Here, we sampled five specimens of Chondrocladia and Cladorhiza as part of the Hidden Biodiversity project, using the SuperMohawk ROV on board the CCGS Amundsen. In October 2015, samples were collected from Scott Inlet and off Qikiqtarjuaq, and retrieved using a custom-built sample elevator. Samples were immediately dissected and processed for DNA and histological analyses. The analysis of these samples is currently in progress.

A video-survey using a Super Mohawk remotely operated vehicle (ROV) was conducted in October 2015 in a site near Cape Dyer, Nunavut. The benthic environment was video-recorded and opportunistically photographed using a high-definition camera (1Cam Alpha, Sub C Imaging, 24.1 megapixels), at a depth of ~750 m along a transect line 935 m long.

A video-survey using a Super Mohawk remotely operated vehicle (ROV) was conducted in October 2015 near Qikiqtarjuaq, Nunavut. The benthic environment was video-recorded and opportunistically photographed using a high-definition camera (1Cam Alpha, Sub C Imaging, 24.1 megapixels), at a depth of ~620-680 m along a transect line 954m long.

A first survey was conducted in and around EL446 onboard the CCGS Amundsen from 16 July to 30 July, 2009. A total of 21 biophysical stations were sampled, involving 25 box core deployments and 18 Agassiz trawl tows. In addition, the Remotely Operated Vehicle (ROV) was deployed once (station 10) for epibenthos observation. A second survey was conducted in EL449 and EL451 onboard the CCGS Amundsen from 12 August to 26 August, 2010. A total of 18 biophysical stations were sampled, comprising 25 box core deployments and 18 Agassiz trawl tows. A third survey was conducted in EL451 and EL453 onboard the CCGS Amundsen from 7 September to 22 September 2011. A total of 13 biophysical stations were sampled, comprising 18 box core deployments and 13 Agassiz trawl tows. The box core was deployed to quantitatively sample diversity and abundance of endobenthic organisms. After retrieval of the box core, a subsample of about 0.125 m2 area and 12-15 cm depth was collected and passed through a 0.5 mm mesh sieve to separate sediment from endofauna. Organisms were immediately preserved in a 4% buffered formaldehyde solution for further taxonomical identification in the laboratory. The volume of sediments sieved from each box core was measured (depth × width × length) to the nearest 1 cm to estimate endobenthic fauna density in each sample. An Agassiz trawl (1.5 m width × 0.7 m height, cod end of 0.5 cm mesh size) was towed on the seabed at a speed of 1.5 - 2 knots for about 3 to 5 minutes to survey epibenthic species diversity and abundance. Retrieved samples were washed with seawater in a sieve (0.5 mm mesh), and organisms were counted and identified to the lowest taxonomical level possible.

Video surveys were conducted in July 2016 aboard CCGS Amundsen, using a Super Mohawk remotely operated vehicle (ROV) at Hatton Basin, Labrador (Canada). ROV dives occurred at two nearby sites (~28 km apart) in the Hatton Basin area (Dives 50 and 51). The benthic environment was video-recorded and photographed using a high-definition camera (1Cam Alpha, Sub C Imaging, 24.1 megapixels) mounted on the ROV, at depths ranging between 556-633 m. ROV transects were conducted to collect video data, and samples of corals and sponges were also collected during dive 51. Box-cores were deployed at the two sites. Sea water was collected at several depth intervals from surface to near-bottom to characterize particulate organic matter and to determine calcium carbonate saturation.

A video-survey using a Super Mohawk remotely operated vehicle (ROV) was conducted in October 2015 at Inner Frobisher Bay, Nunavut. The benthic environment was video-recorded and opportunistically photographed using a high-definition camera (1Cam Alpha, Sub C Imaging, 24.1 megapixels), at a depth of ~59-139 m along a transect line 1.2 km long.

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.

A video-survey using a Super Mohawk remotely operated vehicle (ROV) was conducted in August 2013 in the Disko Fan area, SE Baffin Bay. A multibeam survey was conducted in the area before the ROV dive. The benthic environment was video-recorded using a standard-definition color camera, at depths of ~900-950 m.

The dataset is composed of Ichthyoplankton and zooplankton captured during the ArcticNet cruise aboard the CCGS Amundsen from 2017 to 2019. Three samplers fitted with 200 µm to 500 µm mesh nets were used for zooplankton collection . One was a metallic structure with 4 nets of 1 square meter opening each (2x2 multiple net sampler) for water column integrated sampling pulled vertically over from 10 m above the bottom to the surface to catch mesozooplankton. The other sampler was 2 nets of 1 square meter opening each towed at 10 m depth for 20 minutes at 2 knots to catch ichthyoplankton and macrozooplankton. Finally, a 0.5 square meter opening multinet Hydrobios for stratified sampling into nine layer also hauled vertically from 10 m above the sea bottom to the surface. Zooplankton samples were preserved in a 10% buffered formalin seawater solution and were sieved through 1000 µm and 200 µm sieves for analysis. Ichthyoplankton was identified to the lowest taxonomic level possible, a sub-sample was measured and all larvea were kept in ethanol.

The dataset is composed of adult fish species captured during the ArcticNet cruise aboard the CCGS Amundsen from 2017 to 2019. Pelagic fish were caught with an Isaacs-Kidd Midwater Trawl (IKMT, 9-m2 rectangular mouth aperture with mesh sizes of 11 mm in the first section and 5 mm in the last section). It was deployed from the surface to depths targeting possible aggregation of fish as recorded by the acoustic echosounder from the ship. Demersal and benthic fish were sampled with a bottom beam trawl (3-m2 rectangular aperture with a headline and a footrope of 4.27 m and a cod-end mesh of 9.5 mm) deployed on the seafloor. The pelagic and bottom trawls were towed at ~3 knots for 10 to 20 min. All fish collected by the trawls were measured and identified at least to the family level before freezing at -20°C.