conducted in the Mediterranean Sea have focused on monitoring of only specific environmental compartments, and rarely have highlighted the overall impacts affecting an area. Therefore, using a new multi-compartment monitoring approach and a standardized methodology, this study investigates the abundance, distribution, composition and impact of marine litter on beaches, surface waters, fish and mussels in a coastal area of Tuscany (Italy). Concerning beach macro litter values, significant differences were found among the three beaches analysed, with the highest amount in the Feniglia beach (mean value = 1245 items/100 m). The top items found are cotton bud sticks (32.3 %), which in the winter survey at Feniglia beach, reached a remarkable density of 1983 items/100 m. Microlitter (1-5 mm), was detected in the beach sediments with a mean abundance of 130 items/m 2 . Regarding floating macrolitter, the transect with the highest values was the Feniglia site at 3 nautical miles in autumn (1083 items/km 2 ) while for floating microlitter the highest concentration (832,683 MPs/km 2 ) was found in front of Scarlino. Of the 234 fish analysed from 5 different species, 67 contained microplastics in the gastrointestinal tract (28 %) with a mean value of 0.4 items per individual. The species with the highest occurrence was the European anchovy (Engraulis encrasicolus) (53 %) followed by the bogue (Boops boops) (40 %). Through the application of the Marine Litter Impact Index (MLII), considering all the compartments analysed, the Feniglia area emerges as the ecosystem most impacted by marine litter (mean MLII = 3.5, high). This study highlights how a multi-compartment monitoring approach is crucial for understanding the complex interactions between land, sea, and biota., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:, (Copyright © 2024. Published by Elsevier Ltd.)

Sea turtles can host a wide range of parasitic taxa, some of which may lead to severe diseases, weakening and endangering their health. Assessing free-ranging sea turtles' responses to these potential pathogens using biomarkers can provide valuable insights into the cellular and molecular impacts of parasites. This information can serve as a crucial tool for conservation efforts. During rehabilitation, hematological, genotoxic and innate immune parameters were evaluated in 70 free-ranging sea turtles rescued along the Southern Adriatic coast (Eastern Mediterranean Sea) from 2021 to 2023, 24 of which were found to have parasitic infections. Hapalotrema mistroides, Sulcascaris sulcata and Neospirorchis sp. were identified by coprological and molecular techniques. Some significant differences for biomarkers were associated with these parasites. These findings highlight the importance of considering the infection status of free-ranging sea turtles when evaluating biomarker results, as major pathogens like parasites can influence certain parameters., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest and that they have no actual or potential competing financial interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Halogenated natural products (HNPs) are considered to be emerging contaminants whose environmental distribution and fate are only incompletely known. Therefore, several persistent and bioaccumulative HNP groups, together with man-made polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), were quantified in the blubber of nine sperm whales ( Physeter macrocephalus ) stranded on the coast of the Mediterranean Sea in Italy. The naturally occurring polybrominated hexahydroxanthene derivatives (PBHDs; sum of TetraBHD and TriBHD) were the most prominent substance class with up to 77,000 ng/g blubber. The mean PBHD content (35,800 ng/g blubber) even exceeded the one of PCBs (28,400 ng/g blubber), although the region is known to be highly contaminated with man-made contaminants. Based on mean values, Q1 ∼ PBDEs > MeO-BDEs ∼ 2,2'-diMeO-BB 80 and several other HNPs followed with decreasing amounts. All blubber samples contained an abundant compound whose molecular formula (C 16 H 19 Br 3 O 2 ) was verified using high-resolution mass spectrometry. The only plausible matching isomer was (2 S ,4' S ,9 R ,9' S )-2,7-dibromo-4'-bromomethyl-1,1-dimethyl-2,3,4,4',9,9'-9,9'-hexahydro-1 H -xanthen-9-ol (OH-TriBHD), a hydroxylated secondary metabolite previously detected together with TriBHD and TetraBHD in a sponge known to be a natural producer of PBHDs. The estimated mean amount of the presumed OH-TriBHD was 3000 ng/g blubber, which is unexpectedly high for hydroxylated compounds in the lipids of marine mammals., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Co-published by Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, and American Chemical Society.)

