Researchers outline new plan to promote Murray cod growth

By Jared Prestwidge

RESEARCHERS have released a paper that outlines a new strategy to increase Murray Cod numbers in the Murray River.

In 2013, researchers from CPS Enviro, the Arthur Rylah Institute (ARI) and North Central Catchment Management Authority (NCCMA) added environmental water to the existing irrigation flows in Gunbower Creek, an anabranch of the Murray River.

The aim was to generate an environment that would enhance the abundance of the endangered fish and promote population recovery.

Three specific irrigation flow conditions are known to promote Murray Cod growth: a steady spring flow to keep Murray Cod on their nests, some areas of permanent fast flowing water, and higher winter flows for small fish.  

Changes in the creek five years before and after the implementation were then evaluated to see if numbers of juvenile Murray cod increased.

Dr Ivor Stuart said the results were encouraging.

"By monitoring Murray Cod in Gunbower Creek for five years before, and five years after the change in management of water flows, we could assess if it could increase survival of both locally spawned and stocked fingerlings," he said.

"We found many more juvenile Murray Cod after the modified flows, which is a very encouraging sign, and these flows are now implemented annually.

"There's no reason why we now can't apply this approach to manage water to many other rivers to benefit this important fish species."