Phytoplankton composition and abundance were investigated from Labrador Sea up to Kennedy Channel, in Frobisher Bay, in the Canadian Arctic Archipelago (Lancaster Sound, Barrow strait, Franklin strait, Victoria Strait, Queen Maud Gulf), as well as in Beaufort Sea and in Amundsen Gulf from 14 July to 06 October 2016. Sampling was carried out with a CTD-rosette system. Water samples were collected at 7 optical depths (100, 50, 30, 15, 5, 1 and 0.2% of surface irradiance) determined with a Secchi disk and a PNF-300, at the depth of the maximum chlorophyll fluorescence, and at 2 depths in the aphotic zone (generally 75m and 100m). Incident PAR was measured continuously during the cruise with a LI-COR PAR sensor. Water samples were collected for the determination of size-fractionated chlorophyll a and pheopigments (>0.7 um; >5 um; >20 um], total and dissolved organic carbon and nitrogen (TOC/DOC/DN), total particulate carbon and nitrogen (TPC/TPN), phytoplankton identification, pico-, nanophytoplankton and heterotrophic bacteria abundance, as well as pigment signature by HPLC. Note that most of these variables were not measured at all depths. Size-fractionated primary production (>0.7 um; >5 um) was measured at the 7 optical depths including the depth of the maximum chlorophyll fluorescence using the 14C-method (JGOFS protocol) with on-deck in situ simulated incubations.
