There's no need to carp on about native fish

There’s no need to carp on about native fish

Chris EdwardsJanuary 22, 2025, 7:23 amJanuary 21, 2025

A small group of Goulburn-Murray Water (GMW) employees have made a big contribution to the preservation of native fish populations along the Murray River.

GMW manages Torrumbarry Weir on behalf of the Murray Darling Basin Authority (MDBA).

In 1992, a fishway was constructed at the weir. Fishways allow fish to bypass barriers such as weirs and other regulators and migrate along the river. They are crucial in sustaining native fish populations in heavily irrigated areas.

However, Torrumbarry’s fishway is unique because it also includes a ‘carp trap’.

This trap is a large metal cage at the end of the fishway, where all fish passing through are caught. GMW’s Torrumbarry storage officers lift the cage daily and separate the fish, sending the native fish down a fish slide that takes them upstream of the weir and the carp into a separate cage.

The carp in this cage is then donated to Charlie Carp, a business that turns carp into fertiliser.

Torrumbarry Senior Storage Officer Luke Simpson said filtering the carp out of the fishway could be a significant undertaking.

“Often, we get just a few carp a day, but we have had days where we have caught more than 2000 carp in the trap,” he said.

“During times like this, we need to lift the trap out three times daily to eliminate all the carp.

“We’re a pretty small team here at Torrumbarry so that it can be a fair bit of work.”

Carp are bottom feeders. They stir up mud on the riverbeds, which affects water quality and prevents sunlight from reaching aquatic plants that native fish need for food.

Since the fishway was installed in the early 1990s, more than 120,000 carp have been removed using the fish trap.

Simpson said he was glad the Torrumbarry team could help rid the system of the invasive species.

“Fishways like the one at Torrumbarry have proven incredibly valuable to supporting native fish populations,” he said.

“We get plenty of silver perch, golden perch, and bony bream through the fishway.

“Carp are obviously one of the main threats to these native fish, so it is beneficial to remove the carp while also providing safe passage to the native species.”