The risk of petroleum hydrocarbon contamination in the Canadian Arctic has increased due to the loss of sea ice from global warming that has contributed towards an an extension of the open-water season for marine transport within the Northwest Passage. The potential of the native bacterial communities to withstand and attenuate potential accidental spills of petroleum hydrocarbons within this pristine and fragile environment is unknown. As a first step toward increasing this understanding, bacterial communities in melt water from the bottom layer of sea ice cores (sea ice bottom) and surface water from 23 locations around Cornwallis Island, NU, Canada were scrutinized for their hydrocarbon degradation capacity.