Current status of a wild population of chum salmon on the Sanriku Coast, based on DNA genotype-based kinship estimation

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07904
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: The University of Tokyo
• Principal Investigator: Minegishi Yuki 東京大学, 大気海洋研究所, 助教 (80793588)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: サケ / 自然産卵 / 小鎚川 / 遡上 / 産卵床 / 繁殖生態

Outline of Final Research Achievements

The aim of this study was to reveal the current status of natural spawning of chum salmon returning to a river without implementation of stock enhancement program, in order to understand the local ecological characteristics of wild chum salmon populations on the Sanriku Coast, the Pacific side of the Honshu Island, Japan. The field survey through the entire season for 3 years revealed the period, number and area of escapement and the number and distribution of spawning redds for the first time. A comparison with a river with stock enhancement found that a wild population has a substantial size despite that stock enhancement program has not been operated and suggested that there is a need to re-evaluate the effect of stock enhancement program. DNA genotype-based kinship estimation among all individuals of the returning adults requires more analyses.

Free Research Field

分子生態学

Academic Significance and Societal Importance of the Research Achievements

日本のサケ資源は孵化放流事業により造成されたと考えられてきた。本研究により、日本のサケ資源管理上、存在しないとされていた野生魚と自然産卵の実態が、三陸地方の河川全体で初めて、定量的に明らかになった。本研究で得られた成果は、三陸のサケ地域個体群の理解および保全の礎となるだけでなく、資源保全および持続的利用を目指す上で、最も基礎的な情報を提供し得る。また、その希少性・地域性から、観光および教育資源としての価値も高く、食資源だけに止まらない三陸産サケの新たな価値観の創生に繋がる。