The Dog Lake area is located in the interlake region of central Manitoba, immediately to the east of the narrows of Lake Manitoba. The town of Ashern is about 12 km to the northeast. Dog Lake contains numerous low islands that are frequented by colonial waterbirds. The shores are rocky and irregular in shape with numerous shallow bays and stands of emergent and submergent wetland vegetation, and rocky mudflats. The maximum depth of the lake is less than 15 feet. The surrounding landscape is rolling with aspen parkland, rangeland, and cropland being present.
Dog Lake is an extremely important nesting area for colonial waterbirds. During surveys completed in 1996, a total of 990 Common Tern nests were recorded along with 1,050 American White Pelican nests. For Common Terns, this represents about 2% of estimated North American population, while for American White Pelicans, this represents about 1.3% of the world's estimated population. The pelican colony has supported large numbers of birds for at least 30 years; in the late 1960s, 800 nests were recorded, and in 1971 1,650 nests were recorded.
Dog Lake is also significant for nesting Great Egrets. It is the only location in Manitoba where this species nests regularly, with a total of 21 nests being recorded in 1996 (about 10% of the national population). There appear to be less than 200 pairs of Great Egrets in Canada, with over 140 pairs on the Pelee Island Archipelago on Lake Erie in southern Ontario. In addition to the Great Egrets, about 40 pairs of Great Blue Herons also nest in the Dog Lake heronry.
Other species that nested in large numbers include Ring-billed Gulls (5,100 nests) and Double-crested Cormorants (82 nests). In total, this site supported at least 8,284 colonial nesting waterbirds in 1996.
The lake is also recognized as an important nesting area for Canada Geese, and during the summer and fall large numbers of waterfowl use the lake for moulting and staging prior to migration. Flocks of 1,000 to 5,000 waterfowl are observed regularly. Migrant shorebirds also use the site, especially during dry years when more mudflats are exposed.
Conservation responses/actions for key biodiversity
The waters and all of the islands within Dog Lake have been identified as a Wildlife Management Area. The islands have also been identified as a Game Bird Refuge (since 1957) and game bird hunting continues to be prohibited on them. Recently, the Manitoba Ecological Reserves Advisory Committee has recommended that the Dog Lake Islands (580 ha in total) be designated as a provincial Ecological Reserve. In Manitoba, Ecological Reserves receive the highest form of available protection.
Local residents are interested in having a stable water system (outlets for high water years and inlets from Lake Manitoba in low water years) in this naturally variable ecosystem. Extensive drain developments build to address this concern led to other problems in wetter years.