Textbook Notes (290,000)
CA (170,000)
Western (10,000)
GEOG (300)
Chapter 8

Geography 2131A/B Chapter Notes - Chapter 8: Nautical Mile, Algal Bloom, North Baffin Dialect


Department
Geography
Course Code
GEOG 2131A/B
Professor
Jamie Baxter
Chapter
8

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CHAPTER 8: OCEANS AND FISHERIES
-Canada has the longest coastlines, the longest inland waterway, the longest archipelago, and the
second-largest continental shelf of any country in the world
-EXCLUSIVE ECONOMIC ZONE: the area of exclusive fishing rights granted to Canada in the 1982 United
Nations Convention on the Law of the Sea the zone came into force in 1994 200 nautical miles
-area of extension of Canadian claim (beyond 200 nautical miles) possible under U.N. Convention on the
Law of the Sea as of 2002, this claim had not been initiated
-wild capture fisheries valued at 3.4 billion in 2010
-aquaculture valued at 927 million in 2010
CANADA’S ARCTIC OCEAN: Canada’s coldest ocean, contains about 173,000 kilometers of coastline -
majority of the area is covered seasonally by ice 1 to 2 metres of thick
-maximum sunlight enters the water column in July, after the ice breaks up, limiting phytoplankton
production to the late summer; as a result, Arctic waters produce only about one quarter of the organic
biomass per unit area compared with that produced over the east and west coast continental shelves
-major currents influencing Arctic waters include the flow of polar water southeast through the
archipelago, the West Baffin Current, and the Hudson Bay gyre, a circular current that creates a small,
nearly closed circulation system characterized by nutrient enrichment and high levels of biological
productivity
-currents help maintain open water areas called polynyas
-POLYNYAS: an area of unfrozen sea water, created by local water currents in northern oceans they act
as biological hotspots and serve as vital winter refuges for marine mammals
-the largest polynyas, the North Water in north Baffin Bay allows an early and persistent phytoplankton
bloom
-subsistence hunting and fishing does dominate the Arctic region however, some commercial fishing
does occur - the polar waters only have a certain amount of commercial fishing potential
-subsistence hunting mainly by aboriginal peoples (for food and cultural continuity)
-Narwall is hunted for subsistence but some people hunt them for their valued husks
-arctic ecosystems are particularly vulnerable to contamination by chemical compounds because they
have been transported long distances (in gaseous or vapour from the atmosphere) these compounds
are persistent and lipophilic, which means they tend to concentrate in fatty and protein-rich tissues
-compounds such as PCBs and DDTs bioaccumulate readily in fatty tissues of long-lived animals at the
tops of the food chains
-the long and complex food web (with five trophic levels) in Arctic marine systems allows persistent
contaminents to become highly concentrated in top predators this concentration happens because
predators at each higher level of the food chain accumulate the total chemical contaminent burden of all
their prey
-BIOMAGNIFICATION: the cumulative increase in the concentration of a chemical in successively higher
levels of a food web this explains why PCB levels in marine mammal blubber may be a million or more
times higher than those in the Arctic ocean water
-even locals and Inuits are vulnerable to this toxic chemicals because they are consuming the fish as well
-THREATS TO ECOSYSTEM INTEGRITY IN THE ARCTIC
-Hydroelectric Development: hydroelectric dams and developments in Quebec, Ontario, and
Manitoba will continue to affect rives flowing to the Arctic primarily by increasing water flows
and decreasing summer flows this may also affect changes in ocean currents, nearshore
conditions, nutrient availability, phytoplankton production, etc, fish migrating into the area, etc
etc.
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