CentralNotice From Wikipedia, the free encyclopedia Jump to: navigation , search The Brayton Point Power Station in Massachusetts discharges heated water to Mount Hope Bay . [1] Thermal pollution is the degradation of water quality by any process that changes ambient water temperature . A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. When water used as a coolant is returned to the natural environment at a higher temperature, the change in temperature decreases oxygen supply and affects ecosystem composition. Fish and other organisms adapted to particular temperature range can be killed by an abrupt change in water temperature (either a rapid increase or decrease) known as "thermal shock." Urban runoff — stormwater discharged to surface waters from roads and parking lots —can also be a source of ele...