After a 40-year absence, Murray crayfish is set to be reintroduced to South Australia's River Murray. 

The Aquasave Nature Glenelg Trust has been granted permission to release the species into the river in the next couple of weeks, with releases to take place in areas of Berri and Loxton at the end of April.

According to Sylvia Zukowski, senior aquatic ecologist at Aquasave Nature Trust Glenelg; “Murray crayfish have been declining in distribution and abundance all throughout Australia … but unfortunately in SA the last record was in early 1980s”.

The water quality in South Australia and the regions selected for the release have the necessary well-oxygenated and fast-flowing water required for the species.

Dr Zukowski also revealed that a breeding program is planned for the future, ideally breeding the animals in captivity after the initial reintroduction. 

“Hopefully in the long term, the plan would be to actually start a breeding program which would be amazing and keep doing reintroductions on a yearly basis,” she said.

Overfishing, river regulation, pollution, and salinity have all contributed to the decline of the Murray crayfish in South Australia. 

They have a long life span of up to 30 years and do not begin breeding until about age 8. 

When young, they can be cannibalistic in nature, making breeding even more difficult.

“We'd obviously be targeting initially those sections that are well suited to Murray crayfish,” said Dr Zukowski. 

“They're not like a fish that can travel downstream and repopulate, they don't move further than 300 or 400 metres.” 

The experts say that the reintroduction of Murray crayfish to the River Murray is an important step in preserving this species, and it will hopefully pave the way for their recovery in South Australia.