Concerns about the health of Lake Wanaka’s trout and salmon fishery last summer have prompted further investigations by Otago Fish & Game this summer.
Last year’s fisheries survey of 211 Lake Wanaka anglers revealed the brown trout catch rate sank from 0.13 fish per hour in 2020›2021 to 0.06 last season. For rainbow trout, the rate fell from 0.09 to 0.07.
The survey recorded just one salmon, but Fish & Game is aware of many more reports of salmon caught during the season.
The 211 surveyed anglers put in a total of 234 hours of fishing. Almost 190 caught no fish.
Otago Fish & Game officer Ben Sowry said not only did trout go off the bite last season, but they were in poorer condition than previously.
Anglers spent an average of seven hours fishing for every fish caught on the lake last season and many were concerned for the fishery, he said.
‘‘Catch rates fluctuate from season to season, but we want to look closely at the health of this renowned fishery,’’ Mr Sowry said.
One probable influence was the hot summer temperatures from January to March as fish moved deeper to cool waters.
This season’s study includes underwater acoustic surveys in lakes Wanaka, Hawea and Wakatipu, a monitoring workshop, angler interviews and catch monitoring.
Fish & Game has run angler surveys for the past three fishing seasons.