Date: September 2, 2019
Location: Lat: 40.90572°, Lon: -66.50047°
Dive Depth Range: 535 - 754 meters (1,756 - 2,475 feet)
Today we dove on the southern wall of an unnamed minor canyon north of Kinlan Canyon. Major shelf-incised canyons in this region have received a fair amount of attention in terms of exploration; however, minor slope canyons like the one targeted during this dive remain mostly unexplored. The planned dive track was designed to cross the canyon axis in order to assess the geologically recent sediment transport history of the canyon, as well as the benthic communities of the area.
The remotely operated vehicle (ROV) reached the seafloor near the northern wall on the canyon, where the current was relatively swift. The floor of the canyon was predominantly soft sediment, with a similar biological assemblage as that observed at the Dive 03 site, composed of quill worms, lantern sharks, schools of fin squid, and deep-sea red crabs. Several clumps of Lophelia pertusa skeleton were observed in the bottom of the canyon with sediment displaced around them, suggesting that they fell off the northern canyon wall, but no living specimens were observed. As we traveled across the canyon axis, we observed abundant evidence of slope failure in the form of large boulders, which hosted sponges, cup corals, plexaurid corals, and Venus flytrap anemones. Upon reaching the southern wall of the canyon, we discovered sheer walls of sandstone and limestone heavily encrusted with corals, sponges, and other invertebrates. We documented three large specimens of Atlantic Halibut, an endangered species. The planned ascent up the southern canyon wall was halted to evade a suspended fishing line, and we also found other evidence of fishing gear along the bottom. Shortly after beginning our ascent along the wall, the canyon wall abruptly transitioned to a more mildly sloping, fine sediment environment, similar to the Northeast Channel dive site.