The South Australian Government is working in conjunction with the Murray Darling Basin Authority (MDBA
) to construct fishways to allow the passage of native fish from the sea to the Hume Dam – an amazing distance of 2,225 kilometres. Twelve major barriers such as dams and weirs are currently blocking fish movement in the Murray between the sea and the Hume Dam.
Fishways are being installed while upgrading the locks and weirs along the river. Work on locks seven, eight, nine and ten have been completed. Over the coming years work will be undertaken on locks one to six and this is expected to be completed by 2012.
Native fish in the Murray-Darling Basin have suffered a decline in both numbers and distribution. A variety of factors have contributed to this decline including exotic fish, water pollution and habitat deterioration.
Locks, weirs and barrages have also impeded the movement of fish species along the river. Fish move along rivers for breeding, safety and the establishment of new territories.
Consisting of a series of interconnected pools in a gently sloping structure, the fishways allow native fish to migrate upstream, moving from pool to pool, and to take their time according to their swimming abilities.
National fish experts will monitor the fishways to assess their effectiveness. Initial estimates indicate that every year over 100,000 native fish will pass through each of the new fishways at locks seven to nine. Scientists are now investigating carp separation trials at the fishways and it is hoped this will provide an effective way of removing large amounts of this pest species.
Fishways will greatly benefit the River Murray environment and help to protect native fish species.
Native fish strategy - Murray-Darling Basin Authority