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For other uses, see Pond (disambiguation). Pond_sentence_0

A pond is an area filled with water, either natural or artificial, that is smaller than a lake. Pond_sentence_1

It may arise naturally in floodplains as part of a river system, or be a somewhat isolated depression (such as a kettle, vernal pool, or prairie pothole). Pond_sentence_2

It may contain shallow water with aquatic plants and animals. Pond_sentence_3

Factors that affect the type of life found in a pond include depth and duration of water level, nutrients, shade, presence or absence of inlets and outlets, effects of grazing animals, and salinity. Pond_sentence_4

Ponds are frequently man-made, or expanded beyond their original depth and bounds. Pond_sentence_5

Among their many uses, ponds provide water for agriculture and livestock, aid in habitat restoration, serve as fish hatcheries, are components of landscape architecture, may store thermal energy as solar ponds, and treat wastewater as treatment ponds. Pond_sentence_6

Ponds may be freshwater, saltwater, or brackish. Pond_sentence_7

Technical definitions Pond_section_0

The technical distinction between a pond and a lake has not been universally standardized. Pond_sentence_8

Limnologists and freshwater biologists have proposed formal definitions for pond, in part to include 'bodies of water where light penetrates to the bottom of the waterbody,' 'bodies of water shallow enough for rooted water plants to grow throughout,' and 'bodies of water which lack wave action on the shoreline.' Pond_sentence_9

Each of these definitions has met with resistance or disapproval, as the defining characteristics are each difficult to measure or verify. Pond_sentence_10

Accordingly, some organizations and researchers have settled on technical definitions of pond and lake that rely on size alone. Pond_sentence_11

Even among organizations and researchers who distinguish lakes from ponds by size alone, there is no universally recognised standard for the maximum size of a pond. Pond_sentence_12

The international Ramsar wetland convention sets the upper limit for pond size as 8 hectares (80,000 m; 20 acres). Pond_sentence_13

Researchers for the British charity Pond Conservation (now called Freshwater Habitats Trust) have defined a pond to be 'a man-made or natural waterbody that is between 1 m (0.00010 hectares; 0.00025 acres) and 20,000 m (2.0 hectares; 4.9 acres) in area, which holds water for four months of the year or more.' Pond_sentence_14

Other European biologists have set the upper size limit at 5 hectares (50,000 m; 12 acres). Pond_sentence_15

In practice, a body of water is called a pond or a lake on an individual basis, as conventions change from place to place and over time. Pond_sentence_16

In North America, even larger bodies of water have been called ponds; for example, Crystal Lake at 33 acres (130,000 m; 13 ha), Walden Pond in Concord, Massachusetts at 61 acres (250,000 m; 25 ha), and nearby Spot Pond at 340 acres (140 ha). Pond_sentence_17

There are numerous examples in other states, where bodies of water less than 10 acres (40,000 m; 4.0 ha) are being called lakes. Pond_sentence_18

As the case of Crystal Lake shows, marketing purposes can sometimes be the driving factor behind the categorization. Pond_sentence_19

Formation Pond_section_1

Ponds can result from a wide range of natural processes. Pond_sentence_20

Any depression in the ground which collects and retains a sufficient amount of precipitation can be considered a pond, and such depressions can be formed by a variety of geological and ecological events. Pond_sentence_21

Rivers often leave behind ponds in natural floodplains after spring flooding, and these can be very important to breeding fish, particularly in large river systems like the Amazon. Pond_sentence_22

Retreating glaciers can leave behind landscapes filled with small depressions, each developing its own pond; an example is the Prairie Pothole Region of North America. Pond_sentence_23

Many areas of landscape contain small depressions which form temporary ponds after spring snow melts, or during rainy seasons; these are called vernal ponds, and may be important sites for amphibian breeding. Pond_sentence_24

Some ponds are created by animals. Pond_sentence_25

Beaver ponds are the best-known example, but alligators also excavate ponds as well. Pond_sentence_26

In landscapes with organic soils, fires can also create depressions during periods of drought; these become open water when normal water levels return. Pond_sentence_27

Characteristics Pond_section_2

A defining feature of a pond is the presence of standing water, which provides habitat for wetland plants and animals. Pond_sentence_28

Familiar examples might include water lilies, frogs, turtles, and herons. Pond_sentence_29

Often, the entire margin of the pond is fringed by wetland, and these wetlands support the aquatic food web, provide shelter for wildlife, and stabilize the shore of the pond. Pond_sentence_30

Some grazing animals like geese and muskrats consume the wetland plants directly as a source of food. Pond_sentence_31

In many other cases, however, the pond plants fall into the water and decay. Pond_sentence_32

Many invertebrates then feed on the decaying plants, and these invertebrates provide food for wetland species including fish, dragonflies, and herons. Pond_sentence_33

The open water may allow algae to grow, and these algae may support yet another food web that includes aquatic insects and minnows. Pond_sentence_34

A pond, therefore, may have combinations of three different food webs, one based on larger plants, one based upon decayed plants, and one based upon algae. Pond_sentence_35

Hence, ponds often have many different animal species using the wide array of food sources. Pond_sentence_36

They, therefore, provide an important source of biological diversity in landscapes. Pond_sentence_37

