Lasts nearly 80 miles across the seabed of the central Arctic, Langseth Ridge is rugged, barren and generally inhospitable. And it should be: Unlike the more productive oceans, fewer nutrients swirl in here, thanks to the ice above blocking the light. However, thousands of years ago, the tops of the slopes were shaken by volcanic activity, producing sulfur that provided food for tubeworms — species you may have seen. video about hydrothermal vents in other parts of the world. Or more precisely, sulfur provides food for the symbiotic bacteria inside the worms, which convert it into energy, keeping the animal alive.
The volcanic activity in Langseth Ridge is long dead, but life is still alive. Today in the magazine Nature Communicationsscientists described How a previously unknown type of ecosystem has flourished under the ice, along towering ridges about 2,000 feet deep. “No one knows what is living on these giant mounds,” said Antje Boetius, director of the Helmholtz Center for Polar and Marine Research at the Alfred Wegener Institute and co-author of the paper. “And when I say giant mounds, imagine we’ll have on Earth an uncharted mountain 3.8 kilometers high – really huge – and no one has walked there yet. No one took pictures, no one knew what kind of flora and fauna were living there.”
With the help of a remote control car dangling from an icebreaker, Boetius and her colleagues discovered that the ridge is now dominated not by worms, but by giant sponges, each up to 3 feet wide. They are on average 300 years old, but some are much older. Curiously, sponges have evolved a similar bacteria-based survival strategy — only they feed on tubes left behind by worms, which have been dead for 2,000 years. Thus, an extinct fossil hydrothermal ecosystem powers an even more exotic combination of life.
“It’s like a forest,” said Teresa Maria Morganti, an ecologist and sponge expert at the Max Planck Institute for Marine Microbiology and lead author of the new paper. “It really is a hot spot of life in the middle of the desert. It’s really fascinating that they were able to exploit this ancient community before. ”
The projection is extremely complicated. Light beige are sponge spicules, while dark brown are worm tubules.
Photo: Morganti, et al., Nature CommunicationsThe foundation of the ridge ecosystem is a dense carpet made up of spines, the tiny structure of silica that sponges use to build their bodies. The pad creates a complex three-dimensional matrix for other animals like shrimp, but it also betrays what sponges do in the dark: They move around in search of food, leaving behind trails in pads.
