EFFORTS to re-establish native fish in Thegoa Lagoon at Wentworth, western NSW, are underway with environmental water flows set to begin refilling the lagoon this week.
The NSW Office of Environment and Heritage (OEH) is managing this water flow, with the support of the Murray Lower Darling Environmental Water Advisory Group and community groups, in keeping with a Thegoa Lagoon Management Plan.
OEH Senior Environmental Water Management Officer Paul Childs said up to 1,800 megalitres of environmental water had been allocated to refill the lagoon by June 30.
“This refill follows a program of carp eradication which saw more than five tonnes of these fish removed from Thegoa Lagoon last year. Carp are an invasive pest species that threaten native aquatic ecosystems,” Mr Childs said.
“A drying phase over summer has taken care of any remaining carp and the installation of removable carp screens at either end of the lagoon will help to keep adult carp out as the lagoon refills.
“We have also scheduled the delivery of water for the cooler months when carp are not actively moving or spawning. These efforts combined should create ideal conditions for native fish species to establish themselves and thrive in the lagoon,” he said.
Several small, protective “fish hotels” will be placed in the lagoon prior to watering in partnership with the Barkindji Mauraura Elders Employment Team (BMEET).
These wooden structures will provide habitat and protection for small-bodied native fish as they re-populate the ephemeral lagoon and the Murray Darling Freshwater Research Centre will be working with BMEET to monitor the use of the fish hotels.
“The process of wetting and drying is a natural process for wetlands like Thegoa Lagoon,” Mr Childs said.
“It allows sediments to stabilise and the aquatic seedbank to reset.
“For Thegoa Lagoon, it has been an important step in improving the health of the wetland and providing opportunities for other agencies keen to contribute to the future of this valuable community asset,” he said.