Geology and Landscape Development
The Submerged (Bras d'Or) Lowland forms a fringe around the upland areas of central and eastern Cape Breton (see Figures 8 and 19). The lowlands are underlain by Windsor Group strata containing siltstone, shale, reddish sandstone, limestone, gypsum, anhydrite, and salt. These strata once ranged in thickness from 650-1,200 m. They were often laid down in cyclical deposition patterns under a variety of conditions: in shallow offshore environments, in restricted basins where there was greater evaporation, and in open basins. The depositional basins lay around and between the upland blocks of the Creignish Hills, North Mountain, Sporting Mountain, East Bay Hills, and Boisdale Hills (see Figure 29).

During the Tertiary period a dramatic drop in sea level, probably caused by crustal uplift after the formation of the Cretaceous planation surface, allowed deep erosion to take place.

Washabuck Click to enlarge

At that time, major features such as the Gulf of St. Lawrence were carved out, and in central Cape Breton the lowlands were eroded to well below present sea level. When the land subsided, the sea was able to enter through two channels, the Great Bras d'Or and Lennox Passage, forming a deep lake 180 m deep in a few places, with access to the sea. Now the Windsor strata form an eroding broken fringe at sea level around the base of the uplands. The landscape consists of steep slopes with some cliffs, dropping to a coastal plain where there are white gypsum deposits and red sedimentary strata. The uplands, lowlands, and channels are oriented in a northeast-southwest direction in accordance with the structural trend in Cape Breton.

Freshwater and Coastal Aquatic Environments
Most of the streams in this District are short, fast-flowing first- or second-order streams that drain directly into the Bras d'Or Lake down steep banks. The exception occurs in the area around Denys Basin and St. Patricks Channel, where larger systems include the River Denys and River Inhabitants. Tributaries feed into these systems from the Creignish Hills (sub-Unit 313a) to the northwest. The River Denys is also fed by streams flowing from North Mountain to the south in sub-Unit 313b.

The water at the head of St. Patricks Channel is stratified as a result of the restriction of tidal influences at Little Narrows. This creates an interesting marine benthic and freshwater pelagic community.

The largest wetland complex, Big Marsh, a productive wildlife habitat, is associated with the River Denys and contains elements of shallow freshwater marsh, shrub swamp, and grassy meadow.

Soils
Shales and mudstones have produced most of the soils in this area. Gypsum occurrences are very frequent and produce improved drainage in soils immediately above them. Well-drained Falmouth, imperfectly drained Queens, and poorly drained Kingsville soils predominate. These are loams and clay loams derived from clay loam tills. Areas of coarser-textured Thom and Westbrook soils also occur. Millar soils have developed on outwash deposits. Although these are coarse-textured sandy loams, they are poorly drained because of the depressional topography.

Plants
This Unit is part of Loucks' Sugar Maple-Hemlock, Pine Zone, but the heavy soils and repeated disturbances have resulted in a largely coniferous forest, with White Spruce, Balsam Fir, and scattered Eastern Hemlock. Shade-tolerant deciduous trees are found on some of the better-drained slopes. Red Maple and White Birch occur in mixed stands. Oldfields and former pasture have regenerated in pure stands of White Spruce, or in spruce and fir. Black Spruce and larch grow in the wetter areas. The salt marsh vegetation is influenced by fresh water and includes Sweet Grass.

Animals
The Submerged Lowland District includes a mix of flat or rolling softwood or mixed forest habitats, oldfields, open brackish water, sheltered marshy inlets, and exposed rocky shoreline.

Bald Eagle Click to enlarge

The Bras d'Or Lake supports a distinct warm-water marine community that is impoverished compared with other estuaries or coastal waters in Nova Scotia. Polychaete and bivalve communities are found in the mud and gravel bottom. The Unit provides very important Bald Eagle nesting habitat, particularly in the vicinity of Boom Island. Great Blue Heron and Double-crested Cormorant colonies are also present. River Denys and the upper Denys Basin are important areas for waterfowl production and act as a staging area for migrating Teal, Black Duck, and Ring-necked Duck; this is also known as a wintering area for Bald Eagles. The estuaries and streams provide good muskrat and mink habitat. Snowshoe Hare and bobcat also use habitats in this Unit.

Scenic Quality
Fine scenery is found along all shores of the Bras d'Or Lake and its associated channels. Where the lowland is squeezed between lake and mountains (e.g., Whycocomagh, north side of West Bay, and south side of East Bay), very high scenic ratings are attained. This District's scenic resources, however, lie mostly offshore and are only fully available to those with boat access to the lake. The inland area between North Mountain and the Creignish Hills is less attractive than the lakeshore, though scattered farms add interest.

Cultural Environment
The shores of Bras d'Or Lake have long been an important area for the Mi'kmaq, and today several Mi'kmaq reserves are located around the lake, including Eskasoni, the largest in the province. Since the 1970s, various aquaculture operations for oysters, trout, and salmon have been started in Bras d'Or waters with

Island Point Click to enlarge

varying degrees of success. People of Scottish descent settled the fertile tracts of land around Bras d'Or Lake in the first quarter of the nineteenth century, clearing large tracts of forests for farming and often selling timber for export or shipbuilding. Many of these farms have since been abandoned and regenerated into forests. Since Bras d'Or Lake is accessible from the sea, the import-export trade thrived here in the nineteenth century. Visual clues to this former activity are the many remnants of wharves around the lake. Baddeck alone had three major wharves and numerous cargo sheds, principally shipping produce from surrounding farms to the Newfoundland market. Nineteenth-century records indicate that fishing activity took place here, with catches of cod, herring, and mackerel. Significant mineral deposits exist in this area, with gypsum mining at River Denys and Little Narrows, and limestone quarried at Irish Cove. Boating and sailing have become popular activities on the Bras d'Or Lake.

Sites of Special Interest

• Spectacle Island Game Sanctuary - nesting cormorants
• Alexander Graham Bell Museum - aspects of the area's history, focusing on the inventions of Bell at his summer home in Baddeck
• Island Point - spectacular example of karst topography

Provincial Parks and Park Reserves

• Big Harbour Beach
• Ross Ferry
• Baddeck Inlet
• Battery
• Orangedale
• Hay Cove
• Irish Cove
• Castle Bay
• Blacketts Lake
• Dundee

Scenic Viewpoints

• Whycocomagh Bay
• Baddeck
• Marble Mountain
• Irish Cove

Associated Topics T2.4 The Carboniferous Basin T3.1 Development of the Ancient Landscape T6.1 Ocean Currents T6.4 Estuaries T8.1 Freshwater Hydrology T11.4Birds of Prey T11.8 Land Mammals T11.17 Marine Invertebrates T12.2 Cultural Landscapes T12.3Geology and Resources T12.11Animals and Resources

Associated Habitats H1.1 Offshore Open Water H1.2 Offshore Benthic H2.1 Rocky Shore H2.5 Tidal Marsh H3.1 Freshwater Open-Water Lotic H3.3 Freshwater Bottom Lotic H5.2 Oldfield H6.2 Softwood Forest (Sugar, Fir Association; White Spruce Association) Associated Offshore Unit 916 Bras d'Or Lake