Much microplastic research is done in our planet's oceans; relatively little is done closer to shore. Researchers at the College of Charleston have recently published an analysis of microplastics found in fish in Charleston Harbor in Charleston, SC, a major US port and estuary ecosystem.

The researchers surveyed the microplastic content found in the digestive systems of 284 fish representing five different species with different feeding behaviors: the bay anchovy and Atlantic menhaden (plankton feeders), spotted seatrout (fish-eater), spot (bottom-feeder), and the striped mullet (bottom-feeder and detritus-eater).

They organized the microplastics by color and type, including tire particles, foams, fibers, or fragments. They found that fibers were the most common type of microplastic (77.4 percent of the total number of microplastic samples) consumed by all types of fish. Fibers were also the most prevalent form of microplastics found within the Charleston harbor water column (69 percent). And in a first for microplastic research, the scientists found tire wear particles inside of living organisms.

Tire particles are particularly alarming because they can discharge dangerous components like mineral oils, antiozonants, and other eco-toxic chemicals. Further research into how organisms consume microplastics, and how they move through the food chain, is needed to identify how animals interact with microplastics in their environments.