Yang L., Kawaguchi T., Fortunato H.


Microplastics derived from anthropogenic pollution have become a major issue in today’s society. Available data points to their presence in all terrestrial and marine ecosystems. There is a growing body of literature documenting their presence in many organisms including humans where they may cause serious health problems. Sources of these microplastics are multiple, from trash dumped in rivers and lakes and traveling to the ocean, fishing tools such as nets, ropes, baskets to a range of chemicals dumped in water sources.

Marine organisms often absorb microplastics through food or directly from the water in the case of filter species. Particles are then deposited in the respiratory organs, guts, pallial cavity and other organs. When these species are used as food, these particles are transferred to the consuming organisms where they accumulate.

Oysters are a very important component of Japan’s fisheries industry being both consumed inside the country and exported. Therefore, their quality is of utmost importance for the industry’s success. This study aimed to evaluate the presence of microplastics in cultivated oysters (Crassostrea gigas (Thunberg, 1793)) from four localities in the Pacific coast of Japan.

Oyster soft tissue was digested following a standard protocol, and the dried suspension examined for the presence of microplastics using fluorescence, Raman scattering, and SEM microscopy. Preliminary data showed the presence of a varied amount of microplastics of different coloration (mostly forming red/pink and green fibers) and sizes ranging from 200 - >2000 µm. Raman scattering spectra indicate that the most plausible material is Nylon 66 and urethane, the most frequently used material in oyster aquaculture fishing gear.

We will discuss obtained results in the light of worldwide information concerning microplastics’ presence in shellfish. We hope these data help to provide advice to the aquaculture industry and stakeholders.