Microplastics (MPs) contaminate the oceans from the poles to the equators and from the sea surface to the deep sea. In addition, MPs have been recorded in freshwater systems, including in lakes, rivers and streams globally. Not only an aquatic issue, MPs infiltrate terrestrial ecosystems in landfills, agricultural settings, along beaches, and even in the air. It therefore comes as no surprise that MPs have been identified as a global pollutant of concern that is capable of long-range transport and causing adverse effects in wildlife, but limited information is available for Canadian Arctic regions. Consequently, the NCP has identified assessing the presence and distribution of MPs in Arctic marine ecosystems a priority. The Arctic Monitoring and Assessment Programme (AMAP) has also added Marine Plastics and MPs to their list of Chemicals of Emerging Arctic Concern. We collected water, sediment and zooplankton for MPs in the summer of 2019 as a part of ArcticNet from on board the CCGS Amundsen. Additional water and sediment samples were collected from the R/V William Kennedy in western Hudson Bay and Chesterfield Inlet as a part of GENICE. Water samples were collected by bucketing surface water and filtered through a polycarbonate filter that captured the microplastics. Sediment samples were collected from push cores in a box corer, the top 0-5cm was collected. Zooplankton samples were collected from Tucker Nets using 250um mesh size and then speciated. All samples were distributed to collaborators at Universities of Toronto, McGill and Western Ontario for further processing and analysis. Analysis will be done by FTIR and/or Raman Spectroscopy.

This data is currently in relation to twelve piston cores collected aboard CCGS Amundsen, one on cruise 2014805, two on cruise 2015805, six on cruise 2016804, and three on cruise 2017805. Information about these cores (Location, length, grain size, radiocarbon dates, etc.) can be found by searching the NRCan Expedition Database.

A deep water (100 to 1500 m), continental slope-focused field program was carried out over four years, covering the eastern, central and finally, the western Beaufort Sea regions during survey expeditions in 2011, the western Beaufort in 2012, and 2014. This was supported through the BREA program (Beaufort Regional Environmental Assessment) with funds from AANDC (Aboriginal Affairs and Northern Development). Research activities were conducted in collaboration with ArcticNet, the Geological Survey of Canada (GSC), Imperial Oil, and British Petroleum and Chevron Canada. The primary survey platform was CCGS Amundsen. Supplementary datasets from these collaborators contributed to survey concepts and specific targets but are not part of the BREA dataset. An amalgamation of all the continental slope-related data (from and including 2009) are included in the dataset. Data generated through these activities included multibeam (ca. 9500 square km at 50 m resolution) and sub-bottom profiler sonars (nearly 41 000 km) and seabed sediment cores to investigate deep water geohazards through geotechnical, stratigraphic, age-dating, and interpretations of geo-features and processes related to sediment instability. These data continue to be a primary dataset for GSC (Geological Survey of Canada) scientists to enable their present focus on assessment of seabed instability.

The multibeam bathymetry data is acquired with a multibeam sonar Kongsberg EM302. For complete acquisition and processing description, see the Polar data Catalogue Metadata CCIN 12586 and 12732. Additionnal post-processing and data cleaning of the bathymetry was performed using the CARIS HIPS&SIPS 9.0 and BASE Editor 4.1. Sub-bottom profiles showing seabed stratigraphy were acquired with a Knudsen 320-BR sub-bottom profiles, operated at a frequency of 3.5 kHz. The profiles were processed using the Natural Resources Canada software suite. Ten (10) sediment cores from various locations are stored in the Laboratoire de Géoscience marine's (LGM) core archive. Each core was logged with a CT-scan. Further analysis will be performed in the next months/years.

Sediment cores were collected onboard the CCGS Amundsen during ArcticNet cruise 0502 (2005) using a box corer, penetrating the seafloor to a maximum of 50 cm. Samples were stored in a freezer (- 20 °C) onboard the Amundsen until the end of the cruise, then shipped to the Freshwater Institute (FWI), where they were maintained in storage at - 20 °C. Subsamples were processed at the University of Victoria Marine Micropaleontology Laboratory in October-November 2010. A gentle version of the standard palynological protocol was applied to oven-dried samples of known volume. Steps are as follows: (1) add 10 % hydrochloric acid in room temperature; (2) sieve with distilled water through a 120 micrometre and a 15 micrometre nitex mesh, retaining the fraction in between; (3) add 48% hydrofluoric acid in room temperature for 2-4 days followed by 20 minutes in 10 % hydrochloric acid; (4) sieve through precise 15 micrometre mesh with gentle sonication for 10-60 seconds. The final residue of samples was placed in sealed storage vials and stored in + 4 °C. Aliquots of residue were mounted in glycerine jelly on microscopic slides with cover slips. Dinoflagellate cysts are studied primarily with Zeiss Standard 20 microscope under bright-field oil-immersion and 500X and 1000X magnifications. At least 300 dinoflagellate cysts species and cyst types will be identified on each slide together with pollen, freshwater algae and other palynomorphs.

The cores were collected using a small gravity corer aboard the MV Nuliajuk in September 2014, and a piston corer aboard the CCGS Amundsen during October of 2014 and 2015. Initial data included records of sample location and core length. Laboratory work has produced lithological logs, photography and x-radiography, grains size analysis, and radiocarbon dates from the cores sampled in 2014. For the 2015 cores, lithological logs, photography and x-radiography have also been obtained, with grains size analysis and radiocarbon dating in progress.