Anthropogenic debris, including plastics, has recently been identified as a major threat for marine mammals and the Marine Strategy Framework Directive aims to achieve the good environmental status of European waters by addressing among other criteria, the effects of marine litter on biota. This study implemented for the first time a non-invasive technique for collecting monk seal samples to assess microdebris ingestion in combination with identifying plastic additives and porphyrins biomarkers. A total of 12 samples of monk seal faeces were collected from marine caves in Zakynthos Island, Greece. A total of 166 microplastic particles were identified; 75 % of the particles were smaller than 3 mm. Nine phthalates and three porphyrins were detected. A strong correlation was found between the number of microplastics and the concentration of phthalates. The values of both phthalates and porphyrins were found lower than in other marine mammal tissues, suggesting that seals might not be impacted by them yet., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Although the seafloor is an important sink for marine litter, its less accessible environment makes seafloor litter the least studied component. Nevertheless, detailed monitoring of its composition and spatial distribution is urgently needed to develop appropriate mitigation strategies in areas exposed to multiple anthropogenic pressures, such as the Adriatic Sea. Commercial fisheries such as bottom trawls can serve as an opportunistic platform for collecting data on seafloor litter and help researchers in addressing the lack of data through Fishing for Litter initiatives. In this study, the crews of twelve trawlers from two Italian Adriatic ports collected seafloor litter as part of their Fishing for Litter initiatives. In addition to the classical scheme, the collected litter was sorted on board into different bags, and speed, duration and geographical coordinates of each haul were recorded to allow an assessment of both densities and spatial distribution. More than 600 kg of litter was removed from the seafloor by the fishers in approximately 1 month and characterised by the researchers on the docks. Most of the found items were made of synthetic polymers and related to packaging, fisheries and aquaculture activities. Abandoned, lost or discarded fishing gear and mussel nets were identified as of particular concern in the maritime compartment of Chioggia and Civitanova Marche, respectively. Three hotspots for marine litter were identified: near the Venice lagoon, in the centre of the northern basin and at greater depth in the central Adriatic. This study provides a detailed picture of the spatial distribution and composition of seafloor litter in the areas studied and highlights the importance of increased cooperation between fishermen and scientists to improve the identification of hotspots and sources while removing marine litter from the seafloor and raising awareness of the problem., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Plastic pollution has been extensively documented in the marine food web, but targeted studies focusing on the relationship between microplastic ingestion and fish trophic niches are still limited. In this study we investigated the frequency of occurrence and the abundance of micro- and mesoplastics (MMPs) in eight fish species with different feeding habits from the western Mediterranean Sea. Stable isotope analysis (δ 13 C and δ 15 N) was used to describe the trophic niche and its metrics for each species. A total of 139 plastic items were found in 98 out of the 396 fish analysed (25%). The bogue revealed the highest occurrence with 37% of individuals with MMPs in their gastrointestinal tract, followed by the European sardine (35%). We highlighted how some of the assessed trophic niche metrics seem to influence MMPs occurrence. Fish species with a wider isotopic niche and higher trophic diversity were more probable to ingest plastic particles in pelagic, benthopelagic and demersal habitats. Additionally, fish trophic habits, habitat and body condition influenced the abundance of ingested MMPs. A higher number of MMPs per individual was found in zooplanktivorous than in benthivore and piscivorous species. Similarly, our results show a higher plastic particles ingestion per individual in benthopelagic and pelagic species than in demersal species, which also resulted in lower body condition. Altogether, these results suggest that feeding habits and trophic niche descriptors can play a significant role in the ingestion of plastic particles in fish species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The impacts of microplastics on filter feeders megafauna have recently received increased attention. These organisms are potentially exposed to plastic ingestion and the release of added/sorbed contaminants during feeding activities. An assessment of microplastic abundance and the chemical impact of Phthalates esters (PAEs) were performed in neustonic samples and skin biopsies of Balaenoptera physalus and Rhincodon typus inhabiting the Gulf of California (Mexico). Sixty-eight percent of the net tows contained plastics with a maximum of 0.24 items/m 3 mainly composed of polyethylene fragments. PAE levels were detected both in environmental and skin biopsy samples, with the highest values in the fin whale specimens (5291 ng/g d.w). Plasticizer fingerprint showed a similar distribution pattern between neustonic samples and filter-feeding species, with DEHP and MBP having the highest concentrations. The detection of PAE levels confirmed their potential role as plastic tracers and give preliminary information about the toxicological status of these species feeding in La Paz Bay., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

