{"Bibliographic":{"Title":"Passage behavior and survival for radio-tagged yearling chinook salmon and juvenile steelhead at Lower Monumental Dam, 2008","Authors":"","Publication date":"2010","Publisher":""},"Administrative":{"Date created":"08-16-2023","Language":"English","Rights":"CC 0","Size":"0000123368"},"Pages":["SH153\nPassage behavior\nUn5595\n2008\nand survival\nfor radio-tagged\nyearling chinook salmon\nand juvenile steelhead\nat Lower Monumental Dam,\nFish Ecology\nDivision\n2008\nNorthwest Fisheries\nScience Center\nNational Marine\nby\nFisheries Service\nEric E. Hockersmith, Gordon A. Axel,\nRandall F. Absolon, Brian J. Burke, Kinsey E. Frick,\nSeattle, Washington\nBenjamin P. Sandford, and Darren A. Ogden,\nJanuary 2010","NWFSC083\nSH\n153\nLibrary\nNorthwest Fisheries Science Center\nUn5595\n2725 Montlake Blvd. E\nSeattle, WA 98112\n2008\nPassage Behavior and Survival for Radio-Tagged Yearling Chinook Salmon and\nJuvenile Steelhead at Lower Monumental Dam, 2008\nEric E. Hockersmith, Gordon A. Axel, Randall F. Absolon, Brian J. Burke, Kinsey E.\nFrick, Benjamin P. Sandford, and Darren A. Ogden\nReport of research by\nFish Ecology Division\nNorthwest Fisheries Science Center\nNational Marine Fisheries Service\nNational Oceanic and Atmospheric Administration\n2725 Montlake Boulevard East\nSeattle, Washington 98112\nto\nWalla Walla District\nNorthwestern Division\nU.S. Army Corps of Engineers\n201 North 3rd\nWalla Walla, WA 99362-1875\nContract W68SBV80438584\nJanuary 2010","ii","EXECUTIVE SUMMARY\nIn 2008, NOAA Fisheries evaluated passage behavior and estimated relative\nsurvival of radio-tagged river-run hatchery yearling Chinook salmon Oncorhynchus\ntshawytscha and juvenile steelhead O. mykiss at Lower Monumental Dam on the Snake\nRiver in relation to operation of a removable spillway weir (RSW). Fish were\nPIT tagged, and surgically implanted with a radio transmitter at Lower Monumental\nDam. Treatment groups were comprised of 1,183 yearling Chinook salmon and\n1,187 juvenile steelhead released 41 km upstream from Lower Monumental Dam.\nReference groups were comprised of 980 yearling Chinook salmon and 994 juvenile\nsteelhead released into the tailrace of Lower Monumental Dam. Releases occurred\nduring both daytime and nighttime operations for 26 d from 28 April to 22 May. Project\noperations during the evaluation included either voluntary or involuntary spill 24 h per\nday. River flow, percent spill, and tailwater elevation during releases averaged 99 kcfs,\n34%, and 441 ft msl, respectively.\nFor yearling Chinook salmon, median forebay delay was 2.2 h overall. During\npassage, the largest proportion (44%) of yearling Chinook salmon first approached Lower\nMonumental Dam near the middle of the dam in the vicinity of the RSW in spillbay 8.\nPassage route distribution was 62, 28, 6, and 4% through the spillway, juvenile bypass\nsystem (JBS), turbines, and undetermined routes, respectively. Within the spillway, the\ngreatest proportion (45%) of yearling Chinook salmon passed through the RSW in\nSpillbay 8. For fish with a known passage route, fish guidance efficiency (FGE) was\n83% and fish passage efficiency (FPE) was 94%. Median tailrace egress was 7 min\noverall, and spill efficiency was 1.91 to 1.\nRelative survival was estimated from detections of treatment and reference groups\nat a series of downstream telemetry transects between Lower Monumental Dam on the\nlower Snake River and McNary Dam on the lower Columbia River. Relative dam\nsurvival (~500 m upstream to ~1 km downstream from the dam) for yearling Chinook\nsalmon was 0.934 (95% CI, 0.902-0.968). Relative concrete survival (all passage routes\ncombined to approximately 1 km downstream from the dam) for yearling Chinook\nsalmon was 0.963 (95% CI, 0.929-0.997). Relative survival was 0.976\n(95% CI, 0.943-1.010) for yearling Chinook salmon passing through the spillway and\n0.936 (95% CI, 0.886-0.985) for fish passing through the JBS. Survival for yearling\nChinook salmon passing through the RSW in Spillbay 8 was 1.012 (95% CI, 0.979-\n1.046).\nFor juvenile steelhead, median forebay delay was 2.2 h. The greatest proportion\nof steelhead (48%) first approached Lower Monumental Dam near the middle of the dam\niii","in the vicinity of the RSW in Spillbay 8. Passage distribution was 80, 16, 1, and 2%\nthrough the spillway, JBS, turbines, and undetermined routes, respectively. Within the\nspillway, the greatest proportion of steelhead (70%) passed through the RSW in Spillbay\n8. For fish with a known passage route, FGE was 93% and FPE was 99%. Median\ntailrace egress was 5 minutes overall, and spill efficiency was 2.43 to 1.\nRelative dam survival for juvenile steelhead was 0.982 (95% CI, 0.960-1.005) and\nrelative concrete survival was 1.006 (95% CI, 0.987-1.026). Relative survival was 1.014\n(95% CI, 0.990-1.037) for juvenile steelhead passing through the spillway and 0.977\n(95% CI, 0.930-1.023) for steelhead passing through the JBS. Survival for steelhead\npassing through the RSW in Spillbay 8 was 1.026 (95% CI, 1.004-1.048).