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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Dale M. Robertson</dc:contributor>
  <dc:creator>Richard C Lathrop</dc:creator>
  <dc:date>2021</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Warming of &lt;/span&gt;&lt;span&gt;lake &lt;/span&gt;&lt;span&gt;surface waters &lt;/span&gt;&lt;span&gt;has become a concern &lt;/span&gt;&lt;span&gt;to limnologists and water managers &lt;/span&gt;&lt;span&gt;because a&lt;/span&gt;&lt;span&gt;ir &lt;/span&gt;&lt;span&gt;temperatures, which directly affect &lt;/span&gt;&lt;span&gt;near&lt;/span&gt;&lt;span&gt;-&lt;/span&gt;&lt;span&gt;surface &lt;/span&gt;&lt;span&gt;water temperatures, &lt;/span&gt;&lt;span&gt;are projected to &lt;/span&gt;&lt;span&gt;increase &lt;/span&gt;&lt;span&gt;in Wisconsin (WICCI 2011) as well as globally &lt;/span&gt;&lt;span&gt;(IPCC 2018). This projected &lt;/span&gt;&lt;span&gt;increase is &lt;/span&gt;&lt;span&gt;in addition to &lt;/span&gt;&lt;span&gt;the changes in &lt;/span&gt;&lt;span&gt;air temperatures &lt;/span&gt;&lt;span&gt;that have &lt;/span&gt;&lt;span&gt;already &lt;/span&gt;&lt;span&gt;occurred &lt;/span&gt;&lt;span&gt;in recent decade&lt;/span&gt;&lt;span&gt;s&lt;/span&gt;&lt;span&gt;(WICCI 2011, NOAA 2017)&lt;/span&gt;&lt;span&gt;.&lt;/span&gt;&lt;span&gt;The &lt;/span&gt;&lt;span&gt;deleterious &lt;/span&gt;&lt;span&gt;effects of increased temperatures in &lt;/span&gt;&lt;span&gt;lake surface waters have been extensively &lt;/span&gt;&lt;span&gt;reviewed (&lt;/span&gt;&lt;span&gt;e.g., &lt;/span&gt;&lt;span&gt;Blenckner 2005, Keller 2007, Adrian &lt;/span&gt;&lt;span&gt;et al. 2009, George 2010&lt;/span&gt;&lt;span&gt;)&lt;/span&gt;&lt;span&gt;. Briefly&lt;/span&gt;&lt;span&gt;, t&lt;/span&gt;&lt;span&gt;he &lt;/span&gt;&lt;span&gt;exceedance of thermal preferences &lt;/span&gt;&lt;span&gt;or tolerances of aquatic biota &lt;/span&gt;&lt;span&gt;can cause &lt;/span&gt;&lt;span&gt;altered food webs and &lt;/span&gt;&lt;span&gt;loss of biodiversity &lt;/span&gt;&lt;span&gt;in &lt;/span&gt;&lt;span&gt;lakes &lt;/span&gt;&lt;span&gt;(&lt;/span&gt;&lt;span&gt;De&lt;/span&gt;&lt;span&gt;Stasio et al. 199&lt;/span&gt;&lt;span&gt;6&lt;/span&gt;&lt;span&gt;, Chu et al. 2005, Graham and Harrod 2009, &lt;/span&gt;&lt;span&gt;Woodward et al. 2010, Comte et al. 2013&lt;/span&gt;&lt;span&gt;)&lt;/span&gt;&lt;span&gt;. &lt;/span&gt;&lt;span&gt;W&lt;/span&gt;&lt;span&gt;armer surface water temperature s&lt;/span&gt;&lt;span&gt;can result in &lt;/span&gt;&lt;span&gt;stronger and longer &lt;/span&gt;&lt;span&gt;thermal &lt;/span&gt;&lt;span&gt;stratification