Equinor cold-water coral surveys on the Norwegian continental shelf

As part of regular environmental monitoring, Equinor performs cold-water coral surveys on the Norwegian continental shelf (NCS). Cold-water corals are key species in the marine environment that are known to form two important habitat types: coral reefs and coral gardens. On the NCS, the coral reefs are predominantly made up of the scleractinian coral Desmophyllum pertusum (formerly known as Lophelia pertusa), whereas the coral gardens consist of several soft coral species (gorgonians) grouped together. Both coral reefs and gardens are covered by Equinor’s surveys. The coral surveys are performed using visual ROV inspection according to the Handbook of Species and Habitats of Environmental Concern (offshorenorge.no). The surveyed coral locations are provided as georeferenced polygons that may be plotted in any GIS application. For each surveyed location, the corals are evaluated based on coverage and health. For coral reefs, the approximate living area (m2) and living coral coverage (%) are reported along with a corresponding health classification (poor, fair, good or excellent). For coral gardens, the number of specimens per 25 m2 is reported along with a health classification equivalent to that of coral reefs. Note that both reefs and gardens often are present at the same location.