Long-term trends in the occurrence of red tides in the Seto Inland Sea, Japan

Ishii Daisuke, Yanagi Tetsuo, Sasakura Satoshi

doi:10.5928/kaiyou.23.6_217

Bibliographic Information

Other Title

瀬戸内海における赤潮発生状況の長期変動と赤潮優占群の海域特性
セトナイカイニオケルアカシオハッセイジョウキョウノチョウキヘンドウトアカシオユウセングンノカイイキトクセイ

Search this article

Abstract

<p>We studied the temporal variation and changes in red tide occurrences and the dominant species composing red tides in the Seto Inland Sea based on the red tide basic dataset for the 26 years from 1979 to 2004. This included the “Red Tide Index” (RI), which is capable of as sessing the spatiotemporal scale and impacts of a red tide. We analyzed the temporal changes in the RI in the Seto Inland Sea and Osaka Bay separately. The long-term trend in the RI in the Seto Inland Sea showed both increasing and decreasing trends with a minimum value around 1990. The trend in Osaka Bay has declined markedly for about 30 years. We found that the long-term trends in the RI in both the Seto Inland Sea and Osaka Bay corresponded with the long-term trends in solar radiation and nutrient concentration. The dominant species of red tide were derived using the RI in both the Seto Inland Sea and Osaka Bay. We found that non-diatom species were dominant mainly in the Seto Inland Sea, while in Osaka Bay the dominant species has changed from non-diatom species to diatom species during the past 30 years.</p>

Journal

Oceanography in Japan

Oceanography in Japan 23 (6), 217-236, 2014-11-15

The Oceanographic Society of Japan

Keywords

Details 詳細情報について

Export