Canterbury Lake Investigaton
Canterbury’s high country lakes have been re-opened to trout angling after the Ministry of Primary Industries gave the all clear.
The high country lakes near Arthur's Pass - Lyndon, Pearson, Grasmere, Sarah, Hawdon and Marymere – were closed just before Christmas after trout caught there were found to have rashes over their sides and bellies.
Fish & Game sent samples of the afflicted trout for analysis by MPI experts, along with native fish also found dead in the lakes.
MPI experts say they could not find any virus or bacteria in the trout they tested and whatever caused the rashes was not infectious.
They suggest that something in the environment is responsible.
Based on the results, MPI experts have given the all clear to re-open the lakes and Fish & Game says that will happen immediately.
Fish & Game New Zealand Chief Executive Martin Taylor is welcoming the news.
“We are glad that whatever caused the rashes isn’t infectious. But at the same time, the fact that it occurred is of concern”, Mr Taylor says.
“MPI suggests that the cause is environmental. What we do know is water quality in lakes Grasmere and Pearson has been declining over the last decade and combined with a hot summer, this is the most likely reason for the rashes.
Right: Algal blooms and foam on Lake Hawdon.
“With the continuing drive to intensive farming in the high country, this sort of situation is sadly more likely to occur in the future,” Mr Taylor says.
He says Fish & Game will continue to monitor the situation.
Fish & Game’s North Canterbury Council chair, Trevor Isitt, says the all clear for the lakes is a relief.
He says the lakes will be re-opened straight away and anglers and their families can return to them knowing they are free of anything invasive that could spread to other waterways.
Mr Isitt thanks anglers for their support during the lake closures.
“We would like to thank anglers for their patience through this period. We know it’s been frustrating, but it's better to be safe than sorry when dealing with such threats to our trout fishery.”