Water stagnation

Encyclopedia : W : WA : WAT : Water stagnation

Water stagnation occurs when water stops flowing. Stagnant water can be a major environmental hazard.

Contents

1 Dangers
2 Causes and prevention
3 Life in stagnant water

3.1 Species that may thrive in stagnant water

3.1.1 Bacteria
3.1.2 Fish
3.1.3 Insects
3.1.4 Other

4 Miscellanea
5 See also

Dangers

Mosquito larvae in stagnant water

Malaria and dengue are among main dangers of stagnant water, which can become a breeding ground for the mosquitoes that transmit these diseases.

Stagnant water is dangerous for drinking because of greater rate of the reproduction of bacteria and potential parasites.

Causes and prevention

Stagnant water may be classified into the following basic, although overlapping, types:

Water body stagnation: stagnation in lakes, lagoons, rivers, etc.
Surface and ground water stagnation
Trapped water stagnation. The water may be trapped in human artifacts (discarded cans, tyres, dug-outs, roofs, etc.), as well as in natural containers, such as hollow tree trunks, leaf sheaths, etc.

To avoid ground and surface water stagnation, drainage of surface and subsoil is advised. Areas with a shallow water table are more susceptible to ground water stagnation due to the lower availability of natural soil drainage.

Excessive watering may cause ground or surface water stagnation.

Life in stagnant water

Some plants prefer flowing water, while others, such as lotuses, prefer stagnant water.

Species that may thrive in stagnant water

Bacteria

Various anaerobic bacteria are commonly found in stagnant water.

Fish

Insects

Stagnant water is the favoritre breeding ground for a number of insects.

Mosquito larvae
Fly maggots
Dragonfly nymphs
Nepidae (water scorpions)

Other

A number of species of frogs prefer stagnant water.
Algae
Biofilm
Some species of turtles
*Mata mata

Miscellanea

Pools of stagnant water have been historically used in processing of hemp and some other fiber crops, as well as of linden bark used for making bast shoes. Several weeks of soaking makes bast easily separable due to bacterial and fermentative processes.