"She's pretty scarred and looks like she may have been in the wars a bit over the last year, but the markings are the same."
She suspects the turtle had been living in nearby wetlands.
Several red-eared slider turtles have been spotted around New Plymouth in recent years, including another on Dillon Drive in Bell Block a few months ago.
Halema says if left to roam the female may well have encountered a male and bred, as has happened in other parts of the country.
"With temperatures rising in New Zealand we know this species is now able to successfully hatch eggs in the wild, which is a major concern.
"They can live for up to 50 years and produce around 400 offspring. They are omnivorous and eat everything, including eggs and chicks from birds' nests, native reptiles and fish. They also carry disease."
The turtle is now safe in an outdoor enclosure in Halema's backyard, while a suitable permanent home is found. She's a welcome neighbour for Kawe the eastern water dragon, who was captured on the Herekawe Stream – another abandoned pet that posed a biosecurity risk in the wild.
Taranaki Regional Council environment services manager Steve Ellis urges people to think carefully before they buy a pet such as a red-eared slider turtle.
"A turtle is for life – can you commit to that? And if you do have one you can no longer care for, don't just set it free. Return it to the pet shop or breeder or find someone who can take it on."
The Regional Pest Management Plan for Taranaki sets out rules for the effective management of 20 species of pest plants and animals in the region.
However it's also vital to prevent new pest species becoming established in Taranaki, he says.
"This could happen as a result of pets escaping as well as the threat of new species sneaking into the region on stock or goods. The council works alongside our neighbouring councils and the Ministry for Primary Industries to identify and manage potential pathways as it's crucial we remain on guard at all times."
If you see a red-eared slider turtle in the wild, report it to Taranaki Regional Council on 0800 736 222 or biodiversity@trc.govt.nz.