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?ic? n?+M r?11e?t?nn <br />The primary objective of the study was to document the presence or absence <br />of endangered or threatened species of fish. Previous work indicated the type <br />of gear used would have some influence on species and size of fish caught <br />because of selectivity. Therefore, a variety of gear was used to reduce the <br />bias of selective gear. <br />Fish were collected with the following types of gear: Graduated mesh <br />gill and trammel nets 125' x 6' bar graduations from 1" to 2"; straight <br />trammel nets 90' x 6' middle bar 3", outside bars 8"; hand seines 20' x 4' <br />x 4" mesh and 50' x 6' x ,," mesh; and electrofishing gear using a generator <br />of 2,500 watts capacity. <br />Graduated mesh nets were set in areas considered as having the highest <br />probability of being inhabitated by Colorado River endangered or threatened <br />fish species. The standard net set was usually 24 hours in length. All fish <br />caught were identified as to species, enumerated, and subsampled for size <br />range estimation. Periodically entire catches were individually weighed and <br />measured for calculating age-growth statistics. , <br />Hand seines were used primarily to capture samller fish such as juveniles <br />of the larger species and the physically smaller species of fish which would <br />ordinarily not be taken with other gear. Numbers of fish captured by seining <br />were usually large and varied greatly depending upon a number of factors. <br />Therefore, exact numbers of the various species captured were only recorded <br />for those samples considered significant. For the majority of the seining <br />samples, estimates of the relative numbers of the various species were recorded. <br />All samples were closely examined for the possible occurrence of any endangered <br />or threatened juvenile specimens. <br />(9)