ECOLOGICAL CONSEQUENCES OF HYDROPOWER DEVELOPMENT IN外文翻译.pdf

RIVER RESEARCH AND APPLICATIONS River Res. Applic. 22: 397–411 (2006) Published online 6 January 2006 in Wiley InterScience (). DOI: 10.1002/rra.899 ECOLOGICAL CONSEQUENCES OF HYDROPOWER DEVELOPMENT IN CENTRAL AMERICA: IMPACTS OF SMALL DAMS AND WATER DIVERSION ON NEOTROPICAL STREAM FISH ASSEMBLAGES ELIZABETH P. ANDERSON,a MARY C. FREEMANb and CATHERINE M. PRINGLEa a Institute of Ecology, University of Georgia, Athens, GA, USA b United States Geological Survey, Patuxent Wildlife Research Center, Athens, GA, USA ABSTRACT Small dams for hydropower have caused widespread alteration of Central American rivers, yet much of recent development has gone undocumented by scientists and conservationists. We examined the ecological effects of a small hydropower ˜ plant (Dona Julia Hydroelectric Center) on two low-order streams (the Puerto Viejo River and Quebradon stream) draining ˜ a mountainous area of Costa Rica. Operation of the Dona Julia plant has dewatered these streams, reducing discharge to 10% of average annual flow. This study compared fish assemblage composition and aquatic habitat upstream and down- stream of diversion dams on two streams and along a 4 km dewatered reach of the Puerto Viejo River in an attempt to evaluate current instream flow recommendations for regulated Costa Rican streams. Our results indicated that fish assem- blages directly upstream and downstream of the dam on the third order Puerto Viejo River were dissimilar, suggesting that the small dam (15 m high) hindered movement of fishes. Along