Ice algae and phytoplankton in the late ice-covered season in Notoro Ko lagoon, Hokkaido

• Main Authors: Asami,Hiroki, Imada,Kazushi
• Format: Report
• Language: English
• Published: Hokkaido Fish Hatchery/ Hokkaido Fish Hatchery 2001
• Subjects: Notoro Ko; ice algae; phytoplankton; cell density; chlorophyll; Okhotsk; Polar bioscience; Sea ice
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=6163; http://id.nii.ac.jp/1291/00006163/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=6163&item_no=1&attribute_id=18&file_no=1

The chlorophyll a biomass and species composition of ice algae and phytoplankton were investigated in the late ice-covered season, late February to mid-April 1992,at a fixed station in Notoro Ko lagoon, Hokkaido, Japan. Ice algal biomass was 6.11mg m^2 on February 25. In early March it decreased to one-half and this level of biomass was retained until the end of March. Navicula spp. and Fragilaria spp. dominated in the ice but Fragilaria spp. and Detonula confervacea predominated in the phytoplankton. However, most of the constituent taxa were common to both the ice and water column under the ice. The biomass of phytoplankton began to increase in mid-March in the water column under the sea ice and after ice melting, a remarkable increase occurred in the near bottom layer. The temporal sequence of the ice algal and phytoplankton biomass in Notoro Ko resembled that observed by other researchers in Saroma Ko in the same season, because the climatic and oceanographic conditions of Notoro Ko and Saroma Ko are similar due to their geographical proximity and their connection to the Sea of Okhotsk.