Geology & Seabed Morphology | Sediments | Oceanography Plants | Animals | Cultural Environment | Sites of Interest Topics & Habitats

Geology and Seabed Morphology
The Bay of Fundy is underlain by the Fundian Lowlands formation of Triassic sedimentary rocks. It can be divided into the Inner Bay (Unit 913), consisting of the semi-enclosed Minas Basin and Chignecto Bay, and the Outer Bay (Unit 912), the remaining portion that opens onto the Gulf of Maine. Bottom topography roughly parallels the coastline, sloping gradually away from it.

Tidal currents have formed significant surface features in the Outer Bay of Fundy/Gulf of Maine system, including extensive fields of sand waves, small ripple-like features, and isolated megaripples. The sandwaves are up to 18 m high and 183 m in length. An extensive field of sand waves occurs just east of Grand Manan Island at depths of 60-100 m and in scattered fields to the south and southwest of Lurcher Shoal (60-80 m). Large sand waves (up to 6 m high) with crests perpendicular to the tidal direction occur seaward of Minas Basin in Scots Bay.

Sediments
Shallower portions of the Outer Bay of Fundy have coarse sands and gravel "lag" formed when fine fractions of sediment are removed by currents. Deeper parts have a sandy bottom with silt and clay mixed in, and glacial till in the fringe areas.

The Outer Bay of Fundy lacks the intertidal mud flats and salt marshes of the inner reaches; the bottom consists of exposed bedrock and a coarse sand and gravel substrate winnowed by tidal currents. Rock formations in the Bay of Fundy are extensions of those that make up the shoreline. This area frequently has a range of wave-like bottom features, but often exposed bedrock occurs.

Oceanography
Tidal circulation predominates in the area. Secondary variations on tidal circulation occur seasonally because of freshwater runoff and the proximity of the slope water front. The ocean environment is determined by the environmental condition of Scotian Slope waters far offshore, tidal and residual currents, slope water incursions, and atmospheric influences (see T6.2). Storm waves can also be significant. The Outer Bay is cooler because of deeper water being brought to the surface by tidal action.

Plants
Seaweeds are distributed on rocky shores on both sides of the Bay of Fundy. The biomass is dominated by a small number of species of seaweed, including the rockweeds Ascophyllum nodosum, Fucus vesiculosus, F. edentatus, and F. spiralis. The extreme lower littoral and sublittoral zones are dominated by the kelps Laminaria digitata, L. longicruris, Alaria esculenta, and Agarum cribrosum.

A frontal zone at the south side of the mouth of the Outer Bay leads to high plant productivity, large populations of herbivorous and detritus-feeding animals, and eventually to concentrations of animals of higher trophic levels. The dominant intertidal alga is the rockweed Ascophyllum nodosum.

Tidal mixing at the mouth of the Bay of Fundy is important in the growth, during the summer months, of the dinoflagellates that cause paralytic shellfish poisoning.

Animals
Major stocks of scallops (Digby Scallops) are found in nearshore waters off (and to the east and west of) Digby Neck, partially in response to the elevated productivity in the water. The area also supports strong lobster populations. Herring spend the summer feeding in nearshore zones. Witch Flounder are locally abundant in deeper waters at the mouth of the Bay of Fundy, and large spawning populations of Red Hake occur in Passamaquoddy Bay. Inshore concentrations of Atlantic Halibut are known around Grand Manan. Large populations of the euphausiid Meganyctiphanes I>norvegica are present near the mouth of the Bay of Fundy.

Species of bottom animals are similar to those in the Atlantic Unit 911, but the area has several localized concentrations of particular species, probably related to the tidal currents and rock bottom in some places. Dense beds of the Horse Mussel occur across the Outer Bay from inside Digby Neck to inside Saint John Harbour. Horse Mussels are the most important suspension-feeding organisms in the Unit. Concentrations of the brachiopod Terebratulina septentrionalis occur seaward of those areas in the central axis of the Bay of Fundy. The burrowing polychaete Sternaspis scutata and the tube-building amphipod Haploops fundiensis are common in silt-clay bottoms towards the outer portion on the New Brunswick side. The deep-sea Red Crab occurs in deeper parts of the area on mud, sand, or hard bottoms.

The Outer Bay of Fundy has been recognized as a feeding ground for Right Whales during the summer and autumn. The vicinity of Grand Manan Island is visited by a population of about 200 Northern Right Whales in summer, and they can be observed in Head Harbour Passage, Grand Manan Channel, and along the edges of Grand Manan Basin.

Southernmost breeding colonies of Atlantic Puffin and Razorbill occur on Machias Seal Island near Grand Manan Island in the Outer Bay of Fundy.

Cultural Environment

The highly productive waters of the Outer Bay of Fundy support important fisheries that form the economic basis of many communities. The summer herring fishery, scallops (Digby), and lobsters are most important. Lurcher Shoal is an important area for commercial scallop fishing. Herring are caught from the shore using weirs in some places, adding a distinctive feature to the coastal landscape. Harvesting of dulse, Irish Moss, and the rockweed Ascophyllum nodosum is locally important. Shell fisheries are usually closed in summer because of the danger of paralytic shellfish poisoning. The Annapolis Basin is the site of the first permanent European settlement in Canada (1605), and Digby remains a centre for marine fisheries and transportation. Bay of Fundy tides have been harnessed to generate electricity on the Annapolis River at Annapolis Royal. Tidal marshes have mostly been dyked and drained for farmland. The high productivity of the waters of the Bay of Fundy provide food for seabirds and marine mammals, including the Humpback Whale, which are important tourist attractions.

Sites of Special Interest

• Brier Island - the waters off this island at the mouth of the Bay of Fundy are important feeding areas for seabirds, particularly phalaropes and shearwaters from July to September and murres and kittiwakes in the winter; in fall and winter the Red Phalarope is largely confined to restricted zones such as the tide-rips in the Bay of Fundy; Northern Right Whales are seen in summer
• Digby Neck area - intertidal populations of Common Periwinkle
• "French Shore" of Nova Scotia (St. Marys Bay) - known for coastal fog

  Associated Topics T3.5 Offshore Bottom Characteristics T6.1 Ocean Currents T6.2 Oceanic Environments T11.7 Seabirds and Birds of Marine Habitats T11.12 Marine Mammals T11.14 Marine Fishes T11.17 Marine Invertebrates T12.2 Cultural Landscapes T12.10 Plants and Resources T12.11 Animals and Resources

  Associated Habitats H1 Offshore H2 Coastal Associated Coastal Districts and Units 311 Cobequid Hills 710 Basalt Headlands 810 Basalt Peninsula 820 Cliffs and Beaches