[en] This final report of the 3-year study summarizes activities and results for 1993. Study objectives were to: (1) determine the source of losses (or accounting errors) for adult chinook salmon between Ice Harbor Dam (IHR) and Lower Granite Dam (LGR), and upstream of LGR in the Snake River; (2) identify spawning locations upstream of LGR for calibration of aerial redd surveys, redd habitat mapping, carcass recovery for genetic stock profile analysis, and correction of estimated adult/redd ratios; and (3) estimate passage and migration times at Snake River. 200 fall chinook salmon were radio tagged and tracked with aerial, fixed-site, and ground mobile tracking. Fish were released upstream of IHR at Charbonneau Park (CHAR). 190 of the fish were tracked or relocated away from CHAR. 59 fish descended to below IHR without crossing Lower Monumental Dam (LMO). Another 128 salmon passed upstream of LMO without falling back at IHR. Only 80 salmon passed Little Goose Dam (LGO) without falling back at a downstream dam; 66 of these fish passed LGR. Many fish that fell back reascended the dams. A total of 72 salmon released at CHAR passed upstream of LGR, including fish that had fallen back and reascended a dam. Over 80 percent of the salmon that entered Lyons Ferry Hatchery each year had reached LGO before descending to the hatchery. Extensive wandering was documented between LMO and upstream of LGR before salmon entered Lyons Ferry Hatchery or the Tucannon River. In 1993, 41 salmon were found to be of hatchery origin when recovered. These fish entered Lyons Ferry Hatchery with similar movements to unmarked salmon. Each year a few salmon have remained near the hatchery without entering, which suggests the hatchery may have inadequate attraction flows. Fall chinook passed lower Snake River dams in 2-5 days each on average. Median travel times through LMO and LGO were 1.0-1.3 days each, which was slower than for spring chinook or steelhead in 1993. 5 refs., 21 figs., 20 tabs

[en] In 1993 we completed research directed at characterizing the 0. nerka populations and their interactions with other fish species in five Sawtooth Valley Lakes. Historically, Redfish, Alturas, Pettit, Stanley, and Yellow Belly Lakes provided Snake River sockeye (Oncorhynchus nerka) spawning and rearing habitat (Evermann 1896; Bjornn 1968). All of these lakes, with exception to Yellow Belly, still support 0. nerka populations. In chapter 1 of this report we describe 0. nerka spawning locations and densities, tributary fry recruitment, and results from a habitat survey completed in Redfish Lake. In chapter 2 we review foraging habits of fish that may compete with, or prey on 0. nerka populations. Kokanee fry emergence from Fishhook Creek in 1993 was 160,000. Fry emergence increased nearly five fold over that reported in 1992. Interestingly, spawning densities in 1991 and 1992 were somewhat similar (7,200 and 9,600, respectively). Discharge from Fishhook Creek was markedly higher in 1992 and may have caused the better egg to fry survival. 0. nerka spawning on sockeye beach appeared limited (< 100 fish). Additionally, sockeye beach was the only area that wild or residual sockeye were located. Of 24 adult sockeye released into Redfish Lake, from the brood stock program, two were found spawning in the south end of the lake. Results from the habitat survey indicated that substrate composition on sockeye beach is poor. 0. nerka diet patterns shifted from chironomid prey in June zooplankton prey in September. Rainbow trout consumed a broadrange of prey, with few instances of significant diet overlap with 0. nerka. Northern squawfish, bull char, and lake trout preyed on 0. nerka. Utilization of 0. nerka by predators was greatest in September

No abstract available

[en] This work resulted from a continuing multidisciplinary analysis of species preservation and global change. The paper explores the economic cost of a potential regional warming as it affects one Pacific Northwest natural resource, the spring chinook salmon (Oncorhynchus tshcawytscha). Climate change and planned habitat improvements impact the production and economic value of soling chinook salmon of the Yakima River tributary of the Columbia River in eastern Washington. The paper presents a derivation of the total economic value of a chinook salmon, which includes the summation of the existence, commercial, recreational, and capital values of the fish. When currently available commercial, recreational, existence, and capital values for chinook salmon were applied to estimated population changes, the estimated change in the economic value per fish associated with reduction of one fish run proved significant

[en] The Alaska Department of Fish and Game (ADF and G) investigated the effects of oil on pink salmon eggs incubating in streams and intertidal zones of Prince William Sound following the spill from the Exxon Valdez in 1989. The investigation concluded that mortality in embryos was higher in oiled than non-oiled streams. These authors question the accuracy of the ADF and G's conclusions, claiming that the sampling by the ADF and G took place shortly after spawning completion, thus failing to account for the shock mortality to which embryos are vulnerable for a period of some 20 days after fertilization. Analysis of a subset of ADF and G data showed that sampling shock was a major source of embryo mortality, hence the reported differences in mortality were likely the result of sampling protocol and unequal distribution of sampling effort over time between oiled and non-oiled streams. The authors further claim that compensating for sample timing removed all statistical evidence for an oiling effect in the data subset. These results also help to explain why differences in mortality continued after the oil left the streams, and why differences occurred in those areas upstream of high tide, beyond the physical presence of oil. 21 refs., 3 tabs., 3 figs

