British Columbia: Marine Environment

The Catt-Trax2 Team — Fri, 12 Jan 2007 15:33:05 -0800

Report prepared by April Reed and Meghan McKillop, students in BCIT’s Fish, Wildlife and Recreation program.

British Columbia’s marine environment is composed of a diverse array of physiographic and oceanographic features that make it a truly unique ecosystem. From the ocean floor to the continental rise and shelf to the intertidal zones, an array of species live who are endemic to these regions.

A dominant feature of B.C.’s marine environment is the currents currents. The westerly movement of currents, driven by winds and the rotation of the earth, meet the continental shelf and split to the north (forming the Alaska current) and to the south (forming the California current).The splitting of currents allows for upwelling to occur bringing deep nutrient-rich waters to the surface, making B.C. waters very productive.

BC’s ocean is divided into ecozones, ecoprovinces, ecoregions, and ecosections. Twelve ecosections have been defined according to the different physiographic and oceanographic features.

There is a greater diversity of life in the ocean than on land. The ocean is divided up into different layers based on availability of light and nutrient that determines which organisms can survive in the different layers. The most productive layer is the photic layer which is the light zone near the surface. Forty metres below the surface there is not enough light for photosynthesis to occur, and at a depth of 600 m the environment is in perpetual darkness.

The basis of life in the ocean is produced in the photic layer where photosynthetic organisms are able to change light energy into nutrient-rich carbohydrates that feed the rest of the ocean food chain. The food chain is made up of primary producers, primary consumers, secondary consumers, tertiary consumers, quaternary consumers, scavengers and decomposers.

The primary producers are phytoplankton and algae that contain the green pigment chlorophyll in their cells enabling photosynthesis. The phytoplankton and algae live and thrive in the photic layer where they provide the basis of life for the rest of the marine organisms. The primary consumers are the direct link between primary producers and the rest of the food chain. They are made up of zooplankton. Secondary consumers consist of baleen whales, herring, invertebrates and other vertebrate species. They feed on primary consumers and producers. The tertiary consumers are carnivorous organisms such as salmon and sea birds that feed on secondary consumers. Quaternary consumers are carnivorous organisms at the top of the food chain such as killer whales and sea lions that feed on tertiary consumers. Scavengers and decomposers feed on dead plants and animals and are important in returning nutrients to the ocean and benthic communities.

The marine environment is a delicate ecosystem that relies on all levels of the food web. The combination of physiographic, oceanographic and biological features give rise to the exceptional diversity in B.C.’s marine environment.

References

Acorn, John and Nancy Baron. 1997. Birds of Coastal British Columbia. Lone Pine Publishing, Edmonton, A.B., 38–39, 48–57, 74,128 pp.
Butler, Robert. 2003. The Jade Coast: The Ecology of the North Pacific Ocean. Key Port Books Ltd. 70 The Esplanade. Toronto, Ontario, Canada. M5E 1R2. 176pp.
Cannings, Richard and Sydney Cannings. 2004. British Columbia: A Natural History Revised and Updated. Greystone Books, Vancouver, B.C. 102–137 pp.
Eder, Tamara. 2001. Whales and other Marine Mammals of British Columbia and Alaska. Lone Pine Publishing, Edmonton, A.B., 76–78, 86–89, 92–99,118–123, 129–131, 149–153 pp.
Hewlett, Stefani. 1976. Sea Life of the Pacific Northwest. McGraw-Hill Ryerson Ltd. 176 pp.
Lamb, Andy, Hanby, Bernard P. 2005. Marine Life in the Pacific Northwest: A photographic encyclopedia of invertebrates, seaweeds, and selected fishes. Harbour Publising P.O. Box 219 Madeira Park, BC V0N 2H0. 398 pp.
McConnaughy, Bayard H., McConnaughey, Evelyn. 1986. Audubon Society Nature Guides Pacific Coast. Borzoi Book published by Alfred A. Knopf, Inc. New York
Ocean Link
Wikipedia

Catt-Trax 2 - Marine

British Columbia: Marine Environment

References