Marine microplastic debris: a targeted plan for understanding and quantifying interactions with marine life

Microscopic plastic (microplastic) debris is a marine pollutant that threatens aquatic biota and ecosystems. Microplastics have been detected throughout the world's oceans; however, the relative importance of different processes that control the spatial distribution and long-term fate of microplastics in the marine environment remains largely unknown. Results from laboratory and field studies indicate that interactions between microplastic debris and marine organisms may play an important role in redistributing plastic in the oceans. We provide an overview of the various mechanisms through which marine life and microplastics can interact. By considering coupled physical–biological processes, we also identify regions where these interactions are most likely to occur, and outline a new research agenda that aims to determine their prevalence in the marine environment. We hypothesize that biological interactions are key to understanding the movement, impact, and fate of microplastics in the oceans.