[en] Five alternate sampling designs are compared using 15 d of 24-h continuous hydroacoustic data to identify the most favorable approach to fixed-location hydroacoustic monitoring of salmonid outmigrants. Four alternative aproaches to systematic sampling are compared among themselves and with stratified random sampling (STRS). Stratifying systematic sampling (STSYS) on a daily basis is found to reduce sampling error in multiday monitoring studies. Although sampling precision was predictable with varying levels of effort in STRS, neither magnitude nor direction of change in precision was predictable when effort was varied in systematic sampling (SYS). Furthermore, modifying systematic sampling to include replicated (e.g., nested) sampling (RSYS) is further shown to provide unbiased point and variance estimates as does STRS. Numerous short sampling intervals (e.g., 12 samples of 1-min duration per hour) must be monitored hourly using RSYS to provide efficient, unbiased point and interval estimates. For equal levels of effort, STRS outperformed all variations of SYS examined. Parametric approaches to confidence interval estimates are found to be superior to nonparametric interval estimates (i.e., bootstrap and jackknife) in estimating total fish passage. 10 refs., 1 fig., 8 tabs

[en] The monitoring and evaluation objectives and tasks have been developed through a joint process between the co-managers, Yakama Nation (YN, Lead Agency) and Washington Department of Fish and Wildlife (WDFW). The Science/Technical Advisory Committee (STAC), which consists of core members from the co-managers, employs the services of a work committee of scientists, the Monitoring Implementation Planning Team (MIPT) to develop the Monitoring and Evaluation (M and E) Plan. The process employed by STAC to verify these designated activities and the timing of their implementation involved the utilization of the following principles: (1) YKFP monitoring should evaluate the success (or lack of it) of project supplementation efforts and its impacts, including juvenile post release survival, natural production and reproductive success, ecological interactions, and genetics; (2) YKFP monitoring should be comprehensive: and, (3) YKFP monitoring should be done in such a way that results are of use to salmon production efforts throughout and Columbia basin and the region. Utilizing these principles, STAC and MIPT developed this M and ;E action plan in three phases. The first phase was primarily conceptual. STAC and MIPT defined critical issues and problems and identified associated response variables. The second phase was quantitative, which determined the scale and size of an effective monitoring effort. A critical element of the quantitative phase was an assessment of the precision with which response variables can be measured, the probability of detecting real impacts and the sample sizes required for a given level of statistical precision and power. The third phase is logistical. The feasibility of monitoring measures was evaluated as to practicality and cost. The Policy Group has determined that the M and E activities covered by this agreement are necessary, effective and cost-efficient

[en] Upstream salmon passage though a dam is discussed with respect to three main components: the fishway entrance, the fishway, and the exit. Design considerations and alternative types of components are presented. For fishway entrances, an important consideration is the positioning of the entrance as far upstream as the fish can swim with respect to obstacles. For powerhouses using water diverted from a river, the problem of leading fish past the powerhouse may be overcome by either installing a tailrace barrier or increasing the flow until the home stream odor is sufficient to attract fish. Swimming ability should be the first consideration in fishway design. Fishways with 50 cm drops per pool would be satisfactory in most cases. The problem of headwater fluctuation is overcome through careful fishway selection. Fish locks, hoists, and elevators are other alternatives to pool/weir fishways. The location for a fish exit must be decided on the basis of whether the fishway will be used only for upstream migrations. 5 refs., 1 fig., 1 tab

[en] The objective of this study was to determine if hatchery rainbow trout compete with or prey on juvenile Snake River sockeye salmon Oncorhynchus nerka in Pettit Lake, Idaho. In 1995, a total of 8,570 age-0 sockeye and 4,000 hatchery rainbow trout were released in Pettit Lake. After releasing the fish, gillnets were set in the pelagic and littoral zones to collected diet and spatial distribution data. Interactions were assessed monthly from June 1995 through March 1996. Competition for food was discounted based on extremely low diet overlap results observed throughout the sample period. Conversely, predation interactions were more significant. A total of 119 rainbow trout stomachs were analyzed, two contained O. nerka. The predation was limited to one sample period, but when extrapolated to the whole rainbow trout populations results in significant losses. Total consumption of O. nerka by rainbow trout ranged from an estimated 10 to 23% of initial stocking numbers. Predation results contradict earlier findings that stocked rainbow trout do not prey on wild kokanee or sockeye in the Sawtooth Lakes. The contradiction may be explained by a combination of poorly adapted hatchery sockeye and a littoral release site that forced spatial overlap that was not occurring in the wild populations. Releasing sockeye in the pelagic zone may have reduced or eliminated predation losses to rainbow trout

[en] Predator control fisheries aimed at reducing predation on juvenile salmonids by northern squawfish (Ptychocheilus oregonensis) were implemented for the seventh consecutive year in the mainstream Columbia and Snake rivers