Mesophotic and Deep Benthic Communities
Contact usPhoto: NOAA, Marine Applied Research & Exploration
Diving Deep Below the Ocean Surface
Picture what lies below the ocean surface–what do you see? Many people think of colorful coral reefs, dense kelp forests, or other habitats that lie in the sunny top layer of the ocean. Although these are ecologically and culturally important ecosystems, they represent a tiny fraction of the ocean’s underwater landscape. If you travel past this sunlit zone, you will find diverse communities of plants and animals that thrive in the cooler, darker waters of the deep sea.
Mesophotic and Deep Benthic Habitats
Mesophotic and deep benthic habitats are areas of the seafloor with little to no sunlight. “Mesophotic” refers to the “middle light” zone, which lies between 160 and 980 feet (50–300 meters) below the surface, while “deep” habitats are found at depths exceeding 980 feet (300 meters). These zones are vast and complex, home to a rich diversity of species that represent the foundation of ocean food webs, including colorful octocorals, squat lobsters, brittle stars, anglerfish, sponges, feather stars, and octopuses.
Photo: NOAA, National Marine Sanctuary Foundation, UNCW UVP
Restoring Deep Habitats Injured by the Deepwater Horizon oil spill
These habitats faced an unprecedented threat in 2010 when the Deepwater Horizon (DWH) oil spill injured more than 770 square miles of deep-sea habitat. After the DWH oil spill, federal and state agencies formed the Deepwater Horizon Natural Resource Damage Assessment Trustee Council (DWH Trustees) to assess the impacts and identify actions to restore injured habitats, species, and the services they provide. One restoration type the DWH Trustees identified in the open ocean focuses on an important ecosystem along the seafloor: Mesophotic and Deep Benthic Communities (MDBC). In 2019, the Open Ocean Trustees selected four Mesophotic and Deep Benthic Communities (MDBC) restoration projects.
The four MDBC projects are:
- Mapping, Ground-Truthing, and Predictive Habitat Modeling: Data collected by this project provides crucial information about the abundance, distribution, and locations of mesophotic and deep benthic communities in the region and helps identify areas for restoration, protection, and management.
- Habitat Assessment and Evaluation: Habitat assessment provides information on environmental conditions to inform understanding of structure, function, and changes to habitats over time, natural recovery trajectories, and the effects of restoration efforts in context.
- Coral Propagation Technique Development: This project focuses on restoring habitat-forming coral species, which provide structure and shelter for fish and invertebrates. This project is also developing a better understanding of coral reproduction, lifespan, ideal environmental conditions, and more to inform restoration.
- Active Management and Protection: This project connects the public and natural resource managers to MDBC through education and outreach, and works to identify and mitigate existing threats such as marine debris, invasive species, boat and fishing activity, and legacy oil and gas infrastructure.
The MDBC portfolio is led by the National Oceanic and Atmospheric Administration (NOAA), the Department of the Interior, including United States Geological Survey (USGS) and the Bureau of Ocean Energy Management (BOEM), alongside many academic, nongovernmental organization, and aquarium partners.
Credit: Max Brown, NOAA NCCOS
MDBC and National Marine Sanctuary Foundation
The Foundation is an integral partner in implementing MDBC restoration throughout the Gulf, including in and around the Flower Garden Banks National Marine Sanctuary. The Foundation works with NOAA to provide:
Education and Outreach: Foundation staff are instrumental in bringing people up close to mesophotic and deep benthic habitats. Our team develops and implements education and outreach products including public-facing articles, engaging public venue exhibits and displays, online and in-person events, educational resources, and more.
ROV and Technical Diving: We provide support for tools that power the restoration of these habitats, including remotely operated vehicles (ROVs) and technical diving. This support includes an upgrade to the ROV Mohawk, allowing for deeper operations, and supporting technical diving missions, which brings highly experienced divers to the Gulf to advance restoration efforts.
Aquarium Partnerships: We fund scientific laboratories across the country who are advancing our understanding of coral growth, recruitment, and reproduction in an effort to inform future restoration efforts in the Gulf. Together we are filling critical knowledge gaps and informing future restoration efforts. Many of these aquarium partners also collaborate on the education and outreach initiatives to share their restoration support efforts with visitors through live coral exhibits or educational programming!
Subject Matter Experts: This restoration work requires a large team with a broad range of knowledge and expertise. We provide support to experts at academic institutions across the U.S. so they can dedicate their time in the field and in labs to expanding our knowledge of these habitats to inform restoration.
Photo: Kris Benson, NOAA