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Another method of improving statistical reliability would be to reduce the vaziability of ISMP data. Refining habitat preferences of YOY Colorado squawfish and placing further restrictions on locations sampled could reduce the vaziability somewhat. However, certain restrictions aze already contained in the sampling design and analysis of ISMP data did not identify any preferences that had not already been reported (i.e. Haines and Tyus 1990). Studies currently being conducted by UDWR may improve our ability to distinguish habitat preferences of YOY Colorado squawfish. A third method of improving statistical reliability of ISMP would be to incorporate components of mazk and recapture into the sampling design. This option would provide the best data of all the options considered, but it would also be the most labor intensive. Haines and Modde (1993) successfully conducted mazk-recapture population estimates of YOY Colorado squawfish in a short reach of the Green River. However, capturing and mazking the fish required considerably more time than expended with ISMP. It took about 2 days for athree-person crew to collect and mazk fish in a 10-mile section of river (B. Haines, Fish and Wildlife Service, personnel communication). ISMP crews aze usually able to sample 30 or more miles a day. Further, a population estimate requires two different recapture efforts which would increase the labor requirements even more. Another factor to consider is increased mortality of the small fish because of increased handling. It is impractical to sample all 390 miles of the four ISMP reaches in this manner. However, mazk recapture could be done in small sections of each reach every yeaz to validate the ISMP data. Consideration should also be given to increasing the amount of information collected on fishes other than Colorado squawfish encountered with ISMP. Evaluation of the entire fish community was a major recommendation by Stanford (1993) in his review of studies in the upper basin designed to develop flow recommendations for the endangered fishes. Although all fishes are counted in about one of four seine hauls now, the data could be improved by identifying and counting all species in a lazger percentage of the seine hauls. Investigators considered this option during a review of ISMP in 1989 but felt it was too great of a burden to place on field crews and suggested it be made part of sepaaate studies if reseazchers felt it important (McAda 1989b). Such a separate study is currently being conducted in the Colorado River by the Fish and Wildlife Service. In the second study, CPE calculated for the three most common species (using all seine hauls) generally followed the same trends shown with ISMP (first seine haul in primary backwaters), although there were some exceptions (Fish and Wildlife Service, unpublished data). The less common species were represented in the total catch in about the same ratio as with ISMP data, but there was usually at least one species collected in low numbers that was not observed with ISMP (mean, 2; range, 0-3; Fish and Wildlife Service, unpublished data). Additional work on sympatric fishes in the Green River could also be handled as a related study instead of being added to ISMP. All of the above suggestions should be considered as possible improvements to ISMP. Pazticipants should also consider the relative information gain against the increased effort that some of the options will require. ISMP can undoubtedly be improved. However, the basic sampling design (i.e. seining backwaters in specified reaches with a systematic manner) should remain unchanged. Our ability to monitor long-term trends will be compromised if major components of the sampling program aze modified (Ney 1993). 24