Donna Moot runs Turtle Rescue in Christchurch and is caring for almost 80 turtles. (File photo) Photo: RNZ / Anna Sargent
The number of pet turtles found in waterways across the South Island is increasing, with concerns about the impact they are having on native plants and animals.
The South Island's only dedicated turtle rescue service said it's already at capacity, having taken in more than 100 strays in the last eight years.
Donna Moot has run Turtle Rescue in Christchurch for almost 20 years and she's currently caring for almost 80 turtles at her three-bedroom home in Somerfield, with up to 30 more waiting for adoption being cared for in a large purpose-built pond on another property.
She's worried about what the next few months will bring, as turtles emerge from their winter dormancy.
"My tanks are all full, my ponds are full. I've got a number of sick turtles needing lots of extra care. I'm not getting them rehomed as much as I would like and I don't know where I'm going to fit more in, but I have to take them because there's really no one else around doing that at the moment in Christchurch."
Donna Moot pictured with a turtle. (File photo) Photo: RNZ / Anna Sargent
The worst case she'd seen recently was a female turtle plucked from the sea near a Canterbury river mouth, by a fisherman in three metre swells.
"She was pretty much paralysed on her left side due to the swelling in her limbs. She was in an awful condition, she was passing pus, she was obviously full of pneumonia, and she had probably survived out there for months and months, getting sicker and sicker and sicker and she was suffering greatly when she came to me so I quickly put her out of her misery."
She said stray turtles had been fished out of most of Canterbury's rivers and streams in recent years and had also come to her from as far afield as Nelson and Invercargill.
"It's just cruel, people are releasing them into the waterways because they don't know what else to do with them, there's not the information to tell them when they buy that tiny 50 cent piece size baby turtle off Trade Me that it's going to grow and live 50-odd years and it is becoming an increasing problem."
Tasman District Council's senior biosecurity officer, Lindsay Barber said a red-eared slider turtle was recently found inside the filter of a wastewater treatment plant in Tapawera after the winter floods.
Red-eared slider turtles can destroy native habitats. (File photo) Photo: Laszlo Ilyes / Creative Commons
"How it got there is anybody's guess, it was when the whole place was just awash with water and then it appeared in the wastewater system when all the streams and creeks and the Motueka River were all one.
"So where it came from, we really don't know, it could have been in a pond at the back of somebody's section and they lost it and, you know, it's ended up in the wastewater treatment plant that way."
He said another turtle had been caught in Lake Killarney near Tākaka, after much effort.
"You'd think that catching a turtle would be a relatively easy thing to do, particularly if you put food in a cage. But literally, we spent a couple of years trying to get this turtle, we had the assistance of a guy over in Tākaka who baited the trap every day, and then eventually we got the thing."
Barber said the turtle was the size of a dinner plate and it couldn't be rehomed, so had to be euthanised.
The council had been trying to capture two red eared slider turtles that were living in Borck Creek which runs through Berryfields, in Richmond.
Department of Conservation freshwater ranger Matthew Brady said they could be very hard to catch.
"For something with the reputation of being slow they're very good climbers for starters, so they do escape and they can be pretty quick. If they get scared, they jump in the water and they're gone."
The International Union for Conservation of Nature (IUCN) lists the red-eared slider as one of the world's 100 worst invasive species due to their serious impact on biological diversity and/or human activities, and their illustration of important issues of biological invasion.
Brady said red-eared slider turtles had been a problem in New Zealand for some time and there were concerns rising temperatures could see wild populations boom.
There was evidence they were laying eggs in the wild, but they need to be kept at 22-33 degrees Celsius for 55-80 days to hatch into live young, with only males produced when the temperature was below 28 degrees.
That could change as the temperatures increased.
Brady said the turtles would eat almost anything in the country's waterways, including native fish and birds, and they had no natural predators.
"They live for 50 years and their clutches can be up to 15 eggs, and they might do a few clutches a year. So you do the maths on that and you can get them up to plague proportions.
He said owning a turtle was a big commitment and people should ask for help if they're struggling, instead of releasing pets into the wild.
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