Nutrients In theory, approximately 150 mg of nitrogen and 30
mg of phosphorus are utilized in the conversion of 1 g of hydrocarbon to cell materials (Rosenberg & Ron, 1996). When a major oilspilloccurs in marine and freshwater environments, the supply of carbon is dramatically increased and the availability of nitrogen and phosphorus generally becomes the limiting factor for oil degradation (Atlas, 1984; Leahy & Colwell, 1990). In marine environments, nutrient limitation is generally correlated to the low background levels of nitrogen and phosphorus in seawater (Floodgate, 1984). Nutrient concentrations are more variable in freshwater systems where lakes and wetlands range from oligotrophic to eutrophic; rivers can be nutrientpoor at the source, but generally become nutrient-rich downstream after receiving industrialand domestic effluents and agricultural runoff (Cooney, 1984). Freshwater wetlands are typically considered to be nutrient limited, due to heavy demand for nutrients by the plants. They are also viewed as being nutrient