Vertical distribution and community properties of mesozooplankton in the Japan/East Sea
Mesozooplankton community was studied in the Japan/East Sea. First, the pattern of vertical distribution and diel vertical migration (DVM), if any, was examined with time dependent vertically stratified samples. Then community properties of mesozooplankton in the three distinctive areas, the Korea Strait, the frequently upwelling area and the frontal zone, were investigated. In vertical distribution of mesozooplankton, most taxa have their preferred depth zones of distribution, usually surface area. However, two major components of mesozooplankton, Metridia pacifica and Scolecithricella minor, showed normal DVM patterns, even in the strongly thermal stratified area. Distribution pattern of mesozooplankton showed that the number of taxa appeared was the most abundant in the Korea Strait and southwestern area (the upwelling area), but decreased northward area (the frontal zone). On the other hand, averaged zooplankton abundance increased northward area. Seawater temperature and salinity were very important environmental factors in the study area. However, their influences were rather time accumulated and in a large scales. Our results suggest that food resources seemed to be more important than seawater temperature and salinity when viewed within a relatively small area and as a snap shot.