Seminar

Anthropogenic marine litter pollution is a serious issue facing oceans worldwide. Limited data exists on this pollution issue for South Pacific Island nations. This study presents the first extensive baseline survey of macro-sized marine litter on Mo’orea (0.75 items m-2) and Tahiti (0.95 items m-2), French Polynesia. Locally sourced land-based catchments accounted for the greatest amount of recovered marine litter on both islands. Beverage containers and associated items, such as caps were commonly recovered. Further studies conducted on Mo’orea, demonstrated that micro-litter was prevalent (3.84 items m-2) in beach sands and that 22% of surveyed holothurians had ingested microplastics.

Recent calculations estimate that there are currently 5.25 trillion plastic particles afloat in the world’s oceans. Many of these are microplastics. The purpose of this ongoing study is to investigate how microplastics are distributed in two different marine environments: deep-sea canyons, and nearshore estuaries. To discover whether microplastics are concentrated in these environments, I analyzed microplastics in sediments from Norfolk Canyon and the adjacent continental slope; and the Coos Bay Estuary and the adjacent continental shelf. Sediment samples were taken with a box core and a ponger grab. I submerged sediment in saturated solutions of sodium iodide for floatation. I removed the supernatant to extract plastics through optical microscopy.

Microplastics (<5mm) have been found in nearly all environments on earth and studies have been documented plastic ingestion by a wide range of marine biota. Rhiannon will be covering several topics surrounding this emerging environmental contaminant including sources, fate and effects of microplastics and what Ocean Wise is doing to research this environmental contaminant.