\niv","CONTENTS\nEXECUTIVE SUMMARY\niii\nINTRODUCTION\n1\nMETHODS\n3\nStudy Area\n3\nFish Collection, Tagging, and Release\n3\nTelemetry Monitoring\n6\nData Processing and Analysis\n6\nForebay Residence Time\n8\nApproach and Passage Distribution\n8\nFish Passage Performance Metrics\n9\nTailrace Egress\n10\nSurvival Estimates\n10\nAvian Predation\n12\nRESULTS\n13\nFish Collection, Tagging, and Release\n13\nProject Operations\n19\nForebay Residence Time\n22\nApproach and Passage-Route Distribution\n26\nFish Passage Performance Metrics\n29\nTailrace Egress\n29\nSurvival Estimates\n32\nDetection Probability\n32\nPool Survival\n32\nProject Survival\n32\nRoute-Specific Survival\n32\nAvian Predation\n34\nDISCUSSION\n37\nRECOMMENDATIONS\n39\nACKNOWLEDGMENTS\n40\nREFERENCES\n41\nAPPENDIX A: Evaluation of Study Assumptions\n45\nAPPENDIX B: Treatment and Reference Release Groups for Estimating Survival\n59\nAPPENDIX C: Telemetry Data Processing and Reduction\n69\nV","vi","INTRODUCTION\nThe Columbia and Snake River Basins have historically produced some of the\nlargest runs of Chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss in\nthe world (Netboy 1980). More recently, however, some stocks have decreased to levels\nthat warrant listing under the U.S. Endangered Species Act of 1973 (NMFS 1991, 1992,\n1998, 1999). Anthropogenic factors that have contributed to the decline and loss of some\nsalmonid stocks include overfishing, hatchery practices, logging, mining, agricultural\npractices, and dam construction and operation (Nehlsen et al. 1991). A primary focus of\nrecovery efforts for depressed stocks has been assessing and improving fish passage\nconditions at mainstem dams.\nThe spillway has long been considered the safest passage route for migrating\njuvenile salmonids at Columbia and Snake River dams. Holmes (1952) reported survival\nestimates of 96 (weighted average) to 97% (pooled) for fish passing Bonneville Dam\nspillway during the 1940s. A review of 13 estimates of spillway mortality published\nthrough 1995 concluded that for fish passing via standard spillbays, mortality rates most\nlikely range from 0 to 2% (Whitney et al. 1997). Similarly, recent survival studies of\njuvenile salmonid passage through various routes at dams on the lower Snake River have\nindicated that survival was highest through spillways, followed by bypass systems, then\nturbines (Muir et al. 2001). Pursuant to the National Marine Fisheries Service (NMFS)\n2000 Biological Opinion (NMFS 2000) and subsequent Biological Opinions, project\noperations at Lower Monumental Dam have relied on a combination of voluntary spill\nand collection of fish for transport to improve hydropower system passage survival for\nmigrating juvenile salmonids.\nJuvenile anadromous salmonids in the Columbia River Basin generally migrate in\nthe upper 3 to 6 m of the water column (Johnson et al. 2000; Beeman and Maule 2006).\nHowever, juvenile fish passage routes at dams on the lower Columbia and Snake Rivers\nrequire fish to dive to depths of 15 to 18 m in order to enter a passage route. Engineers\nand biologists within the U.S. Army Corps of Engineers (USACE) developed a\nremovable spillway weir (RSW) to provide surface-oriented spillway passage. The RSW\nuses a traditional spillway and is attached to the upstream face of the spillbay. In the\nlower Snake River, RSWs were installed at Lower Granite Dam in 2001, Ice Harbor Dam\nin 2005, and Lower Monumental Dam in 2008. The RSW at Lower Granite Dam\nreduced migrational delays, improved fish passage efficiency, and provided increased\npassage survival (Plumb et al. 2003, 2004). The RSW at Lower Monumental Dam was\ninstalled in spillbay 8 because the majority of fish first approach the dam in this area\n(Hockersmith et al. 2005; Johnson et al. 1998).","In 2008 we examined passage behavior and survival at Lower Monumental Dam\nin conjunction with operation of the new RSW for yearling Chinook salmon and juvenile\nsteelhead. The goal of this study was to evaluate passage behavior and survival associated\nwith the new RSW at Lower Monumental Dam compared to historical baseline data on\npassage behavior and survival.\nResults of this study will be used to inform management decisions for operation\nof the RSW at Lower Monumental Dam and to optimize survival and passage for juvenile\nsalmonids. This study addressed research needs outlined in SPE-W-00-1 of the USACE,\nNorthwestern Division, Anadromous Fish Evaluation Program.\n2","METHODS\nStudy Area\nThe study area included a 160-km river reach of the Snake and Columbia Rivers\nfrom 5 km downstream of Little Goose Dam (rkm 635) on the lower Snake River to\nMcNary Dam (rkm 470) on the lower Columbia River (Figure 1). Lake Herbert G. West,\nthe reservoir behind the dam extends 46 km upstream. The focus of this study was\nLower Monumental Dam on the Snake River in Washington State, 67 km above the\nconfluence of the Snake and Columbia Rivers. Construction of Lower Monumental Dam\nwas completed in 1969, and the dam is 1,155 m long and 34 m high. The powerhouse\ncontains 6 Kaplan turbines (numbered 1 to 6 from north to south) capable of producing\n810 megawatts of electricity. Total hydraulic capacity of the powerhouse is about 130\nkcfs. In the powerhouse, each turbine unit intake is outfitted with standard length\nsubmersible traveling screens which divert downstream-migrating salmonids into the\njuvenile fish bypass system. Fish entering the powerhouse that are not diverted pass\nthrough turbines. The spillway is 156 m long and consists of 8 spill bays, numbered 1 to\n8 from south to north. Spill bay flow is regulated by operation of tainter-style radial spill\ngates (15 m wide by 18 m high) with the exception of the RSW bay (spill bay 8), where\nflow is regulated exclusively by forebay pool elevation. The RSW was installed during\nthe winter of 2007/2008 and was first operated for fish passage during spring 2008. The\nspillway crest for conventional spillbays is at elevation 483 ft msl and for the RSW bay at\n525 ft msl.