The first 60 penguins have been released from the Wildlife Recovery Centre at Mount Maunganui beach this afternoon.

The little blue penguins have had their feathers cleaned and been given a clean bill of health, after turning up coated in oil following the oil spill when the container ship Rena ran aground on New Zealand’s Astrolabe Reef on October 5th and spilled 400 tons of fuel oil.

“We’re thrilled to have reached the point where we can begin releasing these birds back into the wild, where they belong,” said Alex van Wijngaarden, commander of Maritime New Zealand.

Before being released each bird had to pass blood tests and the “six hour test” – where they swim for six hours without a break to test their waterproofing. Each bird has been micro-chipped and will be returned to the habitat they came from.

The birds released Tuesday are among 343 little blue penguins who have been cleaned so far. Wildlife Response Manager Kerri Morgan said it’s important that wild penguins do not remain in captivity for too long because they can develop injuries and illnesses.

More than 2,000 sea birds died in the spill.