Mörtsjön ( Swedish for " Roach Lake") is a small

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

Huddinge Municipality Huddinge Municipality () is a municipality in Stockholm County, east central Sweden. Its seat is located in Huddinge (), which is a part of Stockholm urban area. The municipality is, with its approximately 110,000 inhabitants, the second most pop ...

, south of

Stockholm Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. Part of the

Orlången Nature Reserve Orlången Nature Reserve (''Orlångens naturreservat'') is a nature reserve surrounding Lake Orlången in central Huddinge Municipality, south of Stockholm, Sweden. Description The reserve, founded in 1998, encompasses a total area of 15 square ...

, Mörtsjön is also one of the smaller lakes of the Tyresån Lake System,

Catchment area

Prince Eugen painted some of his well-known romantic landscapes by the lake in the late 19th century.Two examples are still hanging at the

Waldemarsudde Prince Eugene's Waldemarsudde () is a museum located on Djurgården in Stockholm, Sweden. It was formerly the home of Prince Eugen (1865-1947), a Swedish prince, painter and art collector. The museum houses Prince Eugen's extensive art col ...

museum (see links below). The homestead Charlottendal on the north-eastern corner of the lake is surrounded by old agricultural land where inorganic fertilisers and

pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...

s have never been used, and, as a consequence, contains many rare species, such as common rockrose, dithering-grass and scarlet waxy cap. The lush landscape around the lake makes it popular for walking, bathing, fishing, and other open-air activities.Huddinge Municipality, ''Mörtsjön'', site

Environmental impact

The shallow lake is

eutrophic Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water; ie. the process of too many plants growing on the s ...

. Levels of

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

are relatively high, while levels of

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

are normal. There are very few human structures in the catchment area, why most of nutrients reaching the lake stems from the surrounding forests.

Clearfelling Clearcutting, clearfelling or clearcut logging is a forestry/logging practice in which most or all trees in an area are uniformly cut down. Along with shelterwood and seed tree harvests, it is used by foresters to create certain types of for ...

in the end of the 1970s caused increased levels of nitrogen in the lake over the following years and ensuing

fish kill The term fish kill, known also as fish die-off, refers to a localized mass mortality event, mass die-off of fish populations which may also be associated with more generalized mortality of aquatic life.University of Florida. Gainesville, FL (200 ...

probably caused by

algal bloom An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in fresh water or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompass ...

. The shallowness of the lake still tends to cause a shortage of oxygen, which during winters can suffocate fishes.

Flora and fauna

an inventory of aquatic plants in 1998 resulted in the following list:

reed Reed or Reeds may refer to: Science, technology, biology, and medicine * Reed bird (disambiguation) * Reed pen, writing implement in use since ancient times * Reed (plant), one of several tall, grass-like wetland plants of the order Poales * Re ...

club-rush ''Schoenoplectus'' (club-rush ld World species bulrush or tule ew World species is a genus of plants in the Cyperaceae, sedge family with a cosmopolitan distribution. Note that the name bulrush is also applied to species in the unrelated ...

, narrow-leafed cattail, water horsetail, wood club-rush, greater spearwort, yellow iris, water hemlock, water-plantain,

marsh cinquefoil ''Comarum palustre'' ( syn. ''Potentilla palustris''), known by the common name marsh cinquefoil,Streeter D, Hart-Davies C, Hardcastle A, Cole F, Harper L. 2009. ''Collins Flower Guide''. Harper Collins also purple marshlocks and swamp cinquefoi ...

, marsh-bedstraw, bog-bean, yellow water-lily, white water-lily, broad-leaved pondweed, curled pondweed,

bladderwort ''Utricularia'', commonly and collectively called the bladderworts, is a genus of carnivorous plants consisting of approximately 233 species (precise counts differ based on classification opinions; a 2001 publication lists 215 species).Salmon, Br ...

, and '' Fontinalis'' moss. The lake is a natural habitat for

northern pike The northern pike (''Esox lucius'') is a species of carnivorous fish of the genus ''Esox'' (pikes). They are commonly found in brackish water, moderately salty and fresh waters of the Northern Hemisphere (''i.e.'' holarctic in distribution). T ...

perch Perch is a common name for freshwater fish from the genus ''Perca'', which belongs to the family Percidae of the large order Perciformes. The name comes from , meaning the type species of this genus, the European perch (''P. fluviatilis'') ...

, roach,

rudd ''Scardinius'' is a genus of freshwater ray-finned fishes belonging to the family Leuciscidae, which includes the daces, Eurasian minnows and related species. The fishes in this genus are commonly called rudds. Locally, the name "rudd" without ...

tench The tench or doctor fish (''Tinca tinca'') is a freshwater, fresh- and brackish water, brackish-water fish of the order Cypriniformes found throughout Eurasia from Western Europe including Great Britain, Britain and Ireland east into Asia as far ...

