Unusually large numbers of mutated cane toads with extra limbs and eyes are being found in the Queensland city of Gladstone, researchers say.
Dr Scott Wilson of Central Queensland University said mutations in animals were normal with about 1 percent of cane toads in non-urban areas expressing them.
But the rate of mutated cane toads in the Gladstone was much higher than average with 6 to 8 percent of the population affected, ABC reports.
"All sites in Gladstone [have elevated numbers of mutated toads], whether they be urban or industrial sites," Dr Wilson said.
The "mutations" described included extra legs or deformed skeletons.
The city is home to a coal-powered station and two aluminium refineries but it is not yet known whether these were linked to the toads' mutation rate.
"We're still in the process of looking at what those stresses are - chemicals in the waterways or other types of contaminants or stresses such as changes in the salinity of the water or parasite loads," Dr Wilson said.
The toads were caught by a volunteer group called "Gladstone Toadbusters", who reportedly fetch as many as 500 toads per hour.
Group member Iris Cosgrove told the ABC she collected the toads to protect the environment.
"[I do it] to make it a better habitat for the green tree frogs or the striped marsh frogs, to make it a healthier environment for the other native animals," she said.
Author: Sylvia Varnham O'Regan, Approving editor: Matthew Henry