Native fish dying out in lakes
WA's freshwater fish are dying. An unprecedented investigation of the State's lakes reveals nearly 60 per cent contain no native species.
The year-long survey by the Department of Fisheries and National Resource Management covered from Geraldton to Busselton and east to Northam, looking at the fish bio- diversity of 114 lakes. Only 50 lakes contained any native fish.
Department scientist Craig Lawrence said the findings were alarming, particularly because of the large number of feral fish which have been partly blamed for the rapid native decline.
Loss of habitat because of urban sprawl and the drying up of nearly half the lakes were also blamed. "For the first time we are getting a clear picture of the situation and the results are concerning," Dr Lawrence said.
With native fish a major source of food for recreational fishing species and keeping down insect populations such as mosquitoes, the department will look at breeding native fish for restocking.
"These are the species that control Ross River virus and, in the future, dengue fever, and they are also the basis of the food chain," Dr Lawrence said. "It would be very hard to have a recreational marron industry if there was no food for the marron."
Only 9 per cent of the lakes contained exclusively native fish species, 66 per cent had introduced freshwater species and 12 per cent had no fish.
Last Updated on Sunday, 10 June 2012 17:45
WA's most endangered animals have for the first time been ranked according to their likelihood of extinction.
The list compiled for The West Australian by the newly formed Threatened Species Council reveals how close some animals are to being lost for ever.
The rankings look at population size and the likelihood of survival based on threats from predators, disease and the encroachment of urban sprawl on habitats.
Frogs, turtles, birds and mammals all feature on the list of 16 animals, with the Gilbert's potoroo, which is found only on the south coast, ranked as the species most likely to disappear, with fewer than 100 left in the wild.
Native fish dying in lakes
Classifications from critically endangered through to vulnerable are based on the International Union for Conservation of Nature rankings.
Environment Minister Donna Faragher established the council to address the near-600 threatened species of flora and fauna around WA.
She said several WA agencies were conducting research into endangered species and the council would help make their work more effective.
"There are a range of reasons why we have species that are threatened, whether it is through habitat loss, feral pests or disease, we don't always know all of the science behind it and that is why we need these agencies to be doing that research," she said.
Mrs Faragher said there was no guarantee that the species on the list would be around in 10 years, but her department and other agencies had made a significant commitment towards ensuring they were.
Department of Environment and Conservation director-general Keiran McNamara, who chairs the council, said monitoring the abundance of many species on the list was often difficult because of their small size, low numbers, and cryptic behaviour.
Mr McNamara said fox-baiting had helped some threatened species but in some cases it let cats in as predators.
Last Updated on Sunday, 10 June 2012 17:47
From The West
About 35 bilbies bred in captivity have been released across the South-West in an attempt to bolster stocks of the increasingly endangered mammal.At one time found across 70 per cent of Australia, their numbers have been decimated by foxes and feral cats to the point where scientists no longer know how many are left in the wild.
Now existing in scattered and isolated populations across arid regions of WA, the Northern Territory and south-west Queensland, the bilbies have returned to the South-West for the first time since their extinction from the area 30 years ago.
Environment Minister Donna Faragher said scientists were confident the mammals would survive within the nature reserve at Perup, 50km north-east of Manjimup.
Mrs Faragher said anecdotal evidence suggested bilbies were present within the Perup area until the late 1970s so there was suitable habitat for the species.
Some of the animals were bred and flown from the Department of Environment and Conservation's Peron captive breeding centre at Shark Bay, while others were taken from breeding programs at the Dryandra Woodland, south of Perth.
Their reintroduction into the South-West is part of a national recovery plan for bilbies.
Earlier this month the endangered mammal was ranked 11th on WA's most threatened species list.
The department will monitor the released animals through radio tracking and trapping to check their survival in the wild.
Last Updated on Sunday, 10 June 2012 17:46