Excessive anthropogenic nutrient enrichment of phosphorus and nitrogen allow for rapid growth and multiplication of phytoplankton in the Mississippi River. As phytoplankton continue to rapidly grow under optimal conditions, their biomass is almost doubled every 24 hours. In the water, higher concentrations of organic matter are present because of the high reproductive rate of the phytoplankton over a short period of time. The rapid growth of phytoplankton causes turbidity in the waters of the Mississippi and the Gulf of Mexico. Turbidity is defined as the measure of water clarity by how much the suspended material, such as algae and phytoplankton, constrict the passage of sunlight through water. Hence, as phytoplankton begin to multiply more rapidly, turbidity in the river and gulf increases. The increasing turbidity blocks plants from absorbing sunlight. The process of turbidity results in limited photosynthesis production, and sometimes even death from sunlight deprivation of the submerged aquatic vegetation that are affected by the opaque turbid water accumulating at the surface.