在海水中約有150種以上之浮游性軟體動物出現，經以海富號研究船及海研一號研究船於1991年8月份及12月份在臺灣東北部，25°∼26° N, 121°∼123E°之海域，以北太平洋標準浮游生物網採集。為避免浮游動物日降夜昇之習性，導致日夜採樣所產生之差異，因此進行150公尺深之垂直採樣，以5∼10％之海水福馬林儲存，於實驗室分類計數並換算其單位個體量。在8月份之夏季型，浮游性軟體垂物個體量較多。而此月份自大陸棚邊緣向東南方個體量之分佈，以冷水團出現區域之5個測站，個體量比其周圍區域的浮游性軟體動物出現量要少，可能由硫球海溝之地形所產生湧升流而至形成之冷水團區，會影響浮游性軟體動物量，使其個體量較少。12月份之冬季型則因大陸沿岸流冷水影響，個體量較8月份少，但分佈較均勻，彭加嶼附近自西北向東南方的各測站則捕獲少量之頭足類。
Planktonic mollusks were collected by R/V Hai-Fu and R/V Ocean Researcher I, in the waters off northeastern Taiwan (25°∼26° N；121°∼123° E) during 1991. to avoid variations in abundance due to diurnal vertical migration, zooplankton were sampled by vertically lifting a NORPAC plankton net form a depth for 150m to the water's surface. Samples were preserved in a 5-10% solution of formalin in seawater. Planktonic mollusks were more abundance in summer than in winter. The abundance of planktonic mollusks at five coldwater upwelling station in August 1991 was lower than at adjacent non-upwelling station. Therefore, the abundance of planktonic mollusks may be affected by coldsater eddies formed by the upwelling of the Kuroshio Current along the East China continental shelf. However, in December 1991, the abundance of plankonic mollusks was lower and homogeneous at all station, and cephalopods were collected along a line o five station from northwest t southeast through the Peng-Chia Islands.
