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hydrothermal vents

OLogy Series
geology
card
215

hydrothermal vents

OLogy Series
geology

Imagine you are a marine biologist, traveling far beneath the ocean surface in a submersible. It's a vast, dark desert until you come across a tall group of chimney-like structures on the ocean floor, spewing stuff that looks like black smoke! There are bizarre creatures surrounding them, like bright-red tube worms and giant clams. You just found an underwater hot spring with several black smokers.

Bountiful Bacteria of the Sea
The community of life around black smokers is like none other on Earth. Most ecosystems on the planet are based on organisms like plants that depend on sunlight to produce food. But the food chain at the hydrothermal vents is based on an entirely different organism. Tiny bacteria called Archaea use sulfides from the vents, instead of sunlight, to create food. They can survive extremely hot temperatures and toxic chemicals that would kill most organisms. All the other animals in this unusual community depend directly or indirectly on these bacteria. Plants cannot survive in these harsh conditions. Many animals, such as the tube worms, mussels, and clams, live in symbiosis with the bacteria: the bacteria living on or in their bodies supply them with nutrients, while they provide the bacteria with the sulfides they need to survive. (In a symbiotic relationship, two organisms live close together in a way that benefits at least one. In this case, both organisms benefit.) Some scientists believe that life on Earth—and possibly on other planets—may have formed in environments similar to the one around the blacker smokers.

Black smokers are made up of minerals called sulfides. These minerals come from:

the upper levels of the ocean.

beneath the Earth’s crust.

the sand and rocks on the ocean floor.

Are you right?

Correct!

The minerals that form black smokers are made up of metals and sulfur from beneath the Earth’s crust. The metals and sulfur are carried up through cracks in the ocean floor.

Black smokers deep on the ocean floor actually emit smoke.

Fact
or
Fiction
?

Fiction

Although it looks like smoke, that black stuff is made up of particles that form when near-boiling, metal-rich water from an underwater hot spring mixes with deep-sea water.

Scientists named one black smoker in the Pacific Ocean "Godzilla."

Fact
or
Fiction
?

Fact

The black smoker "Godzilla" grew as tall as a 15-story building before it fell over.

Name: black smokers
Average depth: 7,000 feet (2,100 meters) down
Habitat: deep-sea hydrothermal vents, mid-ocean ridges
First discovered: in 1977 near the Galapagos Islands
Cool fact: More than 300 species of animals live around black smokers.

Image credits: courtesy of University of Washington, J.R. Delaney.