To evaluate the physiological state of the wild fish inhabiting the Biobío River in South-Central Chile, susceptible to the chemical contamination from different sources, biochemical and physiological biomarkers were applied to wild fish Percilia irwini and Trichomycterus areolatus in situ. Fish caught in the Biobío river in low, medium, and high anthropic impacts areas, with different pollution degrees along the river. Ethoxyresorufin O-O deethylase (EROD) activity was evaluated in fish liver. Length, weight, Gonad weight and Liver weight, Physiological Index, and gill and liver histopathology were conducted. Physicochemical parameters (pH, Temperature, Conductivity, and TDS) were measured at each sampling site. The results indicated a deteriorating condition in the biological parameters of both species in a high anthropic zone. Fishes show an increase in physiological indices and EROD liver activity, agreeing with previous studies supporting evidence of reproductive change development as we move downstream the river. Also, an increase in histopathological lesions towards the lower third stretch of the Biobío River. The Integrated Index of Physiological Biomarkers (IPBR) indicated that sites located in the high impact area (P. irwini: BC: 4.09; RC: 3.38; PC: 3.50; SJ: 2.34 and T. areolatus BC: 6.06, PC: 5.37; SJ: 5.42) have the most detrimental environmental quality, compared to reference area. The integrated biomarker analysis demonstrates that the alterations observed are related to the high anthropic activity levels downstream from the sites with the least intervention, demonstrating that the IPBR used is a complementary tool for studies of the Environmental Effects Monitoring approach.

Marine litter is a pollution problem affecting thousands of marine species in all the world's seas and oceans. Marine litter, in particular plastic, has negative impacts on marine wildlife primarily due to ingestion and entanglement. Since most marine mammal species negatively interact with marine litter, a first workshop under the framework of the European Cetacean Society Conference, was held in 2017 to bring together the main experts on the topic of marine mammals and marine litter from academic and research institutes, non-governmental organisations, foundations and International Agreements. The workshop was devoted to defining the impact of marine litter on marine mammals by reviewing current knowledge, methodological advances and new data available on this emerging issue. Some case studies were also presented from European waters, such as seals and cetaceans in the North, Baltic, and Mediterranean Seas. Here, we report the main findings of the workshop, including a discussion on the research needs, the main methodological gaps, an overview of new techniques for detecting the effects of marine litter (including microplastics) on marine mammals and, also, the use of citizen science to drive awareness. The final recommendations aim to establish priority research, to define harmonised methods to detect marine litter and microplastics, enforce networking among institutions and support data sharing. The information gathered will enhance awareness and communication between scientists, young people, citizens, other stakeholders and policy makers, and thereby facilitate better implementation of international directives (e.g., the Marine Strategy Framework Directive) in order to answer the question about the actual status of our oceans and finding solutions., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Marine mammals in the Barents Sea region have among the highest levels of contaminants recorded in the Arctic and the Atlantic walrus (Odobenus rosmarus rosmarus) is one of the most contaminated species within this region. We therefore investigated the relationships bewteen blubber concentrations of lipophilic persistent organic pollutants (POPs) and plasma concentrations of perfluoroalkyl substances (PFASs) and markers of endocrine and immune functions in adult male Atlantic walruses (n = 38) from Svalbard, Norway. To do so, we assessed plasma concentrations of five forms of thyroid hormones and transcript levels of genes related to the endocrine and immune systems as endpoints; transcript levels of seven genes in blubber and 23 genes in blood cells were studied. Results indicated that plasma total thyroxine (TT4) concentrations and ratio of TT4 and reverse triiodothyronine decreased with increasing blubber concentrations of lipophilic POPs. Blood cell transcript levels of genes involved in the function of T and B cells (FC like receptors 2 and 5, cytotoxic T-lymphocyte associated protein 4 and protein