Invasive impacts assessed
Invasive species have been ranked as the highest threat to Australian biodiversity, with habitat loss a close second.
Australia is rich in unique biodiversity but has had a poor track record since European settlement, according to researcher Stephen Kearney from the University of Queensland.
“We are one of only 17 ‘megadiverse’ countries globally, Australia contains over 12 per cent of the world’s vertebrate species. Over 4 out of 5 of our species are found nowhere else on earth,” said Mr Kearney.
“Australia has also recorded 90 extinctions since European settlement, 36 plants, 27 mammals, 22 birds, four frogs and an earthworm, and extinction rates per decade are not improving.
“One of the major causes of Australia’s on-going extinction crisis is our insufficient response to threats to our biodiversity.
“To support improvements in this area we have reviewed the major threats facing over 1,500 species listed as Critically Endangered, Endangered or Vulnerable under Australian environmental law.
“The top factors impacting Australia’s threatened species are invasive species which affect 82 per cent of our threatened species and changes in habitat which affect 74 per cent of species.
“Invasive species include pest animals, plants and diseases. While changes to habitat include things like altered fire patterns and degradation from human activities.
“Around the world the top two impacts on threatened species are habitat loss and change due to agriculture, closely followed by overexploitation activities, such as hunting or timber harvesting.
“Overexploitation threatens around three quarters of imperilled species globally, but only about one quarter of Australian species.
“The large impact of invasive species sets Australia apart from the global trend.
“Globally, invasive species only impact around a third of threatened species, but in Australia they are a threat to 100 per cent of threatened frogs, over 95 per cent of threatened mammals, fish and birds, and to about 80 per cent of threatened plants, insects and reptiles.”
Centre for Invasive Species Solutions chief Andreas Glanznig says invasive species have pushed native species to a crisis point, and without innovation and new management options there will be an ongoing downward spiral.
“Australia is in the midst of an extinction crisis and invasive species don’t stop at state borders, so we need to continue to take landscape-scale and coordinated action against invasive species,” he said.
“It’s now an arms race and we need new and innovative ideas, such as biocontrol agents and genetic technologies, so we see invasive species decline and threatened species rise.”
Stephen Kearney concludes; “The variety of threats facing Australian species highlights the need for a comprehensive approach to manage their impacts, including adequate resourcing, legislative support and better national co-ordination.”