Ocean Matters

Undersea Mining

Mining the Seas

Mining for resources such as metal ore, gold and silver has occurred for thousands of years. It’s only in the last century that mining has gone after oceanic resources. Since the late 1950's, people have been seriously contemplating mining the ocean floor for resources such as diamonds, gold, silver, metal ores (manganese nodules) and even underwater gravel mines. We briefly assess undersea mining and how it can affect the ocean environment.

Types of Undersea Mining

The first real undersea mining began in the late 1950's when a company named Tidal Diamonds was established in the United States. From 1961 to 1970, the company mined 1.5 million carats of diamonds from the ocean floor. Although this is an incredible amount of diamonds, they were unable to stay afloat and were subsequently bought out.

The untapped potential of oceanic mineral resources is staggering. The world’s oceans have much higher concentrations of diamonds than on land. Fluvial (water) processes typically deposit a high percentage of gem quality diamonds in the ocean (a higher percentage than on land). Diamonds on land, however, are easier and cheaper to mine than ocean diamonds. Ocean mining usually involves a type of dredge that brings sediments to the surface (usually to a large boat) where workers and machinery separate the diamonds from the gravel. After the diamonds are removed, the sediments are immediately returned to the ocean bottom. With continued advances in technology, the undersea diamond mining industry is predicted to grow. The largest drawback for the time being is the work involved in bringing sediments to the surface and competition from cheaper, land-based mining companies. Undersea mining is also possible for other resources such as coal, metal compounds, gas hydrates and even gravels for construction purposes.

Potential Impacts of Undersea Mining

There is a broad range of potential environmental problems associated with mining the ocean for resources. The greatest impacts will likely come from undersea dredge mining for various oceanic minerals. During the mining process the dredges dig up the ocean floor, damaging animal habitats and killing fish and invertebrate species. This impact is also true for harbour and marine channel dredges used to keep navigation corridors open for boat traffic. Repairing damage of this kind is nearly impossible considering the nature of deep-sea mining. If an area is subject to intense ocean floor mining its possible that floor-dwelling communities could be destroyed.

Sediment plumes are another problem associated with undersea mining. Once sediments are returned to the ocean floor they may cloud up the water, reducing the amount of light available for photosynthesis for marine organisms. Sediments may also infuse dissolved heavy metals in the water that accumulate in the food chain, further harming marine animals.
As land based minerals become increasingly scarce, the popularity of undersea mining stands to increase. While most ocean minerals remain inaccessible for now, continued technological advances suggest that humans will soon be able to extract additional resources from the ocean floor. From a marine conservation perspective, we must ensure that any such developments do not come to the detriment of the marine organisms that depend on clean and healthy ocean ecosystems for their survival.

For more information go to:

Cyber Diver News Network (news story)

Terra Daily (news story)

EurekAlert - The Dawn of Deep Sea Mining

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