Ecological indicators are tools used to evaluate the state of specific environments by monitoring the ecological characteristics and changes of organisms, and they are widely utilized in environmental monitoring and management. Such indicators should be sensitive to environmental changes, maintain long-term stability, and be easy to investigate and analyze. This study aimed to evaluate whether the spraint density of the Eurasian otter (Lutra lutra) can monitor the state and changes in river ecosystems. Using spraint density data over nine years (2014~2024), we analyzed temporal and spatial changes in otter distribution. Generalized Additive Models were applied to assess annual variability, and spatial clustering and distribution changes were examined using Hotspot Analysis and Geo-SOM (Geo-Self-Organizing Map). The results indicated stable spraint density trends in most sub-watersheds, with higher variability in developed areas. This study highlights the potential of spraint density as a cost-effective and simple ecoological indicator for long-term river ecosystem monitoring.

Abstract
서 론
방 법
    1. 연구 지역 및 수달 분포 조사방법
    2. 경관 규모 수환경에 따른 배설물 밀도의공간적 분리 여부 분석
    3. 경관 규모별 배설물 밀도의 연도별 변동성 분석
    4. 지리자기조직화 지도를 활용한 배설물 밀도의시공간적 변화상 분석
결 과
    1. 중권역별 배설물 밀도
    2. 경관 규모 수환경에 따른 배설물 밀도의공간적 분리 여부 분석
    3. 경관 규모별 배설물 밀도의 연도별 변동성 분석
    4. 지리자기조직화 지도를 활용한 배설물 밀도의시공간적 변화상 분석
고 찰
    1. 공간적으로 구분되는 수달 배설물 밀도 분포
    2. 배설물 밀도의 연도별 변동성
    3. 하천 환경에 따른 배설물 밀도의 시공간적 변화
    4. 하천 환경 상태의 생태학적 지표로 수달 배설물 밀도의사용 가능성
    5. 배설물 밀도를 활용한 수생태계 다양성 보전 관리 방안
    6. 본 연구의 한계 및 향후연구
적 요
REFERENCES

• 김주성(경북대학교 축산BT학과) | Jooseong Kim (Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea)
• 김미현(경북대학교 축산BT학과) | Mihyeon Kim (Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea)
• 김영민(국립생태원 멸종위기종복원센터 복원연구실 포유류팀) | Youngmin Kim (Restoration Research Team (Mammals), Research Center for Endangered Species, National Institute of Ecology, Yeongyang 36531, Republic of Korea)
• 김효겸(한국환경연구원 환경평가본부) | Hyo Gyeom Kim (Division for Land Policy Assessment, Korea Environment Institute, Sejong 30147, Republic of Korea)
• 김현우(국립순천대학교 환경교육과) | Hyun-Woo Kim (Department of Environmental Education, Sunchon National University, Suncheon 57922, Republic of Korea) Corresponding author
• 주기재(부산대학교 생명과학과) | Gea-Jae Joo (Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea) Corresponding author
• 홍성원(경북대학교 축산BT학과) | Sungwon Hong (Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea) Corresponding author