Muddy waters – alien carp eradication from wetlands to protect native fish

The removal of almost 300 large Common Carp from Oaklands Wetland near Marion, SA, was recently undertaken by our aquatic ecology team. This annual fish management in the wetland is an important part of not only maintaining cleaner water but also providing a safe home for the native fish species that live there including the Critically Endangered Southern Purple-spotted Gudgeon. The wetland is an important surrogate site for these little native fish, which breed in the safety of the wetland for later release back into their wild habitat. Last year several hundred Southern Purple-spotted Gudgeon were released back into the River Torrens /Karrrawirra Pari, so it is vital that we keep the wetland in good health and free of introduced pest species like Common Carp. During the drying out process, native fish and turtles are carefully removed and kept in tanks until the wetland is refilled.

Although a very messy, muddy and hard job, it’s also so rewarding to see the wetlands carp-free again. Common Carp are detrimental to all Australian waterways, as bottom feeders they pull out aquatic vegetation, eat the eggs of native fish, and turn water muddy, so it’s vital that they are not put into any wetlands or waterways.

Thanks to the City of Marion, namely Glynn Ricketts, who has kept this important program going for the past five years.

This project is a joint project between NGT, Green Adelaide, the City of Marion and Landscape SA.