New population of rare native fish discovered at Māhia

A potential new population of shortjaw kōkopu, one of the five whitebait species, has been discovered in Māhia.

Hawke’s Bay Regional Council senior scientist Dan Fake said the breakthrough discovery marked the first time the native fish has been found in Hawke’s Bay.

“Shortjaw kōkopu are classified as threatened. This rare fish is also taonga, so we are thrilled to discover a potential population in our region.”

While water testing in the Kopuawhara catchment north of Māhia Peninsula, Hawke’s Bay Regional Council detected the species’ presence using eDNA — an innovative technique that can identify DNA that has shed or been excreted from organisms into the natural environment.

“There’s more research to be done as eDNA only tells us that they are present, not how many are in the catchment. The next step for us is to find out more about their population size and pinpoint where they’re residing.”

Shortjaw kōkopu are rare on North Island’s East Coast, with only a small number recently discovered in Tairāwhiti Gisborne.

Hawke’s Bay Regional Council freshwater ecology technician Andrew Horrell said considering the proximity of both populations, it was likely they were linked.

“We know the Kopuawhara catchment drains into the sea north of Mahia Peninsula. Given the presence of this species in Tairāwhiti, it’s anticipated the Hawke’s Bay population has originated from the same larval supply.”

Hawke’s Bay Regional Council will be working with mana whenua, Department of Conservation (DoC) and landowners to develop a targeted survey and learn more about the shortjaw kōkopu population in Hawke’s Bay.