The St. Ann’s Bay – North Shore region of Cape Breton Island enjoys a range of geology, topography and microclimates, that afford it a diversity of ecosystems both terrestrial and marine, all packed in to a relatively small area. At a latitude of 46 degrees North, the area lies in the transition zone between the temperate hardwood Acadian forest typical of Mainland Nova Scotia and New Brunswick, and the conifer-dominated maritime boreal forest characteristic of Newfoundland and Labrador. This difference is enhanced by elevation and topography, but is both enhanced and moderated by the ocean on the doorstep. Facing northeast out into the Cabot Strait, St. Ann’s Bay comprises highlands of the Cape Breton Plateau to the west and Kelly’s Mountain to the east; steep fore-slopes of the Highlands which descend to the water in St. Ann’s Bay proper and border the Coastal Plain which stretches along the North Shore from Indian Brook to Cape Smokey. The inner bay is relatively shallow, protected by the longshore spit at Englishtown. To the north and east St. Ann’s Bank, a nearshore rise (up to 100 m depth) of the Sydney Bight portion of the Scotian Shelf is divided by a deeper (140 to 200 m) side branch of the Laurentian Channel which parallels the North Shore coastline several km off shore.
Rising 300 m on the west, the Highlands have a colder microclimate and are characterized by boreal forests dominated by balsam fir. Think Christmas trees covered in thick snow. Snowshoe hare bound along on a ten year cycle of population boom and bust. Followed closely by Canada lynx. Moose are plentiful. The steep Fore-slopes that bound the plateau are cut by the deep valleys of mountain streams. North River supports one of the last viable runs of Atlantic salmon on the Atlantic coast of Nova Scotia. Sheltered and warm, and protected by steep slopes from past logging, these valleys harbor a number of climax and old growth stands of tree species approaching their northern limits here. Steep slopes of North River and French River harbor mature Acadian Forest characterized by sugar maple, beech, and yellow birch with pockets of 300 year old hemlock. The steep talus slopes with their deciduous forest mull soils host a rich diversity of soil insects and other invertebrates, and consequently a diversity of small mammals including several species of shrew, rock voles and (the inappropriately named) southern bog lemming. Lots of small prey for a short-tailed weasel. In the trees, look for red squirrels or northern flying squirrels. An American marten could be chasing them. Marten, thought to be extirpated in Cape Breton since the 1970s, were found in North River in the late 1990s, facilitating their re-introduction in the early 2000s. Bald eagles nest in the crowns of white pine which stand above the canopy. Various wood-warblers and (mostly) red-breasted nuthatches feed and nest in the branches below. At the base of the fore-slopes, the Coastal Plain is underlain by different rocks than the plateau and the fore slopes. The underlying rock here was shallow sea bottom during the Carboniferous. About the same time the measures of the Sydney coal fields were accumulating on land, this area was an embayment shallow enough for evaporation to deposit gypsum and other evaporate minerals. The resulting karst topography is evident at Plaster Provincial Park and in sinkhole ponds along much of the Coastal plain. The gypsum is overlain by glacial tills on which the forest grows. Likely originally similar to the Acadian mixed wood forests up the hills and valley to the west, the forest are now largely second growth, dominated by shade intolerant species such as white spruce, white birch and red maple, all indicators of re-growth following agriculture or burning in the late 1800s – early 1900s. The same mammals are found here as on the hillsides. Fox and bobcat are possibly more common here than further up the slope. Introduced to Nova Scotia in the early 1900s, white-tailed deer was very common along the North shore in the late 1980s before the arrival of the coyote. The passerine bird species of the slopes are augmented seasonally by black ducks, ring-neck ducks and teals on the ponds and by mourning dove and ruffed grouse in the borders of old fields.
The hills and lowlands provide the frame. But the water is the picture. This is St. Ann’s Bay we are describing. The ocean on the doorstep shapes the conditions of life on the edge of the continent. The Nova Scotia Current, emanating from the Gulf of St Lawrence and pushing south west to the Bay of Fundy brings warm water in the summer months and tides of sea ice through late winter. Active ice scour along the North Shore limits seaweed growth in the intertidal. In St. Ann’s Harbour (inside the spit), ice action is reduced in the intertidal. Rock weed and wrack are found at the water’s edge. Mussels and oysters grow in the protected shallows, filtering plankton from the water. Large numbers of juvenile white hake found in the harbour suggest it is an important nursery area for that species. Herring and mackerel migrate into the nearshore to spawn in the summer. Sand lance and pipefish inhabit the side coves of the harbour and Ice fishing for brook trout and smelt occurs there as well, in the winters that ice cover permits. Seals, especially Grey Seals (or Horseheads as they are known locally) often haul out on the Englishtown spit in the late winter. Cormorants and gulls are common sights at the ferry. In June the bird islands on the northeast border of the bay are raucous with nesting colonies of great cormorants, puffins, razorbills, kittiwakes and guillemots.
On the inshore shallows of the Bay outside the spit, the gypsum of the adjacent coastal plain has long ago been eroded away. The underlying rocky sea bottom is forested by kelp in places, by coralline alga in other areas where sea urchins are present. Lurking in cover of the rocky bottom, lobster feed on mussels, sea urchins, starfish and bristle worms. They are harvested from May to July. In season, at the end of the spit by the English town Ferry fishermen cast lines from the shore for the mackerel coming in to spawn. Running parallel to the North Shore from Indian Brook to north of Smokey, is a submarine valley locally known as “the Gutter” that spills out into the abyssal Laurentian Channel. Twice daily, the tide brings cold, nutrient- and oxygen- rich water up from the depths to feed the phytoplankton and zooplankton that support the food chain on St. Ann’s Bay. Cod and other ground fish move in to spawn at the top of the Gutter in April and May. This spawning and rearing ground provides an enormous food supply for the puffins, cormorants and razorbills nesting and rearing chicks from the bird islands next door. Sediments swept by the currents and tides off the rockier bank, settle in the depression providing habitat for snow crab, which is fished either in spring or late summer. Whales frequent these waters, as do gannets flashing white against the sky in headlong dives for fish.
By James Brigland