Habitat suitability modeling to predict the spatial distribution of cold-water coral communities affected by the Deepwater Horizon oil spill

Aim: The Deepwater Horizon disaster resulted in the largest accidental
marine oil spill in history and caused extensive injury to deep-sea
habitats, including cold-water coral communities dominated by Paramuricea
species. One of the primary difficulties in assessing the full extent of
the injury to cold-water coral ecosystems is the extreme paucity of
observational data and the subsequent lack of knowledge of their
distribution within the affected region. The aim of this study was to use
habitat suitability modeling to estimate the number of potentially
affected Paramuricea sp. corals across the northern Gulf of Mexico.
Location: Northern Gulf of Mexico Taxon: Cold-water corals in the genus
Paramuricea Methods: High-resolution (12.5 m) models were built using the
maximum entropy (Maxent) approach using remotely sensed data including
seafloor topography, seismic reflectivity, temperature, and the amount of
productivity exported from the surface. Model outputs were used to
estimate the number of potential coral sites in the northern Gulf of
Mexico, delineated as areas with both high habitat suitability scores and
the presence of hard substrate. The number of coral sites was further
adjusted using a ground-truthing procedure using autonomous underwater
vehicle transect data. Results: Across the entire study area in the
northern Gulf of Mexico, there were 558 predicted coral sites, covering an
area of 14.2 km2. Within a 2,291 km2 region shown to have been directly
affected by the spill and subsequent oil plume, there were 66 predicted
coral sites covering an area of 1.2 km2 with an average of 63 corals per
site. Main Conclusions: Our results indicate that the magnitude of injury
stemming from the spill was likely far higher than previously known, and
will help quantify the full extent of the losses incurred as well as
prioritize disturbed areas for future research and restoration efforts.