Distribution

Abstract

The lake charr Salvelinus namaycush is restricted in its native distribution to oligotrophic fresh waters of northern North America largely within the extent of the Pleistocene glaciations. It is the only freshwater species in northwest North America that does not occur in Siberia. A GIS-based native occurrence map linked to the HydroLAKES database does not extend the lake charr range but provides more comprehensive occurrence data than previous maps. The total waterbody area of lakes occupied by lake charr (451,304 km 2 ) is 40% of the total waterbody area across the range. Lake charr occur from 42.020901 latitude in the south to 74.420800 in the north and from −62.700000 longitude in the east to −161.173090 in the west. Lake charr lakes range in surface area from 3.4 to 8,210,000 ha (mean = 9715 ha; median = 191 ha), maximum depth from 2.7 to 614 m, and elevation from sea level to 2035 m ASL (mean = 381 m; median = 366 m). Glaciation, water temperature, dissolved oxygen, depth, and nutrient content are the main variables associated with lake charr native distribution in lakes. Life history variation, physiology, and ecological opportunity are the most likely drivers of lake charr dispersal and colonization.