When the Yarrawonga Chronicle posted a video of European carp swarming in huge numbers at the base of the Yarrawonga Weir last month it certainly piqued local interest.
And not just from residents of Yarrawonga and Mulwala, but also from the environmental group Wangaratta Sustainability Network (WSN), who went on to contact Goulburn Murray Water and scientists from the Arthur Rylah Institute to look into removing some of the carp.
The footage, taken by a Yarrawonga local, showed the fish milling about in a swirling mess of fins and according to Kelvin Berry, Coordinator of WSN’s Carp Removal Program, this was not altogether uncommon.
Apparently the introduced species like the warmer water at the edge of the wall and will rise to the top to eat the algae which forms on concrete structures.
In addition, after recent flooding the carp will come out of the lagoons and backwaters and try to swim upstream to the fresh, oxygenated water coming through the weir gates.
“The WSN formed a partnership with the Arthur Rylah Institute, a division of the Department of Environment, Land, Water and Planning, in 2014 and since then we have secured Communities for Nature Funding to assist with our carp removal program,” Kelvin said.
“We normally take care of around 150km of the Ovens River waterway but this was too good an opportunity to miss.
“WSN volunteers travel with scientists from the Institute and if they catch carp when they are doing their native fish monitoring studies, we take the carp from them and dispose of them humanely in an environmentally friendly way.
“Between 2014 and 2016 we have taken six tonne of carp out of the Ovens River which has reduced the biomass from 85% to 35%.
“This improvement is critical to the data currently being collected for the timing and approval of the release of a virus designed to speed up the extermination of this introduced and destructive species to Australian waterways.
“It is actually better to have less carp for the virus to be released as there will only be a small environmental footprint left when the carp die, whereas with huge numbers of carp which have been recorded in the past, this footprint would be much greater.”
Kelvin said there will be an intensive collection of carp using electronic stunning equipment on May 22 along the Yarrawonga Weir wall.
“There will be four boats targeting the carp at this time,” he said.
“Goulburn Murray Water will regulate the flow through the gates in the lead up to attract the European carp to the area.”