Occurrence and effects of microplastics in tissues of coastal wildlife

, Haave Marte, Olsen Anne-Berit, Schönheit Jürgen, Nilsen Hanne, Gomiero Alessio.

Microplastic is omnipresent in biota, and concerns of human exposure through food. Investigations of wildlife relevant for human consumption and the effects in animals exposed to plastics is warranted. We investigated the concentrations of microplastics (MP) in tissues of fish, seabirds and marine mammals from a plastic polluted area near Bergen, Norway. A standardized autopsy included evaluation of condition, bacteriological and histopathological analyzes. Tissues were analyzed for MP (¿10µm) by pyrolysis Gas-Chromatography/Mass-Spectrometry and inspected by polarized-light -microscopy. We analyzed samples of the GI tract, liver and muscle/fillet from three flatfish, three cod, three seabirds, three otters and one seal, kidneys from seabirds, otters and the seal, gills from the fishes. No large plastic items were observed in the gastrointestinal tracts. Eight of thirteen animals had MP in one or several tissues. MP was found in intestine (5), stomach (4), liver(3), muscle(3). No MP was found in the seal, and only in the stomach wall of one otter. In seabirds MP was found in the intestine, stomach and liver, but not muscle. MP was most common in cod (two of three), but rare in flatfish. The highest MP concentration found was 3.4 µg/g wet weight in cod liver. Three of nine polymers were found: Polyvinylchloride¿polystyrene¿¿polyethylene terephthalate. Other investigated polymers were below the Limit of Quantification (LOQ). In four parallel analyses of cod muscle and two analyses of liver in cod, MP was quantified in one parallel per individual. No MP was observed by microscopy. The results show levels around the current LO. Replicates indicate uneven tissue distribution. No adverse effects were observed related to the presence of MP. The sample size was small, and conclusions cannot be drawn regarding risks. Controls showed very low MP. Further studies are needed elucidate the current wildlife and human exposure.

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