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'..'..-. II" .... .-, , . . 5 impacts will be maximal during vital biological periods in the life cycle of squawfish, the summer spawning period and the winter, cold-water period. Fluctuations in water levels and salinities are the rule rather than the exception in the Colorado River Basin, and even under natural conditions, the San Juan River had periodic salinities higher than 520 mg/l and the flow occasionaly dropped to zero during short time periods. The endemic fish species adapted to these variable conditions in a variety of ways, two of which were an extended life span and larger siZe. These adaptations result in a high, prolonged reproductive potential that can accomodate several years of unsuitable conditions between successful spawnings. However, these fluctuations will be buffered by the Animas- La Plata Project, resulting in stable higher salinities and lower flows than presently or naturally found in the San Juan River. 1t.is my biological opinion that in spite of the alterations to the San Juan River as a result of the proposed project, the action is not likely to jeopardize the Colorado squawfish as a species nor destroy habitat essential to their survival. During the time between the fish reclamation (in 1961) and the present, Colorado squawfish have not re- established their abundance in the San Juan Rivers as they did in the Green River, but do appear to have maintained a small, ,isolated population in the lower river. The proposed project is likely to further degrade the San Juan River to a point that this population will be lost. However, because of the apparent small size of the San Juan River squawfish population and its already tenuous hold on survival, its possible loss should have little impact on the successfully reproducing Green and Colorado River squawfish populations and therefore the species itself. Thus, the "no jeopardy" opinion. However, Section 7 (a) of the Endangered Species Act calls on all Federal agencies to -...utilize their authorities in further- ance of this Act by carrying out programs for the conservation of Endangered Species...." I find the Water and Power Resources Service Draft Environmental Statement woefully negligent in meeting this portion of the Act for this project, and make the following suggentions in an attempt to bring your activities more closely in line with purposes of the Act. 1. Thoroughly survey the native fish populations of the San Juan River. 2. Determine the environmental needs of the Colorado squawfish.