European Carp are a large introduced freshwater fish which are common throughout much of NSW. They are a well known pest species because of their destructive bottom-feeding habits which stir up sediments, reduces water quality and damages habitat for native fish existing in the same ecosystem.
Implementing control actions on this pest species is in line with the National Carp Control Plan and is identified as an action in Council’s Biodiversity Strategy – Maldhangilanha. As a result, Wagga Wagga City Council has engaged an experienced contractor to undertake electrofishing within the Wollundry Lagoon and Marramabidya Wetland to assist with managing European Carp populations and to gather indicative data of native fish populations.
Electrofishing
In June 2021 Council conducted electrofishing in the Wollundry Lagoon and Marrambidya Wetland. Electrofishing is an effective technique used to control European Carp in closed waterways to improve water quality and ecology, also enhancing native fish populations. Around 750kg of European Carp were removed from the two water bodies through the recent activity.
Electrofishing includes the use of a boat with anodes fixed to the bow that creates an electrical current, with a range of 5 metres. Fish within the electric range are temporarily immobilised and will float to the surface. All European Carp are captured with dip nets and disposed of humanely. All other non-targeted fauna are then left in the water and monitored until species become mobile again.
Electrofishing is the main sampling tool for freshwater fish research conducted by NSW Department of Primary Industries. Research has been conducted into the effects of electrofishing on several species of native fish, indicating a very small percentage of fish injuries, and were much less than other sampling methods. There are no reports of any injury to platypus or other aquatic vertebrates resulting from electrofishing in NSW. The use of ice slurry euthanasia is a commonly used practice, with it considered as a humane practice.