| IBA |
Le Pilier de Bois
Montmagny, Québec |
| Site Summary |
| QC099 |
Latitude
Longitude |
47.199° N
70.396° W |
Elevation
Size |
0 - 6 m
1.15 km² |
Habitats:
mixed woods (temperate), other
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Land Use:
Nature conservation and research
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Potential or ongoing Threats:
Oil slicks
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| IBA Criteria: Continentally Significant: Congregatory Species, Nationally Significant: Congregatory Species |
| Conservation status: habitat faunique, colonie d'oiseaux - Quebec (Wildlife Habitat, Bird Colony) |
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Site Description
Le Pilier de bois, part of the Montmagny archipelago, is about 6 kilometres from the St. Lawrence River south shore, near the village of Saint-Jean-Port-Joli, Québec. This small rocky island of 3.6 hectares is uninhabited although a lighthouse remains from earlier times. The sparse vegetation includes Chokecherry, White Spruce, White Birch and Trembling Aspen.
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Birds
Four colonial waterbirds breed on Le Pilier de bois according to surveys conducted since 1990. The most important bird is the Double-crested Cormorant: the average colony size of the last three surveys (1987, 1989 and 1990) was 1,405 pairs, representing about 1.5% of the Atlantic population. This species has increased since only 150 pairs were present in 1971.Black-crowned Night-Herons have not been detected since 1971. A nationally significant 50 pairs were present that year. Common Eiders also used to nest here - the last record was of 20 pairs in 1975. In addition to the cormorants, three other species currently nest on the island. Razorbills have been found nesting here in the last four surveys (1990-1995) with an average of 60 individuals present. Two species of gulls, Herring and Great Black-backed, were present on the island in 1990, with 104 and 15 pairs, respectively. Similar numbers of both species nested here in 1971, but apparently no gulls were present in 1979.
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IBA Criteria |
| Species↓ T | A | I |
Links |
Date |
Season |
Number |
G |
C |
N |
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Note: species shown in bold indicate that the maximum number exceeds at least one of the IBA thresholds (sub-regional, regional or global). The site may still not qualify for that level of IBA if the maximum number reflects an exceptional or historical occurrence.
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Conservation Issues
With the St. Lawrence River being a heavily travelled seaway, oil spills are a ongoing threat. The island was given the status of "Habitat faunique, colonie d'oiseaux” (Wildlife Habitat, Bird Colony), a designation that aims to prevent any habitat-modifying activity. There is little threat of disturbance from people due to the small size of the island and its inaccessibility.
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Fish Habitat
The bulrush marsh is the typical coastal habitat in the region. While the water has in this region a low salinity, tides are still present and reshape continuously the river landscape. Several species, such as the rainbow smelt (population of south shore of the St. Lawrence middle estuary) and Atlantic tomcod exploit the shallow waters of the area. Many migratory species (anadromous and catadromous) are also found in the area. In addition to the two species mentioned above, we found also the American shad, the Atlantic sturgeon and the American eel, all three species being prized for their tasteful flesh.
However, several sources of pressures are threatening both the quality and the availability of aquatic habitats. The expansion of agriculture, the residential development, the creation of new resorts and artificialization of the shoreline represent significant habitat losses. The presence of major obstacles may impede the movement of fish toward their breeding site. Finally, the maintenance of the Seaway for commercial navigation (dredging and the discharge of sediments) reduces the water quality and may cause the destruction of spawning sites. The decrease of the Atlantic sturgeon population of in the St. Lawrence can be assign to this aspect. Because of habitat alteration, high exploitation of commercial and recreational fisheries and non-compliance, the population of striped bass in the estuary of the St. Lawrence disappeared around 1968. In 2002, Quebec government has established an important reintroduction program to rehabilitate the specie. Between 2002 and 2007, more than 6 300 striped bass and 6,5 millions larvae were introduced into the St. Lawrence river. A network monitoring incidental captures has been implemented in 2004, allowing to document the evolution of the population.
30,000 fry and more than a thousand individual larger than 35 cm were introduced into the St. Lawrence. In early summer 2006, over one million . From 2008, up to 50 000 fry are introduced annually over a period of 10 years. The objective of this program is to rehabilitate the striped bass population of the St. Lawrence.
Major species present:
Alewife
American eel
American shad
Atlantic sturgeon
Atlantic tomcod
Lake sturgeon
Rainbow smelt (population of south shore of the St. Lawrence middle estuary)
Sauger
Striped bass
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Plants
Rocky islands are composed of schist and quartzite. Despite the unfavorable conditions for settlement, some plant species are able to grow there. On the windward side, we find mainly mosses and low-lying plants such as juniper and cranberries. Areas more sheltered allow spruce to built small woodlands. In the portion swept by the tides, algae colonize the bedrock.
The geographical barrier created by the St. Lawrence River provides the IBA a kind of natural protection, a protection often enhanced by legal protection. However, water pollution and the risks of oil spills remain a source of concern for the protection of the flora and fauna of this area.
Major species present :
Cranberries
Creeping juniper
Spruces
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