“Alien” Life Forms Discovered

Underwater vent erupting.

Underwater volcano releasing liquid droplets of carbon dioxide. Yellow parts of the plume contain tiny droplets of molten sulfur.

High resolution (Credit: NOAA)

The ocean and atmosphere of our planet are always changing – sometimes quickly, sometimes slowly. Even deep, dark, cold areas of the ocean change, whether or not anyone is there to see them.

In 1977, scientists in a submersible diving near the Galápagos Islands discovered underwater vents — somewhat like a seafloor Old Faithful geyser but in many ways very different.

The Galápagos vents came from volcanic seams on the seafloor and amazingly, scientists found a whole ecosystem living on chemicals pouring from the vents.

Until then, scientists believed all life on Earth was part of a photosynthetic food chain, drawing energy from the sun. The discovery revealed hidden “alien” life forms living on our own planet in the dark ocean depths and relying only on chemicals to survive. Tubeworms and huge clams are among the distinctive inhabitants of Pacific Ocean vent sites, while eyeless shrimp have been found at vents in the Atlantic Ocean.

Tubeworms.

Tubeworms.

High resolution (Credit: NOAA)

Until then, scientists believed all life on Earth was part of a photosynthetic food chain, drawing energy from the sun. The discovery revealed hidden “alien” life forms living on our own planet in the dark ocean depths and relying only on chemicals to survive. Tubeworms and huge clams are the most distinctive inhabitants of Pacific Ocean vent sites, while eyeless shrimp are found only at vents in the Atlantic Ocean.

Visits to the vents in the following years were rare, because the depth was accessible only to the few available deep-diving submersibles. When NOAA’s Office of Ocean Exploration supported a Galápagos vents mission in 2002, it had been 12 years since the last visit.

Scientists were shocked to find that in that time, the spectacular “Rose Garden” of giant tubeworms had completely disappeared. They concluded a lava flow had overrun the site, extinguishing its life. The team did discover a new and smaller community of vent animals nearby, a clear sign of renewing life. The scientists dubbed the new vent area “Rosebud.”

Underwater Volcanoes Erupting Violently

Video of underwater venting.

Video: large burst from the Brimstone Pit.

Download as Windows Media (Credit: NOAA)

Discoveries near the Galápagos and elsewhere inspired scientists to search for even more exotic places of venting: underwater volcanoes. Over the last several years, NOAA’s Office of Ocean Exploration has supported three missions to underwater volcanoes along the “Submarine Ring of Fire” in the western Pacific.

So far, scientists have found more than 30 active vents. One site is venting large quantities of liquid carbon dioxide droplets, and has a large community of organisms, including football-sized mussels, living in the highly acidic environment.

Scientists also have found a crater filled with molten sulfur and have discovered an erupting underwater volcano violently spewing lava, gas, rock and ash. Had scientists witnessed such an eruption on land, they might have been in danger. But underwater, their remotely operated vehicle could get close enough to take video and chemical samples.

Underwater Vents Affect Life on Land

Video: molten sulfur and volcanic gases bubbling out of a vent.

Video: molten sulfur and volcanic gases bubbling out of a vent, keeping the partially-crusted surface of an undersea pond undulating.

Download as Windows Media (Credit: NOAA)

Because the ocean is essential to all life on Earth – driving weather, regulating temperature, and providing oxygen, food, transport, medicines, and energy – it is critical to understand its natural biological, chemical, and physical processes.

Fundamental changes at underwater venting sites, though occurring at the bottom of the ocean, can affect life in the ocean and on land. Scientists believe that volcanic eruptions and venting in the ocean have in the past contributed to global extinctions. Yet we also know that these underwater vents can support some forms of life and produce non-living resources.

If we are interested in gauging future changes and consequences, we must understand what drives changes today. Because the oceans remain vastly unknown, when it comes to ocean exploration, the more we look, the more we will find.

To learn more about NOAA’s efforts to unravel the mysteries of the deep, visit NOAA’s Office of Ocean Exploration Web site. NOAA logo.