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benefits, with a particular focus on improving fine- sediment resources and conditions for endangered native fish. Another experimental effort underway is the manual removal of nonnative fishes in order to protect native fish, particularly humpback chub (see chapter 2, this report). Collaboration As lor collaboration, the EIS outlined an innovative organizational structure for pursuing the GCDAMP. The program is administered by a senior Department of the Interior ollicial (designee) and facilitated by the Adaptive Management Work Group (AMWG), which is organized as a Federal Advisory Committee. The ANIWG makes recommendations to the Secretary of the Interior on how to best alter the operating criteria at Glen Canyon Dam or other management actions to protect down- stream resources in order to fulfill the Department of the Interior's obligations under the GCPA (U.S. Department of the Interior, 1995). The Secretary of the Interior appoints the group's 25 members, who include repre- sentatives from Federal and State resource management agencies, the seven Colorado River Basin States, Native American tribes, environmental groups, recreation interests, and contractors of Federal power from Glen Canyon Dam (fig. 2). The GCDAMP also includes a monitoring and research center (USGS Grand Canyon Monitoring and Research Center), the Technical Work Group, and independent scientific review panels. As directed thus far by the AMWG, monitoring and research on sediment dynamics, cultural resources, native Overview 9 and nonnative fish, and endangered species have been emphasized. Monitoring and research of these resources have resulted in better understanding of their condition and behavior. For example, recent studies suggest that, contrary to expectations under current dam operations, sand contributed from Colorado River tributaries is rapidly exported downstream and does not remain available over multiyear timescales for restoration floods imple- mented between January and July, which is the current implementation schedule. Restoration floods are likely to be more effective if they are carried out in the same year that sand deliveries occur, before the new sand is lost downstream. Progress has also been made in under- standing the dynamics of fish populations and the value of mechanical removal of nonnative lish for enhancing native fish populations. Report Organization The chapters that follow provide status and trend data for the natural, cultural, and recreational resources of the Colorado River ecosystem in Grand Canyon. The report deals first with the aspects of the natural environ- ment that have been most emphasized in monitoring and research-sediment and native fishes-followed by other important environmental factors including climate and drought, water quality, aquatic ecology, debris flows, birds, and shoreline ecology and its associated wildlife. The report then shifts emphasis to various human uses 1 1972 Last verified record of Colorado pikeminnow caught in Grand Canyon at Havasu Creek 1974 First lawsuit filed over Glen Canyon Dam operations by commercial raft operators contending that the disruption of normal flows was interfering with their ability to conduct river trips 1973 Endangered Species Act of 1973 passed to protect and promote the recovery of animals and plants that are in danger of becoming extinct because of the activities of people. The act is administered by the U.S. Fish and Wildlife Service (terrestrial and freshwater species) and the National Oceanic and Atmospheric Administration-Fisheries (marine species) 1 1 ~ ~!l!.~1