Distribution and actual condition of seabed litter in Kagoshima [Japan] Bay

Sampling surveys using a small trawl net were conducted 118 times (May 2003-0ct. 2005) to estimate the distribution and composition of seabed litter at eight stations established in Kagoshima Bay. The sediments collected from the sea bottom contained 54,388 items, 76.9 kg of natural objects and seabed litter. The average density of seabed litter was 2,517 items/square km and 30.3 kg/square km accounting for 3.7% of the total sediments by number. The dominant type of deposited litter on the sea bottom was filmy plastic including plastic bags accounting for 49.0% of seabed litter by number. Seabed litter was found at all stations in Kagoshima Bay whether or not the station was in a fishing ground. The density distribution of filmy plastic was higher in the innermost and central area of this bay similar to the distribution of plant leaves.