Usage of seawater system for long-term study of phytoplankton in the boreal coastal water of Hokkaido, Japan

• Main Author: Satoru Taguchi
• Format: Report
• Language: English
• Published: Hokkaido National Fisheries Research Institute 1992
• Subjects: Polar Biology; Proceedings of the NIPR Symposium on Polar Biology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=5150; http://id.nii.ac.jp/1291/00005150/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=5150&item_no=1&attribute_id=18&file_no=1

Weekly sampling was begun in October 1989 for 13 months to monitor the seasonal change of environmental characteristics and biological events in the boreal coastal water of Hokkaido, Japan. Water sample was taken from a seawater system for aquaculture studies. Concentration of chlorophyll a indicated clearly a seasonality. The low concentration was observed in winter, and spring bloom peaked on March 5 and lasted for eight weeks. The termination of productive season was a result of the change of water mass which occurred in May and June. During summer the concentration was lower than 1.0mg・m^<-3>. No fall bloom was observed. The present monitoring program using the existing seawater system will help to identify the succession of water mass, the seasonal change of chemical environments, and the timing and duration of spring bloom, which may be the important factor for maintenance of the coastal ecosystem including larval fish oroduction.