During the Viking Age, Norse peoples established settlements across the North Atlantic, colonizing the pristine and near-pristine landscapes of the Faroe Islands, Iceland, Greenland, and the short-lived Vinland settlement in Newfoundland. Current North Atlantic archaeological research themes include efforts to understand human adaptation and impact in these environments. For example, early Icelandic settlements persisted despite substantial environmental impacts and climatic change, while the Greenlandic settlements were abandoned ca. AD 1450 in the face of similar environmental degradation. The Norse settlers utilized both imported domestic livestock and natural fauna, including wild birds and aquatic resources. The stable isotope ratios of carbon and nitrogen (expressed as δ13C and δ15N) in archaeofaunal bones provide a powerful tool for the reconstruction of Norse economy and diet. Here we assess the δ13C and δ15N values of faunal and floral samples from sites in North Iceland within the context of Norse economic strategies. These strategies had a dramatic effect upon the ecology and environment of the North Atlantic islands, with impacts enduring to the present day.