Editing Vänern

{{Short description|Largest lake in Sweden}}
{{Infobox body of water
 | name              = Vänern
 | image             = Hällekis industrier sedda fr utsiktstornet på Kinnekulle 6116.jpg
 | caption           = View from [[Kinnekulle]]
 | alt               = Distant view of lake from Kinnekulle
 | pushpin_map       = Sweden
 | pushpin_map_alt   = Location of lake
 | image_bathymetry  = Lake Vänern details.png
 | caption_bathymetry = Detail map of the lake with surroundings
 | alt_bathymetry    = Map of Värnen
 | coords            = {{coord|58|55|N|13|30|E|region:SE_type:waterbody_scale:1500000|display=inline,title}}
 | type              = 
 | inflow            = [[Klarälven]]
 | outflow           = [[Göta älv]]
 | catchment         = 
 | basin_countries   = [[Sweden]]
 | length            = 
 | width             = 
 | area              = {{convert|5,650|km2|abbr=on}}<ref name=Sepp2005/>
 | depth             = {{convert|27|m|abbr=on}}<ref name=Sepp2005/>
 | max-depth         = {{convert|106|m|abbr=on}}<ref name=Sepp2005/>
 | volume            = {{convert|153|km3|mi3|abbr=on}}<ref name=Sepp2005/>
 | residence_time    = 8 to 9 years<ref name=WSTB>{{cite web |title=Lake Vänern |url=https://www.vastsverige.com/en/dalsland/articles/lake-vanern/ |website=www.vastsverige.com |publisher=West Sweden Tourism Board |access-date=1 September 2021 |language=en}}</ref>
 | shore             = 
 | elevation         = {{convert|44|m|abbr=on}}<ref name=Sepp2005/>
 | islands           = [[Brommö]], [[Djurö, Vänern|Djurö]], [[Fågelö]], [[Hammarön|Hammarö]], [[Kållandsö]], [[Lurö]] (22,000 in total, including skerries<ref name=WSTB/>)
 | cities            = 
 | reference         = <ref name=Sepp2005>{{Citation| editor-last=Seppälä| editor-first=Matti|editor-link=Matti Seppälä|title=The Physical Geography of Fennoscandia | url=https://books.google.com/books?id=q33WekTp7tgC&pg=PA145| publisher=Oxford University Press|year=2005| page=145| isbn=978-0-19-924590-1}}</ref>
}}

'''Vänern''' ({{IPAc-en|ˈ|v|eɪ|n|ər|n}} {{respell|VAY|nərn}}, {{IPAc-en|USalso|ˈ|v|ɛ|n|ər|n}} {{respell|VEN|ərn}},<ref>{{Cite American Heritage Dictionary|Vänern|access-date=April 14, 2019}}</ref><ref>{{cite web|url=https://www.collinsdictionary.com/amp/english/vanern|title=Vänern|work=[[Collins English Dictionary]]|publisher=[[HarperCollins]]|access-date=April 14, 2019}}</ref><ref>[https://web.archive.org/web/20190414111707/https://en.oxforddictionaries.com/definition/us/V%25C3%25A4nern "Vänern"] (US) and {{Cite dictionary |url=http://www.lexico.com/definition/V%C3%A4nern |title=Vänern |dictionary=[[Lexico|Oxford Dictionaries]] UK English Dictionary |publisher=[[Oxford University Press]]}}{{dead link|date=September 2022|bot=medic}}{{cbignore|bot=medic}}</ref><ref>{{Cite Merriam-Webster|Vänern|access-date=April 14, 2019}}</ref> {{IPA|sv|ˈvɛ̂ːnɛɳ|lang}})<ref>{{cite book|url=https://runeberg.org/ortnamn/0032.html|author1=Jöran Sahlgren|author2=Gösta Bergman|title=Svenska ortnamn med uttalsuppgifter|language=sv|year=1979|page=28}}</ref> is the largest lake in [[Sweden]], the largest lake in the European Union and the [[List of largest lakes of Europe|third-largest lake in Europe]] after [[Lake Ladoga|Ladoga]] and [[Lake Onega|Onega]] in Russia. It is located in the provinces of [[Västergötland]], [[Dalsland]], and [[Värmland]] in the southwest of the country. With its surface located at {{convert|44|m|ft}} above sea level and a maximum depth of {{convert|106|m|ft}}, the lowest point of the Vänern basin is {{convert|62|m|ft}} below sea level. The average depth is a more modest {{convert|28|m|ft}}, which means that the lake floor is above sea level on average.

Vänern drains into [[Göta älv]] towards [[Gothenburg]] and the [[Kattegat]] opening strait between the [[Atlantic Ocean]]’s North Sea and the [[Baltic Sea]]. It is the only one of the [[List of lakes in Sweden|ten largest lakes in Sweden]] not to drain out to the eastern coastline.  The [[Göta Canal]] built in the 19th century forms a waterway that runs to [[Vättern]] wholly rising when proceeding eastward, and then a navigable river linking the east coast with Vänern. The main inflow of water comes from [[Klarälven]] entering Vänern near [[Karlstad]] with its source in [[Trøndelag]] in [[Norway]].

