Looking into seabed mining in three Pacific countries - PNG (sulphides), the Cook Islands (manganese nodules) and the Marshall Islands (cobalt-rich crusts) - the report aimed to provide information to the Pacific countries about the possible impacts.

"Based on the report--the main net social benefit for mining in PNG for two years, around US$80 million, and for mining manganese nodules in the Cook Islands for 20 years-- will bring a mean social benefit of around US$500 million for the government," said Mr Akuila Tawake, the Pacific Community's deep sea minerals project manager.

He said that the benefits of seabed mining in both PNG and the Cook Islands outweigh the costs, but that this is not the case for the Marshalls.

The report's conclusion was firm in saying that if proper environmental protections were put in place, there would be a far higher possibility of benefits outweighing costs for all three nations.

This follows Nautilus Minerals' statement last year that its planned seabed mining operation in PNG's Bismarck Sea would not discharge any waste into the ocean.

Nautilus hopes to start mining the sea floor by 2018.