South Australia wetland thrives with native aquatic life, offering hope for carp-free future

Teal Flat wetland in South Australia is demonstrating a remarkable recovery, offering a hopeful vision for the future of the Murray River system, once choked by invasive carp. Once murky, the waters are now clear, supporting a rich diversity of native aquatic vegetation and wildlife, a stark contrast to the "mocha coffee brown" of the adjacent Murray River.

Ecologists Amy Rice and Darren Willis from the Murraylands and Riverland Landscape Board are monitoring the thriving ecosystem. They wade through lush ribbon weed and red water milfoil, plants that are now supporting a variety of native fish, birds, frogs, and turtles. "When you come out and have a look at a wetland like this, it never ceases to blow you away," said team leader Darren Willis.

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When you come out and have a look at a wetland like this, it never ceases to blow you away.

The success at Teal Flat is attributed to a specific management technique: isolating the wetland from the river and allowing it to dry out. This process effectively kills the carp. When the wetland is refilled with river water, carp screens are employed to prevent the invasive fish from re-entering. This controlled cycle allows native species to re-establish themselves.

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We've got an amazing array of aquatic vegetation from ribbon weed to red water milfoil, which are supporting an array of different species, from fish to birds to frogs to turtles.

Rice noted the significant difference in water quality, with turbidity readings at Teal Flat at a mere 4.5, compared to 150 in the Murray River. This clarity allows for the flourishing of native plants, which in turn provide habitat and food for native fish, including small-bodied species, and a range of birds like swans and musk ducks.

The broader Murray-Darling Basin faces critical environmental challenges, with carp significantly altering biodiversity. The federal government has listed parts of the river system as critically endangered due to multiple threats, including the dominance of invasive species. Teal Flat's success, achieved without relying on the carp herpes virus, provides a tangible example of what can be achieved through dedicated management and restoration efforts.

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We've got lots of small-bodied native fish utilising the wetland and the different functional groups of birds that are utilising it, such as swans, which are herbivores, to musk ducks, which are piscivores, so they're eating those small fish in there.