In today’s Academic Minute, Dr. Lisa Levin of the Scripps Institution of Oceanography at the University of California San Diego explains the discovery of a new class of deep-sea environment.
Lisa Levin is a professor and researcher at the Scripps Institution of Oceanography at the University of California San Diego. Her lab's research is focused on understanding the ecology of unique marine environments, such as those surrounding methane seeps. She holds a Ph. D. from the Scripps Institution of Oceanography at UCSD.
Dr. Lisa Levin – Seafloor Vent Ecology
A mile under the sea, off the shores of Costa Rica, sits a vast flourishing garden made up of exotic undersea animals. There are deep-sea tube worms, each about 2-3 feet long, forming expansive meadows or giant bushes the size of a small car. The sea floor is dotted with patches of large white clams and brown mussels, with small squat lobsters and pink fish scurrying about. Here at a place called Jaco Scar life is supported by the chemicals in warm fluids emerging from deep in the earth through a conduit in a collapsed , underwater volcano – one that is being dragged under the continent in the great geologic process called subduction.
Researchers in the submersible ALVIN had expected to find a cold methane seep ecosystem characterized by animals reliant on methane as a carbon source. But at Jaco Scar the presence of warm, shimmering fluids emanating from under the tubeworms indicated that we had found something different.
For the last 35 years we have known that animal communities can flourish in the absence of light, by using chemical energy from beneath the seafloor. We had studied hydrothermal vent ecosystems – fueled by sulfide-rich hot springs – and seep ecosystems – fueled by cold fluids rich in methane. These communities were treated as distinct . But now our work at Jaco Scar has blurred this distinction.
Through analyses of chemicals in the fluids, molecular sequencing of the bacteria and animals, and studies of their isotope biomarkers, we learned that this ecosystem contained elements of both vent and seep environments. Perhaps this is why there is there such a profusion of life, and such a high diversity of species. Findings like this one hint at more environments remaining to be discovered in the deep sea. Such discoveries take on added importance as human extraction of resources from deep waters intensifies.