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, I) r , " range were caught that were probably hatched in the early 1990's. In addition, the new 1998 population estimate (using Program CAPTURE) of the lower-reach group indicated that this part of the population has remained steady at about 300 individuals (N = 328; 95% C.l = 193-(35). However, in the upper reach, the catch rate was substantially higher than in 1994 when the last such survey was done: in 1994 the catch rate was 0.69 fisblnet; in 1998, it was 0.97 fish/net, or about a 40"/0 increase (see Fig. I). Compared to the catch rate in 1991 (0.32 fish/net), the 1998 results indicate a 200% (triple) increase in densities of adults in the upper reach. The new popu1ation estimate suggests that catch rates D18Y over-estimate the increase: the 1998 upper- reach point estimate is 435 fish; thus, about a 3 1% increase over the 1994 estimate (332 fish) and a 100 % increase over the 1991 estimate (205 fish). . However, the most interesting aspect of this year's results was the poor condition of adults. Everyone handling the fish noted that they looked skinny and 'snake-like'. When we calculated relative condition and partitioned results by length-c1ass and reach it was readily apparent that fish of all sizes and throughout most of the river were in poor shape. The pattern of declining condition with length in the lower reach and increasing condition with length in the upper reach, as noted in the earlier study, still held true. However, except for the largest and smallest fish, fish of most length-classes had lost considerable weight (see Fig. 2). Based on the 1998 data, a preliminary interpretation is that the carrying capacity for the occupied portion of the Colorado River has been reached. Habitat capacity is defined as the level above which emigration occurs (Mesick 1988; Bartholow et aI. 1994). In the lower reach, this was probably reached during the 199 I - 1994 study when fish lost condition and emigrated to the upper . reach. Numbers there have apparently remained stable since then despite more fish recruiting to the adult popu1ation. In the upper reach, adults had evidently not exceeded their food supply by 1994. However, based on body condition, by 1998 they had. Other evidence along these lines is the history of use of the Redlands fish ladder on the lower Gunnison River. In its first year of operation (1996), only one squawfish used the ladder; however, in 1997, 18 used the ladder, and in 1998, 23 fish used the ladder. Emigration from the Colorado to the Gunnison river clearly picked up in 1997 and may indicate when carrying capacity in the Colorado River was reached. Hopefully, additional data collection in 1999 and 2000 will shed more light on this subject. .