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.

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 dataset is composed of raw files (.raw) recorded with a SIMRAD EK60 three-frequency (38, 120, 200 kHz) split-beam echosounder that was operated continuously during the ArcticNet cruise aboard the CCGS Amundsen from 2017 to 2019. To ground-truth the hydroacoustic signal, various sampling techniques were applied throughout the cruise track such as midwater and bottom trawling as well as plankton net deployments.

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.).

Microplastics pollution has been found across the globe, but with limited information from the polar regions. Although there is evidence of microplastics in the Arctic and Antarctic, little is understood about the sources, fate and extent of contamination. We collected samples and will quantify the amount and identify the types of microplastics in snow (as a surrogate for air), water, sediments and zooplankton sampled from the CCGS Amundsen in and around the Hudson Bay and/or the central and eastern Canadian Archipelago. In addition, we will answer questions about sources and fate using two types of information. First, we will collaborate with an Indigenous community to quantify and type plastic along their shoreline. Second, we will examine patterns of microplastics contamination and compare them with land-use patterns and water and air circulation. Based on previous studies, and our preliminary findings, we believe that microplastics will be present in Arctic samples, but a detailed study will help us better understand how ubiquitous microplastics are, from where they are derived, and how they are preserved or degraded. Microplastics in the Arctic raise concerns about impacts to wildlife and local communities that rely on food from the sea. Results from this study will inform future experiments that answer questions related to such impacts.

Microplastics pollution has been found across the globe, but with limited information from the polar regions. Although there is evidence of microplastics in the Arctic and Antarctic, little is understood about the sources, fate and extent of contamination. We collected samples and will quantify the amount and identify the types of microplastics in snow, ice, water, sediments and zooplankton sampled from the CCGS Amundsen in and around the Hudson Bay and/or the central and eastern Canadian Archipelago. In addition, we will answer questions about sources and fate using two types of information. We will examine patterns of microplastics contamination and compare them with land-use patterns and water and air circulation. Based on previous studies, and our preliminary findings, we believe that microplastics will be present in Arctic samples, but a detailed study will help us better understand how ubiquitous microplastics are, from where they are derived, and how they are preserved or degraded. Microplastics in the Arctic raise concerns about impacts to wildlife and local communities that rely on food from the sea. Results from this study will inform future experiments that answer questions related to such impacts.

Sampling took place on legs 6, 7, 8b, and 9 of the CFL project on the CCGS Amundsen (2008). Zooplankton were sampled with a 1x1m2 (200 µm mesh) net through the moon-pool and with a 1m diameter (200 µm mesh) ring net on the ice at ice covered stations. In open water, samples were collected with 2x1 sq.m (500 µm mesh), 4x1 sq.m (500 and 200 µm mesh), and rectangular mid-water trawl (1600 µm mesh). Samples were live sorted to species and frozen at -25C. Algae were collected from the bottom ice via ice cores and the dive program, from the ice interface/surface water with a Hg clean Niskin and a hose and pump on a 1m arm, and from the chlorophyll a maximum depth via the rosette. Samples in ice were frozen in the dark, while samples in water were filtered via dual filtration following Morrison and Watras (1999) and filters were frozen at -25C. Zooplankton species Calanus glacialis and Calanus hyperboreus were analyzed for total mercury using CVAAS; C. hyperboreus was also analyzed for methyl mercury via Gas Chromatography Atomic Fluorescence Spectrophotometry (GC AFS). The algae samples were analyzed for THg using cold vapour atomic absorption spectrometry (CVAAS) and MeHg using cold vapour atomic fluorescence spectroscopy (CVAFS).

Air, water (grab and passive) and zooplankton samples were collected from on board the CCGS Amundsen in the summer of 2016 as a part of ArcticNet and the Northern Contaminants Program. These samples were collected to determine the occurrence and levels of legacy pesticides and new and emerging priority compounds under the Canadian Chemical Management Plan. Additionally, archived sediment and filtered water samples were screened for and found microplastics.

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.