This summer, NCCOS scientists and partners assessed the state of deep-sea habitats in the Gulf of Mexico as part of ongoing restoration projects in the region following the Deepwater Horizon oil spill in 2010.
Over the course of six weeks aboard NOAA Ship Pisces, the team used a variety of ocean technologies to collect seafloor data and biological samples to characterize deep-sea communities not impacted by the oil spill. The information collected will provide a baseline to support restoration, protection, and management efforts. Building on past work, the researchers focused on deepwater corals, which compose vibrant reefs that are reflective of ecosystem health.
The team used a suite of observational tools to acquire the range of data needed for the project. A REMUS 600 autonomous underwater vehicle (AUV) captured images of the seafloor and gathered bathymetric readings. A Mohawk 18 remotely operated vehicle (ROV) was used to record video and digital images and collect specimens of coral and other organisms for laboratory analysis. Stationary autonomous reef monitoring structures (ARMS) and mesophotic landers gathered long-term data on the seafloor. These devices measured ocean currents, water chemistry, and water quality, while collecting DNA samples that identify micro and macro marine organisms. The ship also conducted multibeam echosounder surveys to determine the depth and roughness of the seafloor. All of these tools operated continuously during the expedition. Images, maps, and samples collected will help expand knowledge about mesophotic (mid-depth) and deep benthic communities (MDBC) by providing insight into how different organisms are connected and distributed across the Gulf of Mexico.
The Deepwater Horizon oil spill released 134 million gallons of oil into the Gulf over 87 days, injuring mesophotic and deep benthic habitats throughout the region. Organisms from microbes to megafauna, such as whales and sea turtles, were harmed, including populations of various octocoral species, including Swiftia exserta, Muricea pendula, Callogorgia delta, and Paramuricea biscaya. These corals grow slowly and are covered with polyps that obtain food and nutrients from deep-sea currents, making the condition of their colonies representative of ecosystem health. MDBC project teams are working to understand how these species reproduce and how populations are recovering. Healthy samples of these organisms collected this summer will undergo genetic and isotopic analyses to improve knowledge about these coral communities and provide context for understanding the performance of restoration efforts.
This summer’s mission was one of many supporting MDBC restoration projects led by NOAA and the U.S. Department of the Interior. The expedition included experts from NOAA, the U.S. Geological Survey, the University of North Carolina at Wilmington, the Woods Hole Oceanographic Institution, Lehigh University, the National Centers for Environmental Information, and the University System of Maryland.