A break for cane toads?

A new and unexpected obstacle is thwarting efforts to control the invasive cane toad populations in Australia: a potential ban on the most commonly used method for killing the animals -- carbon dioxide. Image: Wikimedia commonsThe linkurl:Kimberley Toad Busters;http://www.canetoads.com.au/ (KTB) have been using carbon dioxide exposure to euthanize the toads for five years, successfully eliminating more than half a million pests. But last year, after the cane toad populations made their way into

Jef Akst

| 2 min read

Image: Wikimedia commons

The linkurl:Kimberley Toad Busters;http://www.canetoads.com.au/ (KTB) have been using carbon dioxide exposure to euthanize the toads for five years, successfully eliminating more than half a million pests. But last year, after the cane toad populations made their way into Western Australia (WA), the linkurl:Department of Environment and Conservation;http://www.dec.wa.gov.au/canetoads (DEC) -- a department of the WA government -- announced that they would not support the use of CO₂ until further trials had been done, leaving the KTB nearly weaponless against the rapidly spreading invasion just as the first major wet season rains are starting to fall. (Cane toads have seriously upset Australia's ecosystem, consuming native insects, out-competing the continent's wildlife, and devastating populations of animals that attempt to prey on them but instead get poisoned by their bufotoxin, a milky blend of neurotoxins that cause respiratory arrest -- see our feature on the subject linkurl:here.);http://www.the-scientist.com/article/display/54497/. "This [is an] incredible and bizarre decision by the Department of Environment and Conservation," KTB founder and president Lee Scott-Virtue wrote in an email to The Scientist. "Why would government agency scientists prevent volunteers from using the only method suitable for large scale euthanasia of cane toads that is safe for volunteers?" he noted in a statement released last month. According to KTB, the DEC's decision was based on laboratory experiments by a DEC scientist on just a few toads that suggested CO₂ is an inhumane method of eliminating the pests. KTB, however, claims just the opposite, pointing to their DVD of the procedure, which shows that "the toads are anesthetized immediately when carbon dioxide is applied without signs of stress, [and that they] remain unconscious until their death," volunteer toad buster Sister Dell Collins said in the statement. "How this method could not be considered humane is beyond my comprehension." While other control methods, such as introducing a virus to infect the toads, are in the pipeline, physical removal of the animals is currently the only method Australia has for limiting their spread. For now, because further field trials on the use of CO₂ have been delayed, the DEC and the Department of Local Government and Regional Planning are allowing the temporary use of the method, but request that the toad busters then use blunt trauma for brain destruction -- a method that some toad busters find appalling. "I will not go toad busting and definitely not take children toad busting if we have to bash the cane toads on the head," said KTB indigenous team leader Gorgina Wilson in the statement. "It does not encourage them to be kind and care for all animals, even cane toads. It is not the cane toads fault he is killing our wildlife, it is ours."
**__Related stories:__***linkurl:Will arthritis thwart cane toads?;http://www.the-scientist.com/blog/display/55252/
[2nd December 2008]*linkurl:Cane toads wreaking more havoc;http://www.the-scientist.com/blog/display/54732/
[6th June 2008]*linkurl:Stopping the Cane Toad;http://www.the-scientist.com/article/display/54497/
[April 2008]*linkurl:Say your prayers, cane toads;http://www.the-scientist.com/blog/display/54524/
[4th April 2008]