Rare mudfish returning home

The NZ Transport Agency is putting the finishing touches on a new home for a colony of rare black mudfish discovered in the Waikato.

A large population of the fresh water fish was found living in a drain in the path of the Rangiriri section of the Waikato Expressway.

Before construction work started, they were captured and moved to tanks at the University of Waikato, where they were cared for by a team of ecologists until workers finished creating a new habitat near their original swampland home.

The Transport Agency’s Waikato highway manager, Kaye Clark, said the mudfish would be released back into their new home in early September.

“Our contractor, Fletcher Construction, guided by ecologists, their environmental consultant Mike McConnell, designer MWH and the Department of Conservation, are putting the final touches on the new habitat at the moment,” she said.

“The new habitat measures approximately 500m2, more than three times the size of the area the mudfish were initially found in.

“It includes native plants and a winding stream channel, surrounded by shallower wetland areas.

“Weed species have been removed and the specific layout maximises the potential habitat area.

“Along with expanding the habitat, we have left an existing perched culvert in place, which we believe has helped the colony survive by limiting predatory fish access.”

Kessels Ecology senior freshwater ecologist, Jennifer Price, said the mudfish would be monitored for three years after their return home.

“By monitoring the mudfish annually in spring, we will be able to determine whether they have successfully re-established and reproduced in the new habitat,” she said.

Dr Price said the team had chosen to reintroduce the mudfish at the end of winter, an active period for mudfish, so the fresh water fish could establish themselves before summer.

“The planted vegetation not only provides shelter, but, as it grows, will also help to maintain the water temperature and retain moisture which is essential for their survival,” she said.

The Rangiriri section of the Waikato Expressway is currently under construction and is expected to open in late 2016.

To stay up to date with the project go to: www.nzta.govt.nz/projects/waikato-expressway(external link) or follow us on Facebook at: www.facebook.com/waikatoexpressway(external link)

Mudfish: little wetland wonders

• Once their habitat dries out, mudfish burrow into soil and remain there motionless, breathing air, until the autumn rains refill the wetlands.
• Mudfish exist only in New Zealand and are noted as one of the few fish species worldwide that have such an ability to survive for extended periods out of water.
• Mudfish were once very abundant but are now confined to limited habitats due to a severe loss of wetlands.
• Black mudfish are a threatened species, listed as Declining by DoC.
• The biggest threat to mudfish is loss of habitat, from filling or draining wetlands and drain cleaning.

 
PHOTO: Mudfish. Photo courtesy of Jennifer Price.

For more information please contact:

Natalie Dixon
Media Manager
Waikato and Bay of Plenty region

T: 07 928 7908
M: 021 928 413
natalie.dixon@nzta.govt.nz