SCIENTISTS working on the River Murray have found that native fish species are making good use of new fishways near the Murray Sunset National Park.
Monitoring of fish movement by the Mallee Catchment Management Authority and the Department of Environment, Land, Water and Planning (DELWP) began in 2014 and is showing that movement is aided by the installation of fishways on new structures at Mullaroo Creek and Lower Lindsay River.
DELWP Arthur Rylah Institute scientist Jarod Lyon said: “The fishways are a valuable feature of structures built in 2015 to restore floodplain inundation at the Lindsay-Mulcra-Wallpolla islands.
“Any flow through these structures has to consider the habitat and migration needs of important native fish populations, so we have been monitoring fish at Mullaroo Creek, Lindsay River, Potterwalkagee Creek and the River Murray between locks 7 and 8,” Mr Lyon said.
“The monitoring has been done using radio-telemetry technology, with radio transmitters implanted into 135 fish including Murray Cod, Golden Perch and Freshwater Catfish.
“Logging stations have been placed to record the movement of tagged fish along Mullaroo Creek, Lindsay River, Potterwalkagee Creek and along the River Murray between locks 6 and 8.
“Data from the logging stations has shown that tagged fish were moving around a lot. The fish were travelling between several anabranch reaches within Mulcra and Lindsay Island into the River Murray main channel.
“Of note was an increase in movement of native fish into creeks over spring and early summer during breeding. They are also moving through the newly constructed fishway built at the Mullaroo regulator.
“Many fish are travelling long distances, such as the Golden Perch that travelled from Mullaroo Creek to Lock 11 near Mildura—a distance of over 180km.
“This monitoring is telling us about the current migration and habitat use of native fish within the region, which at times is linked to crucial life cycle events such as spawning.
“This knowledge can provide guidance on the future operation of the structures and environmental water delivery in a way that maximises benefits to native fish populations in the region.”
The fish monitoring was conducted by Arthur Rylah Institute, funded by The Living Murray and coordinated by Mallee CMA.
The Living Murray is a joint initiative funded by the New South Wales, Victorian, South Australian, Australian Capital Territory and Commonwealth governments, coordinated by the Murray–Darling Basin Authority.
