Species range modeling in the Late Glacial Maximum (LGM) landscape strongly suggests the most effective biological barriers promoting arctic land snail diversification were firstly continental ice sheets and secondarily oceans. If continental ice is the most effective barrier, the impending loss of the Greenland ice sheet could lead to intermingling of the European and North American faunas, and a likely loss of biodiversity. We will test this hypothesis in the modern arctic North Atlantic via a Grantová Agentura České Republiky (GAČR) grant funded in December 2019. Because almost 100% biological turnover exists from eastern Canada to eastern Iceland, it is possible to determine the relative effectiveness of both ocean and ice sheet barriers by documenting total regional faunistic turnover from northern Labrador, southern Baffin Island, east and west Greenland, and western Iceland. Field sampling is required on Baffin Island as only a single species list is available, based on observations made over 80 years ago from the Kimmirut area by John Oughton of the University of Toronto, who documented approximately six species all with shell sizes of around 2 mm in maximum dimension (roughly the size of the Queen's nose on a penny). We would like to document regional land snail biodiversity in two southern Baffin Island areas: Kimmirut (potentially including areas within Katannilik Territorial Park) and Iqaluit (likely including areas within Sylvia Grinnell Territorial Park). Within each region, we propose sampling approximately two dozen 1000 m2 areas, representing the full range of terrestrial environments occupied by terrestrial gastropods (e.g. fens, willow scrub,upland rich tundra). At each site we will sieve leaf litter to obtain roughly 300 ml of material, which will be returned to our laboratory to extract roughly 200 adult shells which require microscopic observation for accurate identification. From this we can accurately document total biodiversity at each site. No long-term impacts on regional ecology will be generated through this work: The limited disturbance required to obtain sieved litter will be eliminated after the first precipitation/wind event with the removed shells representing a tiny fraction of total population size (there are 1000 shells present per m2 within appropriate microsites). Our research will be made available not only to the NPC and other Provincial agencies, but will also be disseminated to the international scientific community via a series of high-profile publications.