Appendix B Annual Test and Verification Study Plan Reservoir Survival/Predation, Fishery, Disease

Transcription

1 Appendix B Annual Test and Verification Study Plan Reservoir Survival/Predation, Fishery, Disease Prepared by: Megan Hill Portland General Electric Company and Cory Quesada Portland General Electric Company On behalf of Portland General Electric Company and The Confederated Tribes of the Warm Springs Reservation of Oregon May 2010

2 2010 Draft Annual Test and Verification Study Plan Reservoir Survival/Predation, Fishery, Disease OBJECTIVES AND METHODS Due to the delay of Selective Water Withdrawal operation, 2010 was designated as a pilot year for the Reservoir Survival/Predation, Fishery, and Disease study. We will continue to refine methods in 2010 so that the full study can begin in 2011 when the reservoir has normalized. OBJECTIVE 1: Determine the migratory routes of Chinook salmon and steelhead trout in Lake Billy Chinook (LBC). Determine potential delays in smolt migration that occur in LBC and the Round Butte Dam forebay. Objective 1 will be conducted at a pilot level in 2010 due to transitional reservoir conditions to refine methods and equipment. Forty smolts (thirty steelhead and ten Chinook) will be radio tagged in both the Crooked River and Whychus Creek and followed through the tributaries. These fish will be detected at fixed stations positioned in the upper reservoir arms; they will then be tracked weekly in the reservoir. More details regarding radio-tagging and tracking methods are described in PGE and CTWS (2008) and in the 2009 Juvenile Migration Annual Plan. More comprehensive migration studies are planned for OBJECTIVE 2: Determine the relative impact of smallmouth bass, northern pikeminnow, and bull trout to migrating salmonids in LBC. Smallmouth Bass and Northern Pikeminnow Population Sizes An intensive smallmouth bass mark-recapture study was conducted in cooperation with the Oregon Department of Fish and Wildlife (ODFW) in spring Over 500 smallmouth bass were marked in each arm of Lake Billy Chinook (LBC), and subsequent recapture passes were made with electrofishing. In addition, 220 smallmouth bass stomachs and scale samples were collected. These samples will allow us to complete bioenergetics modeling of smallmouth bass; draft results were made available at the Fish Workshop in March If the bioenergetics model indicates that smallmouth bass are not a significant predator on salmonids in LBC, the PGE/CTWS Page 1 May 2010

3 smallmouth bass portion of this study will not be conducted again in It will be resumed in 2011 or 2012 after the smallmouth bass population has had time to respond to changing reservoir temperatures and the migratory smolt populations respond to changing water currents. During six nights of electrofishing along the LBC shoreline, only nine northern pikeminnow were captured. Electrofishing along the shoreline is an effective method for capturing northern pikeminnow (Peterson 2001 and Shively et al. 1996). Stomachs were removed from the captured northern pikeminnow; no fish were found in the stomach contents. Due to the low densities of northern pikeminnow, we will not sample specifically for northern pikeminnow in However, stomach contents will be analyzed for northern pikeminnow when encountered during other survey efforts. Although not specifically targeted, brown trout were encountered more frequently than northern pikeminnow during the electrofishing surveys. Because brown trout are a known predacious fish, we will also collect stomach samples from brown trout as they are encountered during our sampling. Bull Trout Population Size Bull trout redd counts are currently the only estimate of the bull trout population size. To increase the data regarding bull trout population size, we will assist ODFW with the Bull Trout Spawner Abundance and Disease study again in 2010, if the study is funded. We assisted in 2009 by providing the PIT tags for 750 adult bull trout tagged at Candle and Canyon creek weirs. In addition to providing PIT tags, if angling and/or trap netting of bull trout occurs in the Metolius Arm of Lake Billy Chinook, we will provide assistance. Bull Trout Growth Rates PIT-tag histories are the most accurate way to assess growth. By tagging and recapturing bull trout at different times of the year we can begin to estimate seasonal growth rates. It will likely take several years of tagging and recapture to obtain sufficient PIT-tag data to estimate growth rates. In the interim, growth rates may be estimated from scale or fin ray samples. All bull trout greater than 70 mm total length (TL) encountered during sampling activities (e.g. screw trap operations, redband trout population surveys, etc.) will be scanned for the presence of a PIT tag. If a PIT tag is not already present, a 12-mm full duplex PIT tag will be implanted. Length (TL) PGE/CTWS Page 2 May 2010

