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Mining the ocean floor

It’s not yet a gold rush to the ocean floor, but seabed prospecting is raising concerns.

By Peter N. SpottsStaff writer of The Christian Science Monitor / May 22, 2009

Sea life around deep-ocean hydrothermal vents could be affected by an eventual push to harvest minerals near them.

Courtesy of ‘Volcanoes of the Deep Sea’/Rutgers university


Woods Hole, Mass.

Pompeii worms, clams, and snails with iron scales armoring their feet are not exactly the cuddly icons that open checkbooks during environmental fundraisers.

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But these denizens of the very, very deep are emerging as poster children for concerns about the environmental effects of mining minerals on the deep-sea floor – in particular, around hydrothermal vents that appear in vent fields dotting the length of the globe’s mid-ocean ridges.

For decades, the prospect that companies would seek fortunes on the seafloor has seemed remote, says Porter Hoagland, a marine-policy specialist at the Woods Hole Oceanographic Institution in Woods Hole, Mass.

From the 1950s through the ’90s, the dawn of the age of deep-sea mining was always considered to be 10, 15, or 20 years away, he says. “It was kind of a receding horizon.” But, he adds, conditions have changed.

Deep-sea exploration and extraction technologies have improved. Until the current global economic slump, rising prices for metals added luster to undersea deposits of gold, copper, and other metals. And the International Seabed Authority (ISA) – tasked under the Law of the Sea Treaty to set up rules governing mining and mining exploration under the sea – is moving to draft regulations governing prospecting and exploration of massive sulfide deposits.

The reason: Nautilus Minerals Inc. in Toronto has applied to the government of Papua New Guinea for a lease to mine deposits of copper and gold on the slopes of an active undersea volcano about a mile beneath the Bismarck Sea. Hearings on the application wrapped up in early April.

To be sure, Nautilus’s effort remains a baby step, given the unrealized, widespread hype over deep-sea mining in the 1960s, ’70s, and ’80s. Indeed, the regulations are being crafted “for an industry that doesn’t exist yet,” says Nii Odunton, the ISA’s secretary-general.

But the effort is being watched closely. To many researchers and environmentalists, now is the time to ensure that seafloor ecosystems have advocates at the table. Some marine ecologists are trying to figure out how regulators might set up marine-protected areas along mid-ocean ridges.

But, like deep-sea mining itself, the effort is tentative. Marine biologists haven’t thought much about strategies for minimizing the impact of mining on ecosystems found on or around massive sulfide deposits, says Cindy Van Dover, an oceanographer who heads the marine science and conservation department at Duke University’s Nicholas School of the Environment in Durham, N.C.

“This has not been on our radar screen,” she says. “And this has got to change.”

In many ways, renewed interest in seafloor mining has as much to do with scientists’ discoveries as it does with technology and economics. The first ecosystems around hydrothermal vents were discovered in 1977 along a rift in the eastern Pacific, between the Galápagos Islands and the South American coast. Since then, researchers have identified three types of ridges as they sampled a small portion of the 41,000-mile undersea ridge system.

First were the fast-spreading ridges, identified via the high level of geothermal activity scientists detected as they towed remote sensors through the plumes of hot material the vents erupted, notes Chris German, another marine scientist at Woods Hole.

As researchers discovered successively slower-spreading ridge types, few thought that they would host active hydrothermal hot spots. Hydrothermal activity was thought to tie directly to the speed of spreading.