INVESTIGATOR: Koty Sharp, Roger Williams University
MENTOR: David Rowley, University of Rhode Island
THEME: Environmental Health Science

ABSTRACT: Microplastics particles (<5 mm) are entering the oceans at 5-12 million metric tons annually. Microplastics are small enough to be eaten by filter-feeding organisms, including plankton that are consumed by commercially important fish and seafood species. Recent studies have shown that microplastics are ubiquitous in marine ecosystems, they become coated in unique microbial biofilms that include putative pathogens, and they are consumed by diverse marine organisms across the food web. The fate of microplastics-associated microbes in coastal food webs is undescribed. It is likely that they are bioaccumulated in higher trophic levels and significant seafood species. Microplastics alone, and their ability to act as ingestible hotspots containing potentially pathogenic microbial communities, present a significant threat to human health. The proposed work addresses the consequences of microplastics particles and their associated microbes on the health of local, coastal organisms. The aims of the work include: 1) characterize the microbial community composition of biofilms that colonize microplastics in Narragansett Bay; and 2) determine the potential for plastics-associated microbes to transfer into consumer and across trophic levels to higher-level consumers. Plastic-associated microbial biofilms will be characterized via sequencing analysis and oligonucleotide probe-based microscopy. Based on these results, microplastics experimentally coated with biofilms from a local seawater site will be presented to the coral Astrangia poculata, both directly and indirectly via copepod prey. Probe-based microscopy will be used to determine whether microbes are vectored by microplastics directly into copepods and A. poculata, and/or indirectly, via trophic transfer from copepod prey into A. poculata. The proposed work focuses on a new, underexplored aspect of microplastics pollution: the potential for dispersal and proliferation of novel, potentially harmful microbes in coastal ecosystems, food webs, and ultimately, the human food supply.

RELEVANCE:  The proposed work addresses the consequences of microplastics in Narragansett Bay on the health of local, coastal organisms, focusing on the understudied potential for microplastics pollution to alter microbiomes in coastal ecosystems and food webs. The project, which will reveal basic insights into the microbial and chemical ecology of microplastics, will lay the groundwork for future mitigation efforts to minimize accumulation of pathogenic microbes in coastal ecosystems and the food supply.