Deep sea mining is a relatively new mineral retrieval process that takes place on the ocean floor. Ocean mining sites are usually around large areas of polymetallic nodules or active and extinct hydrothermal vents at about 1,400 - 3,700 meters below the ocean’s surface. The vents create sulfide deposits, which contain precious metals such as silver, gold, copper, manganese, cobalt, and zinc.
The deposits are mined using either hydraulic pumps or bucket systems that take ore to the surface to be processed. As with all mining operations, deep sea mining raises questions about environmental damages to the surrounding areas. As undersea mining grows ever more likely, one major question looms: Can these valuable minerals be extracted on a large scale without causing significant environmental damage, particularly to the unique ecosystems near the deep hydrothermal vents where the minerals accumulate?
Because deep sea mining is a relatively new field, the complete consequences of full scale mining operations are unknown. However, many experts are certain that removal of parts of the sea floor will result in disturbances to the benthic layer, increased toxicity of the water column and sediment plumes from tailings. Removing parts of the sea floor disturbs the habitat of benthic organisms, possibly, depending on the type of mining and location, causing permanent disturbances.
One scientist seeking to address this question is Duke University marine biologist Cindy Lee Van Dover, who was one of the first researchers to explore hydrothermal vents, cataloging numerous species of animals and microbes living in a part of the ocean that biologists once assumed was barren. Today, much of her work is focused on figuring out how drilling into the seabed might disrupt newly discovered life forms, such as the giant tubeworms that thrive near the vents.
In an interview with Yale Environment 360, Van Dover compared the deep sea to America’s Wild West and cautioned that wildlife losses could be similar if mining companies and the International Seabed Authority — the regulatory agency in charge of the ocean’s mineral resources — fail to establish environmentally sound mining practices before deep-sea exploitation begins. To this end, she has gone on research trips with Nautilus Minerals, the Canadian mining company, and is advising the company on conservation issues. But time is short, and Van Dover says she is continually surprised by how swiftly deep-sea mining is developing. "When I heard in 2005 that people were serious about wanting to mine hydrothermal vents, I just laughed," said Van Dover. “Those of us in the biological community just didn’t think mining was going to happen for decades.”
There are vast unknowns to undersea mining. One of the major concerns is the impact to the existing marine life. Van Dover said in her interview: "In some cases these vents have been around for, you know 5,000 years or more, and there’s one example in the mid-Atlantic Ridge of a vent that has built up over 100,000 years. And what we don’t yet understand is, if you were to mine a site like that how quickly will the animals that live there come back? Until we understand the impacts of both a single mining event and a cumulative mining event on one of these older sites, we’re going to wonder how the animals will respond."
By. Andy Soos