Behavior and dam passage of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March 2012 - February 2013

Abstract

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit http://store.usgs.gov ISSN 2331ISSN -1258 Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. AbstractThe movements and dam passage of individual juvenile Chinook salmon (Oncorhynchus tshawytscha) were studied at Cougar Reservoir and Dam, near Springfield, Oregon, during 2012 and 2013. Cougar Dam is a high-head flood-control reservoir with a temperature control tower as its outlet enabling selective withdrawals of water at various depths to control the temperature of water passed downstream. This report describes the second year of a 2-year study with the goal of providing information to inform decisions about future downstream passage alternatives. Inferences were based on the behavior of yearlingsize juvenile Chinook salmon implanted with acoustic transmitters. The fish were released near the head of the reservoir during the spring (March, April, and May) and fall (September, October, and November) of 2012. Most tagged fish were of hatchery origin (468 spring, 449 fall) because of the low number of wild fish captured from within the reservoir (0 spring, 65 fall). Detections at hydrophones placed in several lines across the reservoir and within a collective system used to estimate three-dimensional positions near the temperature control tower were used to determine fish behavior and factors affecting dam passage rates. Most tagged fish made repeated non-random migrations from one end of the reservoir to the other and took a median of 3.7-11.7 days to travel about 7 kilometers from the release site to within about 100 meters of the temperature control tower, depending on season and origin. Reservoir passage efficiency (percentage of tagged fish detected at the head of the forebay) was 97.8 percent for hatchery fish and 74.2 percent for wild fish. Tagged fish commonly were within about 100 meters of the temperature control tower, and often spent considerable time near the entrance to the tower; however, the dam passage efficiency (percentage of dam passage of fish detected at the head of the forebay) was low for fish released during the spring (11.1 percent) and moderate for fish released during the fall (58.1 percent for hatchery fish, 65.2 percent for wild fish) over the 90th percentile of the empirically determined tag life, which was about 90 days. The primary factors affecting the dam passage rate were diel period, dam discharge, and...

Observational data on the effects of infection by the copepod Salmincola californiensis on the short- and long-term viability of juvenile Chinook salmon (Oncorhynchus tshawytscha) implanted with telemetry tags

“…The detection probabilities of the arrays were empirically estimated to be at or near 1.0 during each year of study. Further details of the telemetry detection equipment can be found in Beeman et al [20][21][22].…”

“…This 8 km long reservoir in the west slope of the Cascade mountain range was created in 1963 by the construction of Cougar Dam on the South Fork of the McKenzie River about 74 km east of Eugene, Oregon. During 2011 and 2012, we macroscopically examined 281 juvenile Chinook salmon of natural origin when selecting candidates for surgical implantation of transmitters for a study of in-reservoir behavior and dam passage; details of the source study are described by Beeman et al [20][21][22]. The fish we report on were captured from within Cougar Reservoir using a 91.7 m-long Lampara seine that fished up to 7.6 m deep.…”

Evaluating Head‐of‐Reservoir Water Temperature for Juvenile Chinook Salmon and Steelhead at Shasta Lake with Modeled Temperature Curtains

“…Due to the reservoir's size and shape, it could be difficult for juvenile fish to locate a downstream passage route within the reservoir. In addition, few or no velocity cues are provided for downstream migrants, which may result in migration delays that could increase juvenile vulnerability to predators (OTA 1995;Liedtke et al 2010;Anderson et al 2014;Beeman et al 2014). Fish collection at Shasta Dam could be more challenging because reservoir stratification in the summer and fall may cause fish to occur deeper in the reservoir, where water temperatures are cooler.…”