The development of waterways, for hydropower and other industrial uses, has substantially altered many of the freshwater habitats of the planet and this has had considerable impact upon aquatic organisms. Industrial changes in aquatic ecosystems, including hydropower development, can restrict or delay fish migration, increase predation, affect water quantity and quality, and subject fish to direct damage and stress. This review will focus on the consequences for fish welfare and the progress towards developing the means to pass and protect fish at hydropower dams, at water withdrawal facilities, and in other engineered aquatic environments. It primarily concerns the large mainstem hydropower dams in the Columbia-Snake River Basin in the northwestern United States. Some methods for improving fish passage and protection at hydropower damsinvolve modifications and additions to engineered structures and occasionally use sensory stimuli such as light, sound, turbulence, or electric fields to influence fish distributions. Measures to improve fish survival, like spilling water at a dam to provide non-turbine passage, can cause other problems for fish, for example higher dissolved gas concentrations downstream. Reducing losses of fish in industrial environments is desirable in both the industrialized world, where many fish-related problems currently exist, and in the developing world, here lessons already learned may make future development more cost-effective and benign.

Formulation of recovery plans for endangered salmon populations in the Columbia River Basin of North America is a complex, controversial resource-management issue. This report presents an integrated assessment model to analyze the biological-economic tradeoffs in recovery of Snake River spring/summer-run chinook salmon (Oncorhynchus tshawytscha).

The authors find that the removal of an estuarine predator, the Caspian tern (Sterna caspia), and elimination of adult salmon harvest are recovery measures that markedly increase long-term population-growth rates regardless of transport effectiveness. Dam breaching significantly increases growth rates under the best available estimate of transport effectiveness. The authors also conclude that recovery strategies in the cost-effective set depend on assumptions about transport effectiveness. Tern removal and harvest elimination are generally cost effective. At the best estimate of transport effectiveness, strategies that discontinue smolt transportation or breach dams are prevalent in the cost-effective set. In contrast, strategies that maximize transportation are prevalent in the cost-effective set if transport effectiveness is relatively high.

This paper links biology and economics through an integrated model thus providing a valuable tool for science-based policy and management.

The paper can be downloaded from Michael R. Moore's website at http://sitemaker.umich.edu/micmoore/working_papers

Fish and hydroelectric dams are striving to coexist across the country. With conservation groups as well as state and federal agencies pressing for severe controls on water releases, hydropower production has been cut substantially in many cases. At the same time, dam operators have undertaken some sophisticated construction programs to meet the challenge. To date, many strategies employed on the Columbia and Snake Rivers have been both costly and ineffective. The Army Corps of Engineers is trying to address its problems partly with extensive model studies. But, they have found that "the more you learn, the more complicated it gets." Together the failures of the Corps, as well as other federal agencies have caused the power utilities to call for reductions in spending for all fish programs, which they say are ineffective.

Migratory bull trout (
Salvelinus confluentus
) historically spawned in tributaries of the
Clark Fork River, Montana and inhabited Lake Pend Oreille as subadult and adult fish.
However, in 1952 Cabinet Gorge Dam was constructed without fish passage facilities disrupting
the connectivity of this system. Since the construction of this dam, bull trout populations
in upstream tributaries have been in decline. Each year adult bull trout return to
the base of Cabinet Gorge Dam when most migratory bull trout begin their spawning
migration. However, the origin of these fish is uncertain. We used eight microsatellite loci
to compare bull trout collected at the base of Cabinet Gorge Dam to fish sampled from both
above and further downstream from the dam. Our data indicate that Cabinet Gorge bull
trout are most likely individuals that hatched in above-dam tributaries, reared in Lake Pend
Oreille, and could not return to their natal tributaries to spawn. This suggests that the risk
of outbreeding depression associated with passing adults over dams in the Clark Fork system
is minimal compared to the potential genetic and demographic benefits to populations
located above the dams.

This paper examines the effects of dam construction and operation in the Columbia River Basin on salmon populations. While the hydrograph of the Columbia River has been significantly impacted by dams, the seasonality of regulated flow on the Snake River has been less affected. The Snake River storage has been used for agricultural diversion while the Columbia has been for electrical generation. The reservoir system has effects on flow velocities, water chemistry (nitrogen supersaturation), habitat availability and reliability, and stream temperatures. Dams block about one third of the Columbia River watershed to access by anadromous fish.
Effects of Dams on Salmon;
Fish kills occur as a result of several characteristics of dams. Bruising, descailing, and stress caused by by-pass facilities; susceptibility to prey following delivery from by-pass to outfall; estuary damage; effects on the homing ability of fish; limited success in fish use of by-pass facilities. The effect of migration speed on smolt survival is uncertain but assumed to have an impact. More research is necessary.
Mitigation of Dam's Effects on Salmon:
Seven measures for mitigation of dams' effects on salmon are discussed
1. Fish passage facilities 2. Predator control 3. Transportation 4. Spill 5. Flow augmentation 6. Reservoir drawdown 7. Dam removal.

The Maryland Fish Passage Program's purpose is to restore migratory species to at or near historic levels. There are four major program elements: remove or bypass blockages, reintroduce target species, bio-monitor and educate. The Program has become increasingly more complex since its inception. Much more is known technically than was known several years ago. Funding has become more difficult to obtain, and legal and policy issues are much more complicated that in the early days of the program. As larger blockage sites are remedied, the Program is increasingly turning its attention to smaller blockages, which are the focus of this workshop. Small blockages are far more numerous than the larger ones, and collectively, they close many more miles of historic spawning habitat to migratory fishes and other aquatic animals than do the larger blockages.
Currently, there are forty-four sites on the five year fish passage project priority list. The list is dynamic. There are additions and deletions as new information is learned about specific stream blockage structures and as funding levels change.
In order to consolidate and unify data related to the many blockages, a fish passage database containing nearly 1,000 blockage sites and 47 fields has been developed and is available upon request.
There are similar issues to contend with at privately owned blockage sites. On occasion it is even difficult to determine the ownership of a blockage. Individuals in Florida, Tennessee and California were contacted to find out who actually owns one priority site. Another site is owned by foreign investors who live in Hong Kong and were located in Australia.

We studied the role of technical clarity in successful multi-party negotiations. Our investigations involved in-depth interviews with individuals who were the principal participants in six consultations conducted under the Federal Energy Regulatory Commission's (FERC) hydroelectric power project licensing process. Technical clarity was especially important in the cases we studied because they concerned questions that were science-based. The principal issues in the six cases were fish passage, instream flow for fish habitat, and entrainment of fish in hydropower turbines. We concluded that technical clarity was one of the most critical elements in these conflicts. The most successful negotiations were marked by a shared understanding of technical issues among the parties.