The capture of a red eared slider turtle in Lake Taupō has prompted a strong warning about the need for people not to let this animal become established in the wild in New Zealand, particularly at iconic tourism sites.
Assisted by the Department of Conservation and the Taupō harbourmaster’s office, Waikato Regional Council biosecurity staff, using a net, have captured a turtle at Rainbow Point after one was seen sunning itself on a rock recently.
It is thought the captured turtle was a pet that had either escaped or been released.
“These turtles are ranked as one of the world’s top 100 pests and we are anxious that they don’t become established in our waterways,” said regional council response manager Brett Bailey.
“The turtles are omnivorous and eat native species such as eels and native fish, and compete for food with introduced trout.”
Mr Bailey said the council, Ngati Tūwharetoa and the Department of Conservation were particularly concerned about the potential for the turtles to become established in Lake Taupō, an important tourist destination, and for the turtles to damage fish stocks.
“It’s thought that New Zealand is generally too cold for the turtles, which breed on land, to get established on any scale by breeding in the wild.
“But Lake Taupō has geothermal heat venting at various sites around the lake shore which could potentially create pockets where successful breeding could occur, although DOC advises it thinks only males would be produced at this stage.”
DOC technical advisor on threats Nick Poutu said: “The temperatures of Taupō geothermal banks would still only ensure the gender of the eggs to hatch would be all males so it would not lead to ongoing reproductive success.”
The captured animal has been humanely euthanised and an examination of its stomach contents will be carried out to confirm whether it has been feeding on native freshwater species.
A search at three geothermal venting sites around the lake edge at Taupo has shown no sign of other turtles.
“Tūwharetoa, DOC and the regional council are working together closely on this issue – none of the parties want to see this pest established in the lake or elsewhere given the threat they pose to native freshwater life,” said Mr Bailey.
“It’s very important for turtle owners not to let them escape or dispose of them in waterways – the risks to freshwater life are too great.
“We don’t want a repeat of the koi carp situation in the Waikato where this pest fish has created a significant environmental problem.”
If people don’t want their pets anymore they can contact the council’s biosecurity team on 0800 800 401 for advice.
Responsible pet ownership extends to correct methods of the cleaning and emptying of aquarium tanks. People emptying aquarium tanks into New Zealand freshwater generally pose a major risk of introducing unwanted pest plants and fish into lakes and rivers. DOC freshwater threats ranger Brenda Lawson said: “If people wish to empty water from their aquarium it must poured over land a long distance from freshwater sources. Plant life should be disposed of in the land fill.”
The way for freshwater users to take responsibility for preventing the introduction of unwanted organisms into lakes and rivers is to learn the easy steps of ‘Check Clean Dry’ before moving between waterways. The easy steps are found at www.biosecurity.govt.nz/cleaning. This includes checking gear, cleaning it and drying it before moving between waterways.