120,000 carp and counting

The weir is managed by G-MW on behalf of the Murray Darling Basin Authority.

Fishways allow fish to bypass barriers such as weirs and other regulators so that they can migrate along the river.

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

This trap is a large metal cage at the end of the fishway that all fish that pass through the fishway are caught in.

G-MW’s Torrumbarry storage officers lift the cage out daily and separate the fish, sending the native fish down a fish slide that takes them upstream of the weir, and sending the carp into a separate cage.

The carp are 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 when we have caught more than 2000 carp in the trap,” he said.

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.

Mr Simpson was glad the Torrumbarry team could do their bit in ridding 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 really beneficial to be able to remove the carp while also providing safe passage to the native species.”