Marine Litter Composition and Distribution on the Sea-bed of Tokyo Bay

Abstract

A suevey, ｖia bean trawl, of the abundance, type (plastics, fishing gear, textile and other) and distribution of litter was conducted on the sea-bed of an area in the central portion of Tokyo Bay. Over 4 years period (1989-1991 and 1993) of the litter, plastics (synthetic polymer resin) made up 80-85 % of the total, with 60% of these plastics being of low specific gravity (range 0.86-1.1). These substances due to them being relatively inert and widely distributed pose a sigrlificant pollution threat to fishing grounds and the nearshore marine environment. Litter from fishing activities although quantitatively small were also sigrlificant and pose potential damage to resources via'ghost fishing, after being discarded.