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45 INTRODUCTION Tagging fish is an important technique of fishery management. Tagging giv~s each fish an identity which becomes important as tagged fish are recaptured. It allows us to determine how far the fish has moved and how much it has grown between captures. Tagging can also be used to validate ages derived from scales. If scales are aged at each capture, then the interval between scale ages should correspond with the time between captures. A sufficiently large sample of recapture data can provide estimates of population parameters including population size, mortality, and recruitment (Emory and Wydoski 1987; Nikolsky 1963; Ricker 1975; Weatherly and Gill 1987; Wydoski and Emory 1983). As part of an age and growth study of Colorado sQuawfish in the Upper Colorado River Basin (Upper Basin), I have consolidated all available tagging records from 1978 through 1989 into a single file. These records are being used to establish length-weight relationships of Colorado squawfish. Recaptures will be used to calculate growth rates and validate ages from scales. Tagging records were scattered among Upper Basin agencies; many were incomplete or erroneous. The purpose of this report is to identify problems and corrections in the current data, recommend changes for future data management, and request feedback from researchers with additional records or comments. A summary is included of the number of each species tagged in each ri ver and year. METHODS Since 1978, threatened and endangered fishes have been tagged in the Upper Basin under an interagency cooperative agreement between the U.S. Fish and Wildlife Service (USFWS), Colorado, and Utah. Species tagged included Colorado squawfish Plychocheilus lucius, razorback sucker Xyrauchen lexanus, humpback chub Gila cypha, and bony tail chub Gila elegans. Also tagged were possible hybrids between humpbaCk chub or bony tail and roundtail chub Gila robusla, and razorback sucker and fIannelmouth sucker CalOSlomus latipinnis. All threatened or endangered fishes were tagged with Carlin dangler tags, except in 1978 when Floy anchor tags were used. Unprotected species were usually tagged with FIoy anchor tags. Tags were color coded to identify the river of capture (Table I). Fish captured in some tributaries were tagged the color of the associated mainstem river. Within each color-group, tags were sequentially numbered. Tags are reported herein as tag number followed by first letter of the tag color (1234- G for green tag, number 1234). Most records were retrieved from computer files at USFWS field stations in Grand Junction, Colorado, and Vernal, Utah. These files were released after authorization by the principal investigator of each study. Other records were obtained from agency reports or directly from researchers (Table 2). Contributors included biologists from USFWS, Colorado, New Mexico, Utah, Colorado State University, University of New Mexico, and Bio/West, Inc. All tagged-fish records were combined into a computer database file for management and error checking. Each record included collection and measurement data associated with capture and tagging, or recapture of one fish. Fish that were captured but not tagged were not included in this database. Records were maintained in the format of the USFWS Upper Colorado River Basin RARE Database (Anonymous, 1989). Four new fields were added to simplify use of the database (Table 3). For some recaptured fish, the original tag was replaced with a new tag (Table 4). This was done either to replace a tag in poor condition or to identify a radio-tagged fish with an orange tag. In the consolidated database, all data associated with the original capture was recorded with the new tag number. This prevented duplicate information from existing with both tag numbers and kept records of the same fish together. The original tag number was maintained in the consolidated database with only the tag number and a memo identifying the new tag number.