Freshwater Biodiversity - Chapter 7

Source: Food and Agriculture Organization of the United Nations, 2013, David Coates and Jacquie Grekin, CBD,   "The Youth Guide to Biodiversity" 1st Edition (Chapter 7) Youth and United Nations Global Alliance. Reproduced with permission.

Chapter 7. Verbatim.

Freshwater includes rivers, lakes and wetlands and are habitats which are rich in biodiversity. Such systems provide us with many services such as our drinking water, food (such as fish), a means of transport as well as recreational opportunities. Unfortunately freshwater systems are some of the most endangered habitats in the world and have alarming rates of species extinction.

 lake chad basin, africa. © FA O/Marzio Marzot

What Are Fresh Water Ecosystems?

Simply put, “fresh” water is water without salt, whichdistinguishes these environments from marine, or saltwater, ecosystems. There are many kinds of freshwater ecosystems, such as:

Rivers: in which the water flows, usually towards the sea. 

Lakes: larger areas of standing water (shallow or deep). 

Wetlands: areas of land covered either permanently or temporarily with water, usually shallow, covered by plants (including trees) which grow out of the water or mixed with areas of open water. Examples of wetlands include swamps, marshes, bogs, peatlands, estuaries, mangroves and rice paddies.

Freshwater ecosystems are part of the landscape and interact with land. For example, rainwater falling on land flows into streams and rivers, and fills up lakes and wetlands, carrying with it nutrients and plant material (such as seeds and leaves). 

But freshwater ecosystems also supply water to land environments – for example, they provide water to recharge water stored below ground (groundwater), which supports plants living on land (such as forests). These movements of water are part of the “water cycle” (see box: “The Water Cycle”), which connects land, “groundwater”, freshwater and coastal areas.