Vernal ponds are ponds which dry up for part of the year. Pond_sentence_38

They are so called because they are typically at their peak depth in the spring (the meaning of "vernal" comes form the Latin word for spring). Pond_sentence_39

Naturally occurring vernal ponds do not usually have fish. Pond_sentence_40

The absence of fish is a very important characteristic since it provides amphibians with breeding locations free from predation by fish. Pond_sentence_41

Hence, introducing fish to a pond can have seriously detrimental consequences. Pond_sentence_42

In some parts of the world, such as California, the vernal ponds have rare and endangered plant species. Pond_sentence_43

On the coastal plain, they provide habitat for endangered frogs such as the Mississippi Gopher Frog. Pond_sentence_44

Conservation and management Pond_section_3

Ponds, being small, are easily disrupted by human activity, such as hikers. Pond_sentence_45

Drainage of ponds is a frequent problem in agricultural areas, such as in the prairie potholes of North America. Pond_sentence_46

Although ponds are a useful source of water for cattle, overgrazing and wading can turn a pond into a muddy hole. Pond_sentence_47

Nutrient sources such as fertilized pastures, human sewage, and even lawn fertilizer can cause explosive growth of algae and the loss of rooted plants and many other aquatic species. Pond_sentence_48

Roads near ponds can kill large numbers of amphibians and turtles that may migrate to and from the pond as part of their annual breeding cycle. Pond_sentence_49

Many well-intentioned people introduce fish to ponds, being unaware that some species may eat aquatic plants, stir up sediment, and eat the young of amphibians and many other invertebrate species. Pond_sentence_50

The gentle slope of land into ponds also provides an expanse of habitat for wetland plants and wet meadows. Pond_sentence_51

The construction of retaining walls, or lawns, can severely degrade the life in a pond. Pond_sentence_52

In landscapes where ponds are artificially constructed, they are done so to provide wildlife viewing opportunities, to treat wastewater, or for aesthetic purposes, such as part of a golf course. Pond_sentence_53

The design of a pond determines how productive it will be for wildlife. Pond_sentence_54

In general, gently sloping shorelines with broad expanses of wetland plants not only provide the best conditions for wildlife, but they help protect water quality from sources in the surrounding landscapes. Pond_sentence_55

It is also beneficial to allow water levels to fall each year during drier periods. Pond_sentence_56

Roads and houses should be kept as far away as possible. Pond_sentence_57

Another important way to add ponds back into landscapes is to restore rivers so that they can flood and meander to create large numbers of natural ponds, including vernal pools and wetlands, in river valleys. Pond_sentence_58

Nomenclature Pond_section_4

In origin, a pond is a variant form of the word pound, meaning a confining enclosure. Pond_sentence_59

As straying cattle are enclosed in a pound so water is enclosed in a pond. Pond_sentence_60

In earlier times, ponds were artificial and utilitarian, as stew ponds, mill ponds and so on. Pond_sentence_61

The significance of this feature seems, in some cases, to have been lost when the word was carried abroad with emigrants. Pond_sentence_62

In the United States, natural pools are often called ponds. Pond_sentence_63

Ponds for a specific purpose keep the adjective, such as "stock pond", used for watering livestock. Pond_sentence_64

Pond usually implies a quite small body of water, generally smaller than one would require a boat to cross. Pond_sentence_65

Another definition is that a pond is a body of water where even its deepest areas are reached by sunlight or where a human can walk across the entire body of water without being submerged. Pond_sentence_66

In some dialects of English, pond normally refers to small artificially created bodies of water. Pond_sentence_67

Some regions of the United States define a pond as a body of water with a surface area of less than 10 acres (4.0 ha). Pond_sentence_68

Minnesota, known as the "land of 10,000 lakes", is commonly said to distinguish lakes from ponds, bogs and other water features by this definition, but also says that a lake is distinguished primarily by wave action reaching the shore. Pond_sentence_69

The term is also used for temporary accumulation of water from surface runoff (ponded water). Pond_sentence_70

There are various regional names for naturally occurring ponds. Pond_sentence_71

In Scotland, one of the terms is lochan, which may also apply to a large body of water such as a lake. Pond_sentence_72

In North American prairies, they may be termed playas. Pond_sentence_73

Uses Pond_section_5

Ponds are used for the provision of fish and other wildlife including waterfowl, which is a source of food for humans. Pond_sentence_74

Pollutants entering ponds are often substantially mitigated by the natural sedimentation and biological activities within the water body. Pond_sentence_75

Ponds are also a major contributor to local ecosystem richness and diversity for both plants and animals. Pond_sentence_76

In the Indian subcontinent, Hindu temples usually have a pond nearby so that pilgrims can take baths. Pond_sentence_77

These ponds are considered sacred. Pond_sentence_78

In medieval times in Europe, it was typical for many monastery and castles (small, partly self-sufficient communities) to have fish ponds. Pond_sentence_79

These are still common in Europe and in East Asia (notably Japan), where koi may be kept. Pond_sentence_80

Waste stabilization ponds are used as a low-cost method for wastewater treatment. Pond_sentence_81

In agriculture, treatment ponds may reduce nutrients released downstream from the pond. Pond_sentence_82

They may also provide irrigation reservoirs at times of drought. Pond_sentence_83

Examples Pond_section_6

Some notable ponds are: Pond_sentence_84

See also Pond_section_7


Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Pond.