The Rio Grande Rise is an almost completely unstudied,
geologically intriguing, ecologically mysterious, potential lost continent in
the deep south Atlantic. And it also hosts dense cobalt-rich crusts.
The Rio Grande Rise is a region of deep-ocean seamounts
roughly the area of Iceland in the southwestern Atlantic. It lies west of the
Mid-Atlantic Ridge off the coast of South America and near Brazil’s island
territories. As the largest oceanic feature on the South American plate, it straddles
two microplates. And yet, like much of the southern Atlantic deep sea, it is
relatively under sampled.
Almost nothing is known about the ecology or biodiversity of
the Rio Grande Rise.
As a marine biologists just beginning my deep-sea education, conservation as a priority was an alien concept. The deep sea was the last true wilderness, distant and alien, impossibly difficult to access. We knew that exploitation was coming, companies had been exploring the potential of deep-sea mining for decades, but they always seemed to be generation away. Conservation was a question for my scientific descendants. For my peers and me, we still had a few good decades left in the golden age of exploration that began in the 1970’s with the first discovery of deep-sea hydrothermal vents. That age is about to end.
The reality of deep-sea exploitation is imminent. The first hydrothermal vent mining lease has been issued in the territorial waters of Papua New Guinea. The International Seabed Authority, which regulates seafloor extraction in international waters, has approved the first two mining exploration permits for seafloor massive sulfides in international waters. Manganese nodule extraction, once quashed by a global decline in metal prices, has recently reappeared. Crustal metal deposits are fast becoming a viable resource. The isolation of rare earth elements from the seafloor, a newcomer in deep-sea exploitation, could open up new, massive deposit for critical electronic components. All of these are likely to occur within the next few decades.