Microbial diversity across the Hudson Bay: a river to sea continuum

Many of the key physical, biological and geochemical processes occurring in Hudson Bay, including sea ice growth and decay are strongly linked to freshwater input. Freshwater within Hudson Bay System originates from rivers with large drainage basins and is modified by sea ice formation and melting. Similar to other estuaries, gradients in light, heat and salinity through freshwater and seawater mixing, are predicted to influence microbial community structure. Here, we sampled microbial assemblages using high throughput amplicon sequencing of the V4 region of 18S rRNA and the 18S rRNA gene, along a salinity gradient in the Great Whale River estuary to Hudson Bay, to investigate how these gradients affect planktonic microbial eukaryotes, which includes phytoplankton and protist grazers.