IBA Southern Bight, Minas Basin
Bay of Fundy (near Wolfville), Nova Scotia
Site Summary
NS020 Latitude
Longitude
45.091° N
64.250° W
Elevation
Size
0 - 15 m
221.92 km²
Habitats:
salt marshes/brackish marshes, tidal rivers/estuaries, mud or sand flats (saline), inlets/coastal features (marine), arable & cultivated lands, improved pastureland
Land Use:
Agriculture, Nature conservation and research, Rangeland/pastureland, Tourism/recreation
Potential or ongoing Threats:
Agricultural pollution/pesticides, Cultural use, Disturbance
IBA Criteria: Globally Significant: Congregatory Species, Shorebird Concentrations
Conservation status: National Wildlife Area (federal), Ramsar Site (Wetland of International Significance), Western Hemisphere Shorebird Reserve Network
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Site Description
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.
Birds
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.




IBA Criteria
SpeciesT | A | I Links Date Season Number G C N
American Black Duck 2006 WI 4,696
Black-bellied Plover 1994 FA 2,130
Black-bellied Plover 1994 SP 2,130
Chimney Swift 2012 - 2016 FA 24 - 112
Chimney Swift 2014 - 2016 SP 23 - 90
Chimney Swift 1997 - 2016 SU 28 - 133
Great Black-backed Gull 1990 - 2002 WI 1,720 - 5,736
Herring Gull 1990 - 2015 WI 3,000 - 30,610
Piping Plover 2012 SU 7
Savannah Sparrow 2013 - 2016 FA 18 - 100
Savannah Sparrow 2012 - 2013 SP 19 - 24
Savannah Sparrow 2013 - 2016 SU 20 - 50
Savannah Sparrow 1991 - 2016 WI 19 - 95
Semipalmated Plover 1994 - 2006 FA 1,225 - 5,000
Semipalmated Sandpiper 2010 - 2015 FA 20,000 - 300,000
Semipalmated Sandpiper 1993 - 2012 SU 20,000 - 51,667
Short-billed Dowitcher 1994 FA 1,613
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.
 
Conservation Issues
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.


The IBA Program is an international conservation initiative coordinated by BirdLife International. The Canadian co-partners for the IBA Program are Bird Studies Canada and Nature Canada.
   © Bird Studies Canada