Joint Canada-USA International Seamount Survey update for 2023

In 2022, Canada and the USA conducted a survey of five seamounts in the Cobb Seamount chain using an underwater stereo camera system. Oceanographic data, eDNA and bird and mammal observations were also collected. This joint survey was designed to study deep-sea coral and sponges and their associated taxa. In total 77 camera transects were completed, with a high proportion of them observing glass sponges and corals, particularly those transects below 600 m. Species distribution models were developed predicting both presence and abundance of coral and sponge taxa. Densities of sponges and corals were relatively low and appeared to be related to the oceanographic and geological conditions at the sites. The sizes of sponges and corals were generally large indicating a mature community. The fish fauna was dominated by rockfishes and pleuronectids that are found in the adjacent shelf and slope ecosystems. The communities appeared to be largely organized by depth. Evidence of both historical and present day fishing activity was observed on most of the seamounts. Comparisons were made with shelf and slope systems around the Gulf of Alaska to gauge the uniqueness of the seamount ecosystems. Analysis of the data and samples collected during this survey is ongoing. The data collected during this survey will be useful for the regional fisheries management organization responsible for assessing the risks and sustainability of the Canadian sablefish fishery conducted at these seamounts. The most updated information on the survey results can be found in the figures attached to this document that were presented at the annual PICES Meeting in Seattle, WA, USA in October 2023.