{"id":15361,"date":"2018-10-11T11:18:18","date_gmt":"2018-10-11T09:18:18","guid":{"rendered":"https:\/\/npolar.no\/?page_id=15361"},"modified":"2023-01-24T13:36:06","modified_gmt":"2023-01-24T12:36:06","slug":"arctic-ecosystems-in-fresh-water","status":"publish","type":"page","link":"https:\/\/npolar.no\/en\/themes\/arctic-ecosystems-in-fresh-water\/","title":{"rendered":"Arctic ecosystems in fresh water"},"content":{"rendered":"\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-70qvtf-16dc1513483192a3ad3e4e6c90a43213\">\n.flex_column.av-70qvtf-16dc1513483192a3ad3e4e6c90a43213{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-70qvtf-16dc1513483192a3ad3e4e6c90a43213 av_one_full  avia-builder-el-0  el_before_av_section  avia-builder-el-no-sibling  first flex_column_div av-zero-column-padding  '     ><section  class='av_textblock_section av-695nn7-f1dc85a58ede29ae1864e41504db75de '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/CreativeWork\" ><div class='avia_textblock'  itemprop=\"text\" ><p>Due to the low temperatures and low precipitation, lake ice in Svalbard is very compact and transparent, and little snow settles on it. The relatively clear black ice, together with low snowfall, means that a lot of the light penetrates through and contributes to relatively high primary production under the ice.<\/p>\n<p>In lakes with catchments containing significant glaciers (glacial lakes), increased summer solar radiation causes large volumes of glacial sediments to be transported out into the lakes.<\/p>\n<p>Annual production in Svalbard lakes varies strongly with climatic conditions, primarily temperature and snowfall. However, it is the lack of nutrients, rather than sunlight and temperature, that is considered to be the most significant single factor limiting primary production in Arctic lakes. The exception is lakes that receive large quantities of nutrients from external sources, such as seabirds nesting in the lakes&#8217; catchment basins<\/p>\n<p>Svalbard&#8217;s extreme isolation, in combination with its Arctic climate, has produced freshwater sites with very few species of plankton and benthic animals. Char is the only freshwater fish. Stoneflies, dragonflies, black flies and predaceous diving beetles are among the species found in most of the lakes of Northern Norway, but which have not yet been observed in Svalbard.<\/p>\n<p>The dominant bodies of water are shallow (&lt;2 m) ponds and small lakes created by permafrost. These often have a high production of insects and crustaceans, may be significant biotopes for birds, and are highly vulnerable to permafrost thawing. These permafrost-dammed pools do not normally support fish since they freeze through to the bottom in winter, whereas Arctic char live in effectively all the lakes in Svalbard below the marine limit that do not freeze through (are deeper than 2 m).<\/p>\n<\/div><\/section><\/div>\n<\/div><\/div><\/div><!-- close content main div --><\/div><\/div><div id='av_section_1'  class='avia-section av-lda812bu-85f93b88b823c214702699c2d7caea01 alternate_color avia-section-default avia-no-border-styling  avia-builder-el-2  el_after_av_one_full  avia-builder-el-last  avia-bg-style-scroll container_wrap fullsize'  ><div class='container av-section-cont-open' ><div class='template-page content  av-content-full alpha units'><div class='post-entry post-entry-type-page post-entry-15361'><div class='entry-content-wrapper clearfix'>\n<div  class='togglecontainer av-lda7zb2s-90155e290d09c2dc168955959742c089 av-minimal-toggle  avia-builder-el-3  avia-builder-el-no-sibling  toggle_close_all' >\n<section class='av_toggle_section av-lda7z8xh-c6c3f75e77ada0acd382e35a7008149e'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/CreativeWork\" ><div role=\"tablist\" class=\"single_toggle\" data-tags=\"{All} \"  ><p id='toggle-toggle-id-1' data-fake-id='#toggle-id-1' class='toggler  av-title-above '  itemprop=\"headline\"  role='tab' tabindex='0' aria-controls='toggle-id-1' data-slide-speed=\"200\" data-title=\"Relevant