Drevviken is a 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,...

 in southern 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....

, shared by the four municipalities Stockholm, Haninge

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....

, Huddinge

Huddinge Municipality

Huddinge Municipality is a municipality in Stockholm County in east central Sweden. Its seat is located in Huddinge, which is a part of Stockholm urban area.The municipality is the second most populated in Stockholm County....

, and Tyresö

Tyresö Municipality

Tyresö Municipality is a municipality in Stockholm County in east central Sweden on the coast of the Baltic Sea. Its seat is located in Bollmora.Most of Tyresö Municipality lies within the Stockholm urban area.-History:...

.

While much of the surrounding area is used for one-family houses, the lake and the green space north of it are considered to be of great recreational and natural importance and forms part of a suggested nature reserve around lake Flaten

Flaten

Flaten is a lake in southern Stockholm, Sweden, located just north of Lake Drevviken. The name is also used for the surrounding area and the nature reserve created there in 2007....

.

Catchment area

Approximately two third of the catchment area is occupied by settlements, mostly one-family houses. Three major industrial areas are located within the catchment area which is mostly dominated by forests with minor open grasslands. North of the lake is a deciduous forest containing herbaceous plant

Herbaceous plant

A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...

s and rocks

Rock (geology)

In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...

 covered with brushwoods and lichen

Lichen

Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...

. Additionally, there is a fluvio-glacial deposit with a broad irrigated

Irrigation

Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 marsh and a scenic pine forest

Pine

Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...

; and a wetland

Wetland

A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....

 which is the remnant of a former stream

Stream

A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...

.

Environmental influence

Stormwater

Stormwater

Stormwater is water that originates during precipitation events. It may also be used to apply to water that originates with snowmelt that enters the stormwater system...

 from several suburbs empties into the lake around which are three allotment-gardens

Allotment (gardening)

An allotment garden, often called simply an allotment, is a plot of land made available for individual, non-professional gardening. Such plots are formed by subdividing a piece of land into a few or up to several hundreds of land parcels that are assigned to individuals or families...

. Potentially hazardous activities in the area include a petrol station, an asphalt works, concrete industry, small scale industries, and a closed stock pile covering 9 hectare containing excavated material from the demolition of a major area in central Stockholm in the 1960s. Several traffic routes and a metro track passes through the catchment area.

Flora and fauna

During summers phytoplankton

Phytoplankton

Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...

 are dominated by cyanobacteria and occasionally diatom

Diatom

Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...

s, most commonly Aphanizomenon cf gracile but also Pseudanabaena limnetica, Planktolyngbya sp. and various species of Anabaena

Anabaena

Anabaena is a genus of filamentous cyanobacteria that exists as plankton. It is known for its nitrogen fixing abilities, and they form symbiotic relationships with certain plants, such as the mosquito fern. They are one of four genera of cyanobacteria that produce neurotoxins, which are harmful to...

, of whom only Aphanizomenon

Aphanizomenon

Aphanizomenon is an important genus of cyanobacteria that inhabits freshwater lakes and can cause choking blooms. Studies on the species Aphanizomenon flos-aquae have shown that it can regulate buoyancy through light-induced changes in turgor pressure...

is potentially poisonous and Anabaena frequently causes algal bloom

Algal bloom

An algal bloom is a rapid increase or accumulation in the population of algae in an aquatic system. Algal blooms may occur in freshwater as well as marine environments. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration...

. Carapace

Carapace

A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...

 flagellate

Flagellate

Flagellates are organisms with one or more whip-like organelles called flagella. Some cells in animals may be flagellate, for instance the spermatozoa of most phyla. Flowering plants do not produce flagellate cells, but ferns, mosses, green algae, some gymnosperms and other closely related plants...

s such as Ceratium hirundinella and various dinoflagellate

Dinoflagellate

The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth...

s, are few but important to the lake's biomass

Biomass

Biomass, as a renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel....

. Various rotifer

Rotifer

The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John Harris in 1696, and other forms were described by Anton van Leeuwenhoek in 1703...

s are common zooplankton

Zooplankton

Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...

 but cyclopoid

Cyclopoida

Cyclopoida is an order of small crustaceans from the subclass Copepoda. Like many other copepods, members of Cyclopoida are small, planktonic animals living both in the sea and in freshwater habitats. They are capable of rapid movement...

 copepod

Copepod

Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...

s can also be found. An inventory 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 in 1998 resulted in a list of some 30 species, including Branched Bur-reed

Sparganium

Sparganium is a genus of flowering plants, containing about 20 species in temperate regions of both the Northern and Southern Hemispheres. It was previously placed alone in the family Sparganiaceae...

 and Nuttall's waterweed

Elodea

Elodea is a genus of aquatic plants often called the waterweeds. Elodea is native to North America and is also widely used as aquarium vegetation. The introduction of some species of Elodea into waterways in parts of Europe, Australia, Africa, Asia, and New Zealand has created a significant problem...

 (the latter introduced in Europe during the 20th century and relatively new in Sweden.)

