The Arctic Ocean is experiencing large and small changes throughout the region caused by climate-induced change. Furthermore, increases in human activity and population have been observed throughout the Arctic, leading to an increase in wastewater production within coastal Arctic communities. Wastewater contains high concentrations of nitrogen compounds that are released during summer into coastal seas, via natural purification systems such as lagoons and wetlands, where it can stimulate marine algal production. My thesis research investigated the effect of this anthropogenic nitrogen input on phytoplankton near an Arctic coastal community in the Canadian Arctic Archipelago, namely Cambridge Bay, Nunavut. During discharge, a phytoplankton bloom was triggered by the presence of high nitrogen compounds in the effluent, which influenced both taxonomic composition and production of the phytoplankton community. Before wastewater discharge, flagellate species were dominant in the phytoplankton community, characteristic of the original oligotrophic conditions for the region. However, after discharge commenced, diatom rapidly became the dominant taxa of the bloom. The increase in diatoms was also believed to influence bloom progression as the diatoms were dense enough to sink below a persistent pycnocline and use accumulated nutrients available at depth in the system. A comparison of observations before and after wastewater discharge versus those during shows that the average primary production increased by about 170 mg C m-2 d-1 during discharge. This increase over a 4-week period equated to 68% of total open water primary production from 9 July to 10 October, 2018. Although the local system was not deemed eutrophic, a persistent pycnocline and bounding shallow sills for the local bay create a unique situation that acts to trap wastewater nitrogen compounds at depth. Such a system can lead to increasing stores of nutrients over time if not regularly ventilated. Therefore, strong recommendations are made for future monitoring and research.