Benthic grab samples and underwater towed video samples were collected at long-term ecology sites while onboard the Government of Nunavut vessel MV Nulialjuk and CCGS Amundsen in July and October 2016. On-board the MV Nulialjuk, benthic grab samples (triplicate samples) and underwater towed video samples were collected at 5 long-term ecology stations near Iqaluit. An additional 7 benthic grab samples (triplicate samples) and towed video samples were collected near Cairn Island. On-board the CCGS Amundsen, benthic grab samples were collected at two long-term ecology stations (triplicate samples) near Cairn Island. Sampling gear included a Van Veen grab sampler, box core, and HD GoPro video system. Initial observations suggest that these stations are predominantly muddy sand with some larger cobbles present. Towed video analysis and benthic grab samples indicate the presence of the algae Laminaria sp. and Agarum clathratum and bivalves Mya truncata, Yoldia hyperborea, Clinocardium ciliatum, and Serripes groenlandicus. Ophiuroid echinoderms and tubiculous polychaete worms and tubes are abundant. Once all benthic grab samples and towed video samples are processed, this data will be compared with the historic sample data to answer questions about the nature of long-term change of the benthos at this region in inner Frobisher Bay.

In 2017 and 2018, we sampled about 20 locations across Frobisher Bay, mostly in the deeper portions of outer Frobisher Bay that are only accessible for sampling from large ships. Sample stations were chosen to span the range of depth and slope values in the multibeam sonar dataset, and in 2018 sampling, also included gross bottom morphology, such as ridges and troughs. We also targeted some particular geomorphic features, such as suspected submarine extensions of moraines. In 2017, bottom samples were acquired using box-cores, and small scientific trawl (Agassiz trawl). In 2018, bottom samples were acquired using box-cores, combined with a drop-video camera. Agassiz trawls were collected at two stations in 2018. Sediment samples were described visually and subsamples frozen for grain size and organic content analysis. Where informative, subsamples of lithic fragments within the sediments were kept for mapping. Bottom faunal samples were enumerated and preserved in 2% formalin in seawater, except for larger faunal samples such as soft corals, which were frozen.

The data set includes images of seafloor topography of the Canadian Beaufort Sea, rendered in both grey-scale and colour-shaded false sun-illumination collected by the Geological Survey of Canada (Atlantic and Pacific) through the support of several organizations. The images are derived from soundings from a hull-mounted multibeam sonar system. Two research vessels were involved in its collection. The Canadian Coast Guard vessel CCGS Amundsen conducted 3 successive research-oriented field surveys, from 2009 to 2011 using a Knudsen EM302 multibeam instrument. Between September 10th and October 10th, 2013, the Korean Oceanographic Polar Research Institute (KOPRI) research icebreaker Araon surveyed with an EM122 system. The Amundsen data represent an integration of the 3 successive field surveys, data collection was a part of collaboration between oil and gas industry partners (Imperial Oil Resources/British Petroleum), the GSC-A, and ArcticNet. Collaborators from the University of New Brunswick's Ocean Mapping Group have operated the Amundsen's compliment of geophysical equipment for the past several years, extending into the 2011 Expedition. The GSC-A conducted initial and post analysis of the acquired data. The KOPRI dataset stems from collaboration with the GSC-P. Vertical sound speed profiles were obtained from CTD casting stations and these velocities were applied to the acquisition system for correct depth calculations. Geologic features in the image include large and smaller submarine landslides with associated cliffs, faults, translational blocks, retrogressive failure, debrites and evacuation chutes. Sediment cover and areas devoid of cover together with cross-cutting relationships indicate a range in age and process. Other features include mud volcanoes indicating past and recent efflux of mud and fluids to the seabed on the upper slope, iceberg, sea-ice and floating glacier-driven seabed scour, influence by currents and/or past sea-level which limited and locally removed shelf-break glacial and post-glacial muds, incision of shelf-break canyons with differential sediment infill, seabed current-influenced distribution of recent muds derived ultimately from the Mackenzie River, influence on recent distribution of shelf-break muds by the Beaufort Jet, and finally structural disturbance of outermost shelf muds, probably related to degradation of permafrost and fluid migrations, forming mounds, collapses and associated basins.

Agassiz trawl was deployed from the CCGS Amundsen to collect macrofauna. Catches were passed through a 2 mm mesh sieve. When possible, specimens were identified to the lowest taxonomic level, then count and weight. The unidentified specimens were preserved in a 4% seawater-formalin solution. Box corer was deployed to quantitatively sample diversity, abundance and biomass of infauna and to sample sediment. Sediments of a surface area of 0.125 m2 and 10-15 cm in depth were collected and sieved through a 0.5 mm mesh and preserved in a 4% formaldehyde solution for further identification in the laboratory. Sub-cores of sediments were collected for sediment pigment content, organic matter, sediment grain size, porosity; for sediment pigments, the top 1 cm was collected, although for sediment grain size, the top 5 cm was collected. Sediment pigment samples were frozen at -80°C, and porosity, organic matter and sediment grain size samples were frozen at -20°C.