Far North has almost half of NZ’s turtle strandings

One of the 19 turtles that have stranded in Te Hiku in recent months, an unprecedented number, with 10 ready for release back into the ocean.

An unusually high number of turtle strandings has kept Far North Department of Conservation staff busy, with 19 washed ashore in Te Hiku over spring and summer, with some set to be released back into the ocean.

DoC said turtles regularly strand on Far North beaches - they strand more in Northland than anywhere else - but 19 over that time was a lot.

It was possibly the highest number of turtle strandings ever recorded in NZ.

Sadly, some of the turtles could not be saved, but 13 had survived and some will be released back into the ocean in the Far North.

DoC Senior Science Advisor Karen Middlemiss said staff responded to about 40 reports of deceased and live turtle strandings from Cape Reinga to Rakiura / Stewart Island between June last year and now.

‘‘Strandings are far more common in the Northland region than anywhere else around New Zealand,’’ Middlemiss said.

‘‘The number stranded in Rangaunu Harbour was higher than in previous years. This spike could be a one-off occurrence, and we will be closely following to see if it happens again next year so we can look at the trend over time.’’

She said DoC was not sure why the high number of strandings occurred, or if there was a common link.

‘‘We don’t yet have the answers to that, but we think it is likely to be several factors that could have impacted the health of sea turtles, including sea temperature, weather events, food availability, pollution ingestion, and water quality,’’ Middlemiss said.

‘‘Increased public awareness of sea turtle conservation may have also led to more stranding reports this year.

“Scientific studies of large green turtle stranding events in Australia attributed poor health to climate change related storm events that damaged food sources (i.e., seagrass beds) and/or caused poor coastal water quality (e.g., sediment discharge and contaminants from surrounding land).

Turtle strandings are relatively common in the Far North, with this green sea turtle released at Rangiputa Beach on the Karikari Peninsula, in 2022, but 19 strandings over spring and summer is unusually high

‘‘We may, or may not, see the same spike in stranding numbers for Rangaunu Harbour next year, based on the presence/absence of the above factors, but DoC will be monitoring the trend closely with iwi and community support.’’

She said it’s important to note that stranded sea turtles are already sick, no matter how well they look, and that there are strandings every year.

‘‘It is not unusual for turtles to lose condition over cooler months at sea and as water temperature increases, so too does their foraging activity as they start to warm up.

“If they have lost condition their immune system can become compromised making them more susceptible to ill health.

“Increased activity can be the last straw if they are nursing an existing condition. Blood tests and other health diagnostics carried out on live turtles that stranded in Northland this summer, found that most were severely dehydrated and had digestive issues of some sort.”

Nineteen turtles stranded in the district over spring and summer and 13 have been rehabilitated ready for release.

Four turtles were recovered from Te-Oneroa-a-Tōhē Ninety Mile Beach - two green turtles, a hawksbill, and an olive ridley, but unfortunately only one green survived and the others died.

Fifteen turtles stranded in the Rangaunu Harbour, at Rangiputa, East Beach, and Kaimaumau. Fourteen turtles were greens, and one was a black turtle – a subspecies of the green turtle.

Twelve of these turtles, including the black turtle, have survived. This is the highest recorded count of turtle strandings and recovery in New Zealand. Ten turtles are now recovered and ready for release back into the ocean. Dates are yet to be confirmed for the release events.

Middlemiss said DoC is committed to continuing to work with Auckland Zoo and Kelly Tarltons to improve Team Turtles' ability to triage, treat and rehabilitate sick turtles.

“The DoC-led tracking study with our partners will help us better understand how and where green turtles spend their time throughout the year around New Zealand coastlines, and in harbours like Rangaunu, so that we can inform future korero with iwi and community groups around protecting and enhancing habitats of significance for this species.”

Although turtles breed in the tropics and subtropics, there are five species of turtle that are seen in New Zealand waters. Green and leatherback turtles are the most common. There are also loggerhead turtles, hawksbill turtles and olive ridley turtles.

DoC staff attend beached or entangled sea turtles. Those that are alive when found may be sent to a specialist facility such as an aquarium for rehabilitation. Dead specimens may be given to museums and scientists for research and educational purposes.

Data from beached turtles and live sightings are recorded in the New Zealand Amphibian and Reptile Distribution Scheme.

DoC monitors the bycatch of turtles and other protected species in commercial fisheries through its Conservation Services Programme.

All reptiles, including sea turtles, are protected under the Wildlife Act 1953. This means it is illegal to kill or harass any species of sea turtle within New Zealand’s Territorial Sea or Exclusive Economic Zone.

It is also illegal to possess a sea turtle, or any part of a sea turtle, without a permit issued under the Wildlife Act, or evidence that it was legally imported into New Zealand or was in your possession prior to commencement of the Wildlife Act.