WATER FOR THE ENVIRONMENT AUTUMN UPDATE

Fish are key components of Wimmera waterways, influencing local ecosystems and community enjoyment of rivers, lakes and wetlands. Because many waterways are ephemeral, fish populations shift with changing conditions – sometimes generating excitement, sometimes concern.

Wimmera CMA and Arthur Rylah Institute surveys in early autumn recorded promising results following water for the environment releases. They revealed river blackfish at important aquatic refuge sites – demonstrating how targeted water releases maintain water quality, protecting fish during low flow conditions.

At a wetland near Minyip – one of four surrogate habitats established to safeguard rare Murray–Darling Basin fish – survey teams found tens of thousands of olive perchlet and southern purple-spotted gudgeon.

Strong breeding results indicate these species are thriving and are now suitable for potential translocation back into parts of their former range. This shows how targeted environmental water releases and monitoring can support conservation and inform long-term species recovery.

What fish is that?

Despite variable environments, the region supports an impressive mix of species. Water for the environment play a critical role in balancing recreational angling opportunities with protecting native and threatened species.

• Indigenous fish

Proven to naturally occur and breed, such as river blackfish, southern pygmy perch, galaxias, flatheaded gudgeon and Australian smelt.

• Other native Australian species

Present through Victorian Fisheries Authority releases, and include yellowbelly, Murray cod and silver perch. Although not listed as indigenous to the Wimmera, these species, as well as self-sustaining catfish, may have naturally occurred in the region via ancient connections with the Murray-Darling river system.

• Exotic species

Non-indigenous fish such as redfin, tench, goldfish and trout are also in the mix, with trout relying mostly on stocking rather than natural breeding.

• Noxious species

Carp and mosquito fish spread quickly and compete with desirable species, threatening waterway health.

Autumn flows

• Flows into the Wimmera River from Taylors Lake will occur to maintain water quality in the lower Wimmera River.
• Short-duration flows from Wartook Reservoir will replenish drought refuge pools in Upper MacKenzie River and Upper Burnt Creek.