Event Title

Session D2 - Juvenile Steelhead Survival and Predator-Prey Interactions Using JSATS through the Priest Rapids Reservoir in 2011

Location

UMass Amherst

Event Website

http://fishpassage.ecs.umass.edu/Conference2012/

Start Date

5-6-2012 1:50 PM

End Date

5-6-2012 2:10 PM

Description

Background: Public Utility District No. 2 of Grant County, Washington (Grant PUD) owns and operates two hydropower projects on the mid-Columbia River, Wanapum and Priest Rapids dams. Both developments (dam and reservoir) strive to meet a performance standard of 93% survival for downstream migrant juvenile steelhead. Steelhead survival estimation has been completed annually at both developments since 2006 but performance standards have only been met at the Wanapum Development in 2008 and 2009. Survival standards for steelhead have not been achieved at the Priest Rapids Development. While survival through Priest Rapids Dam has been high, we believe steelhead losses have primarily occurred in the Priest Rapids Reservoir due to piscivorous fish and bird activity. This study was designed to measure the survival of downstream migrant juvenile steelhead and to determine where losses from predators occur in the Reservoir. Methods: A total of 53 JSATS receivers were deployed in cross-river arrays at one-mile increments between Wanapum and Priest Rapids dams. Receivers were also deployed in the forebay of each dam and downstream of Priest Rapids Dam. Nearly two hundred predatory fish (northern pikeminnow, walleye, and smallmouth bass) were captured, tagged, and released in April 2011. Acoustic tags were implanted into 1,032 juvenile steelhead smolts randomly selected from run-of-the-river fish; smolts were released upstream of Wanapum Dam in 18 unique release groups, one release per day, starting on May 8, 2011. Test fish were estimated to be 78% hatchery-reared and 22% wild. Array detection efficiencies were highly variable (range 13-97%), depending on the number of receivers per array and the hydraulic conditions at each array.

Results/Management Action: The 2011 steelhead survival through the Priest Rapids Development was estimated at 97%, which is 7% higher than the highest survival rate in the last five years. For the first time, Grant PUD has met the performance standard of 93% Development survival. High river flows likely contributed to high survival rates as river flows were twice the 10-year average (300 kcfs in 2011, 150 kcfs 10-year average). High flows contributed to faster steelhead travel time through the Reservoir (40% faster in 2011 than the 2006-2010 average) that likely limited the exposure time of smolts to piscivorous predators. Additionally, steelhead losses that did occur (3%) were in loosely defined hot-spots that overlapped with the movement of tagged northern pikeminnow. These hot-spots included the tailrace of Wanapum Dam, the entrance to Crab Creek, and the Reservoir immediately upstream of the Priest Rapids Dam forebay. Additional losses from avian predation were confirmed by the recovery of acoustic tags at bird colonies. Though this study was designed to identify zones of migratory steelhead loss between Wanapum and Priest Rapids dams, the measured losses were fewer than expected. We were able to directly measure predation events by northern pikeminnow on migrating smolts, and identify in-river hot-spots of predation.

Comments

Leah Sullivan is a Senior Fishery Biologist with 12 years of experience in conducting small and large scale acoustic, radio and PIT telemetry studies with various anadromous and catadromous to assess downstream and upstream migration, timing, and distribution as it is related to hydroelectric projects in the United States Pacific Northwest and East Coast.

She has 10 years of expertise on hydroacoustic telemetry projects, domestic and foreign, primarily using acoustic telemetry to evaluate the fine-scale three-dimensional behavior of migratory species as they pass downstream or upstream of a variety of hydroelectric projects. Ms. Sullivan is a participant of the Priest Rapids Bypass Design Team where she has collaborated with engineers and biologists on behalf of Grant PUD to design a near future top-spill passage alternative at Priest Rapids Dam.

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Jun 5th, 1:50 PM Jun 5th, 2:10 PM

Session D2 - Juvenile Steelhead Survival and Predator-Prey Interactions Using JSATS through the Priest Rapids Reservoir in 2011

UMass Amherst

Background: Public Utility District No. 2 of Grant County, Washington (Grant PUD) owns and operates two hydropower projects on the mid-Columbia River, Wanapum and Priest Rapids dams. Both developments (dam and reservoir) strive to meet a performance standard of 93% survival for downstream migrant juvenile steelhead. Steelhead survival estimation has been completed annually at both developments since 2006 but performance standards have only been met at the Wanapum Development in 2008 and 2009. Survival standards for steelhead have not been achieved at the Priest Rapids Development. While survival through Priest Rapids Dam has been high, we believe steelhead losses have primarily occurred in the Priest Rapids Reservoir due to piscivorous fish and bird activity. This study was designed to measure the survival of downstream migrant juvenile steelhead and to determine where losses from predators occur in the Reservoir. Methods: A total of 53 JSATS receivers were deployed in cross-river arrays at one-mile increments between Wanapum and Priest Rapids dams. Receivers were also deployed in the forebay of each dam and downstream of Priest Rapids Dam. Nearly two hundred predatory fish (northern pikeminnow, walleye, and smallmouth bass) were captured, tagged, and released in April 2011. Acoustic tags were implanted into 1,032 juvenile steelhead smolts randomly selected from run-of-the-river fish; smolts were released upstream of Wanapum Dam in 18 unique release groups, one release per day, starting on May 8, 2011. Test fish were estimated to be 78% hatchery-reared and 22% wild. Array detection efficiencies were highly variable (range 13-97%), depending on the number of receivers per array and the hydraulic conditions at each array.

Results/Management Action: The 2011 steelhead survival through the Priest Rapids Development was estimated at 97%, which is 7% higher than the highest survival rate in the last five years. For the first time, Grant PUD has met the performance standard of 93% Development survival. High river flows likely contributed to high survival rates as river flows were twice the 10-year average (300 kcfs in 2011, 150 kcfs 10-year average). High flows contributed to faster steelhead travel time through the Reservoir (40% faster in 2011 than the 2006-2010 average) that likely limited the exposure time of smolts to piscivorous predators. Additionally, steelhead losses that did occur (3%) were in loosely defined hot-spots that overlapped with the movement of tagged northern pikeminnow. These hot-spots included the tailrace of Wanapum Dam, the entrance to Crab Creek, and the Reservoir immediately upstream of the Priest Rapids Dam forebay. Additional losses from avian predation were confirmed by the recovery of acoustic tags at bird colonies. Though this study was designed to identify zones of migratory steelhead loss between Wanapum and Priest Rapids dams, the measured losses were fewer than expected. We were able to directly measure predation events by northern pikeminnow on migrating smolts, and identify in-river hot-spots of predation.

http://scholarworks.umass.edu/fishpassage_conference/2012/June5/27