Exploring of salmon spawning sites and abundance using Steller's sea eagle tracking in Hokkaido

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660156
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Aquatic bioproduction science
• Research Institution: Kitami Institute of Technology
• Principal Investigator: Matsumoto Kei 北見工業大学, 工学部, 研究員 (90507170)
• Co-Investigator(Kenkyū-buntansha): NAKAYAMA Keisuke 神戸大学, 工学(系)研究科(研究院), 教授 (60271649)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: シロザケ産卵河川 / オオワシ / 安定同位体比 / レーダー観測 / 海由来栄養

Outline of Final Research Achievements

In winter, although Steller’s sea eagles can be seen at salmon spawning sites in Hokkaido, little is known for their potential as a field indicator which allows us to estimate the salmon abundance. In this study, we examined temporal and spatial distribution of eagles along the salmon spawning river in eastern Hokkaido. More eagles occurred in the riparian forests in relation to salmon abundance. The spatial patterns of eagles were matched the results from radar observations beside the spawning sites. We also tested how the salmon runs and eagle’s consumption affected on marine derived nutrient inputs into the terrestrial ecosystem based on the use of stable isotope signature (δ15N, δ13C) of terrestrial plants. Stable isotope ratios of plants from spawning sites were higher than those from non-spawning sites. Thus, eagle occurrences and stable isotope signature can be the index of salmon abundance in the spawning rivers.

Free Research Field

寒冷地生態工学