They may be small but weevils are having a big impact on the management of Salvinia weed in natural areas and dams, including Baldwin Swamp Environmental Park.
Bundaberg Regional Council’s Heales Road biocontrol facility is a breeding site for the weevils which have been a critical facet of Baldwin Swamp’s integrated pest management plan.
Land Protection Officer Guy Hancock said Salvinia weed was an introduced species to the native landscape.
“It was primarily used in fishponds and fish tanks many years ago,” Guy said.
“It doubles its size, given the correct conditions, very, very quickly.
“People then disposed of it in waterways and then it gets in and chokes up our beautiful waterways.”
Guy said the true effectiveness of the weevil could be witnessed within the lagoons in Baldwin Swamp.
“The weevils will eat down and munch away at the root system of Salvinia.
“The Salvinia itself will then sink to the bottom of the water body and it will decompose and rot away.”
He said it was a valuable alternative to the use of chemicals in such an important natural area.
“Where we can we move away from a lot of herbicides as general practice.
“It’s one of the tools for best practice.”
Between the weevils, physical removal of the weed and booms to contain the spread of the weed Natural Areas Officer Sally Obst said the improvements in Baldwin Swamp had been beneficial to the park’s ecosystem.
“The Salvinia weed grows prolifically in certain conditions and it can create really thick, dense mats of the plant at the surface of the water,” Sally said.
“When we remove this it improves the water flow, further improving the water quality and it allows this really important oxygen exchange at the surface of the water.
“The most obvious improvement you can see from the recent program is open clear lakes, allowing this water flow and providing more habitat for our aquatic plants and animals.”
Guy said the weevil breeding program was also available for the benefit of landholders who had issues with Salvinia weed in private dams.
“We provide Salvinia that is infected with weevils free of charge to put into their waterways if they have Salvinia.
“This gives landholders and Council another tool in the kit as such to controlling weeds.
“If people are interested, if they have Salvinia in their dams and they would like a herbicide alternative to controlling it, feel free to give Council a call.”
Council’s Land Protection team can be contacted on 1300 883 699.
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