The Îles Sainte-Marie are located on the north shore of the Gulf of St. Lawrence, near the town of La Romaine. The site boundaries correspond to the Îles Sainte-Marie Migratory Bird Sanctuary. The area includes thirteen islands covered mostly by tundra and stunted conifers, and a marine area extending one kilometre around the archipelago. Rocky outcrops and several freshwater ponds are also part of the varied landscape. The shrub layer is represented by Balsam Fir, Black Spruce, Labrador Tea and Bog Myrtle. There are many species of ground layer plants, including arctic-alpine plants and lichens. On Île de l’Ouest, there is a lighthouse and two small residences which are occupied during the fishing season (April to December). The surrounding marine waters of the Gulf of St. Lawrence are important feeding areas for many pelagic mammals, such as Blue, Fin, and Humpback whales, and Common Porpoise.
With 14 breeding species, this site is one of the richest bird colonies in the Gulf of St. Lawrence. All of the typical marine species of the gulf have colonized these islands at one time or another, except for Northern Gannet and Caspian Tern. Common Murre and Razorbill breed at the site in globally significant numbers. The numbers of Common Murres have been increasing since the 1970s, peaking at 25,308 birds in 1993, which is over 2% of the North American Atlantic population. Razorbill numbers have also been increasing recently, with 3,342 birds recorded in 1993, representing 4.5% of the North American population. Both of these species have been expanding since the creation of the sanctuary, which is noteworthy considering their limited breeding range in southern Québec.
Common Eiders (ssp. dresseri) nest in almost nationally significant numbers, with 599 and 628 pairs in 1988 and 1982, respectively. Almost 1% of the Atlantic Double-crested Cormorant population also nests here: in 1993, 740 pairs were surveyed. Their close relative, the Great Cormorant, nests in small numbers but they are nonetheless almost significant on a national basis: an average of 47 pairs for the last 4 surveys (1982 to 1994) was recorded.
Thick-billed Murres have not nested here since 1962, when there were two pairs, and the 1993 surveys showed no nests of Leach’s Storm-Petrel (compared to 28 and 52 pairs in 1988 and 1982, respectively), suggesting that they too no longer breed at the site.
Other species, such as Black Guillemot, Red-throated Loon, Herring Gull, Great Black-backed Gull and Black-legged Kittiwake, nest on the islands, but in smaller numbers.
BirdLife International (2021) Important Bird Areas factsheet: Îles Sainte-Marie. Downloaded from http://www.birdlife.org on 13/06/2021.