A phytoplankton bloom under sea ice recorded with a moored system in lagoon Saroma Ko, Hokkaido, Japan

• Main Authors: Mitsuo Fukuchi, Kentaro Watanabe, Atsushi Tanimura, Takao Hoshiai, Hiroshi Sasaki, Hiroo Satoh, Yukuya Yamaguchi
• Format: Report
• Language: English
• Published: National Institute of Polar Research/National Institute of Polar Research/National Institute of Polar Research/National Institute of Polar Research/Faculty of Agriculture, Tohoku University/Tokyo University of Fisheries/College of Liberal Arts, Saitama University 1989
• Subjects: Polar Biology; Proceedings of the NIPR Symposium on Polar Biology; Sea ice
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=5044; http://id.nii.ac.jp/1291/00005044/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=5044&item_no=1&attribute_id=18&file_no=1

A phytoplankton bloom under the fast ice formed in a lagoon, Saroma Ko, Hokkaido, Japan, was recorded with a long-term chlorophyll-measuring buoy moored at 3m of water depth of 6m for 161 days from December 1986 to May 1987. A total of 1938 sets of time series data (in situ chlorophyll a, temperature and depth) at two-hour intervals were obtained. Chlorophyll a was low (less than 1 μg/l) under cold temperature below -1.5℃ until middle March. From middle March to middle April, when the fast ice still covered the lagoon surface, chlorophyll a increased greatly to 4-5 μg/l. Thereafter it decreased to 2 μg/l.