Title: Physical gradient influences on sea ice algae in the Canadian Arctic
Abstract
Ice algae living within the bottom interstices of sea ice significantly contribute to the amount of the primary production in the Arctic Ocean in the late-winter/spring. This thesis examines the influence of physical gradients, namely sub-ice currents and riverine input, on ice algal concentration and composition during the spring bloom. Through two separate case studies, it was found that (i) increased sub-ice currents in tidal straits enhance nutrient supply to bottom ice, supporting greater ice algal biomass, (ii) improved mechanisms of nutrient supply were proposed that explain the increased biomass as a result of strong sub-ice currents, and (iii) freshwater inflow to the marine system also has a negative influence on biomass, reducing biomass associated with decreasing salinity. These findings will help identify new biological hotpots of ice algal production in the Arctic, while highlighting a negative, yet limited, influence surrounding hydroelectric controlled river output during winter.