Copyright © The Oceanographic Society of Japan. Standing Crops of Planktonic Ciliates and Copepod Nauplii in the Subarctic North Pacific and the Bering Sea

• Main Authors: Northern North, In Summer
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2000
• Subjects: Bering Sea; Oyashio; Pacific; Subarctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.575.8665; http://www.terrapub.co.jp/journals/JO/pdf/5703/57030333.pdf

Abundances and biomasses of planktonic ciliates and copepod nauplii, major compo-nents of the microzooplankton community, were investigated in the subarctic North Pacific and the Bering Sea in summer of 1997. Their regional variation was illus-trated by demarcating the entire area into five regions. Ciliates always predominated both in abundance (>94%) and biomass (>78%) over nauplii. Regional means of ciliates in the water column were higher in the Alaskan Gyre (120 × 106 cells/m2) and the Western Subarctic Gyre (110 × 106 cells/m2) in terms of abundance, and rich in the Bering Sea Gyre (360 mgC/m2) and the Western Subarctic Gyre (340 mgC/m2) in terms of biomass. By contrast, standing crops of ciliates were poor in the Oyashio Region (67 × 106 cells/m2; 170 mgC/m2) and the Transition Region (64 × 106 cells/m2; 160 mgC/m2). The values of biomass reported here are generally in agreement with the values reported previously from the Bering Sea Gyre and the Alaskan Gyre but are considerably higher than the previous value found in the Western Subarctic Gyre. No significant correlations could be found between chlorophyll a crop and standing crops of ciliates and copepod nauplii over the entire subarctic North Pacific and the Bering Sea during this summer. grazing pressure on phytoplankton by microzooplankton, which varies from region to region (Miller et al., 1991; Banse, 1995). It is therefore important to illustrate the regional variation of standing crops of microzooplankton throughout the subarctic North Pacific by employing a uniform method. In this study we investigated the abun-dances and biomasses of planktonic ciliates and copepod nauplii over the area from the east to west of the subarctic North Pacific and the Bering Sea in summer.