Gulf of Alaska
Despite the dominance of downwelling-favorable winds, the water overlying the northern coast of the Gulf of Alaska has achieved high biological productivity. Several physical processes enhance its nutrient supply and primary productivity. Nutrients can be transported to the northern part of the Gulf of Alaska through advection, river discharge, estuarine circulation, tidal mixing, mesoscale eddy formation and transport, sediment resuspension, the relaxation of summer downwelling winds, Ekman transport of surface water from the central Gulf of Alaska basin onto the shelf during winter. This is important for marine mammals, fish and birds. The productivity in the Alaska Current System supports some of the nation's largest fisheries and large numbers of birds and mammals.