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phosphates and nitrates — such as found in some detergents, fertilizers, and human and animal wastes — since they can destroy the delicate oxygen content in the water.
A mountain stream plunging over rocks and dancing in the sunlight contains abundant oxygen. Fish and other aquatic animals, which take oxygen from the water through their gills, thrive in these clear streams. But when we add too much organic matter or nutrients such as phosphates and nitrates, microbes and algae begin to multiply rapidly, using up oxygen faster than it can diffuse in from the air.
Fertilizers hasten the growth of aquatic plants, whose development and decomposition consume further supplies of oxygen. Fish cannot survive in this contaminated water, and die. This process, called “eutrophication,” eventually fills ponds and streams with muck and turns them into swamps or mar^ shland.
The Environmental Protection Agency (EPA) points out that soil erosion,
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