The GOA The Gulf of Alaska is renowned for its marine productivity, generating billions of dollars in income from the fishing industry, not to mention the tourists who come to catch a lunker. A north wind is responsible for the productivity in the Gulf of Alaska. The wind (blowing north to south, so deflecting westward) pushes water off of the coast of Alaska. This deficiency drives deeper waters to upwell. Upwelling water brings nutrients from the depths to surface waters, where organisms utilize them. As water is forced south toward the center of the subarctic gyre, it displaces water which must go down. since water generally does not compress. Another way to think of this is the Ekman transport diverts water away from the center of the gyre, so a gradient forms at the surface toward the center, which is the sink. The Alaska gyre's edges are then replenished by upwelling, as the water forced down in the center displaces deeper water that cycles back to the surface at the edge. source: http://www.pmel.noaa.gov/people/hermann/globecpub99/sitka-web-jan2000.htm