Through a collaborative effort with other federal agencies and academic and research institutions, USGS is working to fill data gaps, determine baseline conditions, and characterize key community conditions at mesophotic and deep benthic sites impacted by the Deepwater Horizon oil spill.

The Science Issue and Relevance: The life histories, diversity, and population structures of the species that make up mesophotic and deep benthic communities (MDBC) in the Gulf of Mexico are not well understood. However, these factors play a critical role in these communities’ potential for recovery from damage, such as oil spills and other human activities. A better understanding of the mesophotic and deep-sea communities is needed to inform planning for active management and restoration. The goal of this project is to fill data gaps, determine baseline conditions, and characterize key community conditions at injured sites from the Deepwater Horizon (DWH) oil spill, as well as reference sites.
While some areas of injured resources are known, this project will locate other sites and determine areas where resource restoration or other complementary management measures may be needed and are most likely to succeed. This project will determine the distribution, genetic diversity, and connectivity of MDBCs within the DWH-impacted zone and provide insight to fundamental aspects of injured resources, such as their biology and ecology. Community ecology and temporal variability will be evaluated in impacted, potentially impacted, and reference zones, providing data to inform the effectiveness of restoration actions. This will help fill critical gaps in our understanding of the health, biodiversity, recovery, and resilience of MDBCs following the DWH spill and support the restoration and recovery of these species and habitats.
Methodology for Addressing the Issue: Specimens from mesophotic and deep benthic areas will be collected on multiple research expeditions in the Gulf of Mexico. Sampling will focus on known locations of target species populations and previously studied soft-sediment habitats. In addition to multibeam bathymetric maps, extensive remotely operated vehicle (ROV) image surveys of coral communities in the northwestern Gulf of Mexico are available from previous projects performed by USGS and various partners. These expeditions will allow documentation of living marine resources and assess the status of benthic communities in mesophotic and deep-sea areas. Samples for genetic and isotope analyses will be taken from collected specimens. Statistical methods that integrate independent datasets (isotopic, genetic, and habitat suitability) will be applied to provide greater resolution than any dataset alone. All results will be integrated and displayed via geonarratives, which allow different data layers, including dispersal pathways, sources and sinks of populations, and suitable habitats for mesophotic and shallow-water species, to be overlain onto a map to visualize the potentially complex patterns of connectivity among shallow and mesophotic areas in the Gulf of Mexico.
Future Steps: Deep-water benthic information in the Gulf of Mexico is urgently needed to guide potential management decisions associated with conventional energy, renewable energy, and marine minerals in response to the 2019 Presidential Memorandum’s (PM) Section 2 National Strategy on Ocean Mapping, Exploring and Characterizing the U.S. Exclusive Economic Zone (NOMEC). The findings from this project will contribute to our understanding of ecosystem status and connectivity in the Gulf of Mexico since the DWH oil spill, the processes that shape these environments, and the long-term impacts of disturbances on these habitats.
Connectivity of Coral Ecosystems in the Northwestern Gulf of Mexico
USGS DISCOVRE: Benthic Ecology, Trophodynamics, and Ecosystem Connectivity – Lophelia II: Continuing Ecological Research on Deep-Sea Corals and Deep Reef Habitats in the Gulf of Mexico
Quantifying changes to infaunal communities associated with several deep-sea coral habitats in the Gulf of Mexico and their potential recovery from the DWH oil spill
Growth rates and ages of deep-sea corals impacted by the Deepwater Horizon oil spill
Coral communities as indicators of ecosystem-level impacts of the Deepwater Horizon spill
Impact of the Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico
- Overview
Through a collaborative effort with other federal agencies and academic and research institutions, USGS is working to fill data gaps, determine baseline conditions, and characterize key community conditions at mesophotic and deep benthic sites impacted by the Deepwater Horizon oil spill.
Sources/Usage: Public Domain. Visit Media to see details.Swiftia sp. located at Diaphus Bank in the Gulf of Mexico that shows some dead coral tissue. The Science Issue and Relevance: The life histories, diversity, and population structures of the species that make up mesophotic and deep benthic communities (MDBC) in the Gulf of Mexico are not well understood. However, these factors play a critical role in these communities’ potential for recovery from damage, such as oil spills and other human activities. A better understanding of the mesophotic and deep-sea communities is needed to inform planning for active management and restoration. The goal of this project is to fill data gaps, determine baseline conditions, and characterize key community conditions at injured sites from the Deepwater Horizon (DWH) oil spill, as well as reference sites.
While some areas of injured resources are known, this project will locate other sites and determine areas where resource restoration or other complementary management measures may be needed and are most likely to succeed. This project will determine the distribution, genetic diversity, and connectivity of MDBCs within the DWH-impacted zone and provide insight to fundamental aspects of injured resources, such as their biology and ecology. Community ecology and temporal variability will be evaluated in impacted, potentially impacted, and reference zones, providing data to inform the effectiveness of restoration actions. This will help fill critical gaps in our understanding of the health, biodiversity, recovery, and resilience of MDBCs following the DWH spill and support the restoration and recovery of these species and habitats.
