낙동강 하구역의 강우-수문학적 영향에 의한 동물플랑크톤 군집조성 변화

Abstract

The zooplankton community composition of the Nakdong River estuary can be categorized by the hydrological and environmental characteristics. Nakdong River estuary is regulated by the Nakdong River Estuary Barrage(NREB), to prevent salt-water intrusion into the lower part of Nakdong and to maintain river-reservoir. During monsoon season, the level of total barrage discharge increases, flushing out large amount of freshwater through the barrage gate. Zooplankton in estuaries are often distributed by species along the salinity gradient. Zooplankton species community composition were investigated at 11 stations in May and October, 2015 and at 21 stations in May, July and September, 2016. Water temperature, salinity, chlorophyll-a, total suspended solids and nutrients were measured for the environmental characteristics. Study stations were divided into 3 zones by the hydrological characteristics marine(st.1-9), estuarine(st.10-16), freshwater(st.17-21). The average precipitation and average barrage discharge during sampling periods were 1.4 ㎜ and 394 ㎥/day in May 2015, 5.6 ㎜ and 257 ㎥/day in Oct. 2015, 0.05 ㎜ and 311 ㎥/day in May 2016, 4.5㎜ and 205 ㎥/day in July 2016, 11.2㎜ and 730 ㎥/day Sep. 2016. 79 species of zooplankton were identified cladocerans, copepods, chaetognaths, foraminiferans, siphonophores, salps, hydroids, pteropods, macrobenthic larvae, and appendicularians appeared during the study periods. r intrusion into the lower part of Nakdong and to maintain river-reservoir. During monsoon season, the level of total barrage discharge increases, flushing out large amount of freshwater through the barrage gate. Zooplankton in estuaries are often distributed by species along the salinity gradient. Zooplankton species community composition were investigated at 11 stations in May and October, 2015 and at 21 stations in May, July and September, 2016. Water temperature, salinity, chlorophyll-a, total suspended solids and nutrients were measured for the environmental characteristics. Study stations were divided into 3 zones by the hydrological characteristics marine(st.1-9), estuarine(st.10-16), freshwater(st.17-21). The average precipitation and average barrage discharge during sampling periods were 1.4 ㎜ and 394 ㎥/day in May 2015, 5.6 ㎜ and 257 ㎥/day in Oct. 2015, 0.05 ㎜ and 311 ㎥/day in May 2016, 4.5㎜ and 205 ㎥/day in July 2016, 11.2㎜ and 730 ㎥/day Sep. 2016. 79 species of zooplankton were identified cladocerans, copepods, chaetognaths, foraminiferans, siphonophores, salps, hydroids, pteropods, macrobenthic larvae, and appendicularians appeared during the study periods.