Drought and ‘systematic degradation’ doom wetlands in New South Wales
By BEN CUBBY, ENVIRONMENT EDITOR
May 4, 2010 THE state’s biggest inland bird-breeding sanctuary is nearing collapse due to lack of water, and the bird population is undergoing ”dramatic upheavals” as some species are pushed out, a new report has found. The Macquarie Marshes – a vast, tangled sprawl of creeks and swamps between Nyngan and Walgett in the state’s northwest – has declined by about half since the 1960s because of the drought and the diversion of water for irrigation. Birds which do well among dead trees are thriving, while others which have evolved in a river red gum environment appear to be breeding less, according to the study by the Australian Wetlands & Rivers Centre at the University of NSW. ”It’s a really stark contrast between different areas in the marshes,” said a researcher, Alice Blackwood. ”Standing in the dried-out areas, you’re surrounded by dead trees and you have to wade through tall shrubs which have moved in, and also you can see that the ground is dried and cracked.” Grey fantails, weebills, striated pardalote and crested shrike-tits, all of which has flourished in wetlands with good tree canopies, are being replaced by birds that live around dead trees, such the hooded robin, rufous songlark, southern whiteface and crested pigeon. The university researchers identified 10 two-hectare sites and then visited each to record all birdlife. The report establishes for the first time that the bird ecosystem is changing as river red gums die from lack of water. Both plant and animal life, which is recognised internationally under the Ramsar treaty for valuable wetlands, are becoming simpler as rainfall patterns change. ”About 50 per cent of the wetland area is gone and more has been subjected to systematic degradation,” said Professor Richard Kingsford, the director of the wetlands centre. The hope is that up to 200 megalitres bought back by the federal and state governments will help rejuvenate sections of the marsh, but those environmental flows won’t be delivered until enough rain falls upstream. ”The 200 megalitres will make a difference, but the general picture is one of decline and the marshes will never be what they used to be,” Professor Kingsford said.
