Manawanui: Marine life thrives as sunken navy ship becomes new artificial reef

Salvors have successfully removed diesel fuel and pollutants from the sunken New Zealand Navy ship, HMNZS Manawanui, that ran aground and sank off the southern coast of Sāmoa in October while conducting a reef survey.

The New Zealand Defence Force has extracted 365,000 litres of fuel from the vessel, involving 284 dives to access 55 different tanks.

Resident Ulugia Su’a Jay Ahfook Schuster, originally from Safata, says leaving the stricken ship on the ocean floor is the best scenario for the environment.

“The ship had taken out a lot of our reef, and that normally takes a long time to grow back," he says.

“The Navy guys were saying that the fish are already starting to come around where the boat is.

“Leaving the boat there will just replace the reef that got damaged, so it fixes the problem a lot faster.”

Schuster is currently in Maninoa, where many divers, salvage crew, and Navy personnel are staying.

“Every day, they’re in and out all the time through the channel. They go and they leave early morning and they’re back late at night.

Divers carry out exploratory missions before the fuel extraction begins. Photo/NZDF Nov 2024

“They’re pretty much seven days a week, unless it’s bad weather.”

The salvage operation, initially expected to take 20 days, ends up taking three months due to adverse weather conditions.

The NZDF says the first phase of recovering the fuel and other pollutants from HMNZS Manawanui has been completed.

Commondore Andrew Brown of the New Zealand Navy says the salvors are now focussing on removing debris, equipment, weapons, and ammunition from the Manawanui wreck.

“It is important for us to remove debris that may come loose and escape from the ship," he says.

“Once equipment and debris has been cleared, we will be taking every effort to make Manawanui as secure as possible.”

An aerial view shows the shipwreck in October 2024. Photo/NZDF

According to Radio New Zealand, some of the extracted diesel is reusable, while 45,000 litres will be sent to New Zealand for proper disposal.

Brown says the Navy is committed to minimising environmental impact and addressing community concerns by clearing debris and returning it to New Zealand.

“We are also initiating and informing a wreck assessment, which includes independent expert studies of the vessel, reef and marine environment.

“This will inform the options for the next steps for Manawanui to allow the New Zealand and Sāmoan Governments to consult on.”

Meanwhile, Schuster says there has been no official response over compensation for the locals affected by five months of disruption and the fishing ban.