가평천 상류역 어류군집의 장기변동 Long-Term Variation of the Fish Community in the Upper Region of the Gapyeong Stream, Korea
pp.432-441
2005년 4월부터 2013년 10월까지 가평천 상류역 어류군집의 장기적인 변화를 조사하였다. 조사기간 동안 출현한 어종은 총 6과 17종 이었으며, 우점종은 Zacco koreanus(상대풍부도 59.9%), 아우점종은 Pungtungia herzi(8.5%) 이었다. 한국고유종은 Coreoleuciscus splendidus외 12종으로 확인되었다. 법적보호종은 멸종위기야생생물 Ⅱ급인 Pseudopungtungia tenuicorpa와 Gobiobotia brevibarba 등 2종으로 조사되었으며, 천연기념물은 Hemibarbus mylodon 1종이었다. 가평천의 수질등급은 최근 9년간 환경부 기준고시에 의거할 때 ‘매우좋음’ 등급을 유지하고 있었다. 육식어종인 Coreoperca herzi의 개체수는 감소하고, 잡식어종인 Zacco platypus는 증가하는 경향을 나타내었다. 군집분석 결과 우점도지수는 0.58∼0.86, 다양도지수는 0.94∼1.77, 풍부도지수는 0.99∼2.39의 범위로 나타났다. Rarefaction curve를 이용하여 연도별 기대 출현종수를 분석한 결과 151개체의 표본에서 예상되는 종은 최대 12종(2005), 최소 5종(2007)으로 나타났다. 가평천 상류역의 Z. koreanus 개체군을 대상으로 전장-체중 상관관계를 분석한 결과 회귀계수 b값은 연평균 3.29±1.11, 비만도는 0.0034±0.0021로 안정적인 개체군과 양호한 생육상태를 유지하고 있었다.
Long-term variation of the fish community in the upper region of Gapyeong Stream was investigation from April, 2005 to October, 2013. The collected species during the survey period were 17 species belonging to 6 families. Dominant species was Zacco koreanus(Relative abundance 59.9%) and subdominant species Pungtungia herzi(8.5%). Korea endemic species were 12, including Coreoleuciscus splendidus. The species of Hemibarbus mylodon was identified as natural monument, and Pseudopungtungia tenuicorpa and Gobiobotia brevibarba were endangered species. Water quality assessment of Gapyeong Stream, had lately maintained the rating of "very good" for nine years, based on the Ministry of the Environment standards notice. It was found that there was a tendency for populations which is Coreoperca herzi carnivorous species decreases, increases omnivorous species Zacco platypus. As a result of community analysis, dominant index was 0.58∼0.86, diversity index was 0.94∼1.77 and richness index was 0.99∼2.39. As a result of using the Rarefaction curve, were analyzed occurrence species expected each year, number of species is estimated from a sample of 151 individuals, up to 12(2005) was at least 5(2007) species. The regression coefficient (b) in relation to length-weight on Z. koreanus population were annual average 3.29±1.11, condition factor slope 0.0034±0.0021, which maintained good growth condition and stabilized population.