A critically endangered turtle that was found near death on a Dargaville beach is set to return to the wild after two years of recuperation.
Named Koha, the juvenile hawksbill turtle has been nursed back to health at Kelly Tarlton's Sealife Aquarium in Auckland.
Its sex is unknown, because testing is invasive, and often non-conclusive with young turtles.
Aquarist Harry Josephson-Rutter says Koha faced a battle to survive after being found in September 2014.
"[It was] in a really, really bad condition, hugely emaciated, absolutely no energy. It couldn’t even lift its own head."
However, since arriving at Kelly Tarlton's, the turtle has almost doubled its weight to 10.5kg.
It could live several more decades in the wild.
Koha will be taken to the Kermadec Islands, about halfway between New Zealand and Tonga, by the National Institute of Water and Atmospheric Research.
Voyage leader Malcolm Clark says Koha will be released near Raoul Island.
"We want to release the turtle close to land so if it needs to haul out on to a beach to recover before it goes on its way again, it's not very far away."
The scientific expedition was heading to the region and will drop off Koha before undertaking its other work.
About half a dozen turtles are taken to Kelly Tarlton's each year after washing up in New Zealand.
Most are relatively common species, and are released at the Poor Knights Islands, off the coast of Northland, after recovering.