Potential impact of Poyang Lake Hydraulic Project on hydrodynamicenvironment and fish habitat

Abstract

The problem of dry water in Poyang Lake has been deteriorating, and the ecological function is declining. Hence, the construction of Poyang Lake Hydraulic Project (PLHP)was proposed. In this study, the potential impact of PLHP on fish was explored by establishing a research framework among hydrodynamics, biological behaviours, spatial distributionand abundance of aquatic organisms. Two scenarios of the current dry water situation and PLHP regulation scheme were simulated, and the variables of water depth, velocity, riverbed surface morphology, habitat area, food resources, movement ability and biological connectivity were discussed. Results show that the effect of PLHP on fish habitat has both positive and negative aspects. For the whole area, the hydraulic project improves the habitat suitability area and food resources of fish, but weakens the migration ability and connectivity with the Yangtze River. The degree of dual influencedepends on the dispatching water level. These results could provide guidancefor the reasonable operation of PLHP and the protection working of fish in Poyang Lake.