Elucidation of the ecology and declining factors of endangered species Arctic lamprey living in the Satoyama area of Noto Peninsula

2017 Fiscal Year Final Research Report

• Project/Area Number: 26340092
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental and ecological symbiosis
• Research Institution: Ishikawa Prefectural University
• Principal Investigator: Yanai Seiji 石川県立大学, 生物資源環境学部, 教授 (20337009)
• Co-Investigator(Renkei-kenkyūsha): Ichion Eiji 石川県立大学, 生物資源環境学部・環境科学科, 教授 (10320912)
• Research Collaborator: Arakawa Hiroaki 石川県立大学, 大学院 ; Lampman Ralph Yakama Nation Fisheries
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: カワヤツメ / 能登半島 / 生息場 / 幼生 / 減少要因 / ワンド / 河川水温 / 遡上能力

Outline of Final Research Achievements

The factor of decreasing lamprey was studied in Noto Peninsula, which is the southern distribution border. In this area, arctic lamprey was captured in 11 rivers before 2000 using special fishing gear called "Kanko", but only 2 rivers have been captured since 2000. The cause of decline was largely influenced by the channel alternation done in the 1980's. For larvae living in muddy substrate, the side cavity topography on which fine grain sediments are deposited is indispensable, but this topography has disappeared due to channel work. Global warming is also important factor, the 29.3 ℃ is upper limit temperature for survive. They need to migrate for low temperature upstream area. However, the migration ability is extremely low (limit height for migration was about 20 cm). It was concluded that improving the river structure that becomes a barrier and restoring continuity of river is important for conservation of this species in the southern distribution border in Japan.

Free Research Field

流域環境学