Publications

The Hanford Reach is one of the few remaining unimpounded sections of the Columbia River. However, because of flow management at upstream dams, there are often large fluctuations in water level. To determine how environmental conditions might affect age-0 resident fishes in the Hanford Reach, we evaluated species composition, distribution, abundance, and standard lengths of larval and...

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Apparent survival and migration rate of radio-tagged hatchery subyearling Chinook salmon released at Iron Gate Hatchery was monitored in the Klamath River to see if the timing of mortality coincided with observations of ceratomyxosis in re-captured coded wire tag cohorts. Despite rapid emigration, these relatively large (mean fork length 92 mm) smolts had a cumulative apparent survival...

We studied the migratory behavior of subyearling fall Chinook salmon Oncorhynchus tshawytscha in free-flowing and impounded reaches of the Snake River to evaluate the hypothesis that velocity and turbulence are the primary causal mechanisms of downstream migration. The hypothesis states that impoundment reduces velocity and turbulence and alters the migratory behavior of juvenile Chinook...

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No abstract available

During 2006, we used acoustic telemetry and a route-specific survival model (RSSM, Skalski et al. 2002) to estimate behavior, passage, and survival of juvenile salmonids during two different spill operations and diel periods at McNary Dam. An evaluation of 12-h versus 24-h spill was proposed for the spring migration period at McNary Dam. However, high river discharge did not allow for...

To estimate the Mt. Graham red squirrel (MGRS) population, personnel visit a proportion of middens each year to determine their occupancy (Snow in this vol.). The method results in very tight confidence intervals (high precision), but the accuracy of the population estimate is dependent upon knowing where all the middens are located. I hypothesized that there might be areas outside the...

This report describes a study of survival and migration behavior of juvenile coho salmon in the Klamath River relative to discharge at Iron Gate Dam in 2006. This was the second year of a multi-year study with the goal of determining the effects of discharge at Iron Gate Dam on survival of juvenile coho salmon downstream. The study was a collaborative effort among U.S. Geological Survey...

Researchers at the USGS Western Fisheries Research Center's Columbia River Research Laboratory, working with the U.S. Army Corps of Engineers, sought to better understand upstream and downstream passage of white sturgeon at dams. A study at The Dalles Dam provided the opportunity to compare two fish ladders; one that passes sturgeon upstream to one that does not, to determine if subtle...

We described behavior and estimated passage and survival parameters of juvenile salmonids during spring and summer migration periods at Lower Granite Dam in 2006. During the spring, the study was designed to examine the effects of the Behavioral Guidance Structure (BGS) by using a randomized-block BGS Stored / BGS Deployed treatment design. The summer study was designed to compare...

Describe reproduction and early life history characteristics of white sturgeon populations in the Columbia River between Bonneville and Priest Rapids dams. Define habitat requirements for spawning and rearing white sturgeon and quantify the extent of habitat available in the Columbia River between Bonneville and Priest Rapids dams. Progress updates on young-of-the-year recruitment in...