Wet weather highlights fishway success and boosts fish migration

NQ Dry Tropics, Lower Burdekin Water and TropWater took advantage of last week’s wet weather by deploying fish monitoring survey traps at Lilliesmere Lagoon to see whether recently installed fishways are working effectively.

Due to the extended dry, this was the first opportunity to test the fishways since they were installed at Beach Road in 2016.  Rain events create acoustic signals that stimulate fish to migrate upstream, so it was a great opportunity to investigate the types of species in the system.

Since 2013 NQ Dry Tropics has worked with Burdekin Shire Council, Lower Burdekin Water and local landowners to improve local wetland health as part of the Reef Rescue Systems Repair project, funded through the Australian Government’s Reef Program.

NQ Dry Tropics Project Manager, Scott Fry, explained that many species of native fish, including barramundi and mangrove jack, need to migrate between freshwater and the ocean to complete parts of their life cycles – but they face many barriers.

“Dams, weirs, and weed chokes can stop juvenile fish getting where they need to go, and that leads to reduced stocks. It’s vital that we open up the waterways to help them migrate, and fishways are a great way to help them navigate physical barriers”, Mr Fry said.

“NQ Dry Tropics has partnered with Lower Burdekin Water on a major investment to construct several automated water delivery structures with built in fishways at Sheepstation Creek and Lilliesmere Lagoon.  

“They allow Lower Burdekin Water to more efficiently deliver irrigation water to its customers,  and help improve fish passage.

“We believe the structures at Beach Road are the first of their kind in Queensland, featuring a vertical slot fishway installed above a culvert. The culvert has baffles installed inside it to provide resting areas for fish as they swim against the flows”, Mr Fry said.

Initial survey results were positive, with seven species found in the traps, including Sleepy Cod and Black Catfish. This proved that the fishways were doing their job and allowing the fish to migrate.

Sleepy Cod, Lilliesmere

It is anticipated that more species will start appearing once a sustained flood pulse re-establishes connectivity with the ocean.

Dave Sartori, CEO of Lower Burdekin Water, said that he was pleased the new gate had operated as designed:

As the rain came down and the lagoon level rose, the gates automatically opened and allowed the water to pass through.  It was pleasing to see the fish in the trap, which confirmed that the fishways were working. The new automated gates have assisted Lower Burdekin Water to better match water supply with irrigation and aquifer recharge demands, and reducing excess irrigation water entering parts of the system where it is not required”, Mr Sartori said.

Dave Sartori (LBW), Christina Buelow (TW), and Nathan Waltham (TW)

NQ Dry Tropics is organising an event at Lilliesmere Lagoon on Saturday 21 April to celebrate World Fish Migration Day. The event will give the community an opportunity to learn more about these structures, see the work being done to promote wetland health, and take part in a barramundi release.

Main photo: Automated gate & fishway at Lilliesmere Lagoon.