Chathams invaded by whistling amphibious Australian

Biosecurity officials are investigating the arrival of unwanted frogs on the Chatham Islands, and whether it may be possible to eradicate them.

The Australian whistling frogs and their tadpoles are predators of freshwater insects and other organisms.

The find has been confirmed by Department of Conservation area manager Alison Davis.

"The Chatham Islands have some of the least modified waterways in New Zealand, with no introduced fish species, and no aquatic weeds of concern," she said.

"I am very concerned at the impact they may have on unique Chatham Island species and animal communities."

The Chathams - 10 islands 800km east of New Zealand - have not had introduced or native frogs until now.

The Chatham Island Council recently contracted the Canterbury Regional Council to carry out its pest control and bisosecurity work. One of the council's environmental scientists, Adrian Meredith, said he was concerned by the discovery.

"Whistling frogs can build up to very high densities and we simply don't know what effect they might have on other aquatic life."

He said the best option was to remove the invading species as soon as possible, but the council needed help from the community to identify how far the amphibians had spread.

Dr Meredith said it was very important frogs or tadpoles were not transported to other sites.

- NZPA