An endangered population of shore birds appears to have recovered well from an oil spill caused by a container ship off the coast of Tauranga.
The Rena spilled about 230 tonnes of heavy fuel oil off Tauranga after grounding on Astrolabe Reef on 5 October 2011.
About 120 dotterels were in the area between Matakana Island and Matata when the oil spilled and 60 were taken into captivity as a preventative measure.
Independent shorebird ecologist Dr John Dowding has monitored the population since the captive birds were released and says more than three-quarters of those dotterels are alive.
"The survival rate of the birds is back to normal after a year, and the majority of them have settled down where we took them from and started breeding again.
"So we're really very happy with that - it was something of an experiment."