A University of Louisiana at Lafayette researcher is leading a study to investigate the significant, complex role of natural methane seepage in the ocean's carbon cycle.
The research is being funded with a $2,995,000 grant from the National Science Foundation’s Ocean Sciences Division. Dr. Davide Oppo, an associate professor of geology at UL Lafayette, is principal investigator of the interdisciplinary, multi-university study. It will involve integrating advanced geochemical, microbiological, geophysical and geological techniques.
The reason? Scientists don’t fully understand how methane moves and changes in ocean environments, or how marine life processes methane, a greenhouse gas that traps heat in the atmosphere. “Studying methane seeps, including their features and how they change over time, offers exciting opportunities for discovery. This is especially true for continental margins, where we still know very little about them,” Oppo said.
Researchers will rely on advanced technology and approaches to explore the sources and fates of methane in underwater environments along the Atlantic Coast. Hundreds of oceanic methane seeps have been documented, from New England to South Carolina. At such seeps, methane rises to the seafloor, supporting unique ecosystems and at times bubbling into the water column.
“The research aims to uncover how methane travels from deep-sea subsurface to the ocean water column and how it interacts with the environment,” Oppo said.
He will coordinate the use of high-tech ocean exploration tools such as autonomous underwater vehicles and “Alvin,” a submersible human-occupied vehicle. The HOV, which is part of the National Deep Submergence Facility, can send up to three scientists to depths of over 21,000 feet for as many as 10 hours. That enables data collection and observation of the seafloor and water column.
The underwater vehicles will be carried and deployed from larger vessels as part of several upcoming expeditions for the multi-year research project. The study, Oppo explained, is important. As climate change leads to rising ocean temperatures and more intense storms that mix heat downward to the seabed, the amount of methane released into the ocean could increase significantly.
Understanding how methane is managed by the ocean’s systems – and by microscopic organisms that consume methane called methanotrophs – is crucial for predicting its impact on global climate and ocean health, he added.
“There’s a chance that there are huge, unexplored methane seep areas in other parts of the world, just like those along the U.S. Atlantic Coast,” Oppo said. “Our research could reveal new information that helps improve how we estimate global methane emissions.”
As project leader, Oppo will collaborate with Dr. Samantha Joye, a professor at the University of Georgia; Dr. Sunita Shah Walter, an assistant professor at the University of Delaware; and Dr. Adam Skarke, an associate professor at Mississippi State University.
Photo caption: A UL Lafayette researcher is leading a multi-university study funded by the National Science Foundation to examine the role of natural methane seepage in the ocean's carbon cycle. Researchers will explore underwater environments along the Atlantic Coast via autonomous underwater vehicles and submersible human-occupied vehicles deployed from larger vessels. Photo credit: Submitted photo