Community structure of genus Skeletonema in coastal waters

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07508
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: Katano Toshiya 東京海洋大学, 学術研究院, 准教授 (00509820)
• Research Collaborator: Yamada Machiko
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 珪藻赤潮 / Skeletonema / 競争 / 群集組成

Outline of Final Research Achievements

Primer sets against 10 Skeletonema species for Real time PCR and multiplex PCR were developed. Species composition of Skeletonema in Tokyo Bay and the Ariake Sea was evaluated using these PCR techniques. In both bays, more than 6 species of Skeletonema including freshwater species of S. potamos were detected. Especially in the bottom sediment of the rivers inflowing to the bays, we detected high abundance and many species of Skeletonema were detected. These results imply that bottom sediments of these rivers possibly play important role as the seed bank of Skeletonema bloom in estuaries. In the competition between winter dominant species of S. japonicum and S. marinoi-dohrnii complex, in addition to environmental factors, endogenous factor (valve diameter) strongly affects on the results of the competition.

Free Research Field

水界生態学

Academic Significance and Societal Importance of the Research Achievements

珪藻Skeletonema属は、世界中の多くの内湾に出現し、とりわけ富栄養な水域で優占することが知られている。東京湾とアメリカのナラガンセット湾ではどちらも植物プランクトンの90%以上が、Skeletonemaとされる。2005、2007年のSarnoらの発表によりS. costatumは、8種にも分類された。この新しい分類体系に基づく種同定は、単離と単離株の種同定に依存し多大な労力と時間を要していたが、本研究で開発されたプライマーセットにより迅速な種判別および定量解析が可能になった。世界の内湾で季節を問わず赤潮を起こすSkeletonemaの動態について今後大きく研究が進むことが期待される。