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<br />1 <br /> <br />:1 <br />'. <br />.., <br /> <br />, <br />.; <br /> <br />.;.~ <br /> <br />.-, <br /> <br />') <br /> <br />. ; <br /> <br />".: <br /> <br />:. ..~ <br /> <br />(".:?J, <br />c.; <br />l~ <br />Q'" <br />CJI <br />"I <br /> <br />Review of Draft Report: <br />Flow Recommendations for the San Juan River <br />David L. Galat, Ph.D. <br /> <br />This review covers the 16 September 1998 Draft for Chapters 1-6 and the 4-December 1998 Draft <br />for Chapters 7 and 8. It treats only the lechnical aspects of the Report as they relate to the project <br />objectives. <br /> <br />Strengths <br />My professional emphasis on large river ecology has familiarized me with research on many large <br />rivers throughout the world. The thoroughness, goal orientated approach, and overall research <br />quality of this effort rank it very high among those I've encountered. The greatest strength of the <br />effort is linking hydrology, geomorphology and life history requirements of the listed fishes to <br />recommend flow requirements. A second strength is that the flow recommendations incorporate <br />statistical variability rather than relying on mimicry of any specific annual hydrograph. Importantly, <br />the approach is adaptive in that modifications in recommendations are incorporated in the plan based <br />on new information. Additionally, the SJRIP Biology Committee recognized the difficulty of <br />evaluating responses of wild endangered fishes to changes in Navajo Dam flows in the San Juan and <br />proactively responded by stocking squawfish and razorbacks. While some might find fault with this <br />approach, in my opinion, it was the besl strategy to maximize information learned from controlled <br />flow releases. <br /> <br />The amount and detail of life-history information briefly summarized for lhe Colorado squawfish <br />and razorback sucker is impressive compared with many non-game species. The authors have <br />capitalized on this knowledge base to compensate for the low numbers of these fishes currently <br />present in the San Juan River and provided a mosl comprehensive analysis of flow and habitat effects <br />on critical life-history evenls. They abstracted relevant portions of detailed studies (e.g., <br />invertebrates, detritus and periphyton biomass) to determine flow needs of fishes, withoul dwelling <br />on the details. <br /> <br />The San Juan and Green and Colorado ri vers were contrasted whenever possible to show similarities <br />and differences. This placed the SJRlP effort into a regional context, but also emphasized its <br />uniqueness. <br /> <br />This report does an excellent job of summarizing and integrating what is known about the target <br />fishes life hislories from a wide variety of sources and relating them to the San Juan. Moreover, it <br />presents realistic and objective conclusions which, it is acknowledged, may not always be clear cut. <br />For example, the authors state based on a thorough review of the evidence that photoperiod, <br />temperature, and flow all playa role in cuing squawfish spawning. <br /> <br />Chapter 7 was very helpful to a non-hydrologist like myself to understand lhe fundamentals of the <br />modeling process without too much detail. Sufficient qualifications were included to assure the <br /> <br />Comments and Responses <br /> <br />Flow Recommendations Draft Report <br /> <br />Galat - 1 <br />