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Ecosystems threatened by deep-sea mining: report

Published by MAC on 2007-05-18

Ecosystems threatened by deep-sea mining: report

by The Ottawa Citizen

18th May 2007

A Canadian plan to scoop gold, silver, zinc and copper from the sea floor has hit a bump on the way to the bottom.

The $300-million U.S. plan by Vancouver-based Nautilus Minerals Inc. to mine in the South Pacific poses a serious threat to fragile ecosystems that need better protection, says a report in the journal Science today.

It says environmental regulations need to catch up with the deep-sea miners targeting "hydrothermal" vents, which are rich in both precious metals and ancient life forms. Bacteria, worms and clams thrive in the scalding, sulphur-laden waters percolating out of the sea-floor vents where some scientists speculate life may have originated billions of years ago.

"They could be the cradle of life," says Jochen Halfar, a marine geologist at the University of Toronto and co-author of the report.

Vent systems, which are found at hundreds of spots around the world, are not well understood and little is known about how mining will affect them, says Mr. Halfar. He is also concerned clouds of mining silt and debris will be carried elsewhere on ocean currents.

The plan is to mine extinct vents, which have formed metres-high chimneys on the sea floor and are surrounded by thick mineral-rich sediments that have spewed out of the vents over the eons. But some of the sites Nautilus is targeting are less than a kilometre from active vents "where there is a likely potential of smothering, clogging and contamination of vent communities," say Mr. Halfar and his colleague, marine ecologist Rodney Fujita with California-based Environmental Defense.

Mr. Halfar said in an interview that an "independent environmental assessment" is needed of Nautilus's plan to mine off the coast of Papua New Guinea.

David Heydon, president and CEO of Nautilus, says the company and its investors have $300 million riding on the Papua New Guinea project, the first of what he hopes be many deep-sea mining operations around the world.

He says Mr. Halfar is raising "red herrings" and his concerns are "very presumptuous."

"He's making a presumption that the rules aren't going to be followed, and he's making a presumption that the PNG (Papua New Guinea) government will do a lesser job," says Mr. Heydon, who insists existing rules are adequate.

Mr. Heydon says the company hopes to start mining in 2009. It plans to use remotely operated machines to grind up the deposits, which are about two kilometres beneath the surface. The ore will be pumped up a huge pipe to a ship. The waste water will be returned to deep water and close to two million tonnes of ore a year will head to dry land for processing, says Mr. Heydon.

The company has laid claims in the Bismarck and Solomon Seas that cover an area larger than Great Britain, but Mr. Heydon says mining will be done on patches not much bigger than a couple of football fields. "There's no blasting involved," he says. The pits left on the sea floor will be about 20 metres deep.

He says Nautilus is committed to minimizing the environmental impact and "sustaining" the vent ecosystems.

He says some creatures are sure to die, but likened it to "cutting worms in half while digging in a garden." He says that is the price of providing consumers with copper and other precious metals.

He says it also comes down to a choice between "saving snails" and raising the standard of living, health and education in Papua New Guinea, which he says will reap big benefits from the operation.

He says deep-sea mines will have much lower environmental impact than land-based mines because they contain such high levels of copper and other minerals. They won't produce as much waste rock or greenhouse gases as land-based systems per unit of minerals extracted, he said.

Dozens of scientists have been spending time on the company's ships assessing what Nautilus describes as the "massive" sea floor mineral deposits. They are also studying the worms, crabs, snails and other creatures living around the vents, and the ocean currents that could carry off mining debris.

The researchers come from institutions around the world, including the University of Toronto, says Mr. Heydon.

The company is preparing environmental impact assessments for the government of Papua New Guinea, which has yet to grant the company operating permits and leases.

© The Ottawa Citizen 2007


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