==History==
The southeastern part of the Vänern is a depression that appears to have been formed by erosion of [[Paleozoic]]-aged [[sedimentary rock]] during the [[Quaternary glaciation]].<ref name=HalletalVästgöt2019/> Such erosion would have re-exposed parts of the [[Sub-Cambrian peneplain]].<ref name=HalletalVästgöt2019>{{Cite report|title=The sub-Cambrian unconformity in Västergötland, Sweden: Reference surface for Pleistocene glacial erosion of basement|date=2019-12-01|url=https://www.skb.com/publication/2495096/TR-19-21.pdf|last=Hall|first=Adrian M.|access-date=2020-11-26|last2=Krabbendam|first2=Maarten|publisher=Swedish Nuclear Fuel and Waste Management Co|publication-date=2019-12-01|last3=van Boeckel|first3=Mikis|last4=Hättestrand|first4=Clas|last5=Ebert|first5=Karin|last6=Heyman|first6=Jakob}}</ref> Because the Sub-Cambrian peneplain gently tilts towards the north and west in this area, the southeast part of the lake is rather shallow.<ref name=HalletalVästgöt2019/> The western shore of the lake largely follows a [[fault scarp]] associated with the [[Vänern-Göta Fault]].<ref name=HalletalVästgöt2019/>

The lake reached its present form after the [[Quaternary glaciation]] about 10,000 years ago; when the ice melted, the entire [[Central Swedish lowland|width of Sweden]] was covered in water, creating a strait between [[Kattegat]] and the [[Gulf of Bothnia]]. When [[post-glacial rebound]] surpassed a concurrent sea-level rise, lake Vänern became a part of the [[Ancylus Lake]] that occupied the Baltic basin.<ref name=Bjork1995/> Vänern was connected to Ancylus Lake by a strait at [[Degerfors]], [[Värmland]]. Lakes such as Vänern and [[Vättern]] were cut off from the Baltic by further uplifting.<ref name=Bjork1995>{{cite journal |last1=Björck |first1=Svante |author-link=Svante Björck |date=1995 |title=A review of the history of the Baltic Sea, 13.0-8.0 ka BP |journal=[[Quaternary International]] |volume=17 |pages=19–40 |doi=10.1016/1040-6182(94)00057-C |bibcode=1995QuInt..27...19B }}</ref> As a result of this former connection to the sea, there are species here not normally encountered in freshwater lakes, such as the [[amphipoda|amphipod]] ''[[Monoporeia affinis]]''. A [[Viking ships|Viking ship]] was found at the bottom of the lake on May 6, 2009.<ref>{{Cite web|url=https://www.thelocal.se/20090508/19342|title='Viking ship' discovered in Sweden's largest lake|date=2009-05-08|website=www.thelocal.se|language=en-GB|access-date=2019-02-06}}</ref>

A story told by the 13th-century Icelandic mythographer [[Snorri Sturluson]] in his ''[[Prose Edda]]'' about the origin of [[Mälaren]] was probably originally about Vänern: the Swedish king [[Gylfi]] promised a woman, [[Gefjon]], as much land as four oxen could plough in a day and a night, but she used oxen from the land of the giants, and moreover uprooted the land and dragged it into the sea, where it became the island of [[Zealand]]. The ''Prose Edda'' says that 'the inlets in the lake correspond to the headlands in Zealand';<ref>Anthony Faulkes (ed. and trans), ''Snorri Sturluson: Edda'' (London: Everyman, 1987), p. 7.</ref> since this description is much more true of Vänern, the myth was probably originally about Vänern, not Mälaren.<ref>Heimir Pálsson, 'Tertium vero datur: A study of the text of DG 11 4to', p. 44 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-126249.</ref>

The [[Battle on the Ice of Lake Vänern]] was a 6th-century battle recorded in the Norse sagas and referred to in the Old English epic ''[[Beowulf]]''. In ''Beowulf'', Vänern is stated to be near the location of the dragon's mound at [[Earnaness]].<ref>Howell D. Chickering, Jr. (ed. and trans), ''Beowulf'' (New York: Anchor Books, 2006), lines 3030-3032.</ref>

==Geography==
[[File:Vänern by Sentinel-2.jpg|thumb|left|alt=Satellite image of Värnen|Satellite image of Vänern]]
{{See also|Central Swedish lowland}}
Vänern covers an area of {{convert|5655|km2|abbr=on}}, approximately twice the surface area of [[Luxembourg]]. Its surface is {{convert|44|m|abbr=on}} above [[sea level]] and it is on average {{convert|27|m|abbr=on}} deep. The maximum depth of the lake is {{convert|106|m|abbr=on}}<ref>{{Cite web |url=http://www.ilec.or.jp/database/eur/eur-16.html |title=World Lakes Database |access-date=2006-04-22 |archive-url=https://web.archive.org/web/20050802092712/http://www.ilec.or.jp/database/eur/eur-16.html |archive-date=2005-08-02 |url-status=dead }}</ref> The water level of the lake is regulated by the [[Vargön Hydroelectric Power Station]].<ref>{{cite web |title=Våra kraftverk: Vargön - Vattenfall |url=https://powerplants.vattenfall.com/sv/vargon |website=powerplants.vattenfall.com |language=sv}}</ref>

Geographically, it is situated on the border between the Swedish regions of [[Götaland]] and [[Svealand]], divided between several Swedish provinces: The western body of water is known as the ''Dalbosjön'', with its main part belonging to [[Dalsland]]; the eastern body is known as ''Värmlandsjön'', its northern part belonging to [[Värmland]] and the southern to [[Västergötland]].

