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Final Report 2-7 September 2000 2.4.1 Workshops and Technical Reviews An initial task of the Integration Team was to conduct a workshop with principal investigators of the Flaming Gorge Research Group (Appendix C). The workshop was held during the week of 10 November 1997 in Salt Lake City, Utah, to discuss research findings and formulate preliminary flow and temperature recommendations on the basis of those findings. Workshop participants were divided into three technical subgroups: (1) hydrology and geomorphology, (2) Colorado pikeminnow, and (3) razorback sucker and humpback chub. These subgroups met separately, then reconvened with other subgroups and the Integration Team to discuss progress and preliminary findings. Preliminary information on flow and temperature relationships was developed by each subgroup and presented to the group as a whole. From this information on species- and resource- specific relationships, integrated preliminary flow and temperature recommendations were developed and incorporated into a preliminary draft report that was reviewed by the principal investigators. A recurring theme of the workshop participants was the need to restore greater flow variability (annually and seasonally) in the Green River system for enhancement oftemporal and spatial habitat complexity to meet the needs of the endangered fishes. It was understood that such variability would not necessarily directly benefit all species in all years, but, over the long-term, flow variability within and among years would be an important component of flow recommendations to advance recovery of the endangered fishes. The Integration Team and principal investigators held a second workshop in Salt Lake City on 28 July 1998 (Appendix C) to discuss the preliminary draft report and recommendations contained therein. On the basis of discussions at that workshop, a draft report was prepared and subjected to additional peer review. Then the peer-review comments were used in developing a draft final report, which was submitted to the Recovery Program's Biology Committee on 18 May 1999 for review. Biology Committee comments (and those from other interested agencies and individuals) were used in developing a revised draft final report, which recei ved additional review by the Biology Committee and approval by the Recovery Program's Management Committee on 7 April 2000. 2.4.2 Synthesis The inherent difficulties of controlled experimentation in a large, complex ecosystem like the Green River system make it difficult to determine cause-and-effect relationships. Despite the fact that releases from Flaming Gorge Dam can be controlled to manipulate river flows and measure responses, uncontrolled variables (e.g., weather) can have large unforeseen effects. Many of the important variables of interest (e.g., flow, sediment, and temperature) are interrelated such that a change in one is accompanied by a concurrent or later change in another. Thus, any observed response cannot be attributed unequivocally to a specific variable. Antecedent flows and conditions can be important in determining fish food abundance, habitat characteristics, population size, and body condition. Stochastic variations in flow, temperature, and sediment from important tributaries,