Image: Dive and Discover

An international team of scientists from seven universities and three research institutes has released the first images to the public of a collection of hydrothermal vents in the Indian Ocean. To find these vents, located two and a half miles below the sea surface in one of the most far-removed places in the world, the team used the Remotely Operated Vehicle (ROV) Jason and the Woods Hole Oceanographic Institution's Research Vessel Knorr. The devices photographed and returned samples from five groups of vents, known as black smokers for their chimneylike appearance.

Such vents form on the ocean floor along so-called midocean ridges, areas where two tectonic plates drift away from each other. There magma rises, causing volcanic activity on the ocean floor, and seawater seeps down through the cracks where molten rock below the ocean crust heats it to several hundred degrees Celsius. The water then rises again and shoots out of the hydrothermal vents. In the process, it loses most of its oxygen, potassium, calcium, sulfate and magnesium, but gains potassium, calcium, sodium, copper, iron, sulfur and zinc from the earth's crust. When these dissolved metals and sulfur meet the oxygen-rich seawater above, they form black metal-sulfide minerals, creating what appear to be clouds of black smoke. The metals also deposit around the vent, creating a kind of chimney.

Scientists have found fascinating ecosystems surrounding these vents, consisting of microbes, mussels, crabs, tube worms and even fish and octopusesand the new vents along the midocean ridge in the Indian Ocean are no exception. The researchers observed an abundance of different life-forms, including thousands of shrimp, four species of anemones, several snails and crab (see image). They hope to collect the shrimp, mussels and even crabs from the ocean floor and bring them up to the surface during the next few days. Further analysis of these organisms may shed light on how the fauna living at hydrothermal vents to the east and west of them, in the Atlantic and Pacific oceans, are genetically related.