A list of Dragonfly

Dragonfly

A dragonfly is a winged 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...

 larvae produced in 2000 included Red-eyed

Red-eyed Damselfly

Red-eyed Damselfly Erythromma najas is a member of the damselfly family Coenagrionidae.-Appearance:The species is a small damselfly, long, predominantly black with iridescent blue markings. The male resembles blue-tailed damselflies but is distinguished by its large, spaced eyes that are a deep red...

, Variable

Variable Damselfly

Coenagrion pulchellum, the Variable Damselfly or Variable Bluet, is a European damselfly. Despite its name, it is not the only blue damselfly prone to variable patterning....

, and Blue-tailed Damselflies

Blue-tailed Damselfly

The Blue-tailed Damselfly, Ischnura elegans, is a European damselfly.Adult male Blue-tailed Damselflies have a head and thorax patterned with blue and black. They have a largely black abdomen with very narrow pale markings where each segment joins the next...

. Sample fishing in 1997 documented a dozen species, most notably Roach

Rutilus

Rutilus is a genus of fishes in the family Cyprinidae, commonly called roaches. Locally, the name "roach" without any further qualifiers is also used for particular species, particularly the Common Roach Rutilus (Latin for "shining, red, golden, auburn") is a genus of fishes in the family...

 and Zander

Zander

Zander is a species of fish. The scientific name is Sander lucioperca , and it is closely allied to perch. Zander are often called pike-perch as they resemble the pike with their elongated body and head, and the perch with their spiny dorsal fin. Zander are not, as is commonly believed, a pike and...

 but also Northern Pike

Northern Pike

The northern pike , is a species of carnivorous fish of the genus Esox...

, Perch

Perch

Perch is a common name for fish of the genus Perca, freshwater gamefish belonging to the family Percidae. The perch, of which there are three species in different geographical areas, lend their name to a large order of vertebrates: the Perciformes, from the Greek perke meaning spotted, and the...

, Eel

Eel

Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...

, Trout

Trout

Trout is the name for a number of species of freshwater and saltwater fish belonging to the Salmoninae subfamily of the family Salmonidae. Salmon belong to the same family as trout. Most salmon species spend almost all their lives in salt water...

, - of which some have been introduced into the lake - and many others. The lake was struck by crayfish plague

Crayfish plague

Crayfish plague, Aphanomyces astaci, is a water mould that infects crayfish, most notably the European Astacus which dies within a few weeks of being infected...

 in 1950 but crayfish

Crayfish

Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...

 was reintroduced around 1970. North-east of the lake Smooth Newt

Smooth Newt

The Smooth Newt, also known as the Common Newt, Lissotriton vulgaris is the most common newt species of the Lissotriton genus of amphibians. L...

, Common Frog

Common Frog

The Common Frog, Rana temporaria also known as the European Common Frog or European Common Brown Frog is found throughout much of Europe as far north as well north of the Arctic Circle in Scandinavia and as far east as the Urals, except for most of Iberia, southern Italy, and the southern Balkans...

, and Common Toad

Common Toad

The common toad or European toad is an amphibian widespread throughout Europe, with the exception of Iceland, Ireland and some Mediterranean islands...

 were documented in 1996. Noctule bats

Common Noctule

The Common Noctule is a species of bat common throughout Europe, Asia, and North Africa. The UK distribution can be found on the National Biodiversity Network website ....

 documented in the area, previously assigned the status

Conservation status

The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...

 Near Threatened

Near Threatened

Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...

, are now considered Least Concern

Least Concern

Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...

. Soprano Pipistrelle

Soprano Pipistrelle

The Soprano Pipistrelle is a small bat that was only formally separated from the Common Pipistrelle Pipistrellus pipistrellus in 1999....

 has also been seen along the northern shore of the lake. Couples of Great Crested Grebe

Great Crested Grebe

The Great Crested Grebe is a member of the grebe family of water birds.- Description :The Great Crested Grebe is long with a wingspan. It is an excellent swimmer and diver, and pursues its fish prey underwater. The adults are unmistakable in summer with head and neck decorations...

s and Common Tern

Common Tern

The Common Tern is a seabird of the tern family Sternidae. This bird has a circumpolar distribution, breeding in temperate and sub-Arctic regions of Europe, Asia and east and central North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. It is sometimes...

s are breeding by the lake together with colonies of Black-headed Gull

Black-headed Gull

The Black-headed Gull is a small gull which breeds in much of Europe and Asia, and also in coastal eastern Canada. Most of the population is migratory, wintering further south, but some birds in the milder westernmost areas of Europe are resident...

s, Mute Swan

Mute Swan

The Mute Swan is a species of swan, and thus a member of the duck, goose and swan family Anatidae. It is native to much of Europe and Asia, and the far north of Africa. It is also an introduced species in North America, Australasia and southern Africa. The name 'mute' derives from it being less...

s, Canada Goose

Canada Goose

The Canada Goose is a wild goose belonging to the genus Branta, which is native to arctic and temperate regions of North America, having a black head and neck, white patches on the face, and a brownish-gray body....

s, Herring Gulls, and Lesser Black-backed Gull

Lesser Black-backed Gull

The Lesser Black-backed Gull is a large gull that breeds on the Atlantic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa...

s.