Algal blooms. Aerial photograph of the river Grosser Ostersee, Germany with, algal blooms lining the shores (light green). The blooms are caused by phytoplankton, microscopic plants. These blooms occur as a result of a change in the nutrient levels of the river. Contamination by sewage or fertilisers can increase the water's mineral content, which accelerates the growth of all plants, particularly aquatic algae.
Model release not required. Property release not required.