Sustaining Life in Canada's Seas
Burridge, Mary, Healy, Claire, ROM Magazine
Will we learn from our mistakes in the Atlantic and Pacific in time to preserve the Arctic Ocean's fragile ecosystem?
Oceans play such a major role in defining Canada that they form the basis of our national motto: "From Sea to Sea." From the early colonization of this continent by maritime peoples along the Pacific Rim, and European colonization via the Atlantic coast, to future exploration of the Arctic Ocean as it emerges from ice, Canada's past, present, and future are embodied by our three oceans.
Even though the Arctic, Atlantic, and Pacific are interconnected, each has its own unique features: currents, topography, biodiversity. At more than 200,000 km, Canada's is the world's longest coastline, 68 percent of which is in the Arctic. Including the exclusive economic zone (or "200 mile limit"), 36 percent of Canada's territory is ocean.
The earliest recognized and still most renowned underwater feature of Canada's oceans is the Grand Banks off the southeast coast of Newfoundland. There lies a group of underwater plateaus at relatively shallow depths. It is a place where the cold water of the Labrador Current mixes with the warm water of the Gulf Stream, lifting nutrients to the surface. Plankton flourish, providing the foundation of a complex, productive food web and one of the richest fishing grounds in the world. When John Cabot reached the Grand Banks in 1497, legend says there were so many cod in the water that one day his ship ceased moving. When his sailors lowered buckets, they pulled them up filled with cod.
This vast supply of Atlantic cod drew the first European fishers (and, later, settlers) to what is now Canada. For hundreds of years, the cod stocks seemed inexhaustible. But in 1992, following a 20-year decline, the cod population crashed and the fishery collapsed. The cause? Massive overfishing, facilitated by industrial methods and bottom trawling. The cod population was estimated to be 2 billion individuals at its peak, even greater than that of the American bison. The decline of the cod is considered to be the greatest loss of a vertebrate in Canadian history.
Not only did the cod almost vanish but so did 40,000 jobs in Atlantic Canada and a whole way of life.
The Atlantic cod is a keystone species, playing a critical role in shaping the composition of its ecosystem. Its collapse affected not only the fishery, but also hundreds of species linked to it, as predators and prey, by complex food web relationships. Is there any hope for its recovery? The future for cod still seems bleak, although a glimmer of hope did surface in 2010. The southern Grand Banks cod population reached its highest level since 1994--but that was still just 10 percent of what it was in the 1960s. Clearly, only careful management of the cod fishery will enable this population and others to recover. Government, harvesters, retailers, and consumers alike must take part to ensure that such a disaster never occurs again.
On the west coast of Canada, an extraordinary ecosystem known as the Great Bear Rainforest is inextricably linked to the Pacific Ocean. This is one of the largest tracts of temperate rainforest left in the world, covering more than 2 million hectares of land. Here, wild salmon rivers and the adjacent cold-water seas provide food for such magnificent creatures as orca, humpback whale, coastal grey wolf, bald eagle, grizzly bear, and the rare and mysterious spirit bear. Pacific salmon, including chinook, coho, sockeye, chum, and pink salmon, connect life on land, river, and sea. …