Journal of Oceanography, Vol. 62 (No. 1), pp. 37-45, 2006
Joji Ishizaka1,4*, Yasuhisa Kitaura1, Yasuharu Touke2, Hiroaki Sasaki3, Akihiko Tanaka3, Hiroshi Murakami4, Toshikazu Suzuki2, Kazumi Matsuoka1 and Hideaki Nakata1
1Faculty of Fisheries, Nagasaki University, Bunkyo, Nagasaki, Nagasaki 852-8521, Japan
2Graduate School of Science and Technology, Nagasaki University, Bunkyo, Nagasaki, Nagasaki 852-8521, Japan
3Nagasaki Industrial Promotion Foundation, Ikeda, Omura, Nagasaki 856-0026, Japan
4Earth Observation Research and Application Center, Japan Aerospace Exploration Agency, Harumi, Chuo-ku, Tokyo 104-6023, Japan
(Received 30 August 2004; in revised form 3 June 2005; accepted 6 June 2005)
Abstract: High resolution SeaWiFS data was used to detect red tide events that occurred in the Ariake Sound, Japan, a small embayment known as one of the most productive areas in Japan. SeaWiFS chlorophyll data clearly showed that a large red tide event, which damaged seaweed (Nori) cultures, started early in December 2000 in Isahaya Bay, expanded to the whole sound and persisted to the end of February 2001. The monthly average of SeaWiFS data from May 1998 to December 2001 indicated that the chlorophyll peaks appeared twice a year, in early summer and in fall, after the peaks of rain and river discharge. The SeaWiFS data showed that the red tide event during 2000-2001 winter was part of the fall bloom; however, it started later and continued significantly longer than other years. Satellite ocean color data is useful to detect the red tide; however the algorithms require improvement to accurately estimate chlorophyll in highly turbid water and in red tide areas.