Characteristics of Fish Fauna Collected from Near Estuary of Seomjin River and Population Ecology

섬진강 하구 어류상과 주요 종의 개체군 생태

This paper was the result of investigation on fish fauna of natural estuary at Seomjin River, Korea. The total number of fish species collected in this study was 68 species belonging to 26 families. Dominant species in number was Acheilognathus majusculus (relative abundance: 37.4%), subdominant was Tribolodon hakonensis (10.5%). There were seven migrating fishes including Anguilla japonica and T. hakonensis. There were twenty Korean endemic species including Acheilognathus koreensis and Acheilognathus somjinensis. Thirty five species belonging to eight families were collected in upper part of river that dominant species was A. majusculus (38.2%). Thirty seven species were collected in lower part of river that dominant species was A. majusculus (48.5%). Thirty four species were collected in near estuary that dominant species was T. hakonensis (42.6%). In the comparison result of condition factor for several main species populations of Seomjin River were better than Nagdong River populations having estuary barrage. It was considered that almost fish populations of mid-to lower Seomjin River without estuary bank have stable life with natural environment.

하구둑이 형성되지 않은 자연 하천을 유지하고 있는 섬진강 하구의 어류상을 조사하고 주요 어종의 개체군 생태를 분석하였다. 조사 결과 섬진강 하구에서 출현한 어류는 13목 26과 68종이었으며 전체 우점종은 큰줄납자루 (37.4%), 아우점종은 황어 (10.5%)였고 피라미(8.4%), 주둥치(5.1%)순으로 개체수가 많았다. 회유성 어종은 뱀장어, 황어, 은어, 연어, 숭어, 점농어, 민물검정망둑 7종이 출현하였고 한국고유종은 임실납자루와 칼납자루 등 20종이었다. 상류 담수역에서는 8과 35종이 채집되었고 우점종은 큰줄납자루 (38.2%), 아우점종은 참중고기 (11.5%)였으며, 하류 담수역은 13과 37종이 출현하였고 우점종은 큰줄납자루 (48.5%), 아우점종은 피라미 (13.0%)였다. 하구의 기수역은 19과 34종이 확인되었고 우점종은 황어 (42.6%), 아우점종은 주둥치 (13.2%)로 나타났다. 누치 등 주요 종에 대한 개체군 건강도 지수는 하구둑이 설치된 낙동강 집단에 비해 높게 나타나 하구둑 조성이 없는 섬진강 어류 집단이 안정적인 성장을 하고 있다고 본다.