Shocking fish extracted
The Wangaratta Sustainability Network (WSN) and the Arthur Rylah Institute (ARI) teamed up for a coordinated extraction of carp at Lake Mulwala recently to rid the waterways of the wretched fish.
Director - Fisheries Management, Policy, Science and Licensing for Victorian Fisheries Authority Jarod Lyon said the operation had to take advantage of the recent lowering of the lake.
“The removal was organised by Wangaratta Sustainability Network and occurred to take advantage of the low water levels in Lake Mulwala to target carp aggregations for removal,” Mr Lyon said.
“In this case the operation is opportunistic given carp are aggregating in response to the lowering of the lake.”
Volunteers from the WSN including local Kelvin Berry, Yarrawonga locals including Luke Cookshank as well as keen fishermen identified the ‘hot spots’ for carp before the ARI were brought in with their electro specific equipment.
The ARI brought an electro-fishing crew to the Ovens and Murray rivers to target the carp ‘hot spots’ before an electric current was sent through the water to stun the fish and bring them to the surface.
Although all fish suffer from the electric shock, the native fish are left to recover which they overcome within minutes while the carp are pulled out and euthanised.
“The time when the lake is lowered and in the process of refilling again provides the perfect opportunity to catch the carp,” Mr Berry said.
“As the warm water from upstream comes down the carp swarm together in the lagoons to keep warm which makes it easier to stun and net them.
“People like Luke Cookshank who works at the weir wall were pivotal to helping us on this mission as he continually provided information on water levels and the hot spots for the fish which was vital to the formation of the operation and where and when we were going to work.”
This operation was also imperative to establishing the quantity of carp in Lake Mulwala as it helps determine the future state of the waterways as well as assisting in the estimation of the unwanted fish in lakes of a similar size and geography.
“Carp are not a good fish and can often ruin the reproduction of native fish and other marine life in the waterways,” Mr Berry said.
“This operation helps us to prevent the carp from destroying the spawning habitat of the Murray cod and other native fish.”
Mr Lyon said the WRN and ARI had joined in a partnership over the past few years with carp numbers an ongoing battle however the operation is only possible through funding from differing governing bodies and businesses.
“In terms of how often an operation like this should occur really depends on spatial and temporal scale,” Mr Lyon said.
“What I can say is that these types of control efforts can have a localised impact on carp populations.”
“Jason Mullens from North East Water was fantastic in helping us get the project started as well as working with us throughout the three-day operation and Mulwala Water Ski Club CEO Peter Duncan was fantastic with coming on board with funding to get the process kick started,” Mr Berry added.
“Without the differing forms of assistance from these people and organisations this operation could not go ahead and our waterways would be jam-packed with the desolate fish.”
All fish are stunned to the surface once the ARI uses the electro shock but only carp are removed and euthanised.