\nFish Collection, Tagging, and Release\nRadio tags were purchased from Advanced Telemetry Systems Inc. 1 , had a\nuser-defined shut-off after 10 d, and were pulse-coded for identification of individual\nfish. Each radio tag measured 14.3 mm in length by 6.4 mm in diameter, had a volume of\n351 mm³, and weighed 0.8 g in air. Each tag had a 30-cm long external antenna.\nRiver-run, hatchery yearling Chinook salmon and juvenile steelhead were\ncollected from the smolt collection facility at either Lower Monumental or Little Goose\nDams from 26 April to 22 May. We used only hatchery-origin yearling Chinook salmon\nand run-of-the-river juvenile steelhead that were not previously PIT tagged, that had no\nvisual signs of disease or injury, and that weighed 12 g or more. Fish were anesthetized\nwith tricaine methanesulfonate (MS-222) and sorted in a recirculating anesthetic system.\nFish for treatment and reference release groups were randomly selected from the daily\nsmolt-monitoring sample and transferred through a water-filled, 10.2-cm hose to a\n1 Reference to trade names does not imply endorsement by the National Marine Fisheries Service, NOAA.\n3","Washington\nN\nSnake River\nLittle Goose Dam\nLower Monumental Dam\n2\n3\nIce Harbor Dam\n4\n65\nMcNary Dam\nRiver\n0\n30\n60\nkilometers\nFigure 1. Detail of the study area showing release locations (O) for radio tagged fish and\nradio telemetry transects used for estimating survival at Lower Monumental\nDam in 2008. Transects include: 1 = forebay of Lower Monumental Dam,\n2 = Lower Monumental Dam primary survival transect 30 km downstream of\nthe dam in the forebay of Ice Harbor Dam, 3 = transect at the mouth of the\nSnake River; 4 = transect at Burbank/Finely Railroad Bridge, and 5 and 6 =\ntransects in the forebay of McNary Dam. The tailrace and all routes of passage\nat Lower Monumental and Ice Harbor Dams were also monitored.\n4","935-L holding tank. Following collection and sorting, fish were maintained via\nflow-through river water and held a minimum of 18 h prior to radio tagging.\nFish were surgically tagged with a radio transmitter using techniques described by\nAdams et al. (1998). A PIT tag was also inserted with the radio transmitter SO that test\nfish could be separated by code in the fish collection system and returned to the river\n(Marsh et al. 1999). Surgical tagging was conducted simultaneously at three tagging\nstations. During a 4-h shift, approximately 200 fish were tagged.\nImmediately following tagging, fish were placed into aerated 9-L buckets until\nthey recovered from the anesthesia (2 fish per bucket). Buckets were then closed and\nplaced into a large holding tank (1.5-m wide, 2.5-m long, 0.5-m deep) that\naccommodated up to 28 buckets and supplied with flow-through water during tagging\nand holding. Fish were held a minimum of 24 h for recovery and determination of\npost-tagging mortality.\nRelease procedures followed those used in 2004 at Lower Monumental Dam\nduring a study to evaluate passage and survival (Hockersmith et al. 2005) except the\ntreatment release location was further upstream in 2008. After a post-tagging recovery\nperiod, fish were transported in their recovery buckets to release locations (41 km\nupstream from Lower Monumental Dam or into the tailrace). Immediately prior to\ntransport to release locations, transmitters of all tagged fish were checked for operation\nand to verify that codes were recorded correctly in the database. To provide mixing of\ntreatment and reference groups, treatment groups were released all at one time twice\ndaily\n(morning and afternoon periods), and reference release groups were released over a 6-h\nperiod twice daily (daytime and nighttime periods).\nTreatment groups were transported upstream by truck, then transferred\nwater-to-water from the tank to a release tank mounted on an 8.5 X 2.4-m barge while\nstill in their recovery buckets. Treatment groups were released 41 km upstream from\nLower Monumental Dam in the middle of the river channel. Reference groups were\ntransferred in their recovery buckets to a holding tank on the rear of a truck and then\ndriven to their release location 1,250 m downstream from Lower Monumental Dam.\nUpon arrival at the release site, reference fish were maintained via flow-through river\nwater until release. Fish were released one or two at a time, with the entire group\nreleased over a 6-h period during both the daytime and nighttime release periods.