tyrosine phosphatase non-receptor type 22) were increased with plasma PFAS concentrations. These results suggest that changes in thyroid and immune systems in adult male walruses are linked to current levels of contaminant exposure., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The gastrointestinal tracts of 229 demersal fish belonging to two species (Mullus barbatus, Merluccius merluccius) were examined for microplastic ingestion. Samples were collected in 3 different FAO Geographical Sub-Areas (GSA-9, GSA-17, GSA-19) of the Mediterranean Sea. Ingested microplastics were characterized using a stereo-microscope: observed, photographed, measured and categorized according to size class, shape and colour. Plastic fragments (ranging from 0.10 to 6.6 mm) were detected in 23.3% of the total investigated fish; a total of 65 plastic particles (66% constituted by fibers) were recorded. The percentage of plastic ingestion shows high variability between the two species and among the different sampling area. The highest frequency (48%) was found in European hake from GSA-19. These preliminary results represent a baseline for the implementation of the Marine Strategy Framework Directive descriptor 10 in Italy as well as an important step for detecting microplastics in bioindicator species from different GSAs., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this study we have identified and characterized microplastic particles (MPs) found in six fish species of commercial importance in central Chile. The fish species belong to different trophic levels and were obtained from the oceanic and coastal habitats. To analyze MPs, the fish gastrointestinal content was extracted, analyzed and characterized using a microscopy equipped with Fourier-transform infrared spectroscopy (FT-IR). The MPs found in fish samples were mainly constituted by red microfibers (70-100%) with sizes ranging between 176 and 2842 μm. Polyester, polyethylene (PE) and polyethylene terephthalate (PET) were identified as the prevalent polymers detected. The coastal species showed the presence of microfibers with a higher size and abundance (71%) compared to oceanic species (29%), suggesting there is a greater exposure risk. These findings are consistent with results found in other investigations worldwide. However, further research is still needed to accurately establish the potential exposure risk for the public consuming these fish and the impact of MPs in the Chilean fishery activities., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Few studies have focused so far on plastic ingestion by sharks in the Mediterranean Sea. The aim of this paper was to determine, for the first time, the plastic litter ingested by blue sharks (Prionace glauca), categorized as "Critically Endangered" in the Mediterranean Sea by IUCN, caught in the Pelagos Sanctuary SPAMI (North-Western Mediterranean Sea). The analysis of the stomach contents was performed following the MSFD Descriptor 10 standard protocol implemented with FT-IR spectroscopy technique. The results showed that 25.26% of sharks ingested plastic debris of wide scale of sizes from microplastics (<5 mm) to macroplastics (>25 mm). The polyethylene sheetlike user plastics, widely used as packaging material, are the most ingested debris. This research raises a warning alarm on the impact of plastic debris on a threatened species, with a key role in the food web, and adds important information for futures mitigation actions., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Monitoring efforts are required to understand the sources, distribution and abundance of microplastic pollution. To verify the abundance of microplastics along the Tuscan coastal waters (Italy), water-column and surface samples were collected in two seasons across four transects at different distances to the coast (0.5, 5, 10 and 20 km), within the implementation of the European Marine Strategy Framework Directive. The results show an average concentration of 0.26 items/m 3 in the water-column samples and 41.1 g/km 2 and 69,161.3 items/km 2 of floating microplastics, with an increase with the distance to the coast The seasonality and the sampling area do not affect the abundance of microplastics. The most abundant size class is 1-2.5 mm as fragments and sheets suggesting that fragmentation of larger polyethylene and polypropylene items could be the main source of microplastics. These data represent the application of a harmonized protocol to make the data on microplastics comparable and reliable., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The Mediterranean Sea has been described as one of the most affected areas by marine litter in the world. Although effects on organisms from marine plastic litter ingestion have been investigated in several oceanic areas, there is still a lack of information from the Mediterranean Sea. The main objectives of this paper are to review current knowledge on the impact of marine litter on Mediterranean biodiversity, to define selection criteria for choosing marine organisms suitable for use as bioindicator species, and to propose a methodological approach to assessing the harm related to marine litter ingestion in several Mediterranean