Mitigating Fish Entrainment With Fish Protection Screens at Water Pumping Sites

ABSTRACTThe Murray‐Darling Basin (MDB) is one of the most regulated and fragmented river systems in Australia. The basin's extensive river infrastructure development has supported growing water demands for irrigation, industry, domestic, and electricity production, but increased use of pumps for water diversion threatens aquatic species and biodiversity conservation. Of particular concern is the entrainment of fish from natural waterways into water intake infrastructure, which causes the loss of millions of fish every year in the MDB. Fish protection screens have been installed to prevent fish entrainment, but few studies have empirically evaluated their effectiveness, and none in Australian rivers. We investigated the effectiveness of fish screens in reducing the entrainment of multiple aquatic species and debris at differently sized discharge pump diversions in Australia. Screening pumps reduced fish entrainment by 93%–100% and debris entrainment by over 99%. When appropriately designed and operated, fish screens reduced fish, crustacean, and debris entrainment by small and large water pumps in multiple riverine environments. Impingement of organisms at screen installations requires further investigation. We recommend fish protection screens as a complementary tool for supporting native fish recovery and river management programmes, while still enabling an effective water supply for human needs.