Tons of Queensland sugar had to be pumped overboard after a bulk carrier crashed into a coral reef in Papua New Guinea, but authorities are unsure what damage it might do to marine life. Marine salvagers dumped the spoiled sugar into the ocean in order to refloat the Zhi Qiang on July 13 after it hit Long Reef, between Samarai and Misima Islands, 12 days earlier.
The listing ship was towed to Port Moresby for repairs.
Virgil Poanchina, a safety manager with PNG's Maritime Safety Authority, told AAP today no fuel had spilled from the ship when it was holed but seawater had spoiled sugar in two holds and it was pumped off to gain buoyancy.
"It was necessary to do this to save the vessel, to save bigger impacts to the reef."
The authority was investigating whether the sugar might damage marine life, he said.
"I have no idea. Maybe in the long term."
The authority would reserve its rights to penalise the ship's operators if it was found the sugar caused significant environmental damage, Mr Poanchina said.
The ship, managed by Cosco Hong Kong Shipping, was bound for South Korea.
It was refloated with the aid of two tugs, one sent from Brisbane by Australian salvage company Adsteam Marine and one from the PNG firm Pacific Towing.
An Adsteam Marine spokeswoman said temporary repairs were being made to the ship and arrangements made to secure the remaining cargo of sugar before the vessel was handed back to its owners, perhaps next week.