Interactions between microorganisms and marine microplastics: A call for research

Synthetic thermoplastics constitute the majority by percentage of anthropogenic debris entering the Earth’s oceans. Microplastics (≤5-mm fragments) are rapidly emerging pollutants in marine ecosystems that may transport potentially toxic chemicals into macrobial food webs. This commentary evaluates our knowledge concerning the interactions between marine organisms and microplastics and identifies the lack of microbial research into microplastic contamination as a significant knowledge gap. Microorganisms (bacteria, archaea, and picoeukaryotes) in coastal sediments represent a key category of life with reference to understanding and mitigating the potential adverse effects of microplastics due to their role as drivers of the global functioning of the marine biosphere and as putative mediators of the biodegradation of plastic-associated additives, contaminants, or even the plastics themselves. As such, research into the formation, structure, and activities of microplastic-associated microbial biofilms is essential in order to underpin management decisions aimed at safeguarding the ecological integrity of our seas and oceans.