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" temperature. This ability may actually be tied to size or to something else, like age, life stage, maturation, etc. The size and condition of one-year-old mainstem chub should be compared with same age fish in the LCR to determine the growth impact of cold temperatures and this analysis put here. Pg. 126, C. 1, P. 2. Your section on "cues" does not mention photoperiodicity in chub. Has this been investigated? Is there any evidence of the chub responding to temperature or discharge from the LCR? If so, what about cues for chub above the LCR which stimulate them to move to the LCR at the same time as chub below the LCR? How could river temperature and discharge be cues for the chub when temperatures are constant and discharge is not seasonal? Pg. 126, C. 2, P. 2. Trout and other predatory and non-predatory fish are routinely added to the Colorado River and their introductions are often in direct conflict with the desire to protect endangered native fish from extinction. Your comment on trout not being detrimental to chub may not be complete. Young trout in tributaries may have a big impact on young native fish hatched 3-4 months after them and competing for food and space. Your statement probably refers to adult impacts but should be revised to reflect possible impacts identified by Larry Riley for tributaries as well as trout foraging on young chub below the LCR. Pg. 127, C. 1, P. 2. You state the information on habitat needs is "quite limited" then speculate on the major threats to the razorback as being "habitat alterations." If we do not know what the razorbacks need, then we do not know what changes to those needs will do. This conclusion needs to reflect our lack of data. ;~ \ ~; ,,' .', ,'.0 Pg. 127, C. 1, P. 3. Critical habitat is the area considered bv the USFWS as essential ,for recovery, not necessarily the area needed by razorback. The DEIS should be revised to reflect this. Also, John Hamill of the USFWS Upper Colorado Recovery Program has stated that designation of critical habitat is not needed to recover these species, probably because of the Recovery Implementation Program. Some explanation of the significance of this designation to river management is needed. '., :;)l , ",:,. ~:. , ' " ,> , Pg. 127, C. 2, P. 1. Razorback may have always been rare in the canyon, according to Minckley (1991). It may have only been used for migration between spawning and rearing areas. Therefore, designating the canyon as critical habitat seems poorly supported and unnecessary for recovery. Some speculation on the future use of canyon habitat by razorback is warranted. Pg. 130, C. 2, P. 3. A site may be deemed in need of protection simply because an archaeologist defines it as a site needing protection. Is there no avenue for public input to this process? ~:. " ;. 107 ~.-:". .:. 28