The depths of the Atlantic Ocean are home to fascinating geological features and unusual life forms. The Mid-Atlantic Ridge (MAR) is a massive underwater mountain range, 1,700 to 4,200 meters (1 to 2.6 miles) below sea level, that runs from the Arctic Ocean to the Southern Ocean. It is a hot spot for hydrothermal vents, which provide habitat for unique species that could provide insight into the origins of life on Earth.
Hydrothermal vents are fueled by underwater volcanic activity or seafloor spreading, and they spew superheated, mineral-laden water from beneath the ocean floor. As the water cools, minerals precipitate out, forming towers containing copper, gold, silver, and zinc. These minerals are used in electronics such as mobile phones and laptop computers and in cars, appliances, and bridges.
Vent ecosystems support unique species, mostly bacteria, that derive their energy from mineral-rich vent waters rather than sunlight. These microbes form thick, nutrient-rich mats along the seafloor that support shrimp, mussels, worms, snails, and fish. The MAR’s vent fields were discovered only in 1985, and scientists expect future expeditions to reveal new vents and species.1
The International Seabed Authority (ISA), which is responsible for managing deep-sea mining and protecting the marine environment from its impacts, has entered into exploration contracts along the MAR with France, Poland, and Russia. Once mining begins, equipment will remove or degrade habitats and create sediment plumes that could smother nearby life, while noise and light could also negatively affect deep-sea species. Recovery times for vent communities are unknown.2
Most marine scientists agree that effective protection of the MAR will require a precautionary approach to seabed mining that includes excluding large areas of the seafloor from mining and establishing stringent rules governing how it can occur outside those protected areas.