Water is a very essential component of life and without it drastic changes can take place in the environment and endanger living beings. Water is the primary factor that controls the environment and - also the plant and animal life. Fluctuating water levels for varying lengths of time lead to the development of plants and animals different from those found in habitat that is purely aquatic or totally dry. Water is found in oceans, seas, rivers, lakes, ponds and wetlands. However, we shall confine the discussions to wetlands and lakes only.