Phosphates and Aquatic Plant Growth: Understanding the Impact

Plants require phosphorus to grow. Organic phosphates in particles or in solution stimulate aquatic plant growth.

Phosphate Sources

• Phosphates can come from detergents and organic pesticides that run off into the water. Phosphorus also comes from the erosion of natural rock.

Limiting Nutrient

• Because phosphorus may represent the single nutrient that limits the growth of aquatic plants, most areas in the US ban phosphorus-containing detergents, according to the MadSci Network.

Excessive Growth

• When aquatic plants multiply excessively, they consume large amounts of oxygen in the water and can clog waterways.

Decay

• More plants also means an increase in dead vegetation. The organic decay also consumes dissolved oxygen and can harm other aquatic life, such as fish.

Ideal Concentrations

• Healthy phosphate levels in water range from 0.04 to 0.21 mg per L depending on factors such as the local rock substrate, according to Sewanee University.