Lower Murray Darling Catchment Management Authority Native Fish Release

Issues

Poor water quality in the Murray Darling Catchment due to the presence of carp has impacted the numbers of fish, crayfish and other aquatic animals. Releasing large numbers of native fingerlings into the Murray River will assist in boosting native fish populations.

Project Summary

The Lower Murray Darling Catchment Management Authority (LMD CMA) sought funding from Club Marine to procure and release approximately 22,200 native fish into the Murray River between Euston and Balranald, NSW, to improve native fish stocks in the areas and to mimic a spawning event which has not happened for several years due to drought. Their long term goals are to reduce carp numbers, which may reduce turbidity and improve water quality.

LMD CMA also sought funding to purchase water monitoring kits to build capacity by training local students in water quality testing.

Before the project was implemented in2010, drought and lack of flooding meant that spawning of native fish in the lower Murray River reach has been significantly reduced or in some areas had not occurred for several years. Restocking of fish replaces fingerlings and juveniles to re-dress the age and population dynamics of the river system. As carnivores, Murray cod have a life expectancy of over 100 years and the capacity to grow over 50kg. As carnivores, these native fish will feed on carp. Fish are sourced from a licensed hatchery, the parent stock collected in the same river reach as the releases will occur.

On Thursday, 12th February 2009, 22,000 fingerlings were released into the Murray River at Euston boat ramp. Lower Murray Darling Chair, Mark King, said the release was a great bonus to the river and brought the total number of fingerlings released by the LMD CMA and its corporate partners to over 382,000 since 2005.

Two water testing kits were also provided to Euston Public School and Balranald Central School. These will be used by students to gain experience in monitoring and reporting water quality of their section of the Murray River as part of monitoring the environment the fish are living in.

It is impossible to undertake a detailed assessment of survival as the fish are being released into a river system that is populated by other fish, and also because the fish can migrate hundreds of kilometres within the river system and when floods occur, native fish move into wetlands and floodplains. However it has been a great boost to the river and with the continuation of the drought, there have been no flood events to trigger spawning, so limited new fish have hatched.