It will be cooler if you close to a body of water
A contractile vacuole works just the same as the name suggests, in that it expands and contracts. The point of the contractile vacuole is to pump water out of the cell through a process called osmoregulation, the regulation of osmotic pressure. It occurs in freshwater protists, but mainly in the kingdom Protista as a whole.
Eutrophication results in the death of trout and other fish as a result of asphyxiation from the lack of oxygen. Eutrophication involves the enrichment of water by nutrients salts such as phosphates, nitrates among others, that causes structural changes of the aquatic ecosystem such as; increased production of algae and aquatic plants, depletion of fish species, deterioration of water quality and other effects that impact negatively the aquatic ecosystem.