Vertical distribution of zooplankton biomass in the Sea of Japan

Vertical distribution of total zooplankton biomass and major taxonomic groups are investigated by layers to depths of 2500-3400 m on the basis of three series of net plankton collections. Zooplankton is most abundant above 1500-2000 m. Since true deep-water species do not occur in the Sea of Japan, biomass drops much more sharply at greater depths than it does in the ocean. Since few carnivores inhabit the deep layers, abundant remains of planktonic organisms fall to the bottom, and carnivorous detritovores feeding on these remains are dominant in deep water bottom fauna.本研究依托三套分层浮游生物网采集的样本，对2500~3400米水深区间内的总浮游动物（zooplankton）生物量及主要分类类群的垂直分布特征开展系统调查。浮游动物生物量在1500~2000米以浅水域最为富集。由于日本海不存在纯正深水物种，其生物量随水深增加的衰减幅度远大于开阔大洋。由于深水层中食肉动物极少，大量浮游生物遗骸沉降至海底，以这些遗骸为食的食肉性碎屑食性动物构成了深水底栖动物群落的优势类群。