Aquatic ecology and Biodiversity

Unit 9- Freshwater environment

9.1. Freshwater environment
The abundance of water on the earth's surface is a unique feature that distinguishes the blue planet from others in the solar system. The balance, continuation and overall equilibrium of a system based on a balance of a specific set of values considered normal in maintaining the specific system is referred as homeostasis. This can refer to an environment, planet, or body. All living things must maintain a level of homeostasis to survive. The term homeostasis is often considered in science and in medicine as a means of maintaining the equilibrium of the body.

The earth's hydrosphere consists chiefly of the oceans, but technically includes all water surfaces such as seas, lakes, rivers, and ground waters. About 97.5% of the water is saline, while the remaining 2.5% is fresh water. The majority of the fresh water is currently in the form of ice. The aquatic habitats together with their communities are called aquatic ecosystems. Aquatic communities of organisms are dependent on each other and on their environment. Environment with water is called as aquatic ecosystem. An ecosystem refers to all the living and non-living things of plants and animals of an area and their interactions. Water is a medium which immediately surrounds the aquatic organisms. Water is described as the mother of life. It is a liquid gold and is the universal solvent. It occupies 71% of the earth surface.