Clever use of water for the environment in two northern Victorian wetlands is helping a critically endangered fish thrive.

The Murray hardyhead is a small native fish that has suffered from degraded habitat, altered flows, introduced predators, climate change, and water regulation.

Once widespread and common, it is now critically endangered, surviving in only a handful of places in Victoria. Two of those places are Round Lake (Kunat Kunat) and Lake Elizabeth near Kerang, thanks to stocking from the Arthur Rylah Institute (ARI), DEECA and environmental flows.

Both lakes are saline, which has given the North Central Catchment Management Authority (CMA) the perfect opportunity to create the right conditions for hardyhead survival and breeding by managing salinity levels.

“We’re able to use water for the environment to keep salinity at the perfect level for the Murray hardyhead, but way too high for its predators,” North Central CMA Project Manager Amy Russell said.

“Fresh water at the right time of year ensures the right breeding conditions and that the eggs and larvae survive, and allowing water levels to drop and become more saline as the fish grow is bad news for any introduced fish species, such as the eastern gambusia that target the hardyhead.

 “That’s allowing the fish to flourish, with the right conditions for them and their food sources at the right time of year.” 

Ms Russell said the latest monitoring results from the ARI showed the strategy was working well.

“The size ranges of fish caught indicates successful spawning and recruitment, which is great news,” she said.

“Lake Elizabeth is a standout and now one of the most important sites in the State for this species. Even if you pop in for a quick visit, you’ll see thousands swimming around.

“Managing the right amount of water at the right time of the year is making a big difference to the Murray hardyhead at Kerang, as well as to other threatened species across the region and the state.”   

The flows are authorised by the Commonwealth Environmental Water Holder and the Victorian Environmental Water Holder (VEWH) in line with its Seasonal Watering Plan 2023-24.

The monitoring was undertaken as part of DEECA’s Wetland Monitoring and Assessment Program for environmental water (WetMAP).

Updates of water deliveries are posted on the North Central CMA’s website.