Dammträsk
Encyclopedia
Dammträsk is a small man made lake
within the Tyresån Lake System
, located in Haninge Municipality
, south of central Stockholm
, Sweden
.
The lake receives water from Övre and Nedre Rudasjön
south of the lake and empties into Drevviken north of it. Located just south of the residential area Kvarntorp, and north of the densely populated central Haninge, the wetland lake receives considerable amount of nutritive salts.
, Dammträsk is one of the lakes in Haninge already to contaminated to be regarded as vulnerable. It has been a conscious decision to redirect water from Rudasjön to Dammträsk, and, as much of the waste the lake receives is sedimented into the lake, Drevviken, the lake downstream is saved from contamination. The price to pay, has been the dense vegetation in the lake. Two abandoned facilities by the lake, a dry cleaner and a gas station, has contaminated the area surrounding the lake. In 2005, the area was restored and some 276 tons of earth containing chlorinated hydrocarbons
and 595 tons containing petroleum
was removed.
s around the lake, which makes it relatively biodiverse
(3/5 on a scale where 1 means high biodiversity). One of the interesting species of aquatic plant
s in the lake is Common Mare's Tail
. Grass Carp
has been introduced in the lake.
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
within the Tyresån Lake System
Tyresån Lake System
Tyresån Lake System is a number of lakes in Sweden with a common basin of 251.5 km2....
, located in Haninge Municipality
Haninge Municipality
Haninge Municipality is a municipality in Stockholm County in east central Sweden. Its seat is located in Handen.Haninge Municipality was formed in 1971 when Västerhaninge and Österhaninge were united....
, south of central Stockholm
Stockholm
Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...
, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
.
The lake receives water from Övre and Nedre Rudasjön
Nedre Rudasjön
Nedre Rudasjön is a lake of Södermanland, Sweden....
south of the lake and empties into Drevviken north of it. Located just south of the residential area Kvarntorp, and north of the densely populated central Haninge, the wetland lake receives considerable amount of nutritive salts.
Environmental impact
The lake and the surrounding wetlands, together with local forests, are regarded as a valuable local natural resource worth to protect. However, while the lake system as a whole is regarded as sensitive to further loads of surface runoffSurface runoff
Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...
, Dammträsk is one of the lakes in Haninge already to contaminated to be regarded as vulnerable. It has been a conscious decision to redirect water from Rudasjön to Dammträsk, and, as much of the waste the lake receives is sedimented into the lake, Drevviken, the lake downstream is saved from contamination. The price to pay, has been the dense vegetation in the lake. Two abandoned facilities by the lake, a dry cleaner and a gas station, has contaminated the area surrounding the lake. In 2005, the area was restored and some 276 tons of earth containing chlorinated hydrocarbons
Organochloride
An organochloride, organochlorine, chlorocarbon, chlorinated hydrocarbon, or chlorinated solvent is an organic compound containing at least one covalently bonded chlorine atom. Their wide structural variety and divergent chemical properties lead to a broad range of applications...
and 595 tons containing petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
was removed.
Biodiversity
An inventory of the local vegetation concluded there are 27 species of vascular plantVascular plant
Vascular plants are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant. Vascular plants include the clubmosses, Equisetum, ferns, gymnosperms and angiosperms...
s around the lake, which makes it relatively biodiverse
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
(3/5 on a scale where 1 means high biodiversity). One of the interesting species of aquatic plant
Aquatic plant
Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...
s in the lake is Common Mare's Tail
Common Mare's Tail
The Common Mare's tail, Hippuris vulgaris, is a common aquatic plant of Eurasia and North America.The species is also sometimes called Horsetail, a name which is better reserved to the Horsetails of genus Equisetum...
. Grass Carp
Grass carp
The grass carp is a herbivorous, freshwater fish species of family Cyprinidae, and the only species of the genus Ctenopharyngodon. It is cultivated in China for food, but was introduced in Europe and the United States for aquatic weed control...
has been introduced in the lake.