Dealing with Fish under the Pump: Why Irrigators Are Well-Placed to Lead Native Fish Recovery in the Murray-Darling Basin

Irrigated agriculture is the largest user of water in the Murray–Darling Basin (MDB) and there has been substantial development over the past 100 years in water diversion and storage. Larger-bodied fish enter irrigation canals or can be entrained by pumps, and early life stages (eggs, larvae and 0+ fish) are entrained in significant numbers owing to their drifting dispersal strategy and poor swimming ability. To improve native fish populations in the basin there is a need to capitalise on the huge potential that exists for irrigators to be stewards for native fish recovery.  The success of fish screening programs around the world demonstrates that coordinated efforts to screen irrigation diversions could make huge inroads into improving fish stocks in the MDB while also being of direct benefit to irrigators. Although no screening program currently exists in the MDB, significant progress has been made in understanding the scope of fish losses and defining screen design criteria suitable for native fish and local conditions. This presentation outlines the ‘state-of-the-art’ of fish screening in the MDB and discusses what need to be done to overcome the financial and institutional barriers that are hindering irrigators and fisheries managers collaboratively establishing a basin-wide screening program.