Turtles invade Auckland city waterways

New Zealand banned the importation of red-eared sliders in 1965, but it is legal to own and breed the reptiles. Photo / Doug Sherring

Red-eared sliders dumped by frustrated owners.

Auckland is on the brink of an "explosion" in red-eared slider turtles - a pest regarded by conservation authorities as one of the world's 100 most-invasive species.

New Zealand banned the importation of red-eared sliders in 1965, but it is legal to own and breed the reptiles.

With a lifespan of up to 50 years though, families who once bought a cute 4cm pet for children have found decades later they're stuck with a fully grown turtle the size of a dinner plate. Some have been releasing the critters into Auckland's waterways.

As a result, Auckland is staring down the barrel of a serious infestation of the species introduced from the southern United States.

The council has begun a major pest management review, which includes looking at a law change on ownership and a cull of those in the wild.

"People think they're doing what's in the best interest of the animal by releasing these turtles into the wild, but it's really not in the interest of the wider ecosystem," Dr Imogen Bassett, council biosecurity adviser, said.

"We don't have any hard numbers on their abundance but we do know they're commonly found in waterways around much of the region, including wetlands, lakes, creeks, drainage and ditches in southern and western Auckland.

"It's not known whether it's warm enough in those regions for the animals to breed."

Bassett said the full impact on Auckland's ecosystem is not yet known, although existing pressures on Auckland's diminishing wetlands are clear.

"We have lost a huge proportion of our wetlands to drainage. The last thing these already under-pressure water bodies need is to have turtles added to the mix," she said.

UK evidence also says sliders are a threat to nesting waterbirds - taking over nests and preying on eggs and hatchlings. "They are opportunists when it comes to food," she said.

"They will eat vegetation, small birds or insects."

Red-eared sliders, which take their name from a distinctive red stripe behind each eye, also pose a salmonella risk. Manawatu and Waikato are also encountering the species roaming wild.

Waikato Regional Council's pest management review means fines of up to $5000 can now be slapped on anyone caught releasing one of the turtles.

Angie Harvey, who works with SPCA to help rescue the reptiles, has more than 70 sliders at her sanctuary in Massey, West Auckland.

"A lot of people have these animals but want to get rid of them.

"I set up a Facebook page a year ago hoping to educate people on how to look after them, but I have more turtles coming in than going out," she said.

Harvey, who receives no funding for her sanctuary, also called for mass breeding of the species to be stopped in New Zealand.

To donate to Auckland Fish, Turtle and Reptile Rescue visit: givealittle.co.nz/cause/turtletopia