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.

Zooplankton samples were collected onboard the research Icebreaker CCGS Amundsen during Leg 1 in 2005 (4 stations) and Leg 1 in 2006 (8 stations) with a vertically towed net frame equipped with a set of 4 adjacent 1-m2 nets (mesh size 200 µm and 500 µm) from near the bottom to the surface and by trawling an oblique rectangular mid-water trawl (mesh size 1600 µm) or an oblique Tucker net (mesh size 2x500 µm) in the surface layer from 100 m depth to the surface. Samples were placed into 30 ml plastic vials and/or whirl-pak bags and were kept frozen at -20 degree Celsius. Representative sub-samples of individual zooplankton genera were placed in 4 ml glass vials for stable isotope analysis. Three keystone zooplankton genus were included in this study: Calanus spp. (mostly adult Calanus hyperboreus), Themisto spp. (mostly adult Themisto libellula) and Euchaeta spp. THg analysis was conducted at the Freshwater Institute with cold vapour atomic absorption spectroscopy (CVAAS). MMHg analysis was conducted at the University of Ottawa by Gas Chromatography Atomic Fluorescence Spectroscopy (GCAFS). Carbon and nitrogen isotopic analyses were performed at the University of Winnipeg Isotope Laboratory by continuous flow ion ratio mass spectrometry (CF-IRMS). Oceanographic data (Hg levels in water column, salinity, 18O) were collected by our team. Water samples were collected with 24 12-L Niskin bottles attached to a rosette sampler equipped with Seabird 911+ CTD (Sea-Bird Electronics, Inc.).

Zooplankton samples were collected onboard the research Icebreaker CCGS Amundsen during Leg 1 in 2005 (4 stations) and Leg 1 in 2006 (8 stations) with a vertically towed net frame equipped with a set of 4 adjacent 1-m2 nets (mesh size 200 µm and 500 µm) from near the bottom to the surface and by trawling an oblique rectangular mid-water trawl (mesh size 1600 µm) or an oblique Tucker net (mesh size 2x500 µm) in the surface layer from 100 m depth to the surface. Samples were placed into 30 ml plastic vials and/or whirl-pak bags and were kept frozen at -20 Degree Celcius. Representative sub-samples of individual zooplankton genera were placed in 4 ml glass vials for stable isotope analysis. Three keystone zooplankton genus were included in this study: Calanus spp. (mostly adult Calanus hyperboreus), Themisto spp. (mostly adult Themisto libellula) and Euchaeta spp. THg analysis was conducted at the Freshwater Institute with cold vapour atomic absorption spectroscopy (CVAAS). MMHg analysis was conducted at the University of Ottawa by Gas Chromatography Atomic Fluorescence Spectroscopy (GCAFS). Carbon and nitrogen isotopic analyses were performed at the University of Winnipeg Isotope Laboratory by continuous flow ion ratio mass spectrometry (CF-IRMS). Oceanographic data (Hg levels in water column, salinity, 18O) were collected by our team. Water samples were collected with 24 12-L Niskin bottles attached to a rosette sampler equipped with Seabird 911+ CTD (Sea-Bird)

The database consists of hourly atmospheric DMS concentrations, daily SO2 and total sulfate concentrations and three-day concentrations of size segregated aerosol sulfate. Samples were taken on the top of the navigation bridge of the CCGS Amundsen as it cruised along Baffin Bay and the Northwest Passage. Hourly samples of DMS was obtained using a customized DMS sampler. Samples were analyzed using a gas chromatograph fitted with a sulfur chemiluminesence detector (GC-SCD) to obtain atmospheric DMS concentrations. SO2 and total aerosol samples were obtained daily using a high volume sampler fitted with a quartz microfiber filter and K2CO3 treated cellulouse filter. Size segragated aerosol samples were obtained using a highvolume sampler fitted with slotted quartz filters on a 5 stage cascade impactor run for three days each sample. Concentrations of SO2, sulfate and MSA as well as other ions from the filter papers were obtained using ion chromatography. Delta34S values of SO2 and sulfate were obtained using a continuous flow isotope ratio mass spectrometer. Delta34S is reported based on the Vienna Canyon Diablo Troillite (V-CDT) international standard.