, and

crucian carp The crucian carp (''Carassius carassius'') is a medium-sized member of the common carp family Cyprinidae. It occurs widely in northern European regions. Its name derives from the Low German ''karusse'' or ''karutze'', possibly from Medieval Lat ...

. More than 100 individual

mirror carp The common carp (''Cyprinus carpio''), also known as European carp, Eurasian carp, or simply carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Ark ...

s and scale carps were introduced in 1993. Crayfish plague struck the lake in 1979, but since then the

signal crayfish The signal crayfish (''Pacifastacus leniusculus'') is a species of crayfish indigenous to North America. Introduced to Europe in the 1960s to supplement the North European ''Astacus astacus'' fisheries, which were being damaged by crayfish plague ...

has been introduced. Common birds are

mallard The mallard () or wild duck (''Anas platyrhynchos'') is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa. It has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Arge ...

goldeneye ''GoldenEye'' is a 1995 spy film, the seventeenth in the List of James Bond films, ''James Bond'' series produced by Eon Productions, and the first to star Pierce Brosnan as the fictional Secret Intelligence Service, MI6 agent James Bond (lit ...

, and

gull Gulls, or colloquially seagulls, are seabirds of the subfamily Larinae. They are most closely related to terns and skimmers, distantly related to auks, and even more distantly related to waders. Until the 21st century, most gulls were placed ...

, while

heron Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 75 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genus ''Botaurus'' are referred to as bi ...

merganser ''Mergus'' is the genus of the typical mergansers ( ) fish-eating ducks in the subfamily Anatinae. The genus name is a Latin word used by Pliny the Elder and other Roman authors to refer to an unspecified waterbird. The common merganser (''Mer ...

, and

osprey The osprey (; ''Pandion haliaetus''), historically known as sea hawk, river hawk, and fish hawk, is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor, reaching more than in length and a wingspan of . It ...

regularly seek food by the lake among

grey willow Grey willow or gray willow may refer to: *''Salix atrocinerea'', a species of willow native to Europe commonly called grey willow *''Salix cinerea'', a species of willow native to Europe and western Asia, also occasionally called grey sallow *''Sal ...

and

goat willow ''Salix caprea'', known as goat willow, pussy willow or great sallow, is a common species of willow native to Europe and western and central Asia.Meikle, R. D. (1984). ''Willows and Poplars of Great Britain and Ireland''. BSBI Handbook 4. . De ...

Aspen Aspen is a common name for certain tree species in the Populus sect. Populus, of the ''Populus'' (poplar) genus. Species These species are called aspens: * ''Populus adenopoda'' – Chinese aspen (China, south of ''P. tremula'') * ''Populus da ...

, and

alder Alders are trees of the genus ''Alnus'' in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species ex ...

are standing by the shores of the lake,

long-tailed tit The long-tailed tit (''Aegithalos caudatus''), also named long-tailed bushtit, is a common bird found throughout Europe and the Palearctic. The genus name ''Aegithalos'' was a term used by Aristotle for some European tits, including the long-tail ...

and

lesser spotted woodpecker The lesser spotted woodpecker (''Dryobates minor'') is a member of the woodpecker family Picidae. It was formerly assigned to the genus '' Dendrocopos'' (sometimes incorrectly spelt as ''Dendrocopus''). Some taxonomic authorities continue to list ...

are present. Other rare species frequently visit the lake, for example the

black-throated diver The black-throated loon (''Gavia arctica''), also known as the Arctic loon and the black-throated diver, is a migratory aquatic bird found in the northern hemisphere, primarily breeding in freshwater lakes in northern Europe and Asia. It winte ...

. Mammals found by the lake include:

mink Mink are dark-colored, semiaquatic, carnivorous mammals of the genera ''Neogale'' and '' Mustela'' and part of the family Mustelidae, which also includes weasels, otters, and ferrets. There are two extant species referred to as "mink": the A ...

, several

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s such as

northern bat The northern bat (''Eptesicus nilssonii'') is the most abundant species of bat in northern Eurasia occurring from France to Hokkaidō and south to Kazakhstan. Description The northern bat is dark brown or black with some gold touched at the tip ...

common noctule The common noctule (''Nyctalus noctula'') is a species of Insectivore, insectivorous bat common throughout Europe, Asia, and North Africa. Description The common noctule's short fur is dark brown after moulting in June (males) or July/August (f ...

soprano pipistrelle The soprano pipistrelle (''Pipistrellus pygmaeus'') is a small species of bat. It is found in Europe and often roosts on buildings. Taxonomy Until 1999, the soprano pipistrelle was considered as conspecific Biological specificity is the tendenc ...

, and

whiskered bat The whiskered bat (''Myotis mystacinus'') is a small European bat with long fur. Although uncommon, ''M. mystacinus'' is often found around human habitation and around water; it is similar to Brandt's bat (''Myotis brandtii''), from which it wa ...

. Additionally, some of the species of amphibians and dragonflies common in the Stockholm area are present by the lake.

Catchment area

Environmental impact

Flora and fauna

See also

Notes

References

External links