A special conference of some of the country's top environmental scientists has severely criticised the government of New South Wales for protecting brumbies from a cull in the Snowy Mountains.
The academics said at the meeting in Canberra that the policy ignored the science. One said he was "appalled and angry".
Another said the damage the wild horses caused was so severe that it could be detected by satellites from space.
The scientists said the NSW government policy meant more pollution of waterways, higher risk of bush fire, scarcer water sources as well as an increased risk to endangered species.
In May, the NSW Deputy Premier John Barilaro, who is also MP for Monaro, reversed a planned cull of wild horses in the alpine region of the state.
Instead, Mr Barilaro announced that the lethal cull would not happen because of the cultural significance of brumbies.
"Wild brumbies have been roaming the Australian alps for almost 200 years and are part of the cultural fabric and folklore of the high country,” he said at the time.
It's prompted outrage amongst environmental scientists who have been studying the impact of the decision. The Australian Academy of Science has held a special conference on the matter at the Shine Dome in Canberra in partnership with ANU and Deakin University.
Acting as a spokesman for the group, Dr Jamie Pittock of ANU's Fenner School of Environment and Society said NSW had completely ignored the science.
"It's alone in this. It's a rogue state," he said.
Victoria and the ACT have not gone down this route. Both accept that brumbies have to be controlled severely.
Dr Pittock said the causes of damage by the wild horses were multiple. They were hooved animals that trampled the habitat, smoothing new paths which then became waterways taking rain to rivers much faster than was good for the environment. This extra flow gathered dirt and other contaminants and so polluted rivers and streams, reducing the supply of usable water.
He said three million Australians depended on this water in south-eastern Australia.
On top of that, the horses trampled swamps high up in the mountains, swamps known as "moss bogs" which acted as sponges for rainwater. They cleansed the rain and released it steadily to the great benefit of the water supply for people.
Thirdly, he said that some endangered animals that depended on the swamps were even more under threat, in particular the Corroboree frog. "The poor old Corroboree frog is dying", said the associate professor.
Another academic at the conference, Professor Catherine Pickering of Griffith University, said "the scale of the destruction by these feral animals can be seen from space".
The problems arise because brumbies are not indigenous to Australia, which had no hooved animals before Europeans brought them.
Because of this, they disrupt what was the original environment. Dr Pittock said that 61 years ago, Australian scientists pointed out that other introduced, hooved animals – cattle and sheep – were also damaging the Kosciuszko Natioanl Park, and the result of this scientific advice was that cattle and sheep were removed.
The same should happen now with brumbies, according to Dr Pittock. "What the scientists are calling for is for the wild horse act in NSW to be repealed and for the NSW government to commit to a feral horse control program", he said.
That would mean culling.
In response to the condemnation by the scientists, John Barilaro, put out a statement: "The Brumby Bill was introduced to acknowledge the cultural and heritage significance of the Wild Brumby.
"The Bill, which was introduced only months ago, has not changed the status of the Brumby to protected, nor has it changed existing population control operations."
"It has maintained a ban on aerial shooting of wild horses which has been in place for nearly 18 years. Nobody wants to see horses shot from the sky and left dying for weeks as was the case in Guy Fawkes National Park in 2000."
The NSW government was going to set up a group to study ways of control without actively killing horses (unless they posed a direct threat to people). One option could be sterilisation, for example, leading to the gradual decline of the population.
"The Wild Horse Management Plan, which will be implemented in coming months, aims to find a balance between humanely controlling the Brumby population and preserving sensitive areas of the National Park", said Mr Barilaro.
Steve Evans is a reporter for The Canberra Times.