Eradication methods for an invasive crayfish (Procambarus clarkii) inhabiting paddy field areas

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K08005
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Rural environmental engineering/Planning
• Research Institution: Okayama University
• Principal Investigator: Nakata Kazuyoshi 岡山大学, 環境生命科学研究科, 准教授 (70431343)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: アメリカザリガニ / 外来種 / 駆除手法 / 水田水域 / 甲殻類 / トラップ

Outline of Final Research Achievements

The red swamp crayfish (Procambarus clarkii) has negatively affected native species around the world as an invasive species. Invasive crayfish can significantly reduce the abundance of macroinvertebrates, aquatic plants, molluscs and fish. In addition, burrowing behavior of P. clarkii can cause damage of the native species habitat. The purpose of this study was to develop the effective management and eradication methods for P. clarkii inhabiting paddy field areas of Japan. In this study, we clarified and proposed the effective entrance structure and setting season for the shrimp cage and bottle traps for collecting P. clarkii. Furthermore, solutions to reduce the negative effect of burrowing behavior by P. clarkii on paddy fields are very limited. We conducted a laboratory experiment and clarified that invasive crayfish burrows may cause water leakage in paddy fields. We also examined paddy soil conditions that the invasive crayfish cannot make burrows in terms of soil hardness.

Free Research Field

応用生態工学

Academic Significance and Societal Importance of the Research Achievements

アメリカザリガニをはじめとする外来ザリガニ類については，国内外において，在来生態系に与える深刻な影響が大きな問題となっている。また，水田に巣穴を掘ることで水田漏水を引き起こすなど，農業被害も確認されている。このため，国内外において外来ザリガニ類の早急な駆除対策を必要としている現場が多い。
本研究で得られたアメリカザリガニの駆除手法に関する成果は，そのような現場においてすぐに活用できるものであり，社会的な意義が大きいと考えられる。