A New Approach: Mining the Sea The risks and rewards of deep-sea vent mining

Introduction  Copper is non-renewable, we have a finite amount. Geologists have determined copper resources could be exhausted before the end of this century.  As terrestrial mines are exhausted more and more, where will the world's copper come from?  Is it time to start mining the ocean for minerals? What are the benefits? What are the costs? Our project intends to shed some light on this emerging industry.  Copper is non-renewable, we have a finite amount. Geologists have determined copper resources could be exhausted before the end of this century.  As terrestrial mines are exhausted more and more, where will the world's copper come from?  Is it time to start mining the ocean for minerals? What are the benefits? What are the costs? Our project intends to shed some light on this emerging industry.

Mining  In 1970's, the mining industry considered mining Polymetallic Manganese Nodules in international waters. The UN recognized the need for oversight and created legislation.  Today, mining companies are trolling in waters within the jurisdiction of individual countries, bypassing UN regulations.  Instead of PMN's, these companies are focusing on 'black smokers' (hydrothermal vents on the seafloor).

Mining  Most of the technology is already available from the dredging industry and oil and gas industry which has been drilling in the ocean for decades.  Initial samples indicate mining the ocean could be cheaper and more efficient than mining on land. According to mining companies, they intend to mine commercially within five years.  Most of the technology is already available from the dredging industry and oil and gas industry which has been drilling in the ocean for decades.  Initial samples indicate mining the ocean could be cheaper and more efficient than mining on land. According to mining companies, they intend to mine commercially within five years.

Rising Demand, Diminishing Supply  Cu: second-most conductive metal  Used in power grids  Most copper mines operating today at 90% capacity  To provide each of 10 x 10 9 persons (IPCC prediction for 2100) with a stock of 170 kg of copper (the per-capita average for North America) would require 1,700 Tg of copper  In 2006, the US Geological Survey estimated world- wide copper reserves of 950 Tg  Main increase in demand coming from India and China  Rate of discovery not keeping pace with rise in demand  Cu: second-most conductive metal  Used in power grids  Most copper mines operating today at 90% capacity  To provide each of 10 x 10 9 persons (IPCC prediction for 2100) with a stock of 170 kg of copper (the per-capita average for North America) would require 1,700 Tg of copper  In 2006, the US Geological Survey estimated world- wide copper reserves of 950 Tg  Main increase in demand coming from India and China  Rate of discovery not keeping pace with rise in demand

 Reduced ore grades over last 200 years  Deep-sea mining may be necessary

The Geology of Black Smokers  Hydrothermal Vents-Black Smokers  Black Smoker Ecosystems  Hydrothermal Vents-Black Smokers  Black Smoker Ecosystems

Environmental Impacts  Direct impacts to mining sites:  Both cold and hot vents are home to diverse biological communities.  Kill sessile organisms as well as the destruction of their habitat.  Will these areas will be able to recover?  Buffer zones  Still unclear  Direct impacts to mining sites:  Both cold and hot vents are home to diverse biological communities.  Kill sessile organisms as well as the destruction of their habitat.  Will these areas will be able to recover?  Buffer zones  Still unclear

Sediment Plumes  Sediment Plumes:  Particles are released into the water column forming sediment plumes that can drift for hundreds of miles.  Clog the area around vents, cutting off or making toxic food supplies  Economic Exclusive Zones  Environmental regulations are not as rigid  Shallower waters closer to land sediment plumes can have a larger environmental impact.  Sediment Plumes:  Particles are released into the water column forming sediment plumes that can drift for hundreds of miles.  Clog the area around vents, cutting off or making toxic food supplies  Economic Exclusive Zones  Environmental regulations are not as rigid  Shallower waters closer to land sediment plumes can have a larger environmental impact.

Submarine Tailings Disposal  Tailings  Ground up metals, such as cadmium, copper, iron, lead, manganese, mercury, silver, and zinc, as well as sulfides.  Sulfides + air + water -> sulfuric acid  Tailings are disposed from an underwater pipe in a continuous current to the seafloor.  Argued that since the tailings are disposed of deep in the water they won’t be as exposed to oxygen and thereby have less of a chance of creating sulfuric acid.  Upwelling  Tailings  Ground up metals, such as cadmium, copper, iron, lead, manganese, mercury, silver, and zinc, as well as sulfides.  Sulfides + air + water -> sulfuric acid  Tailings are disposed from an underwater pipe in a continuous current to the seafloor.  Argued that since the tailings are disposed of deep in the water they won’t be as exposed to oxygen and thereby have less of a chance of creating sulfuric acid.  Upwelling

More harmful than terrestrial mining?  Deep sea mining potentially has greater efficiency; less mining can yield the same amount or more of precious metals.  Also argued that it has less of an impact on the populations in areas surrounding mining sites; however it is difficult to predict how these populations will be affected by altering ocean environments  Deep sea ecosystems are much less understood and more difficult to monitor. At present, environmental risks associated with terrestrial mining are better known and easier to contain.  Deep sea mining potentially has greater efficiency; less mining can yield the same amount or more of precious metals.  Also argued that it has less of an impact on the populations in areas surrounding mining sites; however it is difficult to predict how these populations will be affected by altering ocean environments  Deep sea ecosystems are much less understood and more difficult to monitor. At present, environmental risks associated with terrestrial mining are better known and easier to contain.

Policy Implications  A small window of time to setup guidelines and regulations now before a large amount of economic investment can cause a lot of resistance.  Even though it’s taking place in EEZs it can still be considered an international issue since sediment plumes can drift into international waters causing problems similar to transboundary air pollution.  A small window of time to setup guidelines and regulations now before a large amount of economic investment can cause a lot of resistance.  Even though it’s taking place in EEZs it can still be considered an international issue since sediment plumes can drift into international waters causing problems similar to transboundary air pollution.