Waikato University's electric fishing boat (left) stuns fish by passing a strong electric current through two octopus-like electrodes which are lowered into the water when in use. Red-finned perch found in the lower reservoir at Zealandia Sanctuary in Wellington (right) (images: A. Ballance)
Pest fish are a significant problem in many New Zealand's lakes and rivers, and one for which there is no easy solution. Nick Ling from the University of Waikato is investigating ways to effectively control pest fish, and Alison joins him and his team for an unusual night's fishing for European red-finned perch in the lower reservoir in the Zealandia sanctuary in central Wellington. Waikato University runs New Zealand's only electric fishing boat, and boat driver Warrick Powrie explains how the boat produces a large electric current which temporarily stuns fish.
Raewyn Empson from Zealandia reports that the recent rotenone operation to remove introduced brown trout from the upper reservoir went very well - about 450 brown trout were taken out, while 159 banded kokopu and 7 koura were caught and then safely returned once the poison had disappeared. Final proof that trout have been completely removed from the dam won't be known until more fishing is carried out next summer.
Our Changing World recently featured Nick Ling in a story about mudfish - listen to that story here.
