Seasonal and perennial sea ice constitutes an important habitat for the marine ecosystems of Greenland as well as throughout the Arctic marine ecoregions. Polynyas and leads are areas of open water surrounded by sea ice that are highly productive and sustain a diverse and abundant array of marine Arctic and migratory species. These remote and icy refuges may thereby sustain species throughout the marine food web, from the tiniest copepod that grazes on the mass of algae on the ice edge, to the elusive ivory gulls that may be seen feasting on the abundant fish stocks that thrive in these ice-encircled open water areas. The migratory patterns of narwhals and bowhead whales are shaped by the melting and freezing of the ice, and seasonal movements to a series of predictable open water areas of high productivity as the northern polynyas, sustain these long lived species and the trophic food chain upon which they subsist.. The most biologically productive open water area between Canada and Greenland is northern Baffin Bay; the North Water Polynya (NOW). It is the world’s largest Arctic polynya at about 80,000 square kilometers. Named the ’North Water‘ by 19th century whalers who relied on it for spring passage, the polynya is kept open by wind, tides and an ice bridge on its northern edge. Although thin ice forms in some areas, the North Water Polynya occurs seasonally at the same time and place each year. Culturally, the lives of the Inuit’s in Greenland and Canada have been shaped by the extreme conditions these populations have existed under, their dependency on natures resources in the form of fish, birds, and land- and marine mammals. The Inuit communities of Avanersuaq (Northwest Greenland) and Pond Inlet, Nanisivik, and Grise Fjord in Canada have historically relied on the abundance of marine life in and around the North Water for their food, clothing, shelter, and essential cultural and economic well-being.