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" Certainly lowered summer flows should allow the water to wann up more. However, note that the recommended flows ramp down to baseflow (700 - 1,200 cfs) very rapidly in July in order to wann up the river. This could result in stranding of insects and fish and surely decrease productivity of riverine food webs. Moreover, backwaters might be too shallow to support food webs that need. to , . be sustained. Work is underway by the to provide a better estimate of flow-backwater relationship in the key reaches of the Colorado River (Doug Osmundson, U.S. Fish and Wildlife Service, Grand Junction, CO, personal communication). In general, the rationale for baseflows is much more refmed and data-based than on the Green River. Spring flows on the Colorado rivers were recommended on the basis of departure from historical records and the need to flush the rivers to revitalize low velocity habitats that are thought to be critical to the survival of the fishes. I support the intent, based on my review and synthesis of the ecology of the river given above. However, the spring flow recommendations were also rationalized in part on the perceived need to provide intermediate flows 50% of the time to foster favorable recruitment of squawfish (i.e., frequency of peak: flows were based on data in Figure 4). Similar data were not presented to support this flow recommendation on the Green River, although I understand that 1983-84 cohorts were low in relation to flows of record (Tim Modde, U.S. Fish and Wildlife Service, Vernal, UT, personal communication). The flow-recruitment relationship should be thoroughly examined and presented in the context of adult captures over the long-term flow record in both rivers. I noted in Section ill above my concerns with the flow-recruitment relationship of Figure 4; but, if the general relationship of Figure 4 is valid, and I think these are indeed pivotal data, clearly a tradeoff exists. High flows in the Colorado River (and elsewhere) may be expected to produce in- and off-channel habitats that are critical to squawfish and razorback sucker at the expense of recruitment of squawfish. Intermediate flows may produce stronger squawfish cohorts as habitat quality in general deteriorates, and perhaps, dramatically influence survival of razorback cohorts because wetlands or gravel pits they need cannot be accessed I think the recommended flows, if implemented as interim flows over a reasonably long (five years) time period, can allow the consequences of this tradeoff to be clarified. 60