A big bird has been called in to help the little birds, as the National Parks and Wildlife Service starts to clean up Big Island off Port Kembla to improve its value as a breeding habitat.
The helicopter was in action on Wednesday morning, making about 10 trips to the north end of the island with a sprayer drum of herbicide to clear noxious weeds.
The island, a vital breeding ground for several species of seabirds, has become overgrown with the dominating kykuyu grass and the smothering flowering plant morning glory.
For seabirds that need to dig burrows to nest and roost, the densely matted weed cover – up to 1.5 metres deep in parts – might as well be made of concrete.
National Parks and Wildlife Illawarra area manager Tony Horwood said a small area – 0.78hectares of the island’s 17 hectares – would be sprayed first.
‘‘The island used to support numerous species of seabirds, and those numbers have dwindles significantly over the last two decades,’’ he said.
‘‘We believe that’s directly associated with the severe infestation of kykuyu and morning glory on the island.
‘‘The birds use these islands as stepping stones up and down the coast.’’
Before it became overgrown, the island could count little penguins, short-tail and wedge-tailed shearwaters, sooty oystercatchers and crested terns among its regular visitors.
About 1500 litres of the herbicide glyphosate (often marketed as RoundUp) was sprayed on the northern end of the island during the operation.
Mr Horwood said there would be no damage to the island or marine ecosystem, as the herbicide was absorbed into plants and degraded in sunlight.
After the spraying, native plants will be reintroduced.
If the program is successful, Mr Horwood hopes to be able to work with other organisations in the community to expand the weed clearing program, with a goal of returning the island to its proper place as a seabird habitat.