-The most important life processes in the oceans or sea water are photosynthesis and respiration. Photosynthesis by plants and other lower organisms uses sunlight to convert CO2 and H2O to a carbohydrate compound; O2 is a by-product of that reaction. Respiration is the process that all organisms use to recover the chemical energy stored in organic compounds. O2 is used to oxidize organic matter and release chemical energy; CO2 and H2O are by-products.
-The rates of photosynthesis and respiration are nearly balanced.all of the organic matter produced by photosynthetic algae is respired by consumer and decomposing organisms.