Water Pollution
Water pollution is any chemical, biological or physical change in water quality that has a harmful effect on living organisms or that makes water unusable for desired uses. The watershed's physical and chemical condition is important because it must be "healthy" for use by plants, animals, and people.
The potential introduction of contaminants to water introduces a dimension of complexity in maintaining the ecological value of estuaries. Because each watershed is a unique ecosystem with respect to its size, position in the landscape, shape, hydrology, soil, and vegetation, its ability to combat the various forms of contaminants depends upon its natural ability to perform at optimal levels.
