Laserfiche WebLink
<br />li"""'"'"' . <br /> <br />e <br /> <br />e <br /> <br />3 <br /> <br />The New Mexico Department of Game and Fish provided a crew, under the <br /> <br />supervision of Mr. Mike Hatch, for a ~o day electrofishing survey of the main <br /> <br />stream San Juan below Navajo Reservoir. Two "runs" were made with a boom-type <br /> <br />shoclr.er IJn June 11 and 12: the first from l~avajo Dam in New Mexico highway 173, <br /> <br />and the second, from U.S. highway 44 in Bloomfield totbe San Juan County <br /> <br />Fairgrounds. The first is a distance of about 6' river tiles and the second, <br /> <br />about 8 miles. TIle results are reported under station Bumbers 12 and 17. <br /> <br />respectively. <br /> <br />A portable electrofishing unit and a backpack shocker were also used with <br /> <br />limited to excellent success on several small tributary streams and braided side <br /> <br />channels of the main stream. <br /> <br />Hoop nets and a small Fyke net were also used, with limited success. <br /> <br />A fine ~esh dip net was used with some success for post-larval and juvenile <br /> <br />fish. Identification of these was aided by the descriptions given in Winn and <br /> <br />Killer (1954). <br /> <br />Because of relatively high water levels (and/or heavy silt loads) during <br /> <br />much of the survey much of the collecting endeavor consisted of intensive seining. <br /> <br />Seine hauls were critically scrutinized with represent~ive portions of each <br /> <br />haul being preserved. Particular care was given to a review of early juvenile <br /> <br />scages with all the specimens having been subsequently examined microscopically. <br /> <br />Each saDlpling method has an element of bias. Hovevet:, by using a combination <br /> <br />of several techinques It is felt that a representative sample was obtained at <br /> <br />most stations. The inability to use the ~lectrofishing unit at. several stations <br /> <br />, <br />due to high water and heavy silt loads undoubtedly resulted in a much lower number <br /> <br />of certain larger fish being taken. However, intensive seining in backwater areas <br /> <br />should have compensated for this in the capture of juvealles. Since the emphasis <br /> <br />of the study has been on the status of endangered spec~s as attempt was made <br /> <br />to collect those biotopes known to support populations of squawfish in other parts <br /> <br />of the Colorado River system. According to Holden (1913) "Adults were primarily <br /> <br />4\ <br />