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Southern Bight, Minas Basin (NS020)

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Southern Bight, Minas Basin (NS020)

Bay of Fundy (near Wolfville), Nouvelle-Écosse

Latitude 45,091°N
Longitude 64,250°O
Altitude 0 - 15m
Superficie 221,92km²

Description du site

The Southern Bight of the Minas Basin, which includes the Avon River situated about 12 km north of Wolfville, is a large embayment in the Minas Basin, Bay of Fundy, south of the boundary line between Medford and Bramber. The Southern Bight is a large tidal embayment, chiefly composed of intertidal mudflats that are divided by river channels into five sections, varying in substrate (sand/silt gradients) and invertebrate fauna. These five sections include Kingsport-Medford, Porters Point, Starrs Point, Evangeline Beach, and Avonport.

Oiseaux

The mud flats at the head of the Bay of Fundy are important staging grounds for an estimated 1 to 2 million shorebirds in late July and early August (in this and other adjacent IBAs). At low tide, vast areas of mud and sand flats, and salt marshes are exposed - the result of the Bay of Fundys tides, which are the highest tides in the world (up to 16 m). The rich red-brown mud harbors millions of Fundy mud shrimp, a vital food source for the Semipalmated Sandpiper. The Southern Bight, Minas Basin and other regions in the Bay of Fundy are the last and most important stopovers for the sandpipers, where they build up fat stores enabling them to make the long southward migration to South America in three to four days. The availability of such a prodigious food supply attracts 50 to 95% of the worlds Semipalmated Sandpipers, along with many other species of shorebirds, to the Bay of Fundy.

Some of these birds are found in the Southern Bight, Minas Basin: 51,667 Semipalmated Sandpipers have been recorded in late July and early August. This figure accounts for 1.4% of the global population. Also, more than 1% of the North American Black-bellied Plover population has been observed at this site. This number is based on data from 1974 to 1983 using an improved estimation method that was reported in Canadian Field Naturalist in 1993.

A high diversity of other migrant shorebirds forage on the large intertidal mud and sand flats throughout the Bight. Commonly observed species include: Red Knot, Sanderling, Short-billed Dowitcher, Least Sandpiper, and Semipalmated Plover. Some of these species may at times occur in numbers exceeding 1% of their North American or global populations, but surveys often do not cover all parts of the basin. Likewise, it is believed that an accurate census of the entire basin would reveal greater than 100,00 shorebirds.

During the spring tides, some of the sandpipers use nearby dyked fields for roosting.

Enjeux de conservation

The Minas Basin area was declared a Hemispheric Shorebird Reserve, under the Western Hemisphere Shorebird Reserve Network (WHSRN) in 1988. The Minas Basin was also separately designated as Ramsar site; Wetlands of International Importance, in the 1980s. In recent years, a commercial harvest of rag-worms, for bait, has disrupted the intertidal invertebrate community and thus staging shorebirds.

Several university thesis studies have been conducted here since the early 1970s, and there are some ongoing surveys, but the most extensive monitoring occurred in 1976 and 1997.

Catégories ZICO Habitats Usages Menaces Potencielles ou Existantes Status de Protection
Bécasseau semipalmé
Nombre Année Saison
20 000 - 30 0002017Automne
20 000 - 25 0002015Automne
30 000 - 50 0002014Automne
20 000 - 25 0002013Automne
20 0002012Été
300 0002010Automne
51 6671994Été
30 0001993Été
Pluvier semipalmé
Nombre Année Saison
3 0002006Automne
2 500 - 5 0002005Automne
1 2251994Automne
Bécassin roux
Nombre Année Saison
1 6131994Automne
Goéland argenté
Nombre Année Saison
3 000 - 6 5432015Hiver
4 3612011Hiver
11 5432010Hiver
5 2172006Hiver
3 2172004Hiver
5 0452003Hiver
8 0622002Hiver
13 7302001Hiver
7 0312000Hiver
4 9811999Hiver
30 6101998Hiver
12 6131997Hiver
12 6881996Hiver
18 1941995Hiver
20 9321994Hiver
19 6341993Hiver
27 7711992Hiver
6 2671991Hiver
10 1631990Hiver
Goéland marin
Nombre Année Saison
2 5562002Hiver
4 0482001Hiver
3 5861998Hiver
2 4981997Hiver
1 7491996Hiver
3 1981995Hiver
5 7361994Hiver
4 5501993Hiver
5 1751992Hiver
2 6491991Hiver
1 7201990Hiver
Pluvier argenté
Nombre Année Saison
2 1301994Automne
2 1301994Printemps
Martinet ramoneur
Nombre Année Saison
70 - 852017Automne
50 - 1502017Été
352016Automne
822016Été
23 - 802016Printemps
52 - 922015Été
40 - 902015Printemps
24 - 1122014Automne
100 - 1332014Été
402014Printemps
262013Automne
542012Automne
282010Été
702003Été
801997Été
Bruant des prés
Nombre Année Saison
502017Automne
25 - 302016Automne
20 - 232016Été
192016Hiver
24 - 402015Automne
502015Été
192014Hiver
18 - 1002014Automne
202013Automne
282013Été
242013Printemps
192012Printemps
192011Hiver
222007Hiver
592005Hiver
402004Hiver
382003Hiver
202001Hiver
292000Hiver
411997Hiver
231996Hiver
451995Hiver
271994Hiver
951991Hiver
Pluvier siffleur
Nombre Année Saison
72012Été
Canard noir
Nombre Année Saison
4 6962006Hiver