Estuaries are waterways where fresh water from rivers mixes with salt water from the ocean. They sustain an abundance of finfish, shellfish and marine microscopic life as well as valuable habitats such as marshes and underwater grass beds. The definition of estuaries may not be widely known, but they are one of the most commonly used natural features on earth. Estuaries, their shores and adjacent drainage basins have always been popular sites for commercial, recreational, industrial and agricultural activities. The number of people and businesses attracted to estuaries by their recreation, commerce and aesthetics is increasing. Almost fifty percent of the population of the United States lives within fifty miles of the coast. The aquatic life that estuaries support is affected by these growing populations and their use of estuarine resources. Pollution and physical alteration have taken their toll on a number of estuaries and threatens others
