Water stagnation occurs when
waterWater is an ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71%...
stops flowing.
Stagnant water can be a major
environmental hazardEnvironmental hazard is a generic term for any situation or state of events which poses a threat to the surrounding environment. This term incorporates topics like pollution and natural hazards such as storms and earthquakes....
.
MalariaMalaria is a vector-borne infectious disease caused by a eukaryotic protist of the genus Plasmodium. It is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria, killing between one and...
and dengue are among the main dangers of stagnant water, which can become a breeding ground for the mosquitoes that transmit these diseases.
Stagnant water can be dangerous for drinking because it provides a better incubator than running water for many kinds of
bacteriaThe bacteria are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, and other parasites.
Stagnant water may be classified into the following basic, although overlapping, types:
- Water body stagnation: stagnation in lake
A lake is a terrain feature , a body of liquid on the surface of a world that is localized to the bottom of basin and moves slowly if it moves at all. Another definition is, a body of fresh or salt water of considerable size that is surrounded by land...
s, lagoonA lagoon is a body of comparatively shallow salt or brackish water separated from the deeper sea by a shallow or exposed sandbank, coral reef, or similar feature. Thus, the enclosed body of water behind a barrier reef or barrier islands or enclosed by an atoll reef is called a lagoon. This...
s, riverA river is a natural watercourse, usually freshwater, flowing toward an ocean, a lake, a sea or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water...
s, etc.
- Surface and ground water stagnation
- Trapped water stagnation.
Water stagnation occurs when
waterWater is an ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71%...
stops flowing.
Stagnant water can be a major
environmental hazardEnvironmental hazard is a generic term for any situation or state of events which poses a threat to the surrounding environment. This term incorporates topics like pollution and natural hazards such as storms and earthquakes....
.
Dangers
MalariaMalaria is a vector-borne infectious disease caused by a eukaryotic protist of the genus Plasmodium. It is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria, killing between one and...
and dengue are among the main dangers of stagnant water, which can become a breeding ground for the mosquitoes that transmit these diseases.
Stagnant water can be dangerous for drinking because it provides a better incubator than running water for many kinds of
bacteriaThe bacteria are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, and other parasites.
Causes and prevention
Stagnant water may be classified into the following basic, although overlapping, types:
- Water body stagnation: stagnation in lake
A lake is a terrain feature , a body of liquid on the surface of a world that is localized to the bottom of basin and moves slowly if it moves at all. Another definition is, a body of fresh or salt water of considerable size that is surrounded by land...
s, lagoonA lagoon is a body of comparatively shallow salt or brackish water separated from the deeper sea by a shallow or exposed sandbank, coral reef, or similar feature. Thus, the enclosed body of water behind a barrier reef or barrier islands or enclosed by an atoll reef is called a lagoon. This...
s, riverA river is a natural watercourse, usually freshwater, flowing toward an ocean, a lake, a sea or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water...
s, etc.
- Surface and ground water stagnation
- Trapped water stagnation. The water may be trapped in human artifacts (discarded cans, plant pots, tires, 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,
drainageDrainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies.-Early history:...
of surface and
subsoil----Subsoil Sub:under or beneath.Soil:Earth and groundis the layer of soil under the topsoil on the surface of the ground. The subsoil may include substances such as clay and/or sand that has only been partially broken down by air, sunlight, water,wind etc., to produce true soil...
is advised. Areas with a shallow
water tableThe water table is the level at which the groundwater pressure is equal to atmospheric pressure. It may be conveniently visualized as the 'surface' of the groundwater in a given vicinity. It usually coincides approximately with the 'phreatic surface', but can be many feet above it...
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 that may thrive in stagnant water
Some plants prefer flowing water, while others, such as
lotusLotus is a genus that includes bird's-foot trefoils and deervetches and contains many dozens of species distributed world-wide. Depending on the taxonomic authority, roughly between 70 and 150 are accepted. Lotus is a genus of legume and its members are adapted to a wide range of habitats, from...
es, prefer stagnant water.
Bacteria
Various
anaerobicAn anaerobic organism or anaerobe is any organism that does not require oxygen for growth and may even die in its presence. There are three types: obligate anaerobes, which cannot use oxygen for growth and are even harmed by it; aerotolerant organisms, which cannot use oxygen for growth, but...
bacteriaThe bacteria are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
are commonly found in stagnant water.
