Matteo Giannetti

Are baleen whales exposed to the threat of microplastics? A case study of the Mediterranean fin whale (Balaenoptera physalus)

Baleen whales are potentially exposed to micro-litter ingestion as a result of their filter-feeding activity. However, the impacts of microplastics on baleen whales are largely unknown. In this case study of the Mediterranean fin whale (Balaenoptera physalus), we explore the toxicological effects of microplastics on mysticetes. The study included the following three steps: (1) the collection/count of microplastics in the Pelagos Sanctuary (Mediterranean Sea), (2) the detection of phthalates in surface neustonic/planktonic samples, and (3) the detection of phthalates in stranded fin whales. A total of 56% of the surface neustonic/planktonic samples contained microplastic particles. The highest abundance of microplastics (9.63 items/m(3)) was found in the Portofino MPA (Ligurian Sea). High concentrations of phthalates (DEHP and MEHP) were detected in the neustonic/planktonic samples. The concentrations of MEHP found in the blubber of stranded fin whales suggested that phthalates could serve as a tracer of the intake of microplastics. The results of this study represent the first warning of this emerging threat to baleen whales.

Fin whales and microplastics: The Mediterranean Sea and the Sea of Cortez scenarios

The impact that microplastics have on baleen whales is a question that remains largely unexplored. This study examined the interaction between free-ranging fin whales (Balaenoptera physalus) and microplastics by comparing populations living in two semi-enclosed basins, the Mediterranean Sea and the Sea of Cortez (Gulf of California, Mexico). The results indicate that a considerable abundance of microplastics and plastic additives exists in the neustonic samples from Pelagos Sanctuary of the Mediterranean Sea, and that pelagic areas containing high densities of microplastics overlap with whale feeding grounds, suggesting that whales are exposed to microplastics during foraging; this was confirmed by the observation of a temporal increase in toxicological stress in whales. Given the abundance of microplastics in the Mediterranean environment, along with the high concentrations of Persistent Bioaccumulative and Toxic (PBT) chemicals, plastic additives and biomarker responses detected in the biopsies of Mediterranean whales as compared to those in whales inhabiting the Sea of Cortez, we believe that exposure to microplastics because of direct ingestion and consumption of contaminated prey poses a major threat to the health of fin whales in the Mediterranean Sea.

Presence of plastic debris in loggerhead turtle stranded along the Tuscany coasts of the Pelagos Sanctuary for Mediterranean Marine Mammals (Italy)

This work evaluated the presence and the frequency of occurrence of marine litter in the gastrointestinal tract of 31 Caretta caretta found stranded or accidentally bycaught in the North Tyrrhenian Sea. Marine debris were present in 71% of specimens and were subdivided in different categories according to Fulmar Protocol (OSPAR 2008). The main type of marine debris found was user plastic, with the main occurrence of sheetlike user plastic. The small juveniles showed a mean±SD of marine debris items of 19.00±23.84, while the adult specimens showed higher values of marine litter if compared with the juveniles (26.87±35.85). The occurrence of marine debris observed in this work confirms the high impact of marine debris in the Mediterranean Sea in respect to other seas and oceans, and highlights the importance of Caretta caretta as good indicator for marine litter in the Marine Strategy Framework Directive (MSFD) of European Union.

Occurrence, relative abundance and spatial distribution of microplastics and zooplankton NW of Sardinia in the Pelagos Sanctuary Protected Area, Mediterranean Sea

Environmental context Plastic materials are accumulating in the marine environment where they can now be found in the remotest areas of the worlds oceans. Microplastics (plastic particles ≤5mm), abundant in marine surface waters, are also found in neritic and pelagic waters of Mediterranean marine protected areas. Microplastics can accumulate along marine food chains, having noxious effects on marine organisms at different trophic levels and creating a serious threat to marine ecosystems. Abstract Floating plastic debris tends to fragment into smaller pieces, termed microplastics, which may increase the likelihood of ingestion of plastics by marine organisms entering the food web. This study analyses the amount and spatial distribution of microplastics and zooplankton in an area near Asinara National Park (NW Sardinia) and overlapping the Pelagos Sanctuary (Mediterranean Sea). Analysis showed microplastics in 81% of the 27 samples analysed, with a mean value of 0.17±0.32 items m–3. From geographic information system processing of the data, microplastics appeared more abundant (by a factor of four) in the pelagic than in the neritic environment, and showed a size range of the same order as major zooplanktonic taxa determined in the area. These findings suggest a potential risk of mesozooplankton and species preying on plankton mistaking microplastics for food. Further functional and toxicological studies are therefore necessary to assess the hazard associated with microplastics in the marine food web.

Pilot study on levels of chemical contaminants and porphyrins in Caretta caretta from the Mediterranean Sea

Perfluorinated compounds (PFCs), synthetic musks compounds (SMCs), bisphenol A (BPA), para-nonylphenol (p-NP) and polybrominated diphenyl ethers (PBDEs) are known for their toxicity and ability to interfere with the endocrine system. The aim of this study was to determine levels and distribution of the above mentioned compounds in liver samples of Caretta caretta and levels of porphyrins that have been proposed as sensitive biomarkers of exposure to contaminants. This paper reports the results for 9 specimens yet analysed. Musk ketone was never detected, PFOA was found in one sample, while PFOS was the prevalent contaminant. For PFCs the levels are lower than the results of studies of comparison. The porphyrins profile showed a predominance of protoporphyrins on coproporphyrins and uroporphyrins, with a positive statistical correlation between levels of PFOS and uroporphyrins. These data represent, for several parameters, the first evidence of contaminant levels and biomarker responses in loggerhead turtles.

First ecotoxicological assessment of Caretta caretta (Linnaeus, 1758) in the Mediterranean Sea using an integrated nondestructive protocol

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.