\nReference fish were released using a flume that extended a minimum of 7.6 m from the\nnorth shoreline out into the river. The reference group release location was based on\ntailrace conditions observed in a 1:55 scale model of Lower Monumental Dam at the\nUSACE Research and Development Center, Vicksburg, MS.\n5","Lower Monumental Dam operations utilized two spill patterns (flat and bulk spill\npatterns) that followed a 4-d random block operating schedule with each pattern operated\nfor 2 d. Both treatments utilized the RSW. In general, the maximum difference in the\ngate openings for spillbays 1 though 6 was less than 2 stops during the flat spill pattern\nand more than 2 stops for the bulk spill pattern. Project operation data were collected\nevery 5 min by the USACE. Project operations assigned to treatment fish were those\ncorresponding to conditions recorded at the time closest to the time of fish passage. For\ntreatment fish that passed the dam with an undetermined passage time, project operations\nwere assigned based on conditions closest to the time of first detection recorded in the\ntailrace. For treatment fish that did not pass the dam, project operations corresponded to\nconditions closest to the time of forebay entry. Operational conditions assigned to\nreference fish corresponded to conditions closest to time of release. The two spill\npatterns to be evaluated (flat and bulk) at flows greater than approximately 100 kcfs\nconverge. Therefore, based on a recommendation by the Studies Review Regional Work\nGroup (SRWG), if Snake River discharge were high in 2008, the operational treatments\nwould be ignored and data grouped into daily replicates.\nTelemetry Monitoring\nRadio telemetry receiver arrays were positioned to determine forebay entrance,\ndam approach, route of passage, tailrace exit, and downstream detection (Figure 1). The\nlocations of fixed telemetry receiver sites at Lower Monumental Dam in 2008 are\nsummarized in Table 1 and Figure 2. Based on past experience, we did not utilize a\ndouble array (Skalski et al. 2002) for evaluating routes of passage because the proportion\nof fish with undetermined passage routes has been typically less than 3%.\nData Processing and Analysis\nTelemetry data were retrieved through an automated process that downloaded\nnetworked telemetry receivers up to four times daily. Data processing and reduction are\nsummarized in Appendix Figure C. After downloading, individual data files were\ncompressed by recording the first time a radio-tagged fish was detected and counting the\nnumber of detections where the time-difference between adjacent detections was less\nthan or equal to 5 min. When the difference between adjacent detections became greater\nthan 5 min, a new line of data was created. All compressed data were combined and\nloaded into a database, where automated queries and algorithms were used to remove\nerroneous data. On the cleaned data set, detailed detection histories were created for each\nradio-tagged fish. These detection histories were used to calculate arrival time in the\nforebay, forebay approach patterns, passage-route distribution and timing, tailrace exit\ntiming, and timing of downstream detections for individual radio-tagged fish\n6","Table 1. Locations of fixed-site telemetry receivers for evaluating passage behavior and\nsurvival at Lower Monumental Dam, 2008.\nNumber of\nLocation\nreceivers\nType of monitoring\nAntenna type\n2 km Forebay\n2\nEntrance line and timing\n3-element Yagi\n0.5 km Forebay\n3\nEntrance line and timing\n3-element Yagi\nTurbine units 1-6\n6\nApproach and passage location\nStriped coax\nSpillbays 1-7\n7\nApproach and passage location\nUnderwater dipole\nTuned loop and\nRSW (spillbay 8)\n2\nApproach and passage location\nunderwater dipole\nStilling basin\n2\nProject passage\nTuned loop\nJuvenile bypass system\n1\nBypass passage\nTuned loop\nTurbine unit draft tubes\n3\nProject passage\nUnderwater dipole\nTailrace exit\nProject passage and egress\n2\n3-element Yagi\nTotal receivers\n25\nForebay entrance line\nPowerhouse\nSpillway\nStilling basin\nJuvenile bypass system\nTailrace exit line\nFigure 2. Lower Monumental Dam plan view showing approximate locations of\ndetection zones for radio telemetry receivers in 2008. Oval lines represent\nunderwater antennas, and triangular lines represent aerial antennas.\n7","Forebay Residence Time\nForebay arrival time was based on the first time a fish was detected on the forebay\nentry line at the upstream end of the boat restricted zone (BRZ) at Lower Monumental\nDam (approximately 500 m upstream from the face of the dam). Forebay residence time\nwas determined for fish that had been released upstream from Lower Monumental Dam\nand detected entering the forebay, detected in a passage route, and detected in the\nimmediate tailrace on the stilling-basin, turbine draft tube, or tailrace-exit telemetry\nreceivers (Figure 2). Forebay residence time for individual fish was calculated as the\ndifference between the first detection on the forebay entrance line at the upstream end of\nthe BRZ and the time of last detection in a passage route prior to passage.