Its main tributary is [[Klarälven]], which flows into the lake near the city of [[Karlstad]], on the northern shore. Other tributaries include [[Gullspångsälven]], [[Byälven]] and [[Norsälven]]. It is drained to the south-west by [[Göta älv]], which forms part of the [[Göta Canal]] waterway, to Lake Viken into Lake [[Vättern]], southeast across Sweden.

The economic opportunities Vänern offers are illustrated by the surrounding towns, which have supported themselves for centuries by fishing and allowing easy transportation to other cities or west by [[Göta älv]] to the sea of [[Kattegat]]. This directly includes: [[Karlstad]] ([[charter]]ed in 1584), [[Kristinehamn]] (1642), [[Mariestad]] (1583), [[Lidköping]] (1446) [[Vänersborg]] (1644), [[Åmål]] (1643), [[Säffle]] (1951), and indirectly [[Trollhättan]] (1916).

The Djurö archipelago surrounds the island of Djurö, in the middle of the lake, and has been given national park status as [[Djurö National Park]].

The ridge (plateau mountain) [[Kinnekulle]] is a popular tourist attraction near the south-eastern shore of Vänern. It has the best view over the lake (about {{convert|270|m}} above the lake level). Another nearby mountain is [[Halleberg]].

==Environment==

[[File:Shore of Lake Vaenern in Sweden.jpg|thumb|View towards lake, Gamla Ekuddens naturreservat, Lake Vänern, Sweden.  Taken from observation tower.]]

[[Environmental monitoring]] studies are conducted annually. In a 2002 report, the data showed no marked decrease in overall water quality, but a slight decrease in visibility due to an increase of [[algae]]. An increasing level of [[nitrogen]] had been problematic during the 1970s through 1990s, but is now being regulated and is at a steady level.

Some bays also have problems with [[eutrophication]] and have become overgrown with algae and plant [[plankton]].

==Fish==
Vänern has many different fish species. Locals and government officials try to enforce fishing preservation projects, due to threats to the fish habitat. These threats include water cultivation in the tributaries, pollution and the [[M74 syndrome]]. Sport fishing in Vänern is free and unregulated, both from the shore and from boats (with some restrictions, e.g. a maximum of three salmon or trout per person per day). Commercial fishing requires permission.

In the open waters of Vänern, the most common fish is the [[European smelt|smelt]] (''Osmerus eperlanus''), dominating in the eastern Dalbosjön, where the average is 2,600 smelt per hectare. The second most common is the [[Coregonus albula|vendace]] (''Coregonus albula''), also most prominently in Dalbosjön, with 200–300 fish per hectare. The populations may vary greatly between years, depending on temperature, water level and quality.

The most important large fish in the lake are [[brown trout]] (''Salmo trutta'') and [[zander]] (''Sander lucioperca''). The most important small fish is the [[stickleback]].

Vänern has five distinguished species of [[Coregonus|whitefish]]: <!-- The correct scientific names need to be found for these species. -->
* ''[[Coregonus pallasii]]'' (also common in Neva, Gulf of Finland, Baltic Sea)
* Lacustrine fluvial whitefish (''[[Coregonus megalops]]'')
* ''[[Coregonus maxillaris]]'' (population mainly known around Sweden)<ref>[http://www.fishbase.org/Summary/SpeciesSummary.php?id=49240 Fishbase]</ref>
* ''[[Coregonus nilssoni]]''
* Valaam whitefish (''[[Coregonus widegreni]]'')
* ''[[Coregonus maxillaris]]''

==Birds==

[[File:Timber observation tower on Lake Vaenern in Sweden.jpg|thumb|Timber observation tower in Gamla Ekuddens naturreservat, Lake Vänern, Sweden]]

The most common birds near Vänern are [[tern]]s and [[gull]]s.

[[Great cormorant]]s have returned and are flourishing. This has contributed to the increase in the population of [[white-tailed sea eagle]]s, who feed on [[cormorant]]s.

==See also==
* [[Hindens Rev]]
* [[Lakes of Sweden]]

==References==
{{Reflist}}

==External links==
{{Commons category|Vänern}}
{{EB1911 poster|Vener}}
* [http://www.vastsverige.com/en/dalsland/articles/lake-vanern/ Official site]
* [http://www.vanermuseet.se Väner museum i Lidköping]

{{Large lakes of Sweden}}
{{Authority control}}

{{DEFAULTSORT:Vanern}}
[[Category:Lakes of Västra Götaland County]]
[[Category:Lakes of Värmland County]]