Sample collection: The sampling was part of the Canadian Arctic Shelf Exchange Study (CASES) in which CCGS Amundsen was frozen in Franklin Bay in the coastal Beaufort Sea (Station FB/200) during winter. Upper mixed-layer microbial plankton communities were sampled 5m below the water surface using the ship CTD rosette system equipped with 12L Niskins during openwater conditions. During the time that the ship was frozen in Franklin Bay from December 2003 to early June 2004, samples were taken using a 5L Niskin bottle from 3m below the bottom ice through a 300mm hole that had been drilled 500m upstream of the ship. HPLC pigment analysis: One to two liter samples of water were filtered onto Whatman GF/F filters and stored frozen at -80C until analysis. Phytoplankton pigments on the GF/Fs were extracted in 3mL of 95 percent MeOH and 100 uL of the extracts was injected into a Varian ProStar HPLC equipped with a Symmetry C8 column. The HPLC peaks were detected by diode-array spectroscopy (350-750nm) and absorbance chromatograms were obtained at 440 (for chls) and 450nm (for carotenoids). Chlorophylls were also detected by fluorescence (excitation: 440nm; emission: 650nm). The HPLC solvent protocol was based on gradient dilution with two solvent mixtures (Zapata et al. 2000): a methanol, acetonitrile, and aqueous pyridine (50:25:25 v:v:v) solution; and a methanol, acetonitrile, and acetone (20:60:20 v:v:v) solution. The flow rate was 1mL/ min, and the equilibration time was 7min.

During the ArcticNet annual cruises of the research icebreaker CCGS Amundsen, characteristics of the near-surface atmosphere (basic meteorological elements, incident radiation, CO2 concentration) are monitored in conjunction with surface sea water properties (temperature, salinity, dissolved CO2 and O2) to observe the relationship between the surface micro-climate and the air-sea exchange, with particular interest in CO2. Central to this integrated dataset, the following meteorological variables were recorded at 1 minute intervals (instrument used to collect each variable is in parentheses, and approximate instrument height above surface is indicated): -Wind speed (RM Young Wind Monitor 05103) - 16m height -Wind direction (RM Young Wind Monitor 05103) -16m height -Air Temperature (Vaisala HMP45C212) - 15m height -Relative Humidity (Vaisala HMP45C212) -15m height -Surface temperature (Everest IR Transducer, 4000.44ZL) - 8m height All instruments were mounted on a meteorological tower on the bow of the research icebreaker CCGS Amundsen.

The Canadian research icebreaker CCGS Amundsen is equipped with an underway ThermoSalinoGraph (TSG) system, which continuously records surface seawater temperature, salinity, fluorescence and sound velocity along the transit route. Quality Assurance/Quality Control (QAQC) data are available for the summer periods between 2005 and 2020, except in 2007, 2008 and 2012 where the system was faulty or the ship was in maintenance. The TSG data were corrected and controlled by comparing them to CTD-Rosette data and in situ measures when available. Outliers and suspicious measurements were removed from the dataset. Variables are provided every 7 minutes. Research programs participating in the Amundsen expeditions between 2005 and 2020 include, ArcticNet, CFL, Geotraces, Malina, IOL and BP, BREA, Weston, Netcare, JAMSTEC, Statoil and iBO, GreenEdge, BAYSYS, Sentinel Nord (BriGHT, BOND), DFO ROV vulnerable marine ecosystem, and the Kitikmeot marine Ecosystem.

Raw data collected using a creative webcam and an acryllic hemispherical mirror dome installed on the roof of the wheelhouse of the CCGS Amundsen. Data were collected from summer to fall 2009 in the Southern Beaufort Sea and Amundsen Gulf areas.