\nOverall forebay residence time was characterized by constructing means and 95%\nconfidence intervals (i.e. the mean I t(0.05, n-1) standard errors, where t was the t-value,\ngiven n - 1 degrees of freedom and a = 0.05, and was approximately 2.0) for the 10th,\n50th, and 90th percentiles of the residence time distributions. Replicates were fish\ngrouped by day of dam passage. These intervals were also constructed by passage route\n(i.e., bypass, turbine, and spillway) where reasonable. For groups with insufficient\nsample size for replicates, intervals for all or some percentiles were not constructed (e.g.,\nturbine and some bypass groups). Time in the bypass route was divided into gatewell and\npost-gatewell segments.\nDifferences in forebay residence time for bypassed VS. non-bypassed fish were\nestimated for paired replicates by constructing confidence intervals as above for the 10th,\n50th (median), and 90th percentiles. Paired t-tests were calculated to assess statistical\nsignificance for a = 0.05.\nApproach and Passage Distribution\nApproach patterns were established based on the first detection at either\nunderwater dipole spillway antennas (Beeman et al. 2004) or on stripped coax underwater\nantennas (Knight et al. 1977) on the standard-length traveling screens. First approach\nlocations were within 18 m of the dam. Route of passage through the dam was based on\nthe last time a fish was detected on a passage-route antenna and was assigned only to fish\nthat were subsequently detected in the tailrace on either the stilling-basin, turbine draft\ntube, or tailrace-exit telemetry receivers (Figure 2). Tailrace detections were used to\nvalidate passage because fish could be detected on a passage-route receiver while still in\nthe forebay.\n8","Spillway passage was assigned to fish that were detected in the tailrace of the dam\nafter last being detected in the forebay on one of the eight antenna arrays that were\ndeployed along each of the two pier noses on the sides of individual spillbays. RSW\npassage was assigned to fish that were detected in the tailrace of the dam after last being\ndetected in the forebay on one of the antenna arrays that were deployed to monitor RSW\npassage. Powerhouse passage was assigned to fish last detected in a turbine intake prior\nto detection in the tailrace of the dam. Fish passing via the powerhouse were further\npartitioned into either turbine or juvenile bypass system (JBS) passage based on the\npresence or absence of a detection in the JBS (either PIT-tag or telemetry detection).\nFish that were assigned to powerhouse passage, but were not detected in the JBS were\nassigned to turbine passage. For analysis of passage-route distributions, we included only\nfish that had been released upstream from Lower Monumental Dam, detected entering the\nforebay, detected again in a passage route, and detected a third time in the immediate\ntailrace either on the stilling-basin, turbine draft tube, or tailrace-exit telemetry receivers.\nFish Passage Performance Metrics\nFish passage performance metrics included spillway passage efficiency (SPE),\nspillway passage effectiveness (SPS), fish passage efficiency (FPE), fish guidance\nefficiency (FGE), surface outlet efficiency (SOE), surface outlet effectiveness (SOS), and\nJBS Passage Efficiency (BPE). These metrics were estimated as follows:\nSPE: Number of fish passing the dam via the spillway divided by the total number of\nfish passing the dam.\nSPS: Proportion of fish passing the dam via the spillway divided by the proportion of\nwater spilled.\nFPE: Number of fish passing the dam through non-turbine routes divided by total\nnumber of fish passing the dam.\nFGE: Number of fish passing the dam through the JBS divided by the total number of\nfish passing the dam through the powerhouse (turbines and JBS).\nSOE: Number of fish passing through a surface flow outlet (RSW, TSW, ITS, corner\ncollector, etc) divided by the total number of fish passing the dam.\nSOS: Proportion of fish passing through a surface flow outlet (SOE) divided by the\nproportion of water passing through the surface flow outlet.\nBPE: The number of fish passing through the juvenile bypass system divided by the total\nnumber of fish passing the dam.\n9","Tailrace Egress\nFor analysis of tailrace egress, we included only fish that had been released\nupstream from Lower Monumental Dam, detected entering the forebay, detected again in\na passage route, and detected a third time in the immediate tailrace. Tailrace egress time\nfor individual fish was calculated as the difference between time of last detection in a\npassage route and time of last detection on the tailrace-exit array (500 m downstream of\nthe dam).\nOverall tailrace egress time was characterized by constructing means and 95%\nconfidence intervals (i.e. means +- t(0.05, n-1) standard errors, where t was the t-value,\ngiven\nn-1 degrees of freedom and a = 0.05, and was approximately 2.0) for the 10th, 50th and\n90th percentiles of the egress time distributions. Replicates were fish grouped by passage\nday. These intervals were also constructed by route of passage (i.e., bypass, turbine, and\nspillway) where reasonable. For groups with insufficient sample size for replicates,\nintervals for all or some percentiles were not constructed (e.g., turbine and some bypass\ngroups).