Date: September 1, 2019
Location: Lat: 41.98381°, Lon: -65.37541°
Dive Depth Range: 975 - 1,494 meters (3,201 - 4,905 feet)
We had a successful dive in the Northeast Channel today, our fourth dive of the Deep Connections 2019 expedition and our last in Canadian waters. This dive site was located near the southern boundary of the Fundian Channel and Browns Bank, in an area of interest to our partners at Fisheries and Oceans Canada due to the dense aggregations of deep-sea gorgonian corals and sponges that have been documented during previous explorations of this area. The purpose of our dive was to characterize the deep-sea benthic communities in an unexplored area of the Northeast Channel in order to provide information to support resource management. Furthermore, we sought to investigate the geological origin of the site, which is thought to be composed of glacial trough mouth fan materials.
The remotely operated vehicle (ROV) reached the seafloor on a relatively flat, soft substrate adjacent to the submarine plateau slope, which was inhabited by bamboo corals, sabellid polycheate tube worms, xenophyphores, halosaurs, and lantern sharks. As we moved up the slope, the bottom transitioned from fine sediment to a fine-grained mantle interspersed with cobbles. The benthic community also shifted with slope and substrate, and we began to see more soft corals and small sponges. When the ROV reached the crest of the plateau, the community shifted back to that seen in the submarine channel axis at the start of the dive. Samples collected during this dive included a glass sponge, a demosponge, and a bubblegum coral (Paragoria sp.).