Winter under-ice limnological and pigment data of the Great Whale River and its freshwater plume into Hudson Bay.

Winter conditions profoundly alter the limnological properties of lotic ecosystems. In 2019, from February 25 to March 1, we sampled the under-ice water column of the Great Whale River and its plume into Hudson Bay. This limnological and pigment dataset is complementary to an amplicon dataset (prokaryotes and microbial eukaryotes) and a metagenomic dataset that are available at the NCBI Sequence Read Archive (BioProject PRJNA999265 and PRJNA999354). It includes data for nutrients (total nitrogen and phosphorus), carbon (dissolved organic and inorganic), dissolved organic carbon characterization (SUVA254, SR, a320, S289), cell abundance measured by flow cytometry, total suspended sediment concentration, specific conductivity, snow depth, ice thickness, under-ice water depth, oxygen concentration, temperature and pigments determined by high-performance liquid chromatography.