Microplastic contamination of two oyster species in Tokyo Bay

In this study, we examined microplastic contamination in the gills and guts of two filter-feeding oyster species, Crassostrea gigas, and Crassostrea nippona, in Tokyo Bay, an area of high-level MP pollution, to determine the extent of contamination. The mean (+/- SD) concentration of MPs in C. gigas in spring was 29.1 +/- 19.9 MPs g(-1) WW in the gills and 181.0 +/- 229.7 MPs g(-1) WW in the guts. For C. nippona, MP concentration in the gills and guts during spring was 144.5 +/- 77.1 MPs g(-1) WW and 149.7 +/- 123.4 MPs g(-1) WW respectively. In summer, C. nippona had a mean (+/- SD) MP concentration of 193.3 +/- 66.9 MPs g(-1) WW in the gills and 302.8 +/- 232.1 MPs g(-1) WW in the guts. MP uptake was significantly higher (p < 0.05) in C. nippona than in C. gigas in spring. Fragment was the dominant shape with a size frequency of 40-60 <mu>m. PE was the most abundant polymer except in the gills of C. gigas, where PA was dominant. MP Polymer composition in oysters corresponded to those in the seawater.