2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts

Dive 17: Gosnold Seamount (Shallow)

Date: July 24, 2021
Location: Lat: 38.293979°, Lon: -62.533148°
Dive depth range: 1,714 - 1,783 meters (5,623 - 5,850 feet)

At a depth of approximately 1,700 meters (5,577 feet), Dive 17 of the 2021 North Atlantic Stepping Stones expedition was one of the shallowest dives we conducted, and we were not disappointed by the diversity and density of life we encountered. Corals in particular were well represented, with many species of large corals growing on larger ferromanganese nodules. Video courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download largest version (mp4, 79 MB).

During Dive 17 of the 2021 North Atlantic Stepping Stones, we saw several Paragorgia bubblegum corals with encrusting zoanthids (in yellow in this image). Coral diversity was high throughout the dive, and we encountered black corals (Bathypathes, Stauropathes, Leiopathes, Telopathes, and Parantipathes); bamboo corals (several species of Keratoisidae and Acanella); octocorals (Paragorgia, Metallogorgia, Iridigorgia, Clavularia rudis, Anthomastus, Hemicorallium, and Chrysogorgia); and the scleractinian, Enallopsammia rostrata.

During Dive 17 of the 2021 North Atlantic Stepping Stones, we saw several Paragorgia bubblegum corals with encrusting zoanthids (in yellow in this image). Coral diversity was high throughout the dive, and we encountered black corals (Bathypathes, Stauropathes, Leiopathes, Telopathes, and Parantipathes); bamboo corals (several species of Keratoisidae and Acanella); octocorals (Paragorgia, Metallogorgia, Iridigorgia, Clavularia rudis, Anthomastus, Hemicorallium, and Chrysogorgia); and the scleractinian, Enallopsammia rostrata. Image courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download largest version (jpg, 1.2 MB).

Dive 17 of the 2021 North Atlantic Stepping Stones expedition took place on Gosnold Seamount. This was the second dive of the expedition on Gosnold, this one taking place at a much shallower depth, on the summit plateau at the northwest end of the seamount.

Much like Dive 16 on Gosnold Seamount, upon arrival to the seafloor, we found abundant ferromanganese nodules as well as seafloor extensively modified by high currents that seem to have been persistent in the region for some time. Diversity and density of biological communities were high throughout most of the dive, with many species of large corals growing on larger ferromanganese nodules and a wide range of sponges, brittle stars, stalked crinoids, and large sea stars were observed as well. Pelagic gelatinous animals were present throughout the dive, which, combined with the high benthic biodiversity, suggests this is potentially a highly productive area.

Remotely operated vehicle Deep Discoverer traverses over an extensive field of ferromanganese nodules that formed the bulk of the hard seafloor substrate for much of Dive 17 of the 2021 North Atlantic Stepping Stones expedition.

Remotely operated vehicle Deep Discoverer traverses over an extensive field of ferromanganese nodules that formed the bulk of the hard seafloor substrate for much of Dive 17 of the 2021 North Atlantic Stepping Stones expedition. Image courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download largest version (jpg, 649 KB).

This chimaera rabbit fish paid us a visit during Dive 17 of the 2021 North Atlantic Stepping Stones expedition, at a depth of 1,725 meters (5,659 feet).

This chimaera rabbit fish paid us a visit during Dive 17 of the 2021 North Atlantic Stepping Stones expedition, at a depth of 1,725 meters (5,659 feet). Image courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download largest version (jpg, 1.2 MB).

A purple sea cucumber seen on the seafloor surrounded by brittle stars. We observed several of these large stands of brittle stars covering rocks and nodules during Dive 17 of the 2021 North Atlantic Stepping Stones expedition.

A purple sea cucumber seen on the seafloor surrounded by brittle stars. We observed several of these large stands of brittle stars covering rocks and nodules during Dive 17 of the 2021 North Atlantic Stepping Stones expedition. Image courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download largest version (jpg, 1.6 MB).

During Dive 17 of the 2021 North Atlantic Stepping Stones, on the summit plateau of Gosnold Seamount, we encountered these alternating wide patches of ripple-ornamented sediment with pteropod tests and ferromanganese chips accumulating on the side of the ripple facing the current and pavement with ferromanganese-coated cobbles, boulders, and nodules.

During Dive 17 of the 2021 North Atlantic Stepping Stones, on the summit plateau of Gosnold Seamount, we encountered these alternating wide patches of ripple-ornamented sediment with pteropod tests and ferromanganese chips accumulating on the side of the ripple facing the current and pavement with ferromanganese-coated cobbles, boulders, and nodules. Image courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download largest version (jpg, 1.3 MB).


Location of Dive 17 of the 2021 North Atlantic Stepping Stones expedition on July 24, 2021.

Location of Dive 17 of the 2021 North Atlantic Stepping Stones expedition on July 24, 2021. Map courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download largest version (jpg, 3 MB).

Image showing the dive track of Dive 17 of the 2021 North Atlantic Stepping Stones expedition. Scale is water depth in meters.

Image showing the dive track of Dive 17 of the 2021 North Atlantic Stepping Stones expedition. Scale is water depth in meters. Image courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download largest version (jpg, 533 KB).