Life Thrives 500 Feet Below Seafloor
Who has the underground scene mastered? Hipsters eat your hearts out, biologists have discovered microbes living 521 feet (129 meters) beneath the seafloor off the coast of Peru.
A recent study published in Nature checked out what’s happening in the underground scene for bacteria, fungi and other microorganisms living in five-million-year-old sediment.
“We knew that all of these cells were buried, but we didn’t know if they were doing anything,” said co-author Jennifer Biddle, assistant professor of marine biosciences at the University of Delaware, in a press release.
Biddle and her team found that those microbes ate, reproduced and moved about, despite being buried more than one and a half American football fields beneath the seafloor.
Sediment cores from the seafloor were analyzed to determine which chemicals the microbes contained. This allowed the team from the University of Delaware and Woods Hole Oceanographic Institution to figure out what the microbes were eating.
The microbes dine on both sulfur and nitrogen containing chemicals, as well as eating the corpses of their fellow denizens of the buried realm known as the deep biosphere, a mysterious ecosystem that exists deep beneath the surface all around the globe.
“By the time you get 100 meters down, the bacteria are eating the leftovers of the leftovers of the leftovers of the leftovers — and they are still yummy for bacteria,” Biddle said.
The team also analyzed the DNA of the organisms. This analysis revealed that the microbes grew flagella, or little hairs used to move around. Before this, scientists were unsure if microbes in the deep biosphere could move beneath the tremendous pressure of sediment and sea water.
IMAGE: The Joides Resolution heads to sea from the Azores to drill sediments on IODP Expedition 339. Most of the Earth’s organic carbon is stored in seafloor sediments. (Joseph Russell / University of Delaware)