Barrage de Beauharnois (11473)
Canada, North America
Site overview
KBA status: confirmed
Year of last assessment: 2008
National site name: Barrage de Beauharnois
Central coordinates: Latitude: 45.3210, Longitude: -73.9020
System: freshwater, terrestrial
Elevation (m): 29 to 49
Area of KBA (km2): 5.52801
Protected area coverage (%): 57.92
KBA classification: Regional
Legacy site: Yes
Site details
Site description: This site is located two kilometres east of the city of Beauharnois, and 30 km west of Montréal, Québec. Barrage de Beauharnois is situated at the mouth of the Beauharnois Channel and borders Lac Saint-Louis (a widening of the St. Lawrence River). The hydroelectric dam, two locks and a Hydro Québec power station are present on the site. From Beauharnois Channel, the water passes through turbines and emerges into three channels before entering Lac Saint-Louis. Immediately below the dam, a road crosses two islets. These islands and the surrounding waters make up this Important Bird Area.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that was identified using previously established criteria and thresholds for the identification of Important Bird and Biodiversity Areas (IBAs) and for which available data indicate that it does not meet global KBA criteria and thresholds set out in the Global Standard.
Additional biodiversity: Thousands of Ring-billed Gulls colonize the islands below the dam from March to December. Throughout the 1990s, an average of 6,742 breeding pairs were present on the island, which is 1% of this species’ national population. During this time the lowest count was 5,449 pairs (1994) and the highest was 8,059 pairs (2000). The landowners have installed exclosures on parts of the islands to prevent the gulls from nesting, but the gulls have moved to another part of the site on the other side of the road. This site is also an important wintering site for gulls. In total, 17 gull species have been seen here. During the winter, gull flocks may contain as many as 25,000 birds. In November and December, Herring Gull flocks and Ring-billed Gull flocks are as large as 15,000 birds. In winter, Great Black-backed Gull, Iceland Gull, and Glaucous Gull are common, and Bonaparte’s Gull is the most common small gull. The dead fish coming out of the turbines are a great food source for the gulls. Hundreds of terns (mostly Black Tern and Common Tern) also frequent the site in spring and fall. Five percent of the national Black Tern population (500 birds in 1984) and close to one percent of the North American Common Tern population has been recorded here. Pomarine Jaeger, Parasitic Jaeger, Laughing Gull, Franklin’s Gull, Little Gull, Black-headed Gull, Ivory Gull, Sabine’s Gull, Mew Gull, Lesser Black-backed Gull, Thayer’s Gull, California Gull, Forster’s Tern, Arctic Tern and Caspian Tern are also seen here irregularly. In addition to the gulls, large numbers of swallows use the site during fall migration. Up to 72,000 Tree Swallows (1976) and 500 Bank Swallows (1977) have been recorded. During migration, small numbers of ducks and shorebirds use the site, and occasionally Barrow’s Goldeneye and Peregrine Falcon (nationally vulnerable) are seen.
Delineation rationale: 2011-06-06 (BL Secretariat): site area updated from 200 ha to 570 ha, following GIS analysis of site polygon by Bird Studies Canada (J. Moore & S. Marquez in litt. 2009).
Habitats
Land use: tourism/recreation | urban/industrial/transport
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Wetlands(Inland) | 71 | |
| Artificial - Terrestrial | 29 |