Observations and preliminary findings from the United States/Canada transboundary cruise to the northwestern Atlantic canyons and Gulf of Maine (CROCHET; HB-24-05)

The Cross Border Coral Habitat Exploration (CROCHET) mission, the fourth highly successful transnational collaboration between the United States and Canada, was designed to increase understanding of deep-sea coral habitats as well as species’ distributions, abundances, diversity and habitat use on both sides of the border. From 18–31 July 2024, a team of international scientists investigated deep-sea coral habitats using the Canadian Remotely Operated Vehicle (ROV) ROPOS aboard NOAA Ship Henry Bigelow. Survey sites included submarine canyons, marine protected areas, and the Gulf of Maine. During 10 ROV dives, video footage and digital still images were taken; specimens were collected for taxonomy, isotopes, and genomic analyses. Water samples, collected at depth using Niskin bottles attached to the ROV and a CTD rosette deployed from the ship, were processed for eDNA analysis. Additionally, physiological experiments, image acquisition for photogrammetry, and multibeam mapping were conducted. Preliminary dive summaries are included. Observations and preliminary findings in both the canyons and the Gulf of Maine further demonstrate the importance of ongoing collaborative