Laserfiche WebLink
<br />6 <br /> <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />Studv Area: <br />The study area for YOY/small bodied fish monitoring extends from river mile RM 180.0 (Animas <br />River confluence) in Farmington, New Mexico, downstream to RM 2.9 (Clay Hills Crossing), <br />just above Lake Powell in Utah. <br /> <br />Collections: <br /> <br />Specimens collected will be inspected to determine if any rare fishes (Colorado pikeminnow, <br />roundtail chub, and razorback sucker) are present in a sample or collection. All identifiable rare <br />fish and all large- bodied native fishes (i.e., flannelmouth and bluehead suckers)>150 mm TL will <br />be released. Specimens fi-om each sampled mesohabitat will be preserved separately. All other <br />specimens will be preserved in 10% formalin and returned to the New Mexico Department of <br />Game and Fish Laboratory for identification, enumeration, and measurement (total length). After <br />processing, all specimens will be accessioned to the UNM Museum of Southwestern Biology, <br />Fish Section. <br /> <br />Obiectives: <br /> <br />The objectives of this portion of the San Juan River monitoring effort are to document occurrence <br />and habitat use in primary channel shoreline and near-shoreline mesohabitats. secondary <br />channels, and backwaters by age 0 Colorado pikeminnow, razorback sucker, and roundtail chub; <br />occurrence and habitat us,: by other native and nonnative fishes is sampled habitats, to obtain data <br />that will aid in the evalu,ation of the responses (e.g" reproduction, recruitment, and growth) of <br />native and nonnative fishes to different flow regimes and other management actions (e.g., <br />impediment modification); to track trends in species populations (e.g., abundance and relative <br />condition); and to characterize patterns of mesohabitat use by common native and nonnative <br />small bodied fishes (including age 0 flannelmouth sucker, bluehead sucker, common carp, and <br />channel catfish). The data will also be available to all researchers and may be used in conjunction <br />with data obtained in other studies to evaluate future management activities. <br /> <br />Methods: <br /> <br />The study reach (Farmington to Clay Hills Crossing) includes geomorphic reaches 6 through 1, <br />with Reach 1 being the most downstream. Previously, as stated in SJRMPP, sampling occurred <br />every third mile within the study reach. Because of the addition of enclosure sampling of near- <br />shoreline primary channel mesohabitats and additional time and resources required, primary <br />channel sampling will occur every fifth mile. To the extent possible, all secondary channels will <br />continue to be sampled. Secondary channels are defined as channels having less than 25% of the <br />volume of flow at the time of sampling and are at least 200 m in length. Inflow at the top of a <br />channel is not necessary for it to be classified as a secondary channel. Y oung-of-year/small- <br />bodies fish monitoring will occur in conjunction with the large-bodied fish monitoring effort. <br />Fieldwork will be accomplished in autumn (late-September through mid-October) and involves <br />one foray through each of three macro-reaches (Farmington-Shiprock, Shiprock-Four Comers, <br />and Four Comers-Clay Hills Crossing). <br /> <br />In addition to structured primary channel sampling, all backwaters and embayments (>25 m') <br />associated with the primary channel within each fifth-mile will be sampled. Large backwaters <br />(ca. 250 m2) outside designated sample-miles will be sampled, if possible. <br /> <br />Sample sites within secondary channels will be a sufficient distance from the inflow to and <br />outflow from the secondary channel to minimize primary channel faunal and physiochemical <br />