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.

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 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 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.

Samples were collected at two sites in the Eastern Canadian Arctic (Figure 1) aboard the scientific icebreaker CCGS Amundsen. The sampling positions at biogenic and non-biogenic habitats were defined during ROV video surveys at the two sites (Figure 2a-d). Positions were carefully selected to avoid overlap between the two types of habitats (i.e., when most of the camera’s field of view was dominated by a single habitat over the course of approximatively 5 meters). At each site, we deployed two box cores (0.5 × 0.5 m) per habitat (i.e., inside the biogenic structures and in the bare sediment; Figure 2e) approximately 200 m apart in FB site and 500 m apart in BB site. From each box core, we collected three sediment cores (i.d = 9.8 cm, H = 30 cm) for a total of six cores per habitat and 12 cores per site. Sediment cores sampled in biogenic structures habitats were visually exempted from biogenic structures. Bottom (10 m above the seafloor) temperature, salinity and oxygen saturation at each site were recorded with a conductivity-temperature-depth (CTD) probe. Sediment cores were incubated in the dark at a temperature-controlled room (2-4°C) until a maximum of 20% of available oxygen was consumed. Sediment samples for chlorophyll a, phaeopigments and sediment properties were also collected from each box core. sediment cores were sieved through a 500 µm mesh sieve to collect infauna. Organisms were fixed with 4% formaldehyde solution. They were sorted under a dissecting microscope in the laboratory and identified to the lowest possible taxonomic level.

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.

Samples were collected at 5 sites ranging in water depth from 100 to 595 m at least once in each season (ice-covered and open-water condition) between March and August 2008 onboard the icebreaker CCGS Amundsen. At each sampling station, an USNEL box corer was deployed for collecting seafloor sediments. From each box core, 5 sub-cores of 11 cm diameter and 20 cm sediment depth were taken for assessing benthic carbon remineralisation in microcosm incubations and 3 additional subcores of 5 cm diameter and 10 cm length were taken for determining sediment properties. Incubations of sediment microcosms were run in a dark, temperature-controlled room (2-4 °C) for 24-48 h. Each sediment microcosm was sieved through a 0.5 mm mesh under running sea water at the end of incubations to determine biomass of macrofaunal communities. The sieve residue was preserved in a buffered 4% seawater-formaldehyde solution and analysed for species composition and abundance under a stereomicroscope in the lab.

A benthic survey using a Super Mohawk remotely operated vehicle (ROV) was conducted in July 2017 at Disko Fan, SE Baffin Bay. The benthic environment was video-recorded and opportunistically photographed using a high-definition camera (1Cam Alpha, Sub C Imaging, 24.1 megapixels), at a water depth of ~930 m. An experimental frame deployed in 2016 was recovered during this ROV dive, but no other collections took place at this site during this dive.

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.

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.