The result is a loss of living resources such as oysters, blue crabs, fish and the bay s underwater grasses. Excess nutrients cause algal blooms - Nutrients, such as nitrogen and phosphorus, are essential for plant growth and, thus, for primary productivity in the estuary. Excess nutrients cause algae populations to grow rapidly, or bloom, and can lead to shifts in algal species that do not support desirable aquatic life. This is why nutrient reduction will help improve the condition of the bay. Algae occur as tiny single-cell plants called phytoplankton or as larger seaweeds growing on rocks and jetties.
Phytoplankton blanket the surface of the water and turn water brown or blue-green.
Algae also grow directly on leaves of SAV, further limiting essential sunlight. The result is that these vital underwater plants die. Many fish, waterfowl and shellfish depend on SAV as their primary habitat and food source. When algae die, they sink to the bottom where their decomposition uses up dissolved oxygen. Dissolved oxygen is a major factor affecting survival, distribution and productivity of living resources in the Chesapeake Bay.