<P> Deep waters are rich in nutrients , including nitrate , phosphate and silicic acid , themselves the result of decomposition of sinking organic matter ( dead / detrital plankton ) from surface waters . When brought to the surface , these nutrients are utilized by phytoplankton , along with dissolved CO ( carbon dioxide ) and light energy from the sun , to produce organic compounds , through the process of photosynthesis . Upwelling regions therefore result in very high levels of primary production ( the amount of carbon fixed by phytoplankton ) in comparison to other areas of the ocean . They account for about 50 % of global marine productivity . High primary production propagates up the food chain because phytoplankton are at the base of the oceanic food chain . </P>
zones of upwelling near the shores of land masses have high primary production because such zones
are rich in nutrients , including nitrate , phosphate and silicic acid