Water pollution has become an issue of great concern in our society.There are overwhelming factors that contribute to the problems of water pollution such as sewage, radioactive wastes, improper disposal of trash on land, and careless beachgoers.There are many types of water ecosystems such as oceans, rivers, lakes, and ponds witch provide homes to many different organisms.This causes a problem for al Ithe organisms because the nutrients cause the algae and water plants to grow to abnormally large sizes.The first few causes of water pollution include sewage and nutrients from fertilizers being dumped into water.As the wastes decompose it uses up oxygen and blocks the flow of water in natural rivers and streams.Fish and other organisms living in water need oxygen just as much as humans need it. Since all aquatic organisms depend onoxygen in the water, without a sufficient supply they will not be able to survive.