523 Tantramar Marshes
The Tantramar Marshes, also known as the Border Lowland, occupy a large area at the head of the Cumberland Basin where the flat terrain meets the sediment-loaded waters of the Bay of Fundy. Extensive grasslands occupy much of the former salt marshes that have been dyked and are no longer exposed to siltation. The John Lusby portion of the Chignecto National Wildlife Area is the only large tract still subject to siltation processes.
Geology and Landscape Development
The marshes built up quickly during a period of land subsidence and rising sea levels. Increasing tidal ranges in the Bay of Fundy during the last 6,000 years have controlled their formation. The marshes have extended further inland during this period but have always been exposed to erosive forces at their outer edges. As the Bay of Fundy enlarges through rising sea levels and the erosion of headlands, continual deposition of sediments in the littoral zone occurs, creating the foundation for future salt marshes outside the present dykelands.
As the marsh erodes, remains of submerged forests and freshwater marshes are uncovered. The best examples are in New Brunswick off Fort Beausejour. Often the stumps and roots are washed away quickly once they have been uncovered, though more are revealed as new areas are exposed. A submerged forest off Fort Lawrence disappeared around 1985. Along the Missaguash River, however, stumps still remain after 150 years of exposure. At previous times the remains of spruce, beech, pine, and Larch have all been seen.
On the flat terrain, fresh water is impeded from flowing into Chignecto Bay (sub-Unit 913b) by the elevated salt marshes. Rising sea levels and siltation have built the marshes higher than the inland areas, forming a low dam behind which extensive freshwater peat bogs have developed. The abundance of freshwater wetlands is one of the most distinctive features of this Unit. Wetlands include dammed reservoirs and waterfowl impoundments.
Acadia soils exhibit little horizon development because of the continued deposition of marine sediments. These silty clay loams are either red-brown or grey with an abrupt boundary; the colour is thought to indicate gleying. When reclaimed and drained, these soils are fertile and valuable agricultural soils.
As the peat is mainly formed on low-lying areas inland of the Acadia soils, it is usually no more than one metre thick. Former forests are often buried in the peat.
Masstown soils are poorly drained because of depressional locations or fragipans. A surface layer of organic material has developed up to 15 cm in depth. The underlying "A" horizon is 25 cm thick. This sandy "A" horizon can dry out very quickly when the water table drops, hence the soil tends to be either saturated or dry.
Lake and bog areas contain a wide variety of aquatic plants. Cattails, bur-reed and sedge associations predominate in emergent areas. Various pondweeds and Yellow Pond-lily occur in open-water areas. Common species include Arrowhead, Water-parsnip, and bulrushes.
A poorly drained lowland forest composed mostly of spruce and fir lies inland from the dyked fields and marshes of the Chignecto Isthmus and forms part of the cool coastal forest around the Cumberland Basin (see also Unit 532).
The Maccan marshes provide significant waterfowl breeding areas and are part of the Cumberland Basin area. High tides usually clear the Lusby Marsh of snow, and each year in late March the first northward flights of Canada Geese and ducks land here to feed. As the ice leaves, many species of ducks move into the managed freshwater marshes. These include Black Duck, Green-winged Teal, Pintail, American Wigeon, Blue-winged Teal, and Ring-necked Duck. The managed marshes have attracted rare or uncommon ducks and marsh birds, including the Northern Shoveler, Gadwall, Redhead, and Ruddy Duck, and the Long-billed Marsh Wren, American Coot, Common Moorhen, Black Tern, Virginia Rail, Sora Rail, and Pied-billed Grebe.
Various species of hawks and owls can be observed hunting small mammals on the marshes year-round. The Marsh Hawk is common in summer, and the Rough-legged Hawk is seen in winter. Shallow lakes, such as Long Lake, support large populations of Brown Bullhead and White Perch. This food source, along with Gaspereau, support several nesting Osprey. The Snowy Owl and Snow Bunting occur commonly in winter on the dyked grasslands.
The marshes also provide good habitat for raccoon, muskrat, mink, fox, beaver, and sometimes otter. Generally, small-mammal diversity is low. The rare Arctic Shrew occurs here, far from other known records. This shrew requires marsh or wet meadow habitat and is usually very limited in range, since continuous large expanses of that habitat are rare. In summer and fall, deer frequent the marshland, but in winter they move westward to more-forested areas in the Tidnish watershed.
Early settlers created farmland by cutting channels to the sea through which the sediment-rich waters of the bay flowed to deposit silts above the peat. The dyking controlled the natural siltation. The John Lusby Marsh is the only remaining salt marsh in this Unit still subject to siltation. Acadian farmers dyked and drained the marshland until 1755, and the English and New Englanders later settled the area in 1760. In the early nineteenth century, a system of tide canals and ditches transformed more marshland into fertile pastures. Where dykelands have been maintained for agricultural use, they are covered by a variety of forage, grain, and introduced plants. Many farms on the Tantramar Marshes were later abandoned, allowing the regeneration of the land. Most farms and homes in the Tantramar Marshes Theme Unit are built on dry ridges, which were once heavily forested. Lands closer to the Cumberland Basin have a deeper accumulation of marine soils and are used for lawn sod cultivation, pasture, or hayland.
The Missaguash and East Amherst freshwater marshes were developed on provincial lands by Ducks Unlimited. The Chignecto National Wildlife Area encompasses the Amherst Point Bird Sanctuary and the John Lusby Salt Marsh. The freshwater impoundments created on the marshes have encouraged a number of new waterfowl and marsh bird species to nest in Nova Scotia. Geese now feed on the dykelands, especially the Amherst sod farm, as much as or more than on the salt marshes.
Today the Tantramar Marshes continue to serve as an important transportation corridor linking Nova Scotia with New Brunswick. The nature of the marshlands and their position to magnetic north resulted in this area being chosen by CBC Radio as a site for short-wave transmission radio towers that span the marshes. This Unit is used extensively for bird-watching. Muskrat are harvested here.
Provincial Parks and Park Reserves
Proposed Parks and Protected Areas System includes Natural Landscape 21.