Abstract: As a new pollutant in marine, microplastic (plastic with the size less than 5 mm) can be ingested by marine biota with significant health effects. Along with more focus on the contamination chemistry and ecological toxicology of microplastic in marine, pollution monitoring and toxicological research based on the biological indicators have recently become a hot topic. Bivalves can serve as indicators of microplastic pollution in microplastic toxicological research because they have extensive filter-feeding activities and can expose directly to microplastic in marine. Here, we critically reviewed the methods of identifying microplastic in bivalves, the accumulation of microplastic ingested by bivalves of different areas, and their ecotoxicological effects on bivalves in laboratory experiments. In addition, we proposed future research directions, including the standardization of bio-monitoring protocols on microplastic pollution by bivalves as indicators and the research on subchronic toxicological effects of microplastic on bivalves under the realistic environmental concentrations.

Key words: plant genome size, nitrogen deposition, drought, typical grassland