\nSurvival Estimates\nSurvival estimates were based on detections of individual fish at Snake River\ntelemetry transects at Ice Harbor Dam, at the mouth of the Snake River, at Columbia\nRiver transects near Burbank, WA, and in the forebay of McNary Dam (Figure 1).\nDetection histories were evaluated independently for treatment and reference groups\nusing the single-release or CJS model (Cormack 1964; Jolly 1965; Seber 1965). Data\nwere analyzed using Survival with Proportional Hazards (SURPH), a statistical software\ndeveloped at the University of Washington (Smith et al. 1994).\nSurvival estimates followed the guidelines described by Peven et al. (2005). Pool\nsurvival was a 41 km reach of the Snake River that extended from ~500 m upstream from\nLower Monumental Dam to the release location ~5 km downstream of Little Goose Dam.\nThe estimates of pool survival were a single-release estimate. Lower Monumental Dam\nsurvival was defined as survival of treatment fish through all passage routes combined\nrelative to survival of tailrace-released reference fish. The \"effect zone\" (Peven et al.\n2005) extended from the forebay entrance array (500 m upstream of the dam) to the\ntailrace control release location. The tailrace release location (reference fish) was\napproximately 1,250 m downstream from Lower Monumental Dam.\nConcrete survival is an estimate of the treatment fish surviving through the\ncombined passage routes of Lower Monumental Dam relative to survival of the tailrace\nreference fish. The effect zone extended from the exit of all passage routes to the tailrace\ncontrol release location. Concrete survival did not include any losses in the forebay.\n10","Capture histories of treatment and reference groups were partitioned into two\nperiods for survival estimation; detection at the primary survival array (30 km\ndownstream from Lower Monumental Dam at Ice Harbor Dam forebay) and detection\ndownstream from Ice Harbor Dam. Treatment groups for estimates of survival were\ncomprised of fish released above Lower Monumental Dam and subsequently detected on\nthe forebay entrance array 500 m upstream from the dam. For estimates of dam,\nconcrete, and route-specific survival, treatment groups were formed based on the date of\npassage. Fish that did not pass the dam were grouped based on date of forebay entry.\nReference fish groups were formed based on release date. For estimates of relative\nsurvival, treatment fish that passed the dam on day i were paired with reference fish that\nwere released to the tailrace on the same day (i.e., day i). Relative survival was estimated\nat the ratio of survival estimates between treatment (numerator) and reference\n(denominator) fish groups for each day. The geometric mean of the daily estimates was\ncalculated to summarize survival for the season. Survival was pooled for survival\nestimates with too few replicates and reasonable sample sizes.\nConfidence intervals for estimates of relative survival were constructed using the\ngeometric mean of daily estimates of survival. Since geometric means were used, the\nratios of proportions were assumed log-normally distributed (Snedecor and Cochran\n1980). Thus, the geometric mean was assumed equivalent to the back-transformed\narithmetic mean of the log-transformed estimates. Confidence intervals were of the form:\nX SE)\nwhere X was the geomean; t was the t-value, given a = 0.05 and 25 degrees of freedom\n(i.e., approximately equal 2); and SE was the standard error of the geomean.\nAn assumption of the CJS model is that fish in all groups have equal probabilities\nof survival and detection downstream from the point of release (i.e., the tailrace of Lower\nMonumental Dam). This assumption is reasonable if release groups have similar passage\ndistributions at downstream detection sites, in this case, at the primary survival array\n30 km downstream from the dam. To evaluate this assumption, we compared differences\nbetween treatment and reference groups in temporal passage distribution at the primary\nsurvival array. Treatment fish were grouped by passage date and were \"paired\" with\ntailrace fish grouped by release date. Confidence intervals (95%) and t-tests were\nconstructed for statistical comparison. Model assumptions and methods used to evaluate\nthem are detailed in Appendix A.\n11","Treatment fish were assumed to have passed the dam through the location where\nthey were last detected and if their passage was confirmed by detection in the immediate\ntailrace. We excluded from analysis any fish that had not been detected on the forebay\nentrance array.\nTo provide continuity between analysis and interpretation of survival and passage\nbehavior, we excluded any fish that did not meet the criteria for both passage behavior\nand survival analyses. These exclusions did not bias any of the estimated parameters, but\ndecreased the precision of estimates, since the effect was to decrease sample size. At\npresent, no formal analysis of adult returns of tagged fish used in this study is anticipated.