<?xml version='1.0' encoding='utf-8'?>
<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>Robert O’Gorman</dc:contributor>
  <dc:creator>Ora E. Johannsson</dc:creator>
  <dc:date>1991</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;We sampled phytoplankton, zooplankton, and alewives&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;Alosa pseudoharengus&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;and measured water temperature in Lake Ontario during 1981&amp;ndash;1986. Through the use of general linear regression models we then sought evidence of control of the eplimnetic zooplankton community (mid-July to mid-October) by producers, consumers, and temperature. Our measures of the zooplankton community were total biomass, cladoceran biomass, and the ratio of large to small&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;Daphnia&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;spp. (&lt;/span&gt;&lt;i&gt;D. galeata mendotae&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;and&lt;/span&gt;&lt;i&gt;D. retrocurva&lt;/i&gt;&lt;span&gt;). Zooplankton population variables assessed were abundance, egg ratio, and productivity. Through factor analysis, factors were created from the standardized, transformed independent variables for use in the regression analyses. Regression models showed significant inverse relationships (&lt;/span&gt;&lt;i&gt;P&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&amp;lt; 0.05) between alewives and&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;Bosmina longirostris&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;(abundance, production, and egg ratio),&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;Ceriodaphnia lacustris&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;(egg ratio), and&lt;/span&gt;&lt;i&gt;Daphnia retrocurva&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;(egg ratio).&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;Bosmina longirostris&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;and&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;D. retrocurva&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;egg ratios were inversely related to algae biomass (&amp;lt;20 &amp;mu;m), thus the smaller algae might be controlled in part by the zooplankton community. Production of&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;C. lacustris&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;was directly related to temperature, as was the production and abundance of&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;Tropocyclops prasinus&lt;/i&gt;&lt;span&gt;. The annual size-frequency distributions of&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;B. longirostris&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;and&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;i&gt;D. retrocurva&lt;/i&gt;&lt;span&gt;&lt;span class="Apple-converted-space"&gt;&amp;nbsp;&lt;/span&gt;were inversely related to yearling alewife abundance and directly related to adult alewife abundance, which suggested that yearlings use a particulate-feeding mode on these zooplankton species more frequently than adults. We found no significant negative correlations among the zooplankton species, which suggested that interzooplankton predation and competition were not as important in structuring the community as were planktivory and temperature.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1577/1548-8659(1991)120&lt;0193:ROPFAT&gt;2.3.CO;2</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Taylor &amp; Francis</dc:publisher>
  <dc:title>Roles of predation, food, and temperature in structuring the epilimnetic zooplankton populations in Lake Ontario, 1981-1986</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>