Cascumpec Bay / Alberton Harbour is located at the base of Prince Edward Islands northeast peninsula, on the east coast. It is a large bay (about 40 km²) that is protected from the Gulf of St. Lawrence by a series of sand spits and barrier islands with sand dunes. The sandy beaches extend to the north past Jacques Cartier Provincial Park. The largest of these islands has been named the Cascumpec Sand Hills. Several estuaries are located along the landward side of the bay, including the Kildare River, Mill River, Foxely River and Trout River. The bay is fairly shallow, and the adjoining land (on Permian sandstone) is quite flat. The south end of the bay directly adjoins a large area of peat lands (known locally as Black Banks).
Like the other bays and inlets along the coast of Prince Edward Island, Cascumpec Bay supports large numbers of staging Canada Geese (from the Newfoundland and Labrador population) during both the spring and fall migration. Over the last six years (1992 97) one-day aerial surveys completed in mid-November have recorded an average of 444 geese. The total number of geese using the site over the entire season is much larger: migratory turnover needs to be factored into the estimate. Usage at this site has been estimated to be as high as 2,000 birds in the spring, and as high 1,700 birds in the fall. These estimates represent just over 1% of the estimated Newfoundland and Labrador breeding population.
On occasion, the Cascumpec Sand Hills support nesting Piping Plovers (identified as globally vulnerable, and nationally endangered). However, their presence is irregular: present in 1978, 1984, 1987, and 1997; and absent in 1991, 1994, 1996 and 1998. Usage at Jacques Cartier Provincial Park (just to the north) is more regular, with two pairs and one single in 1991, one pair in 1994, a non-nesting pair in 1996, two pairs (one nest) in 1997, and one nesting pair in 1998. The threshold for a nationally significant Piping Plover site in Atlantic Canada is the regular occurrence of 4 to 5 breeding birds.
Also present is a Great Blue Heron colony on Oultons Island, and several Osprey nests are located adjacent to the bay. Formerly, a large Common Tern colony was located on the Cascumpec Sand Hills (estimates as high as 1,000 pairs in the late 1980s), but it is now abandoned.
BirdLife International (2020) Important Bird Areas factsheet: Cascumpec Bay/Alberton Harbour. Downloaded from http://www.birdlife.org on 08/07/2020.