\nAvian Predation\nPredation by Caspian terns Hydroprogne caspia, double-crested comorants\nPhalacrocorax aurtius, and gulls Larus spp. was evaluated by physical recovery of radio\ntransmitters and by PIT-tag detection on Crescent and Foundation Islands in the McNary\nDam Reservoir. Radio transmitters and PIT tags were recovered on nesting colonies\nduring fall 2008 after the birds had abandoned their nesting colonies. Radio-tag serial\nnumbers were used to identify individual tagged fish. PIT-tag detections and recovery of\nradio transmitters were provided by NMFS (S. Sebring, NOAA Fisheries, personal\ncommunication) and Real Time Research, Inc. (A. Evans, Real Time Research, Inc.,\npersonal communication). There is an ongoing monitoring effort to detect PIT tags from\nactive avian colonies in the region conducted by NOAA Fisheries and by the Columbia\nBird Research group.\n12","RESULTS\nFish Collection, Tagging, and Release\nThe 2008 study period encompassed between the 3rd and 89th percentile for\nyearling Chinook salmon and between the 1st and 87th percentile for juvenile steelhead\nsmolt passage index at Lower Monumental Dam (Figure 3).\nWe released 1,183 radio-tagged yearling Chinook salmon 41 km upstream from\nLower Monumental Dam and 980 yearling Chinook salmon into the tailrace. For\nyearling Chinook salmon released above the dam, overall mean fork length was 141.9\nmm (SD = 13.1) and overall mean weight was 28.9 g (SD = 8.7). For yearling Chinook\nsalmon released below the dam, overall mean fork length was 142.9 mm (SD = 12.3) and\noverall mean weight was 28.6 g (SD = 7.8; Tables 2 and 3).\nYearling Chinook salmon\nJuvenile steelhead\n100%\n90%\n80%\n70%\n60%\n50%\n40%\n30%\n20%\n10%\n0%\nFigure 3. Cumulative passage distribution of hatchery yearling Chinook salmon and\njuvenile steelhead at Lower Monumental Dam during 2008. Gray area\nindicates study period.\n13","Table 2. Sample size, range, mean, and standard deviation (SD) of fork lengths (mm) for\nradio-tagged, yearling Chinook salmon released at Lower Monumental Dam to\nevaluate passage behavior and survival, 2008.\nForebay treatment group\nTailrace reference group\nTag date\nMin.\nMax.\nMean\nSD\nMin.\nMax.\nMean\nSD\nn\nn\n27 Apr\n30\n124\n184\n145.0\n14.6\n28 Apr\n47\n106\n168\n137.9\n16.1\n---\n32\n106\n167\n143.7\n14.9\n29 Apr\n34\n110\n165\n136.0\n13.5\n34\n112\n172\n140.6\n14.0\n30 Apr\n51\n116\n186\n144.2\n15.3\n36\n115\n159\n136.2\n13.7\n1 May\n53\n115\n171\n138.8\n16.1\n36\n120\n189\n148.1\n16.1\n2 May\n51\n113\n185\n146.6\n17.1\n34\n111\n195\n149.8\n18.5\n3 May\n52\n112\n180\n143.9\n17.2\n33\n122\n176\n148.9\n14.6\n4 May\n52\n113\n193\n146.4\n19.7\n43\n118\n187\n138.8\n13.0\n5 May\n48\n118\n182\n145.4\n14.7\n42\n111\n188\n140.2\n16.7\n6 May\n48\n117\n169\n138.6\n10.7\n44\n117\n178\n144.1\n12.5\n7 May\n53\n123\n181\n143.4\n11.6\n42\n112\n172\n138.2\n8 May\n13.6\n50\n118\n185\n138.4\n12.9\n44\n114\n165\n9 May\n141.1\n12.0\n53\n114\n183\n140.2\n13.6\n41\n123\n182\n144.8\n12.5\n10 May\n51\n114\n177\n141.4\n14.0\n44\n122\n11 May\n188\n145.4\n12.1\n52\n125\n163\n144.9\n9.0\n45\n122\n158\n138.9\n9.6\n12 May\n51\n125\n163\n144.0\n8.0\n44\n125\n162\n140.3\n8.8\n13 May\n51\n118\n169\n136.4\n9.9\n44\n121\n163\n142.0\n14 May\n9.0\n51\n124\n166\n144.1\n10.2\n45\n122\n173\n141.9\n10.1\n15 May\n48\n115\n158\n138.3\n10.5\n42\n122\n163\n16 May\n144.7\n9.6\n50\n125\n161\n141.7\n8.7\n41\n126\n168\n142.9\n17 May\n52\n120\n162\n143.4\n9.0\n9.1\n43\n121\n176\n145.0\n11.6\n18 May\n51\n122\n159\n142.6\n8.3\n44\n121\n160\n19 May\n142.2\n7.9\n52\n118\n159\n141.2\n9.7\n44\n125\n162\n144.3\n8.8\n20 May\n52\n123\n161\n142.0\n8.7\n43\n122\n164\n143.3\n21 May\n9.5\n40\n129\n163\n22 May\n146,4\n8.2\n---\nOverall\n1,183\n106\n193\n141.9\n13.1\n980\n106\n195\n142.9\n12.3\n14","Table 3. Sample size, range, mean, and standard deviation (SD) of weights (grams) for\nradio-tagged, yearling Chinook salmon released at Lower Monumental Dam to\nevaluate passage behavior and survival, 2008.\nForebay treatment group\nTailrace reference group\nTag date\nMin.\nMax.\nMean\nSD\nMin.\nMax.\nMean\nSD\nn\nn\n27 Apr\n30\n20\n64\n33.1\n10.6\n28 Apr\n47\n13\n47\n28.2\n9.4\n---\n29 Apr\n34\n14\n50\n27.3\n8.5\n32\n12\n49\n31.8\n9.2\n30 Apr\n51\n17\n64\n32.2\n10.7\n34\n15\n55\n29.5\n9.1\n1 May\n53\n15\n52\n28.5\n10.5\n36\n16\n43\n26.6\n8.3\n2 May\n51\n15\n54\n30.5\n10.6\n36\n16\n55\n30.6\n9.6\n3 May\n52\n15\n66\n32.7\n12.0\n34\n15\n72\n34.9\n12.6\n4 May\n52\n15\n78\n33.4\n14.4\n33\n17\n53\n33.8\n9.8\n5 May\n48\n18\n61\n31.8\n9.7\n43\n16\n56\n27.3\n8.0\n6 May\n48\n18\n51\n28.9\n6.7\n42\n17\n64\n30.7\n11.4\n7 May\n53\n17\n57\n29.0\n8.4\n44\n17\n54\n30.2\n8.0\n8 May\n50\n16\n57\n26.4\n8.1\n42\n15\n54\n26.9\n8.2\n9 May\n53\n15\n57\n27.5\n8.6\n44\n16\n45\n28.3\n7.3\n10 May\n51\n16\n50\n28.3\n8.9\n41\n16\n57\n29.7\n8.2\n11 May\n52\n18\n44\n30.4\n5.8\n44\n16\n59\n28.2\n8.5\n12 May\n51\n20\n47\n30.2\n5.6\n45\n16\n40\n25.8\n5.5\n13 May\n51\n17\n44\n27.1\n6.5\n44\n18\n50\n27.8\n6.1\n14 May\n51\n18\n56\n29.1\n6.8\n44\n17\n43\n27.6\n5.9\n15 May\n48\n16\n37\n25.6\n5.8\n45\n17\n50\n27.3\n6.4\n16 May\n50\n18\n43\n27.3\n5.4\n42\n18\n42\n28.1\n5.6\n17 May\n52\n16\n41\n27.0\n5.1\n41\n18\n45\n27.0\n6.0\n18 May\n51\n16\n39\n26.5\n5.1\n43\n17\n52\n27.7\n7.0\n19 May\n52\n16\n39\n27.0\n5.3\n44\n16\n39\n28.3\n4.8\n20 May\n52\n18\n40\n25.7\n4.8\n44\n17\n39\n26.3\n4.9\n21 May\n43\n19\n38\n27.8\n5.2\n22 May\n40\n20\n42\n28.5\n5.3\nOverall\n1,183\n13\n78\n28.9\n8.7\n980\n12\n72\n28.6\n7.8\n15","We released 1,187 radio-tagged juvenile steelhead 41 km upstream from Lower\nMonumental Dam and 994 steelhead into the tailrace. For juvenile steelhead released\nupstream from the dam, overall mean fork length was 206.1 mm (SD = 21.7) and overall\nmean weight was 78.8 g (SD = 25.0; Tables 4 and 5). For juvenil steelhead released\nbelow Lower Monumental Dam, overall mean fork length was 208.4 mm (SD = 21.8)\nand overall mean weight was 79.8 g (SD = 25.4; Tables 4 and 5).