When more than 900 brown mudfish in the Wairarapa were transferred to a new wetlands habitat to make way for wastewater storage reservoirs, the district council initially claimed it was a success, but it was later learnt that most of the fish did not survive.
Fish & Game reported that the project in December and January involving 921 mudfish, organised by Carterton District Council, had resulted in virtually none surviving.
In July Greater Wellington Regional Council told the Wairarapa Times-Age that it would undertake further monitoring of the translocated population and would be tracking how the mudfish and their habitat were doing.
“Our immediate focus is on creating additional habitat that we believe will be more suitable for brown mudfish,” it said. “Once we are happy that this new habitat is established, we will relocate the remaining mudfish.”
GWRC believed mudfish were still present in the wetland where they were relocated, but in lower numbers.
“Unfortunately, the habitat created did not develop as we had hoped, in particular in relation to the aquatic vegetation cover that would have provided cover for the mudfish.
“High water temperatures and predation by birds, such as shags and herons, are considered to be among some of the key issues that impacted on the success of the translocation.”
GWRC will continue to work closely with the district council to create a new habitat more similar to the original area the fish were relocated from.
“We will be incorporating the learnings so far to ensure that the project has the best chance of success, in terms of maintaining and enhancing brown mudfish habitat.”
The project will now be led by Alton Perrie, an environmental scientist from GWRC who has “considerable expertise in mudfish”.
Fish & Game Wellington manager Phil Teal has called for an independent inquiry by the Department of Conservation into the transfer.
A Fish & Game senior scientist even advised the project co-ordinators last year that this project was not advisable.
“This is $160,000 of ratepayers’ money that would be much better used on meaningful conservation projects that would benefit all fish habitat,” he said.