Lake Ruatuna, near Ohaupo now has a special barrier to prevent the spread of the invasive pest fish koi carp.
Koi carp are an introduced pest fish resembling giant goldfish and are widespread across the Waikato. The species is unwanted and noxious and therefore a serious ecological threat to the health of freshwater ecosystems. Especially to Lake Ruatuna as it is one of Waikato's most important freshwater ecological restoration projects.
The new grill barrier, a project by the Department of Conservation and Fonterra, is designed to prevent access of adult koi carp upstream. The grill bar has spacings of 30mm allowing movement of native fish like tuna while also preventing adult carp passage.
DoC's Waikato Peat Lakes site lead Dion Patterson says there are only limited options to manage koi carp and barriers act as a last line of defence to help control the spread of this pest fish.