Characterization of Zooplankton Community and Size Composition in Relation to Hydrography and Circulation in the Sea of Japan

摘要

The northern and southern Japan Sea are hydrographically and biologically distinct with% the southern portion being more tropical/ oligotrophic and the northern portion being more boreal/eutrophic. The plankton of the Japan Sea remains poorly understood particularly with regard to high- resolution description of the distribution of plankton taxa and environmental conditions. We described the taxonomic and size composition of the zooplankton community and associated hydrography of the JES during the summer of 1999 using the Video Plankton Recorder (VPR), surveying over both the northern and southern regions the Subpolar Front between, and the Ulleung Basin. The VPR was towyoed between the near-surface and 8O m for over 240 hours and 3500 km., collecting over 600,000 images of plankton, and coincident hydrography. The distributions of identified taxa and hydrographic characteristics were plotted in near-real time at sea. Plankton also were collected at 15 selected stations using a ring net, for silhouette analysis of taxa and size. Dramatically different plankton compositions were observed in the various hydrographic regions.