This ecozone covers the entire Canadian portion of the Pacific Ocean and
extends north to the Bering Sea.
Sea ice is absent for the most part from the northeast Pacific.
Seasonal ice occurs only at the northern boundary in the Bering Sea, in
the Sea of Okhotsk and in the sheltered bays and inlets throughout the
zone, particularly those with freshwater discharges.
Physiographic isolation restricts water exchange between the Arctic
marine ecozone and the Pacific marine ecozone. Temperature and
salinities are higher than in the Arctic Ocean.
These environmental differences are reflected in the differing ocean
plankton species composition of the Arctic and Pacific oceans (Hemleben
et al., 1988). Based on zoogeography and temperature regime, this
ecozone may be considered as a boreal transition zone between the polar
waters of the Arctic and the temperate waters of the Pacific Ocean in
mid-latitudes (Thomson, 1981).
Between the southern tip of Vancouver Island and Dixon Entrance, ocean
surface temperature declines approximately 3 degrees C and reflects a steadily
changing environment with progression northward. At any one latitude
within this ecozone, oceanic water temperatures range approximately 7 degrees C
seasonally, which is reflected by differences in the characteristics of
the biological community.
Marine mammals are represented by Steller sea lions, sea otters,
northern fur seals, killer and grey whales and others. Five species of
salmon, Pacific herring, halibut and other groundfish form the backbone
of the commercial fishery. Overall, this ecozone provides habitat for
approximately 3,800 species of marine invertebrates, representing about
3.5% of the world's invertebrates (B.C. Ministry of Environment, Lands
and Parks and Environment Canada, 1993).
Breeding bird populations include petrels, murrelets and auklets, with
some puffins and murres. All of the B.C. breeding populations of
Brandt's cormorants occur on the west coast of Vancouver Island.
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