New Seep Sustains Life in Deep Sea
UNCW researchers and an international, interagency team of scientists this spring discovered what is perhaps the world's largest methane cold seep.
This discovery could play an important role in advancing scientific understanding of hydrocarbon resources and gas hydrates (important possible future energy resources) along the U.S. continental slope.
The seep lies deep (1450-1610 meters) in the western North Atlantic Ocean just south of the mouth of Norfolk Canyon, far from the life-sustaining energy of the sun. Mussels blanketing the seep rely on bacteria that use the methane to make energy. The process, known as chemosynthesis, forms the basis for life in the harsh environment and could help scientists better understand how organisms can survive under these types of extreme conditions.
"UNCW and Florida State University have done two previous cruises together, and this is perhaps our biggest discovery," said UNCW researcher Steve Ross, co-leader of the investigation team. "Studies of this kind and of these communities help scientists understand how life thrives in harsh environments, and perhaps even on other planets."
The new seep discovery is only the third documented seep site on the U.S. Atlantic Coast, and by far the most extensive; the two seep areas at this site are estimated to be at least a kilometer long and in places hundreds of meters across.
Methane gas erupts from the seafloor in dense bubble plumes from many locations here. Sea cucumbers were also seen tucked into the tight mounds of mussels and shrimp swam above them. Many species of fish, including some with unusual behaviors, were also common around the unique ecosystem.
Stationed aboard NOAA's Ronald H. Brown research vessel, the research team used the diverse capabilities of the Woods Hole Oceanographic Institution's Remotely Operated Vehicle, Jason II, to document and study the newly discovered methane seep. The team captured high definition video, sampled the sediment at the site, collected live mussels for genetic and reproductive studies, collected large dead shells and rocks for aging analysis, took water samples to examine water chemistry and sampled associated animals to examine food webs.
As part of a larger four-year study of mid-Atlantic submarine canyons (co-led by Ross), the marine research expedition was sponsored by the U.S. Bureau of Ocean Energy Management and the National Oceanic and Atmospheric Administration. Major funding for the research expedition was provided by the Bureau of Ocean Energy Management, with NOAA providing funding for the Ronald H. Brown and Jason ROV. U.S. Geological Survey and other collaborators also provided a variety of resources.