Furthermore, a significant detrimental outcome caused by eutrophication in the Mississippi River is the increased uptake of dissolved oxygen by bacteria, in response to higher concentrations of organic matter. After eutrophication starts and is in progress, the phytoplankton reach their maximum population density and begin to die. As the dead phytoplankton accumulate, detritus, or organic matter waste, forms at the surface along with other bacteria and algae. As more phytoplankton die, the higher the concentration of organic matter becomes; and with a higher concentration of organic matter, more bacteria will reproduce.