Laserfiche WebLink
<br />C:") <br />c;J <br />l'~ <br />r " <br />.0::.. <br /> <br />..;.:.. <br /> <br />RESULTS <br /> <br />Historical fish collections in tributaries of the San Juan River <br /> <br />The earliest credible fish surveys within the study area were conducted in the Animas <br />River during 1934 and 1940, The locations for both of these sampling sites were between <br />Aztec and Farmington, Collections confirnled the presence of Catostom/ls latipinnis <br />(flannelmouth sucker), Gila robusla (roundtail chub), Rhinichthys osculus (speckled <br />dace), and Caloslomus discobolus (bluehead sucker). The latter two species were only <br />collected in the 1934 sample, All fish reported during these sampling occasions were <br />native fish (Table 3), <br /> <br />Fish Sampling 1950 - 1969 <br /> <br />Several sampling efforts were conducted on tributaries of the San Juan between 1950 and <br />1969. Most of the sites occurred on the Animas River; however, unlike the previous <br />efforts these site locations were all located upstream from Aztec, Fish species in these <br />collections consisted of native fish (flannelmouth sucker, bluehead sucker, Cot/us bairdi <br />(mottled sculpin), speckled dace, and roundtail chub) and the addition of six non-native <br />fish species; Catostomus commasoni (white sucker), Cyprinella lutrensis (red shiner), <br />Oncorhynchus mykiss (rainbow trout), Pimephales promelas (fathead minnow), Salmo <br />'trulta (brown trout), and Gambusia afJinus (mosquitofish). The La Plata was also <br />, sampled once during 1966. Fish collected in the La Plata were all native species <br />(flannelmouth sucker, bluehead sucker, and speckled dace). Roundtail chub were <br />collected during only one sampling event within this time period. Fifteen individuals <br />were collected on 15 Nov. 1963 at a location I mile North of Cedar Hill in the Animas <br />River. <br /> <br />During 1961, fish sampling was also conducted on the San Juan River to provide pre- <br />impoundment data on existing fish species (Olson 1962b). Results of these sampling <br />efforts are noteworthy because they indicate the presence of Colorado pikeminnow and <br />roundtail chub within an area which is now inundated, Olson (1968) later reported that <br />roundtail chub constituted a large proportion (up to 77%) of gill net collections made at <br />seven locations within Navajo Reservoir. <br /> <br />Drart Final Tributary Report <br />Miller Ecological Consultants, Inc. <br /> <br />January 31, 2000 <br />Page 6 <br />