Thursday, May 5, 2011

Mining of hydrothermal vents

Hydrothermal vents provide some of the most extreme and intriguing environments in the world which host unique ecosystems containing a large abundance of newly discovered species supported in part by chemosynthetic bacteria. This unusual habitat is under threat from exploitation due to the poly-metallic rich sulphur deposits which are formed by hot vent fluids being ejected up through the oceanic crust.  As the vent fluid rises towards the surface of the crust it reacts with the cold surrounding seawater forming the much desired mineral rich precipitates.  Mining the deep sea for minerals was said to be of “science fiction” and always thought to be unrealistic in terms of economic viability.  The discovery of rich deposits including that of silver and gold located within 200 miles of the economic exclusive zone (EEZ) of some countries such as Papa New Guinea (PNG) together with advances in underwater technology and a higher value of such minerals has led to an increased interest in hydrothermal vent mining in these zones. 

Hydrothermal deposits found within international waters have a degree of safeguarding against the prospect of mining. To mine these areas legally requires an independent environmental impact assessment and the payment of royalties to the international seabed Authority (ISA). The discovery of a number of hydrothermal vents both active and inactive located within the Papa New Guinean EEZ was therefore of great interest to a number of mining companies. One such company; Nautilus Minerals, has moved on this devleopment and as of January 2011 they were granted a licence in Papa New Guinea for offshore mineral exploration and potentially exploitation. This licence covered a 59km2 area of mostly inactive hydrothermal vents in the Bismarck Sea.
The licence granted means that Nautilus Minerals, as they desire to be the first company to commercially mine the deep sea for polymetallic sulphur deposits has been given the go ahead and will undoubtedly proceed. The subsequent mining of these vents in papa New Guinea will directly affect and damage the vents ecosystem but this will be concentrated to the area of the licence and the environmental affect can be monitored. Nautilus have often said that deep sea mineral extraction will transform the industry the same way the oil and gas was transformed by offshore drilling. 

If this predicted boom in this industry occurs, there will be very little chance to protect hydrothermal vents which are still not fully researched and understood as ecological communities. Regardless of the rate of development of the industry the fact is that the deep sea mining of hydrothermal deposits will advance due to societies demand for rare and precious mineral resources. This places ecologically valuable and essentially unexplored deep sea ecosystems at risk from a new and emerging industry.

Kirsteen Allison, H2 Marine Resource student. 

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