The data set is composed of raw files recorded with the Kongsberg Maritime SX90 long-range, low frequency (20-30 kHz) fisheries sonar during the CCGS Amundsen 2013 summer expedition in the Eastern Canadian Arctic. The sonar transducer is lowered 2.5 feet below the hull through a gate-valve. The cylindrical 256-elements transducer allows both a horizontal and a vertical sound transmission, and the omni-directional (horizontal) sonar beam can be tilted from +10 to -60 degrees to scan a large portion of the water column. The raw acoustic data were saved onto an external drive and print screens of interesting targets (fish schools) were recorded.

During the ArcticNet annual cruises of the research icebreaker CCGS Amundsen, characteristics of the near-surface atmosphere (basic meteorological elements, incident radiation, CO2 concentration) are monitored in conjunction with surface sea water properties (temperature, salinity, dissolved CO2 and O2) to observe the relationship between the surface micro-climate and the air-sea exchange, with particular interest in CO2. As part of this integrated dataset, the following radiation variables were recorded at 1 minute intervals (instrument used to collect each variable is in parentheses): -Incoming shortwave radiation (Eppley pyranometer, model PSP) -Incoming longwave radiation (Eppley pyrgeometer, model PIR) -Incoming photosynthetically active radiation (Kipp & Zonen, PAR-Lite) All instruments were mounted on a platform above the wheelhouse of the CCGS Amundsen

During the ArcticNet annual cruises of the research icebreaker CCGS Amundsen, characteristics of the near-surface atmosphere (basic meteorological elements, incident radiation, CO2 concentration) are monitored in conjunction with surface sea water properties (temperature, salinity, dissolved CO2 and O2) to observe the relationship between the surface micro-climate and the air-sea exchange, with particular interest in CO2. As part of this integrated dataset, the following radiation variables were recorded at 1 minute intervals (instrument used to collect each variable is in parentheses): -Incoming shortwave radiation (Eppley pyranometer, model PSP) -Incoming longwave radiation (Eppley pyrgeometer, model PIR) -Incoming photosynthetically active radiation (Kipp & Zonen, PAR-Lite) All instruments were mounted on a platform above the wheelhouse of the CCGS Amundsen

The Belcher Glacier seabed mapping program was carried out over a 12-hour period in September 2006 and consisted of: 1) imaging of deeper parts of the inlet using the EM300 30 kHz multibeam sonar on the CCGS Amundsen icebreaker; and 2) detailed mapping adjacent to the tidewater front using the 300 kHz multibeam launch CSL Heron. Data files from this mapping project are archived in ASCII, ESRI, and GTIF formats."

A total of 19 stations were sampled between August and October 2011 onboard the Canadian research icebreaker CCGS Amundsen. Two stations were sampled both in August and October to assess seasonal variability in stable isotope composition. At each station, a USNEL box corer (0.25 m2) was deployed to collect seafloor sediments for the determination of stable isotope composition and pigment (Chl a + phaeopigments) concentrations. From each box core, surface sediments (upper 1 cm) were sampled as three sub-cores using a 60 ml disposable syringe (2.6 cm diameter with a cut off anterior end). Sediment samples were immediately frozen at -20 °C for stable isotope analysis and at -80 °C for pigment analysis. Megabenthic invertebrates were principally collected with an Agassiz trawl (effective opening of 1.5 m and a net mesh size of 40 mm, with a 5 mm cod end liner) with average trawling time and speed of 5 min and 1.5 knots, respectively. At three stations, invertebrates were collected with the box corer. Trawl and box corer catches were washed over a 2 mm sieve under running sea water onboard and 1 to 3 individuals of the most abundant community representatives were collected at each station. Specimens were frozen immediately at -80 °C and identified to the lowest possible taxonomic level in the lab.

Floating microplastics in Frobisher Bay were assessed using a surface trawl. Four replicate tows of a Manta surface trawl with 200 micron mesh were carried out at each of two sites in Frobisher Bay from CCGS Amundsen. Four tows near the city of Iqaluit measured microplastics contamination close to that city, likely of local origin. Four tows in outer Frobisher Bay, spread over a wider distance, measured microplastics contamination from the northern Labrador Sea or from ships traversing Frobisher Bay. Samples were frozen following collection, for later processing.