<?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>James E. Cloern</dc:contributor>
  <dc:contributor>Anne Hutchinson</dc:contributor>
  <dc:creator>Julie W. Ambler</dc:creator>
  <dc:date>1985</dc:date>
  <dc:description>&lt;div id="Abs1-section" class="c-article-section"&gt;&lt;div id="Abs1-content" class="c-article-section__content"&gt;&lt;p&gt;The two estuarine systems composing San Francisco Bay have distinct zooplankton communities and seasonal population dynamics. In the South Bay, a shallow lagoon-type estuary, the copepods&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Acartia&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;spp. and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Oithona davisae&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;dominate. As in estuaries along the northeast coast of the U.S., there is a seasonal succession involving the replacement of a cold-season&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Acartia&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;species (&lt;i&gt;A. clausi s.l.&lt;/i&gt;) by a warm-season species (&lt;i&gt;A. californiensis&lt;/i&gt;), presumably resulting from the differential production and hatching of dormant eggs.&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Oithona davisae&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;is most abundant during the fall. Copepods of northern San Francisco Bay, a partially-mixed estuary of the Sacramento-San Joaquin Rivers, organize into discrete populations according to salinity distribution:&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Sinocalanus doerrii&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;(a recently introduced species) at the riverine boundary, Eurytemora affinis in the oligohaline mixing zone,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Acartia&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;spp. in polyhaline waters (18–30\%), and neritic species (e.g.,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Paracalanus parvus&lt;/i&gt;) at the seaward boundary.&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Sinocalanus doerrii&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;E. affinis&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;are present year-round.&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Acartia clausi s.l.&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;is present almost year-round in the northern reach, and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;A. californiensis&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;occurs only briefly there in summer-fall. The difference in succession of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Acartia&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;species between the two regions of San Francisco Bay may reflect differences in the seasonal temperature cycle (the South Bay warms earlier), and the perennial transport of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;A. clausi s.l.&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;into the northern reach from the seaward boundary by nontidal advection.&lt;/p&gt;&lt;p&gt;Large numbers (&amp;gt;10&lt;sup&gt;6&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;m&lt;sup&gt;−3&lt;/sup&gt;) of net microzooplankton (&amp;gt;64 µm), in cluding the rotifer&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Synchaeta&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;sp. and three species of tintinnid ciliates, occur in the South Bay and in the seaward northern reach where salinity exceeds about 5–10‰ Maximum densities of these microzooplankton are associated with high concentrations of chlorophyll. Meroplankton (of gastropods, bivalves, barnacles, and polychaetes) constitute a large fraction of zooplankton biomass in the South Bay during winter-spring and in the northern reach during summer-fall.&lt;/p&gt;&lt;p&gt;Seasonal cycles of zooplankton abundance appear to be constant among years (1978–1981) and are similar in the deep (&amp;gt;10 m) channels and lateral shoals (&amp;lt;3 m). The seasonal zooplankton community dynamics are discussed in relation to: (1) river discharge which alters salinity distribution and residence time of plankton; (2) temperature which induces production and hatching of dormant copepod eggs; (3) coastal hydrography which brings neritic copepods of different zoogeographic affinities into the bay; and (4) seasonal cycles of phytoplankton.&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;&lt;div id="cobranding-and-download-availability-text" class="note test-pdf-link"&gt;&lt;br&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1007/BF00048694</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Springer</dc:publisher>
  <dc:title>Seasonal cycles of zooplankton from San Francisco Bay</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>