Volunteers reflect on 10 years since Rena grounded off Tauranga in NZ's worst maritime environmental disaster

It's been 10 years today since the Rena grounded on a reef off Tauranga, causing New Zealand's worst maritime environmental disaster.

Eight thousand volunteers spent months cleaning up the coastline and it's had a lasting impact on them. 

Indelible images of hundreds of oil-soaked penguins are etched in Chrissy Jefferson's mind.

The 75-year-old self-confessed bird lady nursed so many back to life in the aftermath of the Rena disaster, she got a tattoo in their honour.

"The thought we would lose some of the 1600-1700 that we have here at the Mount was just devastating, absolutely devastating," she told Newshub.

Over 1000 tonnes of oily waste spilled into the sea and onto the coastline when the Greek-owned container ship hit the Astrolabe Reef on this day in 2011. 

Volunteers young and old came out of the woodwork for the country’s biggest-ever environmental clean-up.

Rena volunteer programme supervisor Brice Fraser said there was a "sense of certainly strong, strong connection to the place". 

"To see the beaches blackened by oil and that spurred them into doing something."

The fact the Rena's owners Daina Shipping were given consent to leave the last of the wreck on the reef still irks some Motiti Islanders, including Buddy Mikaere of Ngai Te Hapu.

"In spiritual terms we are still feeling it here, it's not going to go away," he said.

Daina Shipping and its insurers will pay the price until 2038.

On top of its $650 million salvage operation, it's funding the Astrolabe Trust to monitor the wreck, ensuring it does no more damage to the reef.

Hugo Shanahan from the trust says: "There's a significant bond in place sitting with regional council, all the environmental monitoring work every time someone goes out to do that, that is covered by the owners and its insurer over a 20-year-period".

Marine life is thriving on the wreck and above and tracking shows even some of those oil-soaked birds are now breeding up a storm.