Assessment of microplastic contamination in commercial bivalves from South Korea

Abstract

The plastic use increase worldwide, plastic debris has become ubiquitous in the ocean. As plastic debris is fragmented gradually into small plastics through environmental weathering process, they become available to a wide range of marine species covering from large marine organisms (e.g. mammal, seabird, sea turtle, etc.) to small invertebrates (e.g. bivalves, lugworms, clams, etc.). Among marine species, bivalves are of particular interest because of their substantial filter-feeding activity, resulting direct exposure to microplastics in water column, and its potential risk for human health by seafood consumption. Bivalves are typically eaten whole body without the removal of digestive tract. This study investigated microplastic contamination in commercial bivalves from South Korea. Oyster (Crassostrea gigas) and mussel (Mytilus edulis), accounting for 66.35% of total shellfish consumption in South Korea, were selected as monitoring species and bought randomly from fishery markets in three major cities (Seoul, Busan, and Gwangju). Microplastic pollution was widespread in commercial bivalves from Korea with detection frequency of 93%. The mean microplastic concentration was 0.07± 0.06 particles / g (0.77 ± 0.74 particles / individual) in oyster and 0.12 ± 0.10 particles / g (0.68 ± 0.64 particles / individual) in mussel. Fragment (74%) was dominant type of microplastic, and the most common size class is 100 -