The Namdae stream in Gangneung-si is one of the rivers where salmon stock is mainly maintained by natural spawning rather than artificial seedlings. There are structures including weir, and fish distribution and movement characteristics can be different by these structures. In this study, we investigated the distribution and behavioral characteristics of salmon by sighting survey within 12 km immediately upstream of the river mouth between October 2021 and February 2022. As a result, salmon distributed within 9 km from rivermouth. There were more salmon in the lower reaches of Doosan weir than in the upper reaches of that. The main spawning ground for salmon was between 7-9 km from rivermouth and around the lower part of Doosan weir. Salmon behaved for spawning in the gravel-bed area and undercut slope of the mainstream, such as mating, digging the riverbed, and competition among males. Salmon moved more slowly in the gravel-bed area than sand-bed area. Doosan weir hinders the spawning migration of salmon by frequent flow changes and terraced fishway. This study provides primary information to understand the ecological changes of salmon by environmental changes in the Namdae stream.

Abstract
1. 서 론
2. 자료 및 방법
3. 결 과
    3.1. 남대천 지형 특성
    3.2. 연어 분포 및 이동 특성
4. 고 찰
5. 결 론
감사의 글
REFERENCES

• 김범식(강릉원주대학교 해양생태환경학과) | Beom-Sik Kim (Department of Marine Ecology and Environment, Gangneung-Wonju National University, Gangneung 25457, Korea)
• 정용우(강릉원주대학교 해양생태환경학과) | Yong-Woo Jung (Department of Marine Ecology and Environment, Gangneung-Wonju National University, Gangneung 25457, Korea)
• 김우보(강릉원주대학교 해양생태환경학과) | Woobo Kim (Department of Marine Ecology and Environment, Gangneung-Wonju National University, Gangneung 25457, Korea)
• 홍성익(바다생태리서치) | Sung-Eic Hong (Bada Ecology Research, Gangneung 25434, Korea)
• 이충일(강릉원주대학교 해양생태환경학과) | Chung Il Lee (Department of Marine Ecology and Environment, Gangneung-Wonju National University, Gangneung 25457, Korea) Corresponding author