4 and weight, tagging location, and fish condition will be recorded. In addition, three scales will be removed from a subset of PIT-tagged bull trout and mounted on scale cards (per Pratt 1991). To increase the number of bull trout tagged and recaptured, Portland General Electric Company (PGE) will supply ODFW and/or other cooperating agencies working with bull trout sampling kits. Sampling kits will include a PIT-tag reader, PIT tags, scale cards, and datasheets. Bull Trout Gill/Tangle Net Sampling Pilot Studies The objectives of gill/tangle net sampling in 2010 are to (1) determine the level of gill/tangle net sampling effort likely to be required to conduct the full study in 2011 and beyond and (2) estimate gill/tangle net sampling mortality of bull trout and other fish species. A literature search was conducted to determine the most effective net types and methods for capturing bull trout in lakes and reservoirs. The results of this search are summarized in Table 1. Gill nets have been found to be the most effective method for capturing bull trout (Salow 2005; Flatter 1999); however, catch-per-unit-effort (CPUE) reported for large reservoirs is quite low (Table 1). Mortality is another factor to be considered with gill nets; for example, mortality ranged from 3.3 to 8 percent during short duration gill-net sampling conducted in Idaho (Salow 2005; Flatter 1999). It is unknown what net and mesh size will work best in LBC. We will most likely start with the same methods and net sizes used by Flatter (1999) and modify them as necessary to better suit conditions in LBC. Gill/tangle net sampling will be conducted under the ODFW Section 6 Agreement with USFWS. Therefore, decisions regarding gill net materials, schedules, etc. will be discussed with ODFW. In addition, monthly summaries of bull trout captures and mortalities will be provided to ODFW. The literature search yielded minimal results for use of tangle nets for capturing bull trout. Tangle nets are very similar to gill nets in their appearance and method of deployment. Tangle nets have smaller mesh size than gill nets, which results in fish being captured by the snout and teeth. Tangle nets will be used where possible in place of traditional gill nets during our sampling to decrease mortality. Table 1. Comparison of several studies using gill nets to capture bull trout. Lake Billy Chinook has a maximum depth of 126 m and a surface area of 1,585 ha. PGE/CTWS Page 3 May 2010

5 Paper Parker et al Study Years Lake Harrison Lake,Albert a CA Max Lake Lake Area Depth (m)* (ha)* Target Species ~Density (Fish/ha) Time of Year Duration/ Time of Day Mesh Size (mm) bar mesh # Panels, Panel Length (m) Total Net Size (m) bull trout 7.1 not specified 5, 10 m 50 m long CPUE 5.8 bull trout/1 h of 100 m net set Mortality Osprey Lake, Alberta CA bull trout 15.0 not specified same same same bull trout 38.1 short set (max time 12 min) 25, 38, 51, 76, 102 (streched mesh) m long 17, 37, 50 m long used in combinatio n 30.5 bull trout/1 hr 100 m net set 6 bull trout Allen Deadwood Reservoir, ID bul trout May short duration (1-4 hr), usually 1 hr, occasionally overnight 19,25.5,32, 38,51,64 6, 7.6 m 10 bull trout/125 hrs gill net + 98 hrs 45.7 m overnight trap netting long, 0.25 bull trout/ 1.8 m deep overnight gill net set 0-0.1bull trout/h for daylight sets 4 of 10 caught Salow Lucky Peak Reservoir, ID 1128 bull trout May- mid June recommend 20 min sets 31.8, 50.4, (daylight 8: , :00) m long, 1.25 m deep 7of bull trout/hr (191 were total hrs) bull injured or trout/hr (325 total hrs) mortalities Flatter Arrowrock Reservoir, ID Lucky Peak, ID 1275 bull trout 0.3 March- April 1128 bull trout March May 30 minutes, , 25, 32, 38, 51, m long, 1.8 m deep 149 bull trout/ hrs overall 0.32 bull trout/h (range ) 3.3% for all handling associated with gill netting L'Abee Lund et al Norwegian Lakes artic char June, July/Augus t, September checked at dawn and dusk 12.5, 16, 19.5, 24, 29, artic char/100m2 net area for 24 hrs in epibenthic artic char/100m2 net area for 24 h in pelagic not reported Langeland et al Norwegian Lakes artic char, brown trout checked at dawn and dusk 12.5, 16, 19.5, 24, 29, (CPUE not defined) not reported Ruzycki et al Yellowston e Lake lake trout, cutthroat trout 51.3 no mention large mesh- 57,64,70,7 6,89 small mesh- 19, 25, 32, 38, 51 5, 13.7 m large mesh m long, 3.3 m deep small mesh- 76 m long, 2 m deep vertical nets m deep, 2.1 m wide no mention not a concern Bull Trout Bioenergetics It is likely to take a couple of years to collect a sufficient number of stomachs to conduct statistically sound bioenergetics modeling. Therefore, we will start collecting stomachs of predatory species, analyzing their contents, and cataloging the data in However, the actual bioenergetics modeling will not be conducted until at least PGE/CTWS Page 4 May 2010

