methodology for assessing beach litter of artifical materials (2)

Abstract

Tottori is an appropriate region for monitoring the marine litter in the northwestern Pacific Ocean, because the litter from all the East and Southeast Asian countries contiguous to this sea is washed up on the beaches of Tottori. However, in order to estimate the variation in the quantity and species of the floating marine litter, it is necessary to investigate the processes from floating litter to beach litter. The floating litter is periodically washed up on the beach by the inshore wind and the run-up of waves which are efficiently raised by the inshore wind. Though the resultant litter lies in strips along the wave run-up lines, strong winds selectively disperse some kinds of items from the strips. Furthermore, the strong winds cause the wind blown sand, the high run-up of waves, and the littoral drift of sand, which cover the fresh beach litter with sand at some times, and at other times make the buried old litter emerge. Therefore, in order to evaluate the amount of the beach litter which is freshly washed up from the sea, it is important to consider the monitoring method of reducing the influence of these phenomena.