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Agarden pond is awater feature constructed in awater garden or designedlandscape, normally foraesthetic purposes, to providewildlifehabitat, or for swimming.
Garden ponds can be excellent wildlife habitats and may contribute to the protection of freshwater wildlife.Invertebrate animals (such asdragonflies andwater beetles) andinsectivorousvertebrates such asamphibians (frogs andtoads),turtles andwaterbirds can colonize new ponds quickly.[1]Ornamental fishes are also frequentlystocked in larger ponds to provide aesthetics andalgae control, as well aspest control againstmosquito larvae infestation.
Garden pond owners have the potential to make many original and valuable observations about the ecology of small waterbodies, which garden ponds replicate.
There are several problems that can result from garden ponds. In particular, they can be pathways for the spread ofinvasive plants. In the UK, the invasive speciesCrassula helmsii andMyriophyllum aquaticum have both escaped from garden ponds. These plants cause considerable practical problems in protecting freshwater.[2]
Amphibious species such asfrogs,toads, andnewts are common in garden ponds, especially in overgrown areas withalgae andreeds. Without proper precautions being taken by pond owners, such areas can harbour excessivefrogspawn and may pose a challenge.
Cases of high rodent activity are also common in garden ponds, withfield mice,rats, andvoles taking refuge in freshwater areas such as garden ponds. Consuming pondwater contaminated with raturine can cause infections such asWeil's disease orleptospirosis.
In tropical climates, garden ponds may become breeding sites formosquitoes and increase the spread of diseases carried by these insects.[3]
Ponds may be created by natural processes or by people; however, the origin of the hole in the ground makes little difference to the kind of wildlife that will be found in the pond. Much more important is whether the pond ispolluted or clean, how close it is to other wetlands and itsdepth, particularly whether it dries out from time to time and how many fish (if any) there are.
Naturally, ponds vary more in their physical and chemical conditions from day to day than other freshwater, like rivers. People often install pumps in garden ponds to counter these natural tendencies, particularly to maintain higherlevels of dissolved oxygen. Although this is generally unnecessary for wildlife, it may be essential to keep fish in a garden pond. For ponds with polluted nutrient-richtapwater added to them, filters can be used to reduce the abundance ofalgae.[4]
Ponds outside of gardens are fed by four main water sources:rain,inflows (springs and streams),surface runoff, andgroundwater. The wildlife value of ponds is greatly affected by the extent to which these water sources are unpolluted. Garden ponds are generally not fed by inflows or groundwater, except in the larger and rural gardens. Usually, the pond will be filled by a combination of tap water, rainwater, and surface runoff – and lost toevaporation.
In soils that lack naturalclay, additional water loss todrainage andpermeation is prevented by a liner.Pond liners arePVC orEPDM foils that are placed between the soil of the pond bed and the water. Liners can also be made from puddled clay, and ponds on free-draining soils can even be self-sealing with fine sediments washed into the pond.
Ponds tend to dry out if excessive water is lost to evaporation. Evaporation is more common in the summer season, when increases in temperature and lack of rainfall contribute to dry conditions, creating seasonal ponds (orvernal pools) that usually dry out once a year. These seasonal ponds provide specialized habitat for many plant and animal species, particularly amphibians and invertebrates. Oftentimes, seasonal ponds are utilized as a breeding ground, allowing amphibian (such asfrogs andtoads) and invertebrate (such asfairy shrimp)larvae space to develop without aquatic predators like fish.
Ponds orswimming ponds can be constructed by an isolating membrane or membranes or (on anorganic model sometimes callednatural pools) contained by a layer ofloam. For all variants no chemicals or devices disinfect or maintain water, the water is instead cleared through the use ofbiological filters,aquatic plants, or otherorganisms used in water purification (zooplankton).[5][6][7]
The first such pools were built in the early 1980s inAustria, where they are known as"Schwimmteiche". The first was built by Werner Gamerith and Richard Weixler[8] in Gamerith's private garden in the 1980s.[9]: 16 The market slowly grew, and by 2016 there were around 20,000 such swimming ponds in Europe.[9]: 19
The first public swimming pool in North America built and maintained in this way, was finished at Webber Park inMinneapolis in 2015.[10]
An organization called the International Organization for Natural Bathing Waters (IOB) sets the guidelines for such pools.[11]
Backyards that feature natural pools trade chlorine for plants, don't need to be closed for winter and may feature kois with names like Cutie.
