| Title |
Effects of Fish on the Grazing Pressure of Zooplankton in the Artificial Mesocosms |
| Authors |
임지혁 ( Ji Hyeok Im ) ; 손세환 ( Se Hwan Son ) ; 김진영 ( Jin Young Kim ) ; 오민우 ( Min Woo Oh ) ; 남귀숙 ( Gui Sook Nam ) ; 송영희 ( Young Hee Song ) ; 이옥민 ( Ok Min Lee ) ; 공동수 ( Dong Soo Kong ) |
| Keywords |
Biomanipulation; Ecotechnology; Kyongan stream; Top-down force |
| Abstract |
In a natural water body, a useful ecotechnology to reduce standing crops of phytoplankton is to strengthen the top-down force of zooplankton. However, the predation of fish for zooplankton can make the force weak. This study was conducted to find out the effect of fish on the grazing pressure of zooplankton in the mesocosms established in a eutrophic stream (Kyongan Stream) from October to November in 2010. In the corral with fish, chlorophyll a concentration increased, and a small size cladoceran Bosmina longirostris was dominant. In the corral without fish, chlorophyll a concentration decreased along with the domination of a large cladoceran Daphnia galeata and a large copepod Eudiaptomus japonicus. The size-selective predation of fish appeared to miniaturize the zooplankton community, to narrow their food-size spectrum, and to weaken the top-down force. |