Distribution of surface marine debris in the Narragansett Bay

Cara Megill


Marine plastic pollution has recently gained international attention regarding its significant negative impact on marine organisms as well as its ever-increasing magnitude in the marine environment. Surface water samples collected from the Narragansett Bay have shown the presence of plastic in every sample take to date, yet no baseline for the magnitude of plastic debris exists. Here, we have conducted a spatial sampling design involving five different boat-accessed locations throughout the Narragansett Bay utilizing a manta trawl system to measure the concentration of marine debris within the surface waters of the Bay. Samples were visually analyzed for plastic and other debris particles. An average concentration of 29,325 particle/km2 (0.192 particles/m3) was determined with the highest concentration of marine debris found around Hog Island. The majority of particles within each sample tended to fall within the microplastic (< 5 mm) category rather than within the macroplastic (> 5 mm) category. Compared with literature values of other major bodies of water within the United States, the Narragansett Bay lends itself to be relatively the cleanest.