SEASONAL DISTRIBUTION OF PLANKTIC FORAMINIFERS IN THE EAST SEA (SEA OF JAPAN), A LARGE MARGINAL SEA OF THE NORTHWEST PACIFIC

A time series sediment trap was deployed in the interior of the East S ea (Sea of Japan) (39 degrees 40'N, 132 degrees 24'E) for the period f rom July 1994 to July 1995, Total foraminifera flux varied from 3 to 8 ,200 individuals/m(2)/day, with major peaks during late fall (November ) rind winter (December and January), and a minor peak curing spring ( March-May), Foraminiferal assemblages were dominated by both right- an d left-coiled Neogloboquadrina pachyderma, N. dutertrei, and Globigeri na bulloides, and their fluxes varied seasonally, The highest flux of both right- and left-coiled N. pachyderma throughout all seasons indic ates that the study site was dominated by the cold Subarctic water mas s. The influx from the cold North Korean Current was stronger than tha t of the warm Tsushima Current in the spring. This cold water influx i s evidenced by the highest flux of left coded N. pachyderma and Globig erina bulloides, and the absence of N. dutertrei. The dominance of rig ht-coiled N. pachyderma during January, July, and November-December su ggests a greater influence of the warm Tsushima Current. The absence o f N. dutertrei at the study site and the presence of N. dutertrei in t he North Pacific in spring suggests that the study site in the Japan B asin is isolated from the North Pacific Ocean during the spring. G. bu lloides and N. dutertrei dominate during March and November, respectiv ely. The onset of the winter monsoon (late October-November) is respon sible for the planktic foraminifera flux peak during November.