The fishways are a series of connected pools in a gently sloping structure. They allow native fish to migrate upstream, moving from pool to pool. They can take their time according to their swimming abilities.
We are proud to have built fishways that benefit the River Murray and help to protect our native fish species. Native fish can move from the sea to the Hume Dam. That's an amazing distance of 2,225 km!
There used to be 12 major barriers such as dams and weirs that blocked fish movement between the two points. Fishways have now been installed in all of them.
The installation of additional fishways on branches of the River Murray is in progress. This is part of a wider attempt to improve the habitat and movement of fish throughout the river system.
Native fish in the Murray-Darling Basin have suffered a decline in both numbers and distribution. A variety of factors have contributed to native fish decline. This includes drought, introduced fish species and water pollution. Fish habitats have also been getting worse over time.
Until recently, locks, weirs, and barrages stopped the free movement of fish along the River Murray. Fish move along rivers for breeding and safety. They also create new territories along the river.
National fish experts will monitor the fishways to assess their effectiveness. Initial estimates tell us that more than 100,000 native fish per year will pass through fishways at Locks 7 to 9.
Scientists are investigating carp separation trials at the fishways, with the method already being used at Lock 1. We hope this will be an effective way of removing large numbers of this pest species.
For more information about the fishways project please visit the Murray-Darling Basin Authority's website.
SA Water's carp cage at Blanchetown's Lock One is an effective method of controlling European carp numbers in the River Murray.
European carp are a pest species introduced into the Murray-Darling system in the 20th century. Their adaptability saw the species proliferate in Australian rivers and waterways. European carp are the most abundant large freshwater fish in the Murray-Darling basin.
Carp cause the degradation of river systems due to their feeding habits. The fish regularly uproot native aquatic plants and stir up sediments.
The Lock One carp cage began operation in 2007. Native fish swim underneath the cage and avoid being trapped.
The cage is checked and emptied at regular intervals. It is emptied more often during spring and summer, since carp are most active along the River Murray system between August and April. Around 80 tons of carp have been removed from Lock One in September.
It is illegal to return carp to the River Murray. Carp caught in the SA Water cage are humanely euthanised. The carp are processed by a licensed fisheries company and used in products including fish bait, cat food and fertiliser.
By removing European carp from our river, we assist in protecting our native fish and aquatic biodiversity.