in &lt;/span&gt;&lt;span&gt;deep &lt;/span&gt;&lt;span&gt;lakes&lt;/span&gt;&lt;span&gt;(&lt;/span&gt;&lt;span&gt;Robertson and Ragotzkie&lt;/span&gt;&lt;span&gt;1990, Hondzo &lt;/span&gt;&lt;span&gt;and Stefan 1993, Livingstone 2003, Butcher et al. 2015&lt;/span&gt;&lt;span&gt;)&lt;/span&gt;&lt;span&gt;. This process &lt;/span&gt;&lt;span&gt;in turn &lt;/span&gt;&lt;span&gt;can &lt;/span&gt;&lt;span&gt;cause the &lt;/span&gt;&lt;span&gt;duration and extent of hypolimnetic &lt;/span&gt;&lt;span&gt;anoxia to increase, thus reducing &lt;/span&gt;&lt;span&gt;hypolimnetic refugia &lt;/span&gt;&lt;span&gt;needed for cold&lt;/span&gt;&lt;span&gt;-&lt;/span&gt;&lt;span&gt;and cool&lt;/span&gt;&lt;span&gt;-&lt;/span&gt;&lt;span&gt;water &lt;/span&gt;&lt;span&gt;fish &lt;/span&gt;&lt;span&gt;(&lt;/span&gt;&lt;span&gt;De Stasio et al. 1996&lt;/span&gt;&lt;span&gt;, Magnuson et al. 1997, Jeppesen et al. &lt;/span&gt;&lt;span&gt;2012&lt;/span&gt;&lt;span&gt;, Missaghi et al. 2017)&lt;/span&gt;&lt;span&gt;. &lt;/span&gt;&lt;span&gt;Longer duration of hypolimnetic anoxia &lt;/span&gt;&lt;span&gt;can enhance &lt;/span&gt;&lt;span&gt;eutrophic&lt;/span&gt;&lt;span&gt;ation &lt;/span&gt;&lt;span&gt;because of more internal loading of &lt;/span&gt;&lt;span&gt;phosphorus from bottom sediments &lt;/span&gt;&lt;span&gt;(&lt;/span&gt;&lt;span&gt;Blenckner et al. 2002, &lt;/span&gt;&lt;span&gt;North et al. 2014&lt;/span&gt;&lt;span&gt;)&lt;/span&gt;&lt;span&gt;. &lt;/span&gt;&lt;span&gt;Of parti&lt;/span&gt;&lt;span&gt;cular concern, w&lt;/span&gt;&lt;span&gt;armer water temperatures &lt;/span&gt;&lt;span&gt;favor the growth of toxic &lt;/span&gt;&lt;span&gt;cyanobacteria in &lt;/span&gt;&lt;span&gt;eutrophic systems &lt;/span&gt;&lt;span&gt;(&lt;/span&gt;&lt;span&gt;Paerl and Huisman 2008, Wagner and Adrian 2009, Kosten &lt;/span&gt;&lt;span&gt;et al. 2012&lt;/span&gt;&lt;span&gt;)&lt;/span&gt;&lt;span&gt;.&lt;/span&gt;&lt;span&gt;Another effect of &lt;/span&gt;&lt;span&gt;warmer lake surface temperature&lt;/span&gt;&lt;span&gt;s &lt;/span&gt;&lt;span&gt;is increased &lt;/span&gt;&lt;span&gt;evaporation that can &lt;/span&gt;&lt;span&gt;result in lower water levels&lt;/span&gt;&lt;span&gt;(&lt;/span&gt;&lt;span&gt;Spence et al. 2013, Gronewold and Stow 2014&lt;/span&gt;&lt;span&gt;)&lt;/span&gt;&lt;span&gt;.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:language>en</dc:language>
  <dc:publisher>Wisconsin Department of Natural Resources</dc:publisher>
  <dc:title>Long-term epilimnetic temperature trends in Lake Mendota and Trout Lake, Wisconsin</dc:title>
  <dc:type>reports</dc:type>
</oai_dc:dc>