Download Canada`s Marine Environments

Canada’s Marine Environments
The Arctic Ocean
• Coldest ocean area
• ~173 000 km of
coastline
• Seasonally covered in
ice
• Key Polynyas in the
region
• These are biological
hotspots, unfrozen
sea ice
• Subsistence hunting and fishing are the
major human uses in the region
• Only a small arctic char commercial fishery
• It was probably fished at or above the maximum
sustainable yield
• Large marine mammals dominate the region
• Some subsistence hunting of whales, even the
endangered Bowhead whale
• Bioaccumulations and biomagnifications are
large problems with marine life in the arctic
• Hydroelectric dams on rivers flowing into the
arctic region are having serious affects on
anadromous fish species
• Climate change is the largest and most serious
threat to the Arctic marine environment
• Will/is having dramatic affect on sea ice cover
• Oil/gas exploration as well as diamond mines are
also threatening the area
Pacific Ocean
• Smallest coastline
• Warmest waters
• Mixing of north and
south currents creates
a highly productive
region
• Major fish species
include: 5 species of
salmon, 3 species of
trout
• Cod, flounder, lingcod, herring, shrimp,
crabs, scallops, clams are all important
commercial fish
• Commercial fishing in BC employed 5400
people (declining) made ~ $358 million
• Recreational fishing in BC employed 8900
people and made ~ $675 million
• Today the BC salmon fishery is collapsing
- see articles posted on website
Threats include:
• Rising ocean temps
• El nino
• Wastewater is the
worst offender
• Urban and
agricultural runoff
• Oil
• Chemical spills
Atlantic Ocean
• Used to be world’s
richest ground for Cod
• Said to be so thick
they would slow ships
• 1992 moratorium on
cod
• Stocks declined 97%
in 30 years
• Cod is now and
endangered species
• Coastline is about 40 000 km
• Large continental shelf
• High levels of biological activity because of the
meeting of warm Gulf Stream and cold Labrador
Current
• Upwelling occurs here… lots of nutrients
• Nova Scotia current also plays a role
Threats
• Lack of knowledge
• Marine pollution
• Municipal and
industrial effluent
• Heavy metals
• Improper total
allowable catches
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Pulp and paper mills
Mines
Food processing plants
Agricultural runoff
Discarded fishing nets
(ghostfishing)
• bycatch