An Adaptive Environmental Assessment and Management workshop process was used to assist Grand Canyon scientists and managers in developing conceptual and simulation models for the Colorado ecosystem affected by Glen Canyon Dam. This model examines ecosystem variables and processes at multiple scales in space and time, ranging from feet and hours for benthic algal response to diurnal flow changes, to reaches and decades for sediment storage and dynamics of long-lived native fish species. Its aim is to help screen policy options ranging from changes in hourly variation in flow allowed from Glen Canyon Dam, to major structural changes for restoration of more natural temperature regimes. It appears that we can make fairly accurate predictions about some components of ecosystem response to policy change (e.g., autochthonous primary production, insect communities, riparian vegetation, rainbow trout population), but we are moderately or grossly uncertain about others (e.g., long-term sediment storage, response of native and non-native fishes to physical habitat restoration). Further, we do not believe that existing monitoring programs are adequate to detect responses of native fishes or vegetation to anything short of gross habitat changes. Some experimental manipulations (such as controlled floods for beach/habitat- building) should proceed, but most should await development of better monitoring programs and sound temporal baseline information from those programs.

Adaptive management is appraised as a policy implementation approach by examining its conceptual,
technical, equity, and practical strengths and limitations. Three conclusions are drawn: (1) Adaptive management has been more influential, so far, as an idea than as a practical means of gaining insight into the behavior
of ecosystems utilized and inhabited by humans. (2) Adaptive management should be used only after
disputing parties have agreed to an agenda of questions to be answered using the adaptive approach; this is not how the approach has been used. (3) Efficient, effective social learning, of the kind facilitated by
adaptive management, is likely to be of strategic importance in governing ecosystems as humanity searches for a sustainable economy.

Many case studies in adaptive−management planning for riparian ecosystems have failed to produce useful models for policy comparison or good experimental management plans for resolving key uncertainties. Modeling efforts have been plagued by difficulties in representation of cross−scale effects (from rapid hydrologic change to long−term ecological response), lack of data on key processes that are difficult to study, and confounding of factor effects in validation data. Experimental policies have been seen as too costly or risky, particularly in relation to monitoring costs and risk to sensitive species. Research and management stakeholders have shown deplorable self−interest, seeing adaptive−policy development as a threat to existing research programs and management regimes, rather than as an opportunity for improvement. Proposals for experimental management regimes have exposed and highlighted some really fundamental conflicts in ecological values, particularly in cases in which endangered species have prospered under historical management and would be threatened by ecosystem restoration efforts. There is much potential for adaptive management in the future, if we can find ways around these barriers.

Even unmanaged ecosystems are characterized by combinations of stability and instability and by unexpected shifts in behavior from both internal and external causes. That is even more true of ecosystems managed for the production of food or fiber. Data are sparse, knowledge of processes limited, and the act of management changes the system being managed. Surprise and change is inevitable. Here we review methods to develop, screen, and evaluate alternatives in a process where management itself becomes partner with the science by designing probes that produce updated understanding as well as eco- nomic product.

Renewable natural resources provide important contributions to food, fiber, and recreation in many parts of the world. The economies of some regions a r e heavily dependent on fisheries and forestry, and consumptive use of wildlife (hunting) is a traditional recreational pastime across Europe and North America. The management of renewable resources usually involves public agencies that are responsible for harvest regulation, and often production enhancement, so as to provide sustainable yields into the long-term future (resource husbandry). The track record of such agencies has been spotty: many resources have been mined to low levels before effective harvest regulation could be developed, while others have been managed so conservatively as to miss major harvesting opportunities.

Three key features of renewable resources have made them difficult to manage. First, sustainable production depends on leaving behind a "capital" stock after each harvesting, and there are definite limits to the production rates that this stock can maintain. Second, harvesting is normally undertaken by a community or industry of harvesters whose activities (investment, searching, etc.) are not completely monitored or regulated, so that dynamic responses, such as overcapitalization of fishing fleets, are common. Third, the biological relationships between managed stock size and production rates arises through a complex interplay between the organisms and their surrounding ecosystem; for any particular population, this relationship cannot be predicted in advance from ecological principles and must, instead, be learned through actual management experience.

The Glen Canyon Dam, which was completed in 1963, is one of several multipurpose storage reservoirs on the Colorado River system. The initial operating rules for the Dam were designed to meet requirements for the delivery of water and to yield maximum hydropower revenues through the production of peaking power. Since the early years of its installation, however, the Dam has created new concerns about environmental resources in the Grand Canyon. The Glen Canyon Environmental Studies (GCES), which have been in progress since 1982 under sponsorship of the Bureau of Reclamation, are intended to support the scientificevaluation of relationships between the operations of Glen Canyon Dam and the natural resources of the Grand Canyon. The results of the GCES have been used recently in evaluating a range of possible operating rules for the Dam, in supporting the analysis of alternatives to be listed in the Glen Canyon Dam Environmental Impact Statement, and in setting the stage for long- term monitoring of environmental resources in the Grand Canyon.

Since 1986, the NRC's Committee to Review the Glen Canyon Environmental Studies has evaluated GCES reports as well as other documents produced by the Bureau of Reclamation. The present NRC report provides a review of the Bureau's Draft Federal Long-Term Monitoring Plan for the Colorado River below Glen Canyon Dam. The committee's review deals with all aspects of the draft monitoring plan, including scope of work, protocols for acquisition and archiving of environmental data, organization,justification, and implementation.

