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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>R.F. Villella</dc:contributor>
  <dc:contributor>D. P. Lemarie</dc:contributor>
  <dc:creator>D. R. Smith</dc:creator>
  <dc:date>2001</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;The United States Endangered Species Act (ESA) requires a biological assessment of any activity that is authorized, funded, or carried out by a federal agency and likely to affect a federally listed endangered species or its critical habitat. We developed a standardized survey protocol for biological assessments of the effects of bridge replacements on 2 federally listed endangered freshwater mussels,&amp;nbsp;&lt;/span&gt;&lt;i&gt;Epioblasma torulosa rangiana&lt;/i&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;i&gt;Pleurobema clava,&lt;/i&gt;&lt;span&gt;&amp;nbsp;found in the Allegheny River, Pennsylvania. The protocol combines qualitative sampling to determine species present with quantitative sampling to estimate density. Data on species present satisfy the minimum requirement of a biological assessment, whereas estimates of density are needed to assess the number of individuals that would die as a result of bridge replacement. Some excavation of substrate is necessary for unbiased population estimates because of species and sex-specific differences in detection at the substrate surface. We reduced the amount of excavation and cost of the survey by using a statistical sampling technique called double sampling, which uses counts from excavating a subset of quadrats to calibrate counts from searching the substrate surface of all quadrats. We applied the survey protocol to the Allegheny River at West Hickory where&amp;nbsp;&lt;/span&gt;&lt;i&gt;E. t. rangiana&lt;/i&gt;&lt;span&gt;&amp;nbsp;was the 3&lt;/span&gt;&lt;sup&gt;rd&lt;/sup&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;i&gt;P. clava&lt;/i&gt;&lt;span&gt;&amp;nbsp;was the 4&lt;/span&gt;&lt;sup&gt;th&lt;/sup&gt;&lt;span&gt;&amp;nbsp;most abundant mussel at the site. Only 31% of&amp;nbsp;&lt;/span&gt;&lt;i&gt;P. clava&lt;/i&gt;&lt;span&gt;&amp;nbsp;and 52% of&amp;nbsp;&lt;/span&gt;&lt;i&gt;E. t. rangiana&lt;/i&gt;&lt;span&gt;&amp;nbsp;(80% of females, 45% of males) were detected at the substrate surface. We estimated that 9173 (95% CI: 6309–13,336)&amp;nbsp;&lt;/span&gt;&lt;i&gt;E. t. rangiana&lt;/i&gt;&lt;span&gt;&amp;nbsp;and 7010 (95% CI: 4462–11,013)&amp;nbsp;&lt;/span&gt;&lt;i&gt;P. clava&lt;/i&gt;&lt;span&gt;&amp;nbsp;lived within 50 m of the existing bridge and would be affected immediately by bridge construction. (Population estimates did not include mussels too small to be retained on a 6.35-mm-mesh sieve.) Application of the protocol is not limited to biological assessment under the ESA, but is appropriate where site-specific status of freshwater mussel populations is required.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.2307/1468193</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>University of Chicago Press</dc:publisher>
  <dc:title>Survey protocol for assessment of endangered freshwater mussels the Allegheny River, Pennsylvania</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>