From: NASA MODIS Web
Posted: Tuesday, July 14, 2009
In the upper left corner of the image is Vancouver Island.
Further south is (across from the left) Washington State, and south of Washington, part of Oregon. The bright green patches (one of which is right up against the southwestern shore of Vancouver Island) are caused by millions of tiny ocean plants called phytoplankton. The coastal waters of the Eastern Pacific are productive because wind and ocean currents allow nutrient-rich water from deep in the ocean to rise to the surface. The cold, rising water carries phosphates and nitrates, which act as fertilizer to the phytoplankton that grow in the sunlit waters at the oceanís surface. Since phytoplankton are the base of the food chain, areas that support large phytoplankton blooms tend to have large fish populations. Off the coast of Vancouver Island and Washington State, phytoplankton blooms tend to happen when winds blow down the coast from the north. The winds push the oceanís surface water west, out to sea. Deep water rises up to replace the wind-blown surface water, and it carries the nutrients needed to support phytoplankton blooms.
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