habitats and sub-regions. A new integrated monitoring tool that would provide the information necessary to design and implement future mitigation actions in the Mediterranean basin is proposed. According to bibliographic research and statistical analysis on current knowledge of marine litter ingestion, the area of the Mediterranean most studied, in terms of number of species and papers in the Mediterranean Sea is the western sub-area as well as demersal (32.9%) and pelagic (27.7%) amongst habitats. Applying ecological and biological criteria to the most threatened species obtained by statistical analysis, bioindicator species for different habitats and monitoring scale were selected. A threefold approach, simultaneously measuring the presence and effects of plastic, can provide the actual harm and sub-lethal effects to organisms caused by marine litter ingestion. The research revealed gaps in knowledge, and this paper suggests measures to close the gap. This and the selection of appropriate bioindicator species would represent a step forward for marine litter risk assessment, and the implementation of future actions and mitigation measures for specific Mediterranean areas, habitats and species affected by marine litter ingestion., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Marine litter is any persistent, manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment. Ingestion of marine litter can have lethal and sub-lethal effects on wildlife that accidentally ingests it, and sea turtles are particularly susceptible to this threat. The European Commission drafted the 2008/56/EC Marine Strategy Framework Directive with the aim to achieve a Good Environmental Status (GES), and the loggerhead sea turtle (Caretta caretta, Linnaeus 1758) was selected for monitoring the amount and composition of litter ingested by marine animals. An analogous decision has been made under the UNEP/MAP Barcelona Convention for the protection of the Mediterranean Sea, following the Ecosystem Approach. This work provides for the first time, two possible scenarios for the Marine Strategy Framework Directive GES, both related to "Trends in the amount and composition of litter ingested by marine animals" in the Mediterranean Sea. The study validates the use of the loggerhead turtle as target indicator for monitoring the impact of litter on marine biota and calls for immediate use of this protocol throughout the Mediterranean basin and European Region. Both GES scenarios are relevant worldwide, where sea turtles and marine litter are present, for measuring the impact of ingested plastics and developing policy strategies to reduce it. In the period between 2011 and 2014, 150 loggerhead sea turtles, found dead, were collected from the Italian Coast, West Mediterranean Sea Sub-Region. The presence of marine litter was investigated using a standardized protocol for necropsies and lab analysis. The collected items were subdivided into 4 main categories, namely, IND-Industrial plastic, USE-User plastic, RUB-Non plastic rubbish, POL-Pollutants and 14 sub-categories, to detect local diversity. Eighty-five percent of the individuals considered (n = 120) were found to have ingested an average of 1.3 ± 0.2 g of litter (dry mass) or 16 ± 3 items., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The whale shark (Rhincodon typus) is an endangered species that may be exposed to micro- and macro-plastic ingestion as a result of their filter-feeding activity, particularly on the sea surface. In this pilot project we perform the first ecotoxicological investigation on whale sharks sampled in the Gulf of California exploring the potential interaction of this species with plastic debris (macro-, micro-plastics and related sorbed contaminants). Due to the difficulty in obtaining stranded specimens of this endangered species, an indirect approach, by skin biopsies was used for the evaluation of the whale shark ecotoxicological status. The levels of organochlorine compounds (PCBs, DDTs), polybrominated diphenyl ethers (PBDEs) plastic additives, and related biomarkers responses (CYP1A) were investigated for the first time in the whale shark. Twelve whale shark skin biopsy samples were collected in January 2014 in La Paz Bay (BCS, Mexico) and a preliminary investigation on microplastic concentration and polymer composition was also carried out in seawater samples from the same area. The average abundance pattern for the target contaminants was PCBs>DDTs>PBDEs>HCB. Mean concentration values of 8.42ng/g w.w. were found for PCBs, 1.31ng/g w.w. for DDTs, 0.29ng/g w.w. for PBDEs and 0.19ng/g w.w. for HCB. CYP1A-like protein was detected, for the first time, in whale shark skin samples. First data on the average density of microplastics in the superficial zooplankton/microplastic samples showed values ranging from 0.00items/m 3 to 0.14items/m 3 . A focused PCA analysis was performed to evaluate a possible correlation among the size of the whale sharks, contaminants and CYP1A reponses. Further ecotoxicological investigation on whale shark skin biopsies will be carried out for a worldwide ecotoxicological risk assessment of this endangerd species., (Copyright © 2017 Elsevier Inc. All rights reserved.)