A final day of electrofishing targeting carp (Cyprinuscarpio), on a five kilometre stretch of Billabong Creek, Conargo, occurred on December 20^th, 2023. Carp once again proved to be the dominant fish.

A tally of 266kg carp, all adults, were collected and sent to Charlie Carp for processing into fertiliser. A few goldfish were also caught and native fish were not collected.

“We did see bigger numbers of golden perch, Murray cod and silver perch, than in September’s electrofishing, but native fish were not the target,” said Andrea Mitchell, YACTAC and Refreshing Rivers.

Dr John Conallin, fish ecologist, assisted with scientific monitoring during electrofishing, conducted his own surveying, and submitted two reports with recommendations. His findings showed carp accounted for 70% of abundance and 70% biomass in December 2023’s electrofishing and 75% of abundance and 85% of total fish biomass in September 2023. The results, although shocking, are typical of the Murray Darling Basin which is dominated by carp in both abundance and biomass.

“Adult carp are a management problem in the Billabong and do present a risk to meeting community aspirations of native fish recovery and aquatic plant restoration,” said Dr John Conallin.

Trialling electrofishing to minimise carp numbers is part of a Refreshing Rivers case study project at Conargo which includes revegetation and native fish reintroduction. The aim of the project is to restore and protect Eel-tailed catfish (Tandanus tandanus) habitat and address key threats such as habitat degradation and water quality decline in the Central Billabong.

“Electrofishing is part of an integrated approach using several courses of action to improve waterway health,” said Andrea Mitchell.

Dr John Conallin recommended there be a concerted revegetation program together with targeted carp control which could help to improve habitat quality and bank stabilisation.

YACTAC’s president, Trevor Clark, whose organisation has led the project and has a keen interest in creek water quality believes carp are the main culprit destroying it,

“If we didn’t have carp, it would be so much easier to maintain waterway health,” said Trevor Clark.

Indeed, carp have an insidious impact on waterways, and YACTAC and the Refreshing Rivers Program do aspire to make a difference!