A USGS scientist observes the top of a sediment tube core that has been collected from the Gulf of Mexico seafloor. Methodology for Addressing the Issue: Specimens from mesophotic and deep benthic areas will be collected on multiple research expeditions in the Gulf of Mexico. Sampling will focus on known locations of target species populations and previously studied soft-sediment habitats. In addition to multibeam bathymetric maps, extensive remotely operated vehicle (ROV) image surveys of coral communities in the northwestern Gulf of Mexico are available from previous projects performed by USGS and various partners. These expeditions will allow documentation of living marine resources and assess the status of benthic communities in mesophotic and deep-sea areas. Samples for genetic and isotope analyses will be taken from collected specimens. Statistical methods that integrate independent datasets (isotopic, genetic, and habitat suitability) will be applied to provide greater resolution than any dataset alone. All results will be integrated and displayed via geonarratives, which allow different data layers, including dispersal pathways, sources and sinks of populations, and suitable habitats for mesophotic and shallow-water species, to be overlain onto a map to visualize the potentially complex patterns of connectivity among shallow and mesophotic areas in the Gulf of Mexico.
Future Steps: Deep-water benthic information in the Gulf of Mexico is urgently needed to guide potential management decisions associated with conventional energy, renewable energy, and marine minerals in response to the 2019 Presidential Memorandum’s (PM) Section 2 National Strategy on Ocean Mapping, Exploring and Characterizing the U.S. Exclusive Economic Zone (NOMEC). The findings from this project will contribute to our understanding of ecosystem status and connectivity in the Gulf of Mexico since the DWH oil spill, the processes that shape these environments, and the long-term impacts of disturbances on these habitats.
- Science
Connectivity of Coral Ecosystems in the Northwestern Gulf of Mexico
Connectivity among coral communities influences the probability of speciation and contributes to their ability to adapt to natural and anthropogenic stressors. Results from this study will enhance our understanding of Gulf of Mexcio ecosystems with regional conservation initiatives to inform the restoration of degraded deepwater coral communities and preserve long-term viability of coastal...USGS DISCOVRE: Benthic Ecology, Trophodynamics, and Ecosystem Connectivity – Lophelia II: Continuing Ecological Research on Deep-Sea Corals and Deep Reef Habitats in the Gulf of Mexico
Deep-sea coral habitats are complex ecosystems at the landscape and local level. While these systems may harbor substantial levels of biodiversity, they remain inadequately investigated. - Publications
Quantifying changes to infaunal communities associated with several deep-sea coral habitats in the Gulf of Mexico and their potential recovery from the DWH oil spill
Extensive information is available about infaunal soft-sediment communities in the Gulf of Mexico (Gulf) (Pequegnat et al. 1990, Rowe and Kennicutt II 2009, Wei et al. 2010), particularly from the large-scale sampling effort of the Deep Gulf of Mexico Benthos (DGOMB) project in the early 2000s (Rowe and Kennicutt II 2009). Infaunal soft-sediment communities in the northern Gulf differ by geographiAuthorsJill R. Bourque, Amanda W.J. DemopoulosGrowth rates and ages of deep-sea corals impacted by the Deepwater Horizon oil spill
The impact of the April 2010 Deepwater Horizon (DWH) spill on deep-sea coral communities in the Gulf of Mexico (GoM) is still under investigation, as is the potential for these communities to recover. Impacts from the spill include observation of corals covered with flocculent material, with bare skeleton, excessive mucous production, sloughing tissue, and subsequent colonization of damaged areasAuthorsNancy G. Prouty, Charles R. Fisher, Amanda W.J. Demopoulos, Ellen R. M. DruffelCoral communities as indicators of ecosystem-level impacts of the Deepwater Horizon spill
The Macondo oil spill released massive quantities of oil and gas from a depth of 1500 meters. Although a buoyant plume carried released hydrocarbons to the sea surface, as much as half stayed in the water column and much of that in the deep sea. After the hydrocarbons reached the surface, weathering processes, burning, and the use of a dispersant caused hydrocarbon-rich marine snow to sink into thAuthorsCharles R. Fisher, Amanda W.J. Demopoulos, Erik E. Cordes, Iliana B. Baums, Helen K. White, Jill R. BourqueImpact of the Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico
To assess the potential impact of the Deepwater Horizon oil spill on offshore ecosystems, 11 sites hosting deep-water coral communities were examined 3 to 4 mo after the well was capped. Healthy coral communities were observed at all sites >20 km from the Macondo well, including seven sites previously visited in September 2009, where the corals and communities appeared unchanged. However, at one sAuthorsHelen K. White, Pen-Yuan Hsing, Walter Cho, Timothy M. Shank, Erik E. Cordes, Andrea M. Quattrini, Robert K. Nelson, Richard Camilli, Amanda W.J. Demopoulos, Christopher R. German, James M. Brooks, Harry H. Roberts, William Shedd, Christopher M. Reddy, Charles R. Fisher