Primary Nutrients and Eutrophication
Nitrogen and phosphorus are essential to all life. Both are essential nutrients for plant growth. Aquatic vegetation of the free floating type such as algae depends on dissolved nitrogen and phosphorus compounds for nutrient supply. Growth of these species may also be influenced by the availability of other required elements.
Dense, rapidly multiplying algal growths or blooms sometimes occur in water bodies that periodically receive increased concentrations of nitrogen or phosphorus. These dense growths are generally undesirable to water uses and may interfere with other forms of aquatic life. If the water body undergoes an algae bloom, then algal debris accumulates as a result of the sudden die back of the algal bloom. The decomposition of this oxidizable bloom consumes dissolved oxygen.
The enrichment of a Water body with nutrients is termed eutrophication by limnologists, and is accompanied by a high rate of production of plant material in the water. High production is stimulated by increased amounts of primary nutrients. Troublesome production rates of vegetation presumably can only occur when optimum supplies of all nutrients are present and available, but it seems obvious that the rates at which nutrients can become available must be considered.