Marine Biodiversity in Canada.
Note: Much of this section has been summarized from Day & Roff, 1998 due to their clear and concise description of these environments in the context of marine biodiversity.
Terrestrial Canada is bordered by three oceans (Arctic, Atlantic and Pacific) with 10 of the 12 provinces or territories containing coastal land. Canada harbors the longest coastline in the world with a length of approximately 244,000 km (Day & Roff, 1998). Exhibiting the second largest continental shelf (3.7 million km; DFO, 1997) in the world, it is no wonder that Canada is the home to rocky shores, kelp forests, beaches, estuaries, deep sea, continental shelf, coral reefs and marshes. It hosts a large diversity of species, which utilize 1.3 % of the oceans' surface area. All major phyla of marine organisms exist in Canadian waters including a number of endemic species. Approximately 1100 species of fish exist in our waters (Ocean Voice International) and a number of marine mammals too. These include the humpback, killer, sperm, blue, gray, beluga and Right whales as well as numerous species of dolphins, porpoises, seals, walrus, sea otters and sea lions.
The Arctic Ocean
The arctic and sub-arctic seas of the Canadian north cover an immense area expanding from the Beaufort Sea in the west to Baffin Bay in the east. In addition, this region extends from north of Ellesmere Island to Hudson Bay in the south. The Arctic region is the longest of the Canadian coastlines covering a total of 162 000 km, which represents two thirds of the country's total (Day & Roff, 1998).
The species in the Arctic differ widely from those of the south and exhibit a lower species diversity, probably resulting from the fragile environment located there. The Arctic is a very remote area and it encounters very harsh climate conditions, especially because it is ice-covered for most of the year. There are areas of restricted size termed 'polynyas' that are uncovered for most of the year as a result of ocean circulation and winds. These polynyas are very productive and are most likely linked to food production for much of the arctic marine life.
The Pacific Ocean
British Columbia contains one of the most productive coastal environments in North America, contributing about 4.5 % of the total provincial GDP, which is about twice the value for forestry (Day & Roff, 1998). The west coast encompasses approximately 29 000 kilometres, which is just above 11 % of the country's total (Day & Roff, 1998). This coastal area is of paramount importance to recreational users and industries such as tourism.
Approximately 7000 marine species of flora and fauna have been identified in this region (Austin, 1992), including 616 segmented worms, 1570 Crustaceans, 785 molluscs and 270 sponges. Nonetheless, Austin (1992) estimates that more than double that number most likely exist in these waters. British Columbia actually contains some of the most diverse marine flora in the world, with many species in need of protection (Hawkes, 1994).
The Atlantic Ocean
The Atlantic seaboard contains a massive continental shelf, which varies in width from 110 to 520 kms (Day & Roff, 1998). Its depth varies from 183 to 366 meters on the outer edges (NABST, 1994). The extensive continental shelf has been a rich source of valuable biological resources (i.e. fish, crustaceans, mammals, seaweed), however, currently many of these fisheries are suffering. One very well known example is the northern cod stock, which is now only 5 % of the historical average. Furthermore, the northern right whale population is in decline.
There are many water masses that influence the Atlantic coastal waters of Canada including Hudson Bay, the Labrador current, the St. Lawrence River, the Gulf of St. Lawrence and the Bay of Fundy. Furthermore, the warm, northeasterly flowing Gulf stream affects offshore waters such as those of Georges and Browns Bank.
Austin, B. 1992. Marine Biodiversity in British Columbia, Unpub. summary report, Khoyatan Marine Laboratory & Marine Ecology Station, Cowishan Bay.
DFO (Department of Fisheries and Oceans Canada), 1997. An Approach to the Establishment and Management of Marine Protected Areas under the Oceans Act: A Discussion Paper. January 1997.
Jon Day & John Roff. Planning for Representative Marine Protected Areas: A Framework for Canada's Oceans and the Great Lakes. Draft report for World Wildlife Fund, March 1998.
Hawkes, M.W. 1994. Benthic Marine Algal Flora (Seaweeds) of British Columbia: Diversity and Conservation Status, In Harding, L. and McCullum, E. (eds.), Biodiversity in British Columbia; Our Changing Environment, Environment Canada, Canadian Wildlife Service, 426 pp.
National Advisory Board on Science and Technology, 1994. Opportunities From Our Oceans, Report of the Committee on Oceans and Coasts, National Advisory Board on Science and Technology, Report to Prime Minister of Canada, May 1994