Water stagnation occurs when

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

stops flowing. Stagnant water can be a major

environmental hazard An environmental hazard is a substance, state or event which has the potential to threaten the surrounding natural environment or adversely affect people's health, including pollution and natural disasters such as storms and earthquakes. It can i ...

Dangers

Chad 2019 man drinking dirty water from Batha river reservoir in Oum-Hadjer DSC4381-2

Malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...

and

dengue Dengue fever is a mosquito-borne tropical disease caused by the dengue virus. Symptoms typically begin three to fourteen days after infection. These may include a high fever, headache, vomiting, muscle and joint pains, and a characteristic ...

are among the main dangers of stagnant water, which can become a breeding ground for the

mosquitoes Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small Diptera, flies within the family Culicidae (from the Latin ''culex'' meaning "gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish ...

that transmit these diseases. Stagnant water can be dangerous for drinking because it provides a better incubator than running water for many kinds of

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

and

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s. Stagnant water can be contaminated with

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

and

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

feces, particularly in

deserts A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

or other areas of low rainfall. Water stagnation for as little as six days can completely change bacterial community composition and increase cell count. Stagnant water may be classified into the following basic, although overlapping, types: * Water body stagnation (stagnation in swamp, lake, lagoon, river, etc.) * Surface and ground waters 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 sheath, etc. To avoid ground and surface water stagnation,

drainage Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess of water. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic condition ...

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.

Life that may thrive in stagnant water

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

anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: * Anaerobic adhesive, a bonding a ...

are commonly found in stagnant water. For this reason, pools of stagnant water have historically been used in processing hemp and some other

fiber crops Fiber crops are field crops grown for their fibers, which are traditionally used to make paper, cloth, or rope. Fiber crops are characterized by having a large concentration of cellulose, which is what gives them their strength. The fibers may b ...

, as well as linden bark used for making

bast shoe Bast shoes are shoes made primarily from bast — fiber taken from the bark of trees such as linden. They are a kind of basket, woven and fitted to the shape of a foot. Bast shoes are a traditional footwear of the forest areas of Northern E ...

s. Several weeks of soaking makes

bast fiber Bast fibre (also called phloem fibre or skin fibre) is plant fibre collected from the phloem (the "inner bark", sometimes called "skin") or bast surrounding the stem of certain dicotyledonous plants. It supports the conductive cells of the phloe ...

s easily separable due to bacterial and fermentative processes known as

retting Retting 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.retting ...

. * Denitrifying bacteria *

Leptospira ''Leptospira'' ( grc, leptos, italics=yes, 'fine, thin' and la, spira, links=no, 'coil') is a genus of spirochaete bacteria, including a small number of pathogenic and saprophytic species. ''Leptospira'' was first observed in 1907 in kidney ti ...

* Purple bacteria (both sulfur and non-sulfur)

Fish

Lepisosteidae Gars are members of the family Lepisosteidae, which are the only surviving members of the Ginglymodi, an ancient holosteian group of ray-finned fish, which first appeared during the Triassic, over 240 million years ago. Gars comprise seven livin ...

(gar) *

Northern snakehead The northern snakehead (''Channa argus'') is a species of snakehead fish native to China, Russia, North Korea, and South Korea, ranging from the Amur River to Hainan. It has been introduced to other regions, where it is considered invasive. In ...

fish * Pygmy gourami * Spotted barb *

Walking catfish The walking catfish (''Clarias batrachus'') is a species of freshwater airbreathing catfish native to Southeast Asia. It is named for its ability to "walk" and wiggle across dry land, to find food or suitable environments. While it does not tru ...

* Asian swamp eel

Insects

Stagnant water is the favorite breeding ground for a number of

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s. * Dragonfly nymphs * Fly maggots *

Mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

larvae *

Nepidae Nepidae is a family of exclusively aquatic Heteropteran insects in the order Hemiptera. They are commonly called water scorpions for their superficial resemblance to scorpions, due to their raptorial forelegs and the presence of a long slender p ...

(water scorpions)

Other

* Algae *

Biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

* A number of species of

frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...

s prefer stagnant water. * Some species of

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

s **

Mata mata Matamata () is a town in Waikato, New Zealand. It is located near the base of the Kaimai Ranges, and is a thriving farming area known for Thoroughbred horse breeding and training pursuits. It is part of the Matamata-Piako District, which takes ...

References