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<br />I <br />I <br />" <br /> <br />, <br />:') <br />:,'.:1 <br />-.-;1 <br /> <br />" -~ <br /> <br />~, <br /> <br />.', <br />: .; <br /> <br />:....~ <br />I <br /> <br />........ <br />CO <br />['. <br />~ <br />(;) <br />(~ <br /> <br />Miller et a1. (1993) sampled several San Juan River tributaries in 1992 and found roundtail chub in <br />the La Plata River and the San Juan River above Navajo Reservoir. Miller et a1. (1995) sampled <br />additional tributaries in 1993 and 1994 and found roundtail chub to be abundant in portions of the <br />Mancos and La Plata rivers and in low numbers in the Florida River. One roundtail chub was also <br />collected in the Animas River. <br /> <br />Buntjer et a1. (1993, 1994) and Archer et a1. (1995, 1996) caught five young roundtail chub in 1991, <br />18 in 1992,15 in 1993, 19 in 1994, and 7 in 1995. These fish included YOY and 1- and 2-year old <br />juveniles. They were primarily caught in backwaters and were caught between RM 107 and 130 iri <br />all years except 1995 (Archer et a1. 1996)'when five larvae (11-14 mm) were caught between RM <br />12 and RM 23 in the lower river. Gido and Propst (1995) captured 8 roundtail chub in 1993 and 4 <br />in 1994 in secondary channels between RM 87.4 and 134.9. Seven of the fish were captured in <br />secondary channels at RM 128.6 and RM 134.9. These are generally areas below or only a few <br />miles above the mouth of the Mancos River (RM 122) so it is possible that most of the roundtail <br />chub in the main San Juan River come from the Mancos River or other upstream tributaries that <br />harbor good populations (Buntjer et a1. 1994). <br /> <br />Information for studying habitat use of other native fish is available in data from various SJRRIP <br />researchers as well as data from researchers in other parts of the Upper Basin. Because it has never <br />been a priority to study these other portions of the fish community, many of the data have not been <br />analyzed. <br /> <br />Summary <br />Considerable information is known about the habitat requirements of Colorado squawfish, both from <br />the San Juan System and from other Upper Basin ,rivers. They appear to utilize and require the same <br />habitats in the San Juan River as they do in other Upper Basin rivers. Information on habitat <br />requirements of razorback sucker is primarily from studies in other Upper Basin rivers. Due to the <br />low numbers of razorback sucker in the San Juan River, stocked razorbacks have been used to <br />determine habitat use. Less is known about habitat requirements of other native fishes. Much" <br />information has been collected on these species but has yet to be comprehensively evaluated in terms' <br />of habitat requirements. This will be completed during the integration efforts planned for 1997. " <br /> <br />5.2.5.2. <br /> <br />Identify Sub reaches that Provide Habitats for the Different Life Stages. <br /> <br />Two types of studies were conducted to identify important subreaches for the target fish species. <br />One type included fish sampling studies (Buntjer et a1. 1993, 1994; Lashmett 1993, 1994; Ryden and <br />Pfeifer 1993, 1994, 1995a, 1996a; Miller 1994a, 1995; and others) that showed the areas of a river <br />that the fish use. The second type of study involved habitat characterization (Pucherelli and <br />Goettlicher 1992; Bliesner and Lamarra 1993, 1994, 1995, 1996) which identified the amount of <br />habitat in various parts of the river. Knowing habitat preferences, the habitat studies can potentially <br />show why certain areas are used and can identify areas that the fish are not using that appear to <br />provide the right habitat types. <br /> <br />San Juan River Recovery Implementation Program <br />Summary Report <br /> <br />27 <br /> <br />17 January 1997 <br />PR-576-2 <br />