6 In addition, PGE will fund Matthew Mesa, USGS (Cook, Washington) to complete and field test a bull trout bioenergetics model in At present, all bioenergetics modeling of bull trout is based on the lake trout model. This will greatly increase the accuracy of bull trout bioenergetics modeling in LBC. OBJECTIVE 3: Quantify the number of smolts harvested by anglers in LBC. A spring creel survey will be conducted on LBC to estimate angler harvest of steelhead and Chinook smolts. PGE will contract with ODFW to conduct the annual spring survey. The survey will be conducted as in previous years. PGE will also provide the creel surveyor a PITtag reader that can be used to scan all Oncorhynchus mykiss, Chinook salmon, and bull trout contained in the creel for the presence of a PIT tag. If a PIT tag is present, the PIT-tag number will be recorded and the fish will be measured (TL). OBJECTIVE 4: Determine the impact of disease on anadromous smolts and bull trout in LBC. A subsample of O. mykiss and Chinook smolts and O. nerka captured during sampling activities described above will be sacrificed for disease screening. Ideally, 60 specimens will be collected for each species to increase statistical precision. The actual number taken will vary depending on species availability during sampling activities. Each fish will be individually bagged, labeled, set on ice, and examined for fish pathogens within 24 hours by the on-site ODFW fish pathologist. The method of capture, species, date, time, and water temperature will be recorded for each specimen. Other water quality parameters such as turbidity, dissolved oxygen, and ph will be recorded if possible. PGE/CTWS Page 5 May 2010

7 REFERENCES Allen, D.B Deadwood River bull trout study: Interim report for 1997 studies. U.S. Bureau of Reclamation, Pacific Northwest Region, Cooperative Agreement # FC Langeland, A., J.H. L Abée-Lund, B. Jonsson and N. Jonsson Resource partitioning and niche shifts in artic char (Salvelinus alpinus) and brown trout (Salmo trutta). Journal of Animal Ecology. 60: L Abée-Lund, J.H., A. Langeland, B. Jonsson and O. Ugedal Spatial segregation by age and size in artic char: a trade-off between feeding possibility and risk of predation. Journal of Animal Ecology. 62: Flatter, B.J Investigation of bull trout (Salvelinus confluentus) in Arrowrock Reservoir, Idaho. U.S. Bureau of Reclamation, Pacific Northwest Region, Cooperative Agreement # FC Parker, B.R., D.W. Schindler, F.M. Wilhelm and D.B. Donald Bull trout population responses to reductions in angler effort and retention limits. NAJFM. 27: Petersen, J.H Density, aggregation, and body size of northern pikeminnow preying on juvenile salmonids in a large river. Journal of Fish Biology. 58: Portland General Electric Company and the Confederated Tribes of the Warm Springs Reservation of Oregon (CTWS) Pelton Round Butte Project (FERC 2030) Test and Verification Study: Reservoir Survival/Predation, Fishery, Disease Study. Pratt, K.L Bull trout scale analysis, Metolius River basin, Final Report. For: United States Forest Service, Deschutes National Forest. Bend, Oregon. Ratliff, D.E., S.L. Theisfeld, W.G. Weber, A.M. Stuart, M.D. Riehle, D.V. Buchanan Distribution, life history, abundance, harvest, habitat and limiting factors of bull trout in the Metolius River and Lake Billy Chinook, Oregon, ODFW Information Report Oregon Department of Fish and Wildlife. Portland, Oregon. Salow, T Trap and transport of bull trout from Lucky Peak Reservoir to Arrowrock Reservoir, Idaho: Summary report for years 2000 to U.S. Bureau of Reclamation, Pacific Northwest Region, Technical Report for Arrowrock Dam Biological Opinion # OALS # Shively, R.S., T.P. Poe and S.T. Sauter Feeding response by northern squawfish to a hatchery release of juvenile salmonids in the Clearwater River, Idaho. Transactions of the American Fisheries Society. 125: PGE/CTWS Page 6 May 2010