Management and the prevention of the introduction of new invasive species are key environmental and agricultural policy issues for the Australian federal and state governments.
Feral animals causing most public concern and economic and ecological damage include:
|Image||Name||Species||Overview||Introduced||Reason||Introduced from||Distribution||Feral||Pest||Threat Level||Est Pop||Main Control Measures||Notes/ Ref|
|Cane toad||Bufo marinus||1935||Biological Control (Cane beetle)||South America via Hawaii||Queensland (extensive), northern New South Wales, Top End, Kimberley||No||Yes||High||200 million +||Culling; Trapping; Genetic (under research)||(prolific breeders and bufotoxin kills native animals)|
|Red Fox||Vulpes vulpes||1855||Recreational hunting||Europe||most of Australia, possibly small population in Tasmania||Yes||Yes||Extreme||7.2 million +||1080 baiting; hunting||Elusive prolific predator of native animals and livestock.|
|European Rabbit||Oryctolagus cuniculus||Rabbits in Australia||1788||Recreational hunting||Europe||Throughout Australia (extensive)||Yes||Yes||High||200 million +||rabbit-proof fence; Myxomatosis; Calicivirus (RHD)||Prolific breeders that destroy land.|
|Dromedary Camel||Camelus dromedarius||Australian feral camel||1840||Beast of Burden||India||Central Australia (extensive)||Yes||Yes||Low||500,000 +||Helicopter Culling||Grazer, though arid Australian conditions suit the camel perfectly.|
Feral animals have very few predators in Australia.
Ironically, many early bounties were paid for the extermination of native species that were considered a pest to farmers. The Tasmanian tiger or thylacine was one such program that caused extinction, whilst the Tasmanian Devil, Spotted Quoll and Tasmanian Wedge-tailed Eagle all became seriously threatened by bounties.
At various times, bounties have been in place for invasive species such as the wild dog, dingo and fox. In 2002, a Victorian Fox Bounty Trial began fox bounties which have been in place intermittently since 1893 (only 30 years after introduction). Feral cat bounties in Queensland have also been considered to counter the growing problem. The dingo is subject to various controversial bounty systems in Australia. The Australian wolf sub-species was itself introduced before European settlement, however has been considered native of the mainland and is considered a pest to livestock.
Currently, in the Northern Territory (especially around Darwin) a bounty on cane toads exists. When a live, unharmed toad is taken into certain hotels around the Darwin area a pint of Coopers is offered. Afterwards the RSPCA will humanely dispose of the toads.
Initially introduced to control locust plagues, the Indian Mynah breeds prolifically in urban environments in the eastern states. The mynah poses a serious threat (such that it has been listed in the World Conservation Union's world's 100 worst invasive species). The bird has caused human health concerns due to the spread of mites and disease and it has also been known to force native birds and their eggs from their nests.
Starlings and sparrows are currently closely monitored in south-eastern Western Australia.
Despite the number of Rock Pigeons, many people continue to feed the birds bread crumbs and assist them to breed in great numbers. It is not yet illegal to feed pigeons in Australia, and many local proposals to cull pigeons have been rejected.
The fire ant in particular, with its poisonous stings, poses a direct threat to human lifestyle. Although control is extremely difficult and spread quickly, the species is currently effectively quarantined to South East Queensland
|Common Name||Scientific Name||Extent in Australia||Image|
|Alligator Weed||Alternanthera philoxeroides||WA, NT, QLD, NSW, VIC, SA, TAS|
|Athel Pine||Tamarix aphylla||WA, NT, QLD, NSW, VIC, SA|
|Bitou bush / Boneseed||Chrysanthemoides monilifera||WA, QLD, NSW, VIC, SA, TAS|
|Blackberry||Rubus fruticosus agg.||WA, QLD, NSW, VIC, SA, TAS, ACT|
|Bridal Creeper||Asparagus asparagoides||WA, NSW, VIC, SA, TAS|
|Cabomba||Cabomba caroliniana||NT, QLD, NSW, VIC|
|Chilean Needle Grass||Nassella neesiana||NSW, VIC, SA, ACT|
|Common Gorse||Ulex europaeus||WA, QLD, NSW, VIC, SA, TAS, ACT|
|Hymenachne||Hymenachne amplexicaulis||NT, QLD, SA|
|Lantana||Lantana camara||WA, NT, QLD, NSW|
|Mesquite||Prosopis spp.||WA, NT, QLD, NSW, VIC, SA|
|Parkinsonia||Parkinsonia aculeata||WA, NT, QLD|
|Parthenium weed||Parthenium hysterophorus||QLD, NSW, VIC|
|Pond-apple||Annona glabra||NT, QLD, NSW|
|Prickly Acacia||Acacia nilotica ssp. indica||QLD, NSW|
|Rubber Vine||Cryptostegia grandiflora||WA, QLD|
|Giant salvinia||Salvinia molesta||WA, NT, QLD, NSW, SA|
|Serrated Tussock||Nassella trichotoma||NSW, VIC, TAS, ACT|
|Willows||Salix spp. except S. babylonica, S. X calodendron and S. X reichardtiji||NSW, VIC, ACT|
There are many other noxious weeds through Australia including:
Weed management costs the Australian economy AUD$4 billion yearly, weeds are also an environmental problem, they are the second greatest threat to biodiversity after land clearing. Almost half of Australia's 220 declared noxious weeds (under legislation) were introduced deliberately, one third of these as garden ornamentals.
The Australian Quarantine and Inspection Service is responsible for ensuring that no new species with the potential to become invasive species enter Australia. To raise public awareness, Australian Quarantine has featured Australian celebrity nature lover Steve Irwin on a series of television commercials, with the message Quarantine - Don't mess with it..
Several scientific bodies are involved in research for the control of invasive species. The CSIRO has released of several successful biological control agents and developed chemical agents for pest and weed control. For example, the CSIRO released myxoma virus to control wild rabbits in Australia.. Rabbit hemorrhagic disease escaped containment from an Australian Government research facility and spread across Australia. Rabbit hemorrhagic disease was subsequently legalised for the control of wild rabbits. The moth Cactoblastis cactorum was introduced for the control of prickly pear, and the salvinia weevil Cyrtobagous salviniae for the control of aquatic weed Salvinia. More doubtful biological controls were the cane toad, which was introduced to control the sugar cane destroying cane beetle; instead the cane toad ate anything and everything else—the beetle was not its preferred food source given choice. The cane toad in Australia has become the biological control that is most infamous for having been a complete failure as well as becoming an environmental nightmare. It has also led to much public concern and caution when considering the introduction of new biological controls.
Another example of a poorly researched introduced biological control is the sap sucking lantana bug (Aconophora compressa) also from South America that was introduced into Australia in the 1995 to eat the lantana. Unfortunately, the lantana bug also attacks other trees including fiddlewood trees which has caused distress to some gardeners. The lantana bug had been tested for six years on 62 different plants. Aconophora compressa was the 28th insect introduced to control lantana in about 80 years.
Cooperative Research Centres for weed management and pest animal control, have been established by the federal government. They coordinate research and funding between a number of university and government labs for research into control of invasive species.
The weakening of restrictions on importing raw produce into Australia mandated by the World Trade Organisation Future poses risks of introducing exotic disease organisms Case examples include, Chytrid fungus that is threatening numerous Australian frog species with extinction , and mass pilchards deaths in the Southern Ocean from 1995 onwards that are suspected to have been caused by a virus that may have been brought in with imported pilchards .