Ministry of Environment Ecology

PART II
Ecoregion Unit Descriptions

Cool Oceanic Ecodomain

This Ecodomain extends from the eastern Asian shore to western North America, north of the North Pacific Current (latitude 40 N). It is characterized by counterclockwise rotating oceanic gyres and a slow-moving westerly sub-Arctic current. In western Canada (British Columbia) it occurs from the "200-mile (300 km) Economic Zone" to the continental shelf and is classified into only one Ecodivision.

Sub-Arctic Pacific Ecodivision

Northeast Pacific Ecodivision

This Ecodivision occurs within the oceanic or deep-sea portion of the province. It contains the continental rise portion of the margin of the continent. The Sub-Arctic Current has a broad, slow easterly drift. Near the coast of North America a divergence in the prevailing wind pattern causes the current to split; a northern branch to the northeast into the Gulf of Alaska (Alaska Current). The coast off British Columbia is at the point of this split with the Alaskan Current reaching west of Queen Charlotte Sound in the winter and the northern Queen Charlotte Islands in the summer. The California Current reaches south of British Columbia in the winter and northern Vancouver Island in the summer. In western Canada it is subdivided into only one Ecoprovince.

Northeast Pacific Ecoprovince

Location - This Ecoprovince is the oceanic portion of British Columbia west of the Continental Slope to the "200 mile Economic Expansion Zone". It consists of the Continental Rise and the Continental Slope.

Climate - From late autumn to early spring, winds are predominantly from southeast to southwest as the air circles counterclockwise around the dominant Aleutian Low, while from late spring to early autumn, the combined effect of a greatly weakened Aleutian Low and intensified North Pacific High results in a clockwise flow of air over the ocean. Coastal winds at that time are predominantly from the northwest.

Marine Zonation - This Ecoprovince lies almost entirely in the dilute salinity domain, where fresh water discharge from the coast has diluted the upper layer of the ocean. Most of it is deep sea with epipelagic, mesopelagic and bathypelagic zonation, however, there are a few seamounts that rise to near the surface and a long continental slope with complex zonation that extends the length of this Ecoprovince.

Fauna - Marine mammals that occur in this Ecoprovince include northern fur seal, sperm whale, Pacific white-sided dolphin, and Dall's porpoise.

At least 158 nonpasserine bird species have been reported from the Ecoprovince. Characteristic species include Laysan Albatross, Northern Fulmar, Pink-footed Shearwater, Buller's Shearwater, Short-tailed Shearwater, Red Phalarope, the jaegers, South Polar Skua, Black-legged Kittiwake, and Sabine's Gull. Many passerine species occur at sea but only as migrants. Undoubtedly, thousands perish before reaching land.

This Ecoprovince supports a wide variety of oceanic fishes, some like the great white shark, basking shark, albacore, and ocean sunfish are trans-oceanic migrants, others like the five species of pacific salmon spend part of their life in the deep ocean and the rest over the continental shelves or in freshwater streams. There is a wide variety of fish and the way in which they live, some like the deepsea skate spend their life near the deep ocean floor, while others like the northern lanternfish, and bulbous dreamer live away from the bottom in the deep ocean.

Ecoprovince Subdivisions - The Northeast Pacific Ecoprovince is divided into two Ecoregions, containing five Ecosections.

• The Continental Rise Ecoregion is the deep sea portion of British Columbia. In British Columbia it is represented by two Ecosections.

• The Alaska Current Ecosection is that portion of the deep sea that is predominantly influenced by the counter-clockwise moving Alaska Current. In the British Columbia waters, the current flow is generally northward throughout the year. This Ecosection is part of the dilute oceanic domain, where freshwater discharge has diluted the upper layer of the Northeast Pacific Ocean.
• The Alaska - California Transition Current Ecosection is a portion of the deep sea that is influenced by variable currents; southerly areas may be affected by southward-flowing California Current in summer but remainder of the area is characterized by weak and variable currents. This Ecosection is part of the dilute oceanic domain, where freshwater discharge has diluted the upper layer of the Northeast Pacific Ocean.

 

• The Continental Slope Ecoregion is the steep-walled oceanic area that extends the length of the northwestern potion of the North American Continent. Nutrient-rich, upwelling currents are common throughout its length. In British Columbia it is represented by three Ecosections.

• The Queen Charlotte Islands Slope Ecosection is off-shore from the Queen Charlotte Islands. It is influenced by the northward flowing Haida Current in the winter months, and by the generally, northerly flowing Alaska Current in the summer months. It is a steep-walled slope that extends from the shore of the islands to the Queen Charlotte Trench.
• The Outer Queen Charlotte Sound Ecosection is an oceanic area with complex canyons, troughs and banks, lying midway between the Queen Charlotte Islands and Vancouver Island. This area is influenced by the coalescing of the northward flowing Davidson Current over the Continental Shelf and the northeasterly flowing Alaska Current from the Northeast Pacific.
• The Vancouver Island Continental Slope Ecosection is an area of steep canyons and ridges that lies to the west of the Vancouver Island Continental Shelf. It is influenced by the southerly flowing California Current.

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