March 12, 2007 2:38am CST
They are found in lakes, rivers, oceans or at places which are wet and moist. The largest proportion of photosynthetic activity around the world is due to algae. This activity of the algae facilitates reduction of the carbon dioxide content and increase the oxygen content in the atmosphere. Algae consumed as food by fish and other aquatic animals. There are different kinds of algae. blue green algae, brown and red algae, green algae, and diatoms.