Small but significant species of native freshwater fish are being brought back from the brink of extinction through ambitious and collaborative recovery programs. 

With the support of local landholders, landscape boards, and conservation groups the programs are creating safe refuges, restoring habitats, and removing predators to help wild populations thrive.

In Back Valley Creek, near Victor Harbor, Landscapes Hills and Fleurieu and Nature Glenelg Trust are working with local landholders to protect the genetically distinct, isolated population of southern pygmy perch, a small-bodied fish at risk of extinction.

Recent surveys in the area revealed that an estimated 90 per cent of the population was confined to small, isolated pools - many of which were on the verge of drying out before the arrival of much needed rain. 

With habitat degradation, reduced water availability, and predation by invasive species threatening their survival, urgent intervention was essential. Landscapes Hills and Fleurieu’s Freshwater Ecologist, Tara Daniell explains in more detail.

“Our April surveys along Back Valley Creek gave us an indication of population size and distribution, providing a critical baseline. 

“Between a degraded riparian and aquatic habitat, inclusion of invasive redfin and trout, and limited permanent pools available, the survival of this unique population was in real trouble,” she says.

A dedicated recovery project is focussing on habitat restoration along the creek to improve water quality and vegetation, as well as installing livestock exclusion fencing and alternate stock water sources, to prevent further degradation by year-round stock access.

To ensure the species persisted through summer dry spells, and to allow for the removal of invasive fish species, strategic relocations have seen over 200 southern pygmy perch moved to safe surrogate dams owned by local landholders, including Back Valley’s Andrew Robertson.

While efforts to improve the creek line habitat is ongoing, it is hoped the number of fish in surrogate dams will increase. 

This would eventually enable their re-introduction to Back Valley Creek to boost wild populations and provide a safeguard against local extinction.

Andrew emphasises the importance of adapting these conservation strategies in response to environmental changes.

“Ensuring the survival of species via surrogate dams is a great way to go to protect threatened fish and is particularly important with the changing climate.”

Landscapes Hills and Fleurieu recently held a workshop with landholders at Andrew’s property, where Senior Ecologist Sylvia Zukowski from Nature Glenelg Trust gave a presentation on southern pygmy perch and other local native fish species, giving participants the opportunity to learn more about the project and visit a refuge dam.

The surrogate dam program aiming to save the southern pygmy perch is funded by Landscapes Hills and Fleurieu through the regional landscape levy.

The southern pygmy perch