The HMNZS Manawanui, aground in Samoa. Photo: Supplied / Profile Boats
There is no sign of oil on the beaches of the Samoan marine reserve where the Manawanui sank over the weekend, but local conservationists say they would still like to see the wreck removed to preserve the delicate ecosystem in the area.
The $100 million specialist survey ship hit a reef at the southern end of Upolu on Saturday night and sank Sunday morning.
Locals have been reporting an oil-like substance in the water around the wreck, and rubbish floating everywhere.
The reef that the Manawanui struck is home to an array of fish rays and coral - and is famous for its large population of sea turtles.
Samoa Conservation Society president James Atherton said a local fisherman had reported seeing dead turtles in the area after the sinking, but a quick survey of the area showed that any initial oil leakage had not settled on the shore.
"I had a look at the reef today and it didn't look as as bad as I was thinking it could be, so I was actually a bit relieved.
"I did a very quick survey of the area where the boat went down and then around the coast to the west, where the prevailing currents and winds were taking everything westwards. From what I could see form the shoreline, the oil spill must have been out in the ocean, where it will be dissipated and spread quite quickly.
Fears Manawanui sinking could have serious environmental impacts
Atherton said a drone would be sent up in the coming days to get aerial footage of the coastline and confirm any oil had not reached it.
He told Checkpoint the main issue was now over what would happen to the vessel, and if it was going to be salvaged.
"Because it's probably still full of oil I would imagine, so even if the immediate risk didn't seem to be such a serious problem, it does not mean that risk is gone, because there is going to be quite a lot of oil in that boat to think about.
"In a situation like this ideally, you would take it away, because it might leak in the future. We'd love to see the boat removed."
He said Samoans knew New Zealand would take the matter seriously and look at all the options.
What ship hulls do to reefs
Professor Chris Battershill, chairperson of Coastal Science at the University of Waikato, said the effect of ship hulls on coral reef systems could be quite damaging, because a lot of the antifouling paint came off and became ground into the corals.
"Where that can be cleaned up, then recovery of the corals can happen quite quickly. If it's left there, particularly if it's some of the older style anti-fouling paints that have tin in them, the effects can be quite long-lasting."
Battershill said the Rena grounding, and three other significant grounding events on the Great Barrier Reef, showed that if the amount of fuel lost from the vessel could be reduced and if any crushed coral rubble contaminated by the old-style anti-fouling paints could be removed as best as possible, recovery of those reef systems was "surprisingly quick".
"I never stop being amazed at the resilience of the sea despite everything we seem to be throwing at it at the moment. So that's a good thing but I guess it's only up to a limit."
Getting to the cause
The loss of the ship means the New Zealand Navy is now down to a fleet of five, and a Court of Inquiry is now underway.
David Capie - director of the Centre for Strategic Studies at Victoria University - told Checkpoint the loss of the Manawanui was important because it was useful as a multi-purpose vessel.
"It had capacity to put divers to sea, it had some very advanced capabilities for that. It also could do hydrographic surveys to map the sea bed and reefs and harbours to try and improve maritime charts and update those. And it also has a 100-tonne crane, which means it's very efficient at unloading containers of aid, for example if it's responding to a disaster."
Govt promises to do all it can to clean up sinking of Manawanui
He said it had a "very flexible capability" and had been very busy in the Pacific.
"Just this year it had been cleaning out World War Two ammunitions on Tuvalu and doing science work, most recently off Raoul Island with GNS, DOC and others."
Capie said while there was some information about the sinking - such as the timing of the disaster and the evacuations that took place - there were not many details about exactly what happened on ship.
But he said the Court of Inquiry would be working to get to the bottom of what actually happened in an expeditious fashion.