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<br />o <br /><? <br />~ <br /> <br />( <br /> <br />'- <br /> <br />San Juan Seven Year Research Plan <br /> <br />WORK STATEMENT/PROTOCOL <br /> <br />C:.:' <br /> <br />~ <br /> <br />AUGMENTATrON/TELEMETRY RESEARCH - USFWS (Region-2) <br /> <br />Background: <br />A small and, as yet undefined population of Colorado squawfish inhabits the San <br />Juan River from Lake Powell upstream to at least Shiprock, New Mexico. Studies <br />during the period 1987-1990 (Platania 1990) have resulted the collection of <br />eleven adults and nineteen young-of-year in this river reach. During subsequent <br />sampling in June 1991 a total of four additional adult squawfish were collected <br />in the reach between Four Corners and Shiprock. Three of these fish were <br />implanted with radio transmitters. The fourth died of unknown causes. Since that <br />time, weekly aerial reconnaissance flights and a single raft-mounted monitoring <br />trip during August 1991 have been used to evaluate movement and habitat use of <br />the radio-implanted squawfish. During the raft trip, attempts were made to <br />collect other squawfish in the- vicinity of radio contacts using trammel nets. <br />Those attempts were unsuccessful. <br /> <br />Future efforts in regards to telemetry of Colorado squawfish in the San Juan <br />River include continued collecting to capture, implant and release, and monitor <br />movement and habitat use patterns of wild adults. Emphasis will be placed on <br />COllection efforts in areas where squawfish with active transmitters are present. <br />Thus, successful collection of additional wild squawfish and recapture and radio <br />replacement of currently implanted fish is needed to ensure continuation and <br />completion of this portion of the San Juan Seven Year Research Plan. <br /> <br />The limited number of previous captures of Colorado squawfish in the. San Juan <br />River indicates that the potential exists to collect insufficient adult life <br />history data. The probability that an adequate sample size of adult squawfish <br />will be collected to continue and complete this study element is unknown. Based <br />upon previous collection efforts, it is likely that low numbers of fish will <br />continue to be encountered. However, the relatively new technique of "scare and <br />snare 11 used to capture three of the four squawfish taken during June ~991 <br />sampling may result in more Colorado squawfish captures. <br /> <br />In order to continue adult life history studies concerning movements and habitat <br />use, it may be necessary to implant radio transmitters into hatchery. reared <br />Colorado squawfish, if sufficient numbers of wild adults are not collected. <br />Concerns exist regarding use of hatchery fish in wild conditions, particularly <br />effects of hatchery fish on reproductive success of wild squawfish. <br /> <br />Objectives: <br />1) Determine if hatchery fish can be conditioned to enable rapid recovery and <br />acclimation to natural stream conditions for radio telemetry research, and <br /> <br />2) . Determine if hatchery fish can be physically altered to prevent successful <br />reproduction to prevent potential genetic contamination of wild fish <br />stocks in the river. <br /> <br />Methods: <br /> <br />Method Summary <br />conditioning hatchery fish to current and live food can be accomplished via use <br />of raceways and a diet of hatchery-reared fish. Rendering hatchery fish <br />incapable of successfully spawning while not altering physiological and/or <br />behavioral mechanisms would require physical alteration <br /> <br />Adult Colorado squawfish (1981 year class) spawned at Willow Beach National Fish <br /> <br />A14 <br />