Motiti Island's Ngai Te Hapu and Papamoa hapu Nga Potiki lodged the appeal. Te Runanga O Ngati Whakaue ki Maketu and Te Arawa Takutai Moana Kaumatua Forum joined Nga Potiki's appeal.
They have challenged the decision made a year ago by the Bay of Plenty Regional Council to leave the remains of the Rena, plus its equipment and cargo, on the reef. An independent hearings panel appointed by the council spent six weeks in 2015 hearing evidence on the trust's consent application.
The 38,000-tonne container ship ran into the reef in the middle of the night on October 5, 2011, leading to New Zealand's worst maritime environmental disaster as 300 tonnes of oil leaked into the Bay, killing marine life and washing up along the coastline.
Mr Casey said the issue for the court to decide was whether a few localised and minor effects of the wreck being abandoned were such that consent should be declined.
His reading of the trust's 100-page defence of the consent which began yesterday afternoon was expected to take the rest of today. It would be followed by evidence from the trust's 19 witnesses, taking the rest of this week.
Mr Casey argued that many iwi actively opposed any further work to remove the wreckage because it would cause further damage to the reef and risks to the safety of the salvage team.
"For them, the mauri is recovering, and tangaroa should be left to heal."
He argued that a lot had been achieved in the five-and-a-half years since the grounding. As well as dealing with the immediate aftermath, the owner had gone to considerable lengths to assess and monitor the environment, inform the community, and listen and respond to the issues.
Mr Casey said the owner and insurer had gone to "exceptional" lengths to ameliorate the impacts, both environmental and cultural.
He defended the use of the word "exceptional" under questioning by Environmental Judge and hearing chairman Jeff Smith.
Mr Casey said exceptional applied to the degree to which the owner and applicant had engaged in consultation in a complicated situation, and the extent to which Rena's debris field had been cleaned up - compared with wrecks elsewhere in the world.
The $650 million of removal costs made it the second most expensive clean-up in the history of the world's shipwrecks, he said.
Rena debris recovery operations
- Wreck covers 2.1% of total reef area
- Wreck covers 14.5% of reef's shallow habitat
- Highest portion of the wreckage 3m below low tide
Source: Astrolabe Community Trust