The NRC committee believes that the draft monitoring plan will be of great importance in providing a rational basis for protection of environmental resources in the Grand Canyon. In addition, because of the national and international prominence of the Grand Canyon, as well as the intensive studies that have been sponsored through GCES, the plan may serve as a blueprint or model for other riverine ecosystem monitoring plans in the United States and other countries. For this reason, it is important that the plan be well-designed, clearly explained, and efficient in its proposed collection of data and use of financial resources. The NRC committee believes that the present draft of the long-term monitoring plan does not yet meet all of these criteria.

The present version of the long-term monitoring plan does not contain any estimates of the costs of environmental monitoring, nor does it make any firm recommendations for research that would complement monitoring. The NRC committee believes that these two critical elements should be added to the plan. Given the extensive experience of GCES program personnel with the cost of working in the Grand Canyon over the last decade, it seems reasonable that the plan should provide an estimate of the expenses of monitoring. Failure to specify costs may result in arbitrary omissions from the list of essential variables to be monitored, which would undermine the effectiveness of the monitoring program. As an adjunct to the estimate of cost, it may be necessary for the plan to show in more specific terms what limits of error are acceptable for key variables to be monitored.

Research is also important because monitoring will probably demonstrate some unexpected results; program managers should support research that may help to explain these unexpected results. The draft plan correctly indicates that an important role of research is to improve the efficiency of monitoring. The plan is tied specifically to the preferred alternative for operation of the Dam as derived from the Environmental Impact Statement. The NRC committee believes that the program should extend beyond this to include information that would be relevant to analysis of other potential operations of Glen Canyon Dam that might arise as the preferred alternative is revised or changed due to other causes within the scope of dam operations.

The committee finds a number of problems with frequency of measurement and scope of data collection, both of which may be inadequate for components of the environmental system. In addition, the plan indicates that monitoring should be conducted by noninvasive means, but offers limited guidance in support of this objective. The committee supports greater emphasis on noninvasive methods for studying the Colorado River and is particularly interested in removal of permanent physical installations that are now used in monitoring.

Many parts of the draft monitoring plan are not sufficiently specific about monitoring requirements. For a number of resources, the frequency of monitoring, the sites for monitoring, and the methods for monitoring are not described or are described only in vague terms. Given the long-term commitment that will be essential, and the necessity for stability in data collection, it is important that the monitoring plan be more specific.

In a number of instances, the draft monitoring plan subordinates specific requirements for information to administrative initiatives that will be developed in the future by various resource management agencies outside the long-term monitoring program. The committee believes that the long-term monitoring program must take full responsibility for decisions about the kinds of data to be collected, sites at which data will be collected, and methods for data collection. Blanket delegation of this responsibility to other entities is undesirable and should be avoided.

Unfortunately, the NRC committee finds much of the present version of the draft long-term monitoring plan to be confusing. The plan needs to be extensively revised for improvement of clarity, logical cohesion, and degree of specificity with which monitoring requirements are described.

Finally, the draft monitoring plan does not contain any proposal for administration or management of long-term monitoring. Strategies for administration and management are critical to the success of the program, and should be incorporated in the plan. If the plan does not include a specific proposal for administration, then criteria that must be satisfied by any proposed administrative scheme should be specified. The authors of the plan should consider the advantages of requiring administrative independence for the long-term monitoring program, and open contracting procedures that will allow the managers of the program to maximize cost efficiency and maintain direct control over the scope and quality of data collection in the Grand Canyon.

ABSTRACT: This book is a response to the USGS’s call for a research design that could be used as a framework for prioritizing cultural resources in the Colorado River ecosystem below Glen Canyon Dam. Changing River includes summaries of current environmental conditions and previous research and brings together diverse archaeological opinions about Grand Canyon’s human story. It then presents a theoretical basis for using a landscape approach to organize future research efforts in the canyon. The research presented here explores the geophysical, paleoclimatic, and biological parameters that have shaped the canyon landscape and influenced choices made by humans as they attempted to adapt to this ecosystem. It then focuses on the distribution of cultural materials and patterns using several archaeological approaches, and investigates natural and cultural realms as mutually reinforcing and interacting components of an integrated ecosystem to which humans have applied meaning and value over time.

While the ecology and evolution of partial migratory systems (defined broadly to include skip spawning) have been well studied, we are only beginning to under- stand how partial migratory populations are responding to ongoing environmen- tal change. Environmental change can lead to differences in the fitness of residents and migrants, which could eventually lead to changes in the frequency of the strategies in the overall population. Here, we address questions concerning the life history of the endangered Gila cypha (humpback chub) in the regulated Colorado River and the unregulated tributary and primary spawning area, the Little Colorado River. We develop eight multistate models for the population based on three movement hypotheses, in which states are defined in terms of fish size classes and river locations. We fit these models to mark–recapture data col- lected in 2009–2012. We compare survival and growth estimates between the Col- orado River and Little Colorado River and calculate abundances for all size classes. The best model supports the hypotheses that larger adults spawn more frequently than smaller adults, that there are residents in the spawning grounds, and that juveniles move out of the Little Colorado River in large numbers during the monsoon season (July–September). Monthly survival rates for G. cypha in the Colorado River are higher than in the Little Colorado River in all size classes; however, growth is slower. While the hypothetical life histories of life-long resi- dents in the Little Colorado River and partial migrants spending most of its time in the Colorado River are very different, they lead to roughly similar fitness expectations when we used expected number of spawns as a proxy. However, more research is needed because our study period covers a period of years when conditions in the Colorado River for G. cypha are likely to have been better than has been typical over the last few decades.