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<br />c <br /> <br />a <br />o <br />c-.) <br />v~ <br />....:J <br />l'-.J <br /> <br />Objectives: <br /> <br />Timeline: <br /> <br />Research Need: <br /> <br />( <br /> <br />Methods: <br /> <br />l <br /> <br />from other agencies <br /> <br />Planned for Phase I and II (FY 1991 thru 1994). <br />Some tasks may extend thru Phase III as needed <br /> <br />-To define abundance and distribution of the native <br />and non-native fish corrnnunity with emphasis on <br />adult Colorado squawfish, roundtail chub, and <br />razorback sucker (target species) <br /> <br />-Locate potential spawning areas of target species <br /> <br />-Determine seasonal habitat use and needs of target <br />species <br /> <br />Prior to 1987, irregular sampling efforts had <br />documented a native San Juan River fish fauna of <br />eight species and a possible ninth, including <br />Colorado squawfish, razorback sucker, and roundtail <br />chub. Although not confirmed in the literature, <br />the ninth species (bony tail chub) was found to be a <br />historic component of the fish fauna after <br />reexamination of museum specimens (Platania 1991?) . <br />Surveys during 1987-1989 confirmed the persistence <br />of the Colorado squawfish, razorback sucker, and <br />roundtail chub. <br /> <br />Despite confirmation of survival of Colorado <br />squawfish, razorback sucker, and roundtail chub in <br />the San Juan River questions remain regarding the <br />overall range, boundaries of primary ranges <br />(residency or non-residency in the San Juan River) , <br />location of spawning and nursery habitats, and <br />abundance. . <br /> <br />Research in other upper basin rivers of the <br />Colorado River drainage and preliminary findings <br />from studies conducted in the San Juan River in <br />1991 have shown that tracking radio-tagged fish can <br />result in location of aggregations of the target <br />species (particularly Colorado squawfish) during <br />certain seasons and determination of spawning <br />areas. <br /> <br />Three intensive sampling efforts for adult. and <br />juvenile fish will be conducted on the San Juan <br />River between Shiprock, New Mexico and Mexican Hat, <br />Utah. Two trips will be conducted during the <br />spring and one during the fall, and will consist of <br />a minimum of nine to ten people from the <br />cooperating agencies. <br /> <br />10 <br />