There’s a saying that we know more about the moon than we do about the deep sea. It turns out that’s not actually true, but the ocean is still a vast and mysterious place. Around 50 percent of U.S. marine waters are still unmapped and 75 percent worldwide, according to the NOAA. However, a new study published in the scientific journal Geomatics is taking a step to fix that.
The study, entitled “Mapping and Geomorphic Characterization of the Vast Cold-Water Coral Mounds of the Blake Plateau,” combined bathymetric data from 31 multibeam sonar mapping surveys. This was then analyzed in tandem with imagery from 23 submersible dives, collected as part of the coordinated, multi-year ocean exploration. Researchers then created a nearly complete map of the seafloor of the Blake Plateau, an area located about 100 miles off the southeast U.S. coastline. As a result, they were able to create the first ever estimate of the overall number of potential cold-water coral mounds in that region.
What the researchers found was a massive coral province comprised of 83,908 individual coral mound peak features that covered a 6.4 million acre area. The nearly continuous coral mound features span up to 310 miles long and 68 miles wide, with a high-density core area (nicknamed “Million Mounds” by scientists) that covers 2,400 square miles. To put that in perspective, the study states that the province is three times larger than Yellowstone National park and the core area is larger than Grand Canyon National Park or Everglades National Park.
The coral in question is primarily Desmophyllum pertusum, a stony coral found at depths between 200 – 1,000 meters. These corals grow in frigid temperatures with barely any sunlight, surviving by filter-feeding biological particles. They’re known to be important to local ecosystems, but are still poorly understood, due to a lack of ocean mapping and exploration.
“For years we thought much of the Blake Plateau was sparsely inhabited, soft sediment, but after more than 10 years of systematic mapping and exploration, we have revealed one of the largest deep-sea coral reef habitats found to date anywhere in the world,” said Kasey Cantwell, operations chief for NOAA Ocean Exploration. “Past studies have highlighted some coral in the region, particularly closer to the coast and in shallower waters, but until we had a complete map of the region, we didn’t know how extensive this habitat was, nor how many of these coral mounds were connected. This discovery highlights the importance of exploring our deepwater backyard and the power of interagency collaboration and public-private partnerships.”