Microzooplankton biomass in the Arctic and subarctic Pacific Ocean in summer

• Main Author: Akira Taniguchi
• Format: Report
• Language: English
• Published: Faculty of Agriculture, Tohoku University 1984
• Subjects: Arctic; Pacific; Chukchi; Foraminifera*; Memoirs of National Institute of Polar Research; Phytoplankton; Polar Research; Subarctic; Zooplankton
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1613; http://id.nii.ac.jp/1291/00001613/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1613&item_no=1&attribute_id=18&file_no=1

Microzooplankton biomass and its relative abundance to netzooplankton biomass were estimated in the Chukchi and Bering Seas and the northern North Pacific Ocean in summer. The dominant taxa were ciliates other than tintinnids, tintinnid ciliates and copepod nauplii. While the dominancy in individual number was high in the order described, nauplii were the most important in weight. Regional distribution of ciliates other than tintinnids coincided with that of chlorophyll stocks, being small in oceanic waters in the south, large in shelf waters in the north and largest at the shelf break in the center of the investigation areas. While the same positive relationship to chlorophyll was also observed roughly in tintinnids, it was not always substantial in copepod nauplii. Foraminifera, radiolarians, rotifers, and larvae of pteropods and bivalves formed minor constituents of the microzooplankton assembly. Microzooplankton biomass estimated in this investigation (1.57-26.75g wet weight/m^2) was larger than the previously reported values from various arctic and subarctic seas. Its relative abundance to net-zooplankton (4.4-36.5%) was, though at the same level in other boreal seas, lower than those in the tropical and subtropical seas. This indicates that, in turn, contribution of nanoplankton to total phytoplankton is smaller in the boreal seas but larger in the tropics.