The study area extends from the North Water Polynya to the Chukchi Sea across five geographic regions: North Water Polynya, Canadian Archipelago, Amundsen Gulf, Beaufort Sea and Chukchi Sea (14 stations). We collected data from July to October 2014 aboard the CCGS Amundsen including environmental data (bottom water temperature and salinity), particulate organic matter, sediments, and benthos. Stable isotopes analyses were practiced on benthic samples, particulate organic matter samples and sediments samples. Lipid extraction and ice algae biomarker analysis were practiced on benthic samples and sediments samples.

Zooplankton (Calanus sp., Limacina helacina, Euphasiacea, Clione limacina, Themisto sp., Paraeuchaeta sp, Hyperoche sp. and Sagitta sp.) were collected in net tows during 2003 & 2004 (onboard the CCGS Pierre Radisson and Des Groseillers) and 2005 & 2010 (onboard the CCGS Amundsen). After taxonomical sorting, samples were frozen for chemical analysis. Total mercury (THg) analysis was conducted at the Freshwater Institute, Winnipeg (DFO) using cold vapor atomic absorpotion spectrometry; monomethylmercury (MMHg) was analyzed at the University of Ottawa using gas chromatography atomic fluorescence spectroscopy; stable isotope ratios of nitrogen and carbon were run at the University of Winnipeg Isotope Laboratory using continuous flow ion ratio mass spectrometry.

Bottom water (20 L per station) was collected at 11 stations in Baffin Bay using the CCGS Amundsen’s rosette system. Water was filtered aboard the vessel into glass microfiber (GF-F) filters for Carbon and Nitrogen stable isotopic composition analysis. These data will be used in combination with data on soft coral stable isotopic composition collected from the same region.

The database consists of hourly atmospheric DMS concentration, daily SO2 and total sulfate concentrations and three-day concentrations of size segregated aerosol sulfate. Samples were taken on the top of the navigation bridge of the CCGS Amundsen as it cruised along Baffin Bay and Lancaster Sound. Hourly samples of dimethyl sulfide was obtained using a customized DMS sampler. Samples were analyzed using a gas chromatograph fitted with a sulfur chemiluminesence detector (GC-SCD) to obtain atmospheric DMS concentrations. SO2 and total aerosol samples were obtained daily using a high volume sampler fitted with a quartz microfiber filter and K2CO3 treated cellulouse filter. Size segragated aerosol samples were obtained using a highvolume sampler fitted with slotted quartz filters on a 5 stage cascade impactor run for three days each sample. Concentrations of SO2, sulfate and MSA as well as other ions from the filter papers were obtained using ion chromatography. Delta34S values of SO2 and sulfate were obtained using a continuous flow isotope ratio mass spectrometer. Delta34S is reported based on the Vienna Canyon Diablo Troillite (V-CDT) international standard.

Coral samples were collected in Pond Inlet and Lancaster Sound in Baffin Bay using the CCGS Amundsen’s remotely operated vehicle (ROV). Samples from Agassiz trawl and box-core deployments were also kept as part of this study (11 stations). Samples were collected between 253 and 856 m. Specimens were subsampled aboard and frozen for determination of their carbon and nitrogen stable isotopic composition, as well as for lipids and fatty acids composition, as part of a study focusing on the trophic ecology of cold-water corals. Carbon and Nitrogen stable isotope analysis as well as lipids/fatty acids analysis were performed on tissue samples of soft corals at the Stable Isotopes Laboratory and Lipids Laboratory, Memorial University, respectively.

A remotely operated vehicle (ROV) video survey was conducted at the Saglek Bank location, at a depth of ~500 m in July 2018. The primary purpose of this ROV dive was the geological and biological site characterization across depths, and sampling of dead coral skeletons, live corals for stable isotopes and lipids, and sponges for stable isotopes. Bottom type was mainly sandy gravelly bottom. Small sponges and soft corals (Family Nephtheidae) were abundant at this site (probably Geodia spp.). Other corals observed include red mushroom corals (Family Alcyoniidae, likely Anthomastus sp.), Primnoa resedaeformis (live and dead – skeletons). Primnoa resedaeformis colonies were mostly small, and abundant at certain parts of the dive. No sampling was possible during this dive due to a mix of strong currents and ROV issues.