Deep sea mining to go ahead


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Three months after the expected date, Papua New Guinea's government has granted the world's first deep sea mining license.

The Canadian company Nautilus Minerals want to mine high-grade copper and gold deposits in a 59 km2 area of the Bismack Sea 1.6 km below the surface of the sea and 50km north of the port of Rabaul

When it commences production, which is expected about two and a half years after full project sanction, the Solwara 1 project plans to produce ore at a rate of more than 1.3 million tonnes, containing about 80,000 tonnes of copper and 150,000 to 200,000 ounces of gold a year.

The mining process is complex but involves an "auxiliary cutter" flattening out the sea floor to create a surface that a "bulk cutter" can operate on, ripping the ore apart to be collected by a "collecting machine which sends it to a boat at the surface. On the deck of the boat, the slurry coming up from the sea bed is filtered and the waste is sent back down the pipe to the seabed, where it's released.

Needless to say the potential environmental impacts of this could be devastating.

Paul Tyler from the University of Southampton and chair of the Census of Marine Life said: "Hydrothermal vents have a very distinctive fauna that is only found on hydrothermal vents, so mining close to the vents could wipe out the vents or cause a large amount of damage in the surrounding area."

There is concern that sediment plumes could both cause significant damage to both the water column and the benthic zone, and the deep-sea organisms that inhabit it.

Nautilus claim to have carried out extensive environmental research and impact assessments, and has conservation mitigation strategies in place such as moving organisms for later recolonisation.

Although the indigenous people of Papua New Guinea have protested against the mining, the lease has been granted for an initial term of 20 years. If it proves successful, Nautilus also has its eye on the territorial waters of Fiji, Tonga, the Solomon Islands and New Zealand, which may also harbour commercially exploitable minerals.