- Denitrifying bacteria
Denitrifying bacteria form a necessary part of the process known as denitrification as part of the nitrogen cycle, their primary purpose being to metabolise nitrogenous compounds, with the assistance of the nitrase reductase enzyme, to turn oxides back to nitrogen gas or nitrous oxides for energy...
- Purple bacteria
Purple bacteria or purple photosynthetic bacteria are proteobacteria that are phototrophic, that is capable of producing energy through photosynthesis. They are pigmented with bacteriochlorophyll a or b, together with various carotenoids...
(both sulfur and non-sulfur)
- Leptospira
Leptospira is a genus of spirochaete bacteria, including a small number of pathogenic and saprophytic species...
Fish
- Northern snakehead
The northern snakehead is a fish of snakehead fish native to China, Russia, and Korea. In the United States, the fish is considered to be a highly invasive species...
fish
- Siamese fighting fish
The Siamese fighting fish , also known as the Betta, is one of the most popular species of freshwater aquarium fish. The name of the genus is derived from ikan bettah, taken from a local dialect of Thailand. Betta is...
- Pygmy gourami
*See also: Croaking gourami , which is often confused with the pygmy gourami .The pygmy gourami is a tropical freshwater fish belonging to the Trichopsis genus in the family...
- Spotted barb
The Spotted Barb or Common Barb, Puntius binotatus, is a tropical freshwater fish belonging to the Cyprininae sub-family of the family. It originates in Asia, in Myanmar and the Mekong of Thailand through Indonesia. It is has also become established as an exotic species in Palau...
- Lepisosteidae (gar)
- Walking catfish
The walking catfish, Clarias batrachus, is a species of freshwater airbreathing catfish found primarily in Southeast Asia, so named for its ability to "walk" across dry land, to find food or suitable environments...
Insects
Stagnant water is the favorite breeding ground for a number of
insectInsects are arthropods, having a hard exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae. They are the most diverse group of animals on the planet and include more than a million species that are already described. Insects represent more than half of all...
s.
- Mosquito
Mosquito is a common insect in the family Culicidae...
larvae
- Fly
True flies are insects of the order Diptera , possessing a single pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax....
maggots
- Dragonfly
A dragonfly is a type of insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera. It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...
nymphs
- Nepidae
Nepidae is a family of insects in the order Hemiptera, suborder Heteroptera. They are commonly called water scorpions for their superficial resemblance to a scorpion, due to the modification of the legs, of the anterior pair for predation, and to the presence of a long slender process, simulating a...
(water scorpions)
Other
- A number of species of frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by long hind legs, a short body, webbed digits , protruding eyes and the absence of a tail...
s prefer stagnant water.
- Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in...
- Biofilm
A biofilm is an aggregate of microorganisms in which cells are stuck to each other and/or to a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance . Biofilm EPS, which is also referred to as "slime," is a polymeric jumble of...
- Some species of turtle
Turtles are reptiles of the order Testudines , characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield...
s
- Mata mata
The mata mata is a freshwater turtle found in South America, primarily in the Amazon and Orinoco basins.-Taxonomy:...
Miscellanea
Pools of stagnant water have historically been used in the processing of
hempHemp is the name of the soft, durable fiber that is cultivated from plants of the Cannabis genus, cultivated only for industrial use....
and some other fiber crops, as well as of
lindenLinden is one of three English names for the tree genus Tilia . Several of the common names for species within the Tilia genus have Linden in their names...
barkBark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
used for making
bast shoeBast shoes are shoes woven primarily from bast of the linden tree or from birch bark, a kind of basket fit to the shape of a foot. It is an obsolete traditional footwear of forest areas of Eastern Europe used by poorer population of Finnic people, Balts, and Slavs...
s. Several weeks of soaking makes bast fibers easily separable due to bacterial and fermentative processes known as
rettingRetting is a process employing the action of micro-organisms and moisture on plants to dissolve or rot away much of the cellular tissues and pectins surrounding bast-fibre bundles, and so facilitating separation of the fibre from the stem...
.