We are using statistical models that combine databases of known deep-sea coral beds with information about key habitats to predict and map suitable habitat for deep-sea corals in the U.S. Atlantic and Gulf of Mexico. The resulting habitat suitability maps will improve the conservation planning, management, and exploration of deep-sea coral ecosystems.

Why We Care
Deep-sea coral is a diverse and valuable resource that, among many things, provides habitat for fish and invertebrates. Because of their slow growth rates and vulnerability to bottom disturbance, deep-sea coral ecosystems are particularly important to conserve. The distribution of deep-sea coral is poorly understood because of the logistical difficulty and expense of surveying the deep ocean. Predictive modeling of deep-sea coral habitats is essential for supporting conservation planning and for targeting areas for future mapping and exploration. Modeling can also lead to insights into the environmental factors driving the distribution of deep-sea corals, helping to build our knowledge base of how these unique ecosystems function.

What We Are Doing
We are using statistical modeling techniques to predict areas of the seafloor that are capable of supporting deep-sea corals. Using a statistical machine-learning algorithm called maximum entropy (MaxEnt), we are combining databases of known deep-sea coral locations provided by the NOAA Deep-Sea Coral Research and Technology Program (DSCRTP) and other contributors with environmental and oceanographic data to generate predictive models of deep-sea coral distribution. These models are used to produce regional maps of deep-sea coral habitat.

The project is being conducted in three areas of the United States:

1. the Northeast/Mid-Atlantic, in collaboration with Dave Packer, Amy Drohan, and Dr. Martha Nizinski at NOAA/NMFS Northeast Fisheries Science Center (NEFSC);
2. the Southeast Atlantic, in collaboration with Andy David and Dr. Tom Hourigan at NOAA/NMFS Southeast Fisheries Science Center (SEFSC) and DSCRTP;
3. the Gulf of Mexico, in collaboration with Dr. Peter Etnoyer at NOAA/NOS/NCCOS Center for Coastal Environmental Health and Biomolecular Research and Dr. Chris Jenkins at University of Colorado Boulder.

In these regions, deep-sea coral occurs on the continental shelves and slopes, at ocean depths of approximately 50 to greater than 2,000 meters.

This project is a cross-NOAA collaboration involving funding and collaborators at NCCOS, the NOAA National Marine Fisheries Service (DSCRTP, NEFSC, SEFSC), and the NOAA Office of Ocean Exploration and Research (OER). Additional support for Dr. Peter Etnoyer was provided by the Harte Research Institute at Texas A&M University – Corpus Christi and the Schmidt Ocean Institute.

The original data used to support this modeling effort were collected by a large number of Federal, State, academic, NGO, and industry efforts over many years. We are grateful for their efforts and their willingness to share datasets for this effort. Full descriptions of data contributors to each regional modeling effort can be found in the metadata for each component in the Digital Data Packages available for download below.

What We Found
Thus far we have:

• Generated the highest-resolution (370 meter grid cell size), most complete maps of potential deep-sea coral distribution in the Atlantic U.S. and Gulf of Mexico regions.
• Determined that the amount and location of suitable habitat varies by taxonomic group (e.g., soft versus hard corals).
• Identified (by predictive models) many unexplored areas that are likely to support deep-sea coral communities.
• Discovered that information on substrate, including hard bottom and sediment grain size, is a critical factor for predicting the distribution of many deep-coral taxa.
• Determined that a variety of environmental variables including bottom geomorphology, bottom temperature, bottom salinity, and surface productivity correlate with coral habitat suitability.

Our work is being used to:

• Support conservation and management of deep-sea corals
• Help regional fishery management councils (FMCs) plan benthic habitat management initiatives
• Provide valuable information for offshore spatial planning, including planning for renewable energy installations
• Lead to explorations to map previously undiscovered deep-coral communities
• Lend insight into the environmental processes that shape deep-sea coral distributions.

Next Steps
As deep-coral databases improve, we hope to improve and validate these models with additional field data. We are assisting with the integration of these predictive maps of deep-coral habitat suitability into regional spatial planning processes.