pages\" data-title-open=\"\" data-aria_collapsed=\"Click to expand: Relevant pages\" data-aria_expanded=\"Click to collapse: Relevant pages\">Relevant pages<span class=\"toggle_icon\"><span class=\"vert_icon\"><\/span><span class=\"hor_icon\"><\/span><\/span><\/p><div id='toggle-id-1' aria-labelledby='toggle-toggle-id-1' role='region' class='toggle_wrap  av-title-above'  ><div class='toggle_content invers-color '  itemprop=\"text\" ><p><a href=\"https:\/\/npolar.no\/en\/themes\/vegetation-svalbard\/\">Vegetation in Svalbard<\/a><\/p>\n<\/div><\/div><\/div><\/section>\n<section class='av_toggle_section av-lda7yce4-d1899d0f8c11638b8cd8d49607a68201'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/CreativeWork\" ><div role=\"tablist\" class=\"single_toggle\" data-tags=\"{All} \"  ><p id='toggle-toggle-id-2' data-fake-id='#toggle-id-2' class='toggler  av-title-above '  itemprop=\"headline\"  role='tab' tabindex='0' aria-controls='toggle-id-2' data-slide-speed=\"200\" data-title=\"References\" data-title-open=\"\" data-aria_collapsed=\"Click to expand: References\" data-aria_expanded=\"Click to collapse: References\">References<span class=\"toggle_icon\"><span class=\"vert_icon\"><\/span><span class=\"hor_icon\"><\/span><\/span><\/p><div id='toggle-id-2' aria-labelledby='toggle-toggle-id-2' role='region' class='toggle_wrap  av-title-above'  ><div class='toggle_content invers-color '  itemprop=\"text\" ><ul>\n<li>Svenning, M-A.&nbsp;<strong>Fiskesamfunn i arktiske innsj\u00f8er<\/strong>&nbsp;(Fish communities in Arctic lakes). In: Borgstr\u00f8m, R. og L. P. Hansen (red.). Fisk i ferskvann \u2013 Et samspill mellom bestander, milj\u00f8 og forvaltning. Landbruksforlaget, Oslo, s. 60-65. 2000<\/li>\n<li>Stonehouse, B. 1989.&nbsp;<a href=\"http:\/\/journals.cambridge.org\/action\/displayAbstract?fromPage=online&amp;aid=5423908&amp;fileId=S0032247400019616\">Polar ecology<\/a>. Glasgow, Blackie: New York, Chapman and Hall (Tertiary Level Biology). 222 s. 1989. DOI: http:\/\/dx.doi.org\/10.1017\/S0032247400019616<\/li>\n<li>Smith, L. C., Y. Sheng, G. M. MacDonald &amp; L. D. Hinzman.&nbsp;<a href=\"http:\/\/www.sciencemag.org\/content\/308\/5727\/1429.full\">Disappearing Arctic lakes<\/a>. Science, 308: 1429\u20131429. 2005. DOI: 10.1126\/science.1108142<\/li>\n<\/ul>\n<\/div><\/div><\/div><\/section>\n<\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>The lake ecosystems in Svalbard are largely characterised by low precipitation, thick, clear ice (1.5\u20132 m), a brief ice-free period (1\u20132 months), relatively low water temperatures in summer (up to 6\u20137\u00b0C), low nutrient input, low primary production, low biodiversity, with Arctic char as the only fish species.<\/p>\n","protected":false},"author":20,"featured_media":7526,"parent":3607,"menu_order":11,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"tags":[],"emne":[96,97],"class_list":["post-15361","page","type-page","status-publish","has-post-thumbnail","hentry","emne-arctic","emne-biodiversity"],"acf":[],"_links":{"self":[{"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/pages\/15361","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/users\/20"}],"replies":[{"embeddable":true,"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/comments?post=15361"}],"version-history":[{"count":6,"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/pages\/15361\/revisions"}],"predecessor-version":[{"id":37939,"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/pages\/15361\/revisions\/37939"}],"up":[{"embeddable":true,"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/pages\/3607"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/media\/7526"}],"wp:attachment":[{"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/media?parent=15361"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/tags?post=15361"},{"taxonomy":"emne","embeddable":true,"href":"https:\/\/npolar.no\/en\/wp-json\/wp\/v2\/emne?post=15361"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}