\nPost-tagging mortality was 2.7% (59 fish) for yearling Chinook salmon and\n1.7% (36 fish) for juvenile steelhead. Fish that died during the post-tagging holding\nperiod were released in the planned location to verify the assumption that dead fish were\nnot detected on downstream survival arrays (Appendix Table A16). Treatment fish were\nreleased between 0956 and 1110 and between 1341 and 1512 PDT. Reference fish were\nreleased between 0828 and 1619 and between 2016 and 0401 PDT. One hundred and\nninety-five yearling Chinook salmon and 78 juvenile steelhead were excluded from the\nanalysis because they were not detected entering the forebay. In addition, nine yearling\nChinook salmon and 21 juvenile steelhead were excluded from analysis of the treatment\nfish because they were either transported at Lower Monumental Dam, or their passage\ntiming was either before or after the period of time during reference releases. Fifty\nyearling Chinook salmon and 56 juvenile steelhead were excluded from analysis of the\nreference fish because their release timing was either before or after the period of time\nwhen treatment fish were passing the dam.\n16","Table 4. Sample size, range, mean, and standard deviation (SD) of fork lengths (mm) for\nradio-tagged, juvenile steelhead released at Lower Monumental Dam to\nevaluate passage behavior and survival, 2008.\nForebay treatment group\nTailrace reference group\nTag date\nMin.\nMax.\nMean\nSD\nMin.\nMax.\nMean\nSD\nn\nn\n27 Apr\n34\n187\n239\n213.8\n13.3\n28 Apr\n45\n173\n282\n213.1\n19.4\n---\n29 Apr\n35\n180\n261\n209.4\n19.4\n35\n165\n234\n203.1\n14.5\n30 Apr\n52\n162\n235\n196.0\n14.2\n36\n169\n215\n189.8\n11.5\n1 May\n52\n168\n209\n192.7\n9.4\n34\n170\n208\n191.5\n8.3\n2 May\n53\n179\n213\n196.6\n8.9\n36\n177\n273\n207.9\n20.1\n3 May\n52\n168\n244\n205.3\n16.2\n35\n162\n246\n201.6\n19.2\n4 May\n52\n164\n242\n198.2\n17.0\n35\n179\n259\n205.0\n16.9\n5 May\n50\n156\n240\n199.5\n16.2\n48\n169\n230\n196.3\n14.0\n6 May\n51\n155\n267\n196.0\n19.0\n44\n166\n232\n201.0\n18.0\n7 May\n53\n147\n240\n198.4\n22.3\n44\n158\n260\n196.6\n18.9\n8 May\n52\n154\n253\n200.7\n23.0\n44\n159\n248\n200.5\n24.3\n9 May\n53\n143\n214\n185.6\n14.9\n43\n168\n222\n189.8\n13.2\n10 May\n50\n146\n266\n204.5\n24.6\n44\n149\n278\n206.6\n27.4\n11 May\n44\n148\n261\n224.3\n24.4\n45\n164\n267\n217.2\n22.7\n12 May\n54\n153\n249\n206.0\n25.9\n45\n168\n254\n208.7\n24.0\n13 May\n53\n155\n252\n203.3\n22.7\n44\n135\n253\n211.0\n26.0\n14 May\n51\n150\n249\n209.1\n23.9\n44\n161\n250\n209.1\n22.6\n15 May\n51\n156\n248\n208.7\n20.6\n45\n172\n249\n212.9\n21.7\n16 May\n54\n161\n249\n216.1\n22.4\n44\n153\n249\n213.0\n18.7\n17 May\n49\n162\n253\n215.8\n19.9\n41\n186\n253\n221.8\n16.7\n18 May\n52\n172\n253\n217.6\n17.5\n42\n180\n256\n224.1\n17.7\n19 May\n49\n186\n253\n222.5\n16.2\n41\n182\n244\n222.7\n18.1\n20 May\n46\n189\n264\n225.6\n18.4\n41\n188\n253\n222.7\n16.7\n21 May\n44\n167\n258\n221.9\n18.2\n22 May\n40\n189\n248\n220.4\n16.3\nOverall\n1,187\n143\n282\n206.1\n21.7\n994\n135\n278\n208.4\n21.8\n17","Table 5. Sample sizes, range, mean, and standard deviation (SD) of weights (grams) for\nradio-tagged, juvenile steelhead released at Lower Monumental Dam to\nevaluate passage behavior and survival, 2008.\nForebay treatment group\nTailrace reference group\nTag date\nMin.\nMax.\nMean\nSD\nMin.\nMax.\nMean\nSD\nn\nn\n27 Apr\n34\n34\n59\n120\n89.5\n28 Apr\n45\n45\n46\n197\n90.7\n29 Apr\n35\n35\n51\n158\n85.3\n35\n44\n121\n76.5\n15.6\n30 Apr\n52\n52\n38\n123\n68.6\n36\n41\n88\n61.8\n10.9\n1 May\n52\n52\n43\n86\n64.7\n34\n39\n77\n63.0\n8.2\n2 May\n53\n53\n47\n85\n65.2\n36\n46\n169\n74.7\n20.9\n3 May\n52\n52\n42\n137\n79.2\n35\n37\n136\n76.9\n22.9\n4 May\n52\n52\n41\n140\n72.6\n35\n44\n134\n73.6\n20.8\n5 May\n50\n50\n32\n117\n70.3\n48\n38\n111\n66.2\n15.4\n6 May\n51\n51\n35\n172\n73.6\n44\n43\n117\n78.5\n20.2\n7 May\n53\n53\n26\n126\n71.0\n44\n32\n146\n67.1\n20.7\n8 May\n52\n52\n31\n150\n74.1\n44\n35\n118\n72.1\n26.3\n9 May\n53\n53\n26\n84\n54.5\n43\n39\n84\n57.3\n11.2\n10 May\n50\n50\n27\n155\n77.2\n44\n26\n189\n78.6\n31.6\n11 May\n44\n44\n25\n152\n101.6\n45\n40\n178\n91.4\n30.5\n12 May\n54\n54\n31\n142\n78.7\n45\n40\n149\n79.4\n28.3\n13 May\n53\n53\n32\n135\n80.4\n44\n22\n142\n87.8\n31.6\n14 May\n51\n51\n29\n124\n81.4\n44\n35\n160\n81.5\n29.7\n15 May\n51\n51\n30\n121\n77.1\n45\n42\n135\n81.8\n27.4\n16 May\n54\n54\n36\n139\n90.4\n44\n27\n147\n83.3\n23.6\n17 May\n49\n49\n32\n146\n87.0\n41\n53\n131\n97.9\n18.5\n18 May\n52\n52\n40\n132\n84.9\n42\n53\n136\n99.1\n21.8\n19 May\n49\n49\n54\n141\n97.8\n41\n52\n147\n99.3\n25.4\n20 May\n46\n46\n48\n147\n95.6\n41\n48\n133\n88.0\n21.5\n21 May\n44\n38\n131\n90.7\n20.9\n22 May\n40\n56\n136\n88.1\n20.5\nOverall\n1,187\n25\n197\n78.8\n25.0\n994\n22\n189\n79.8\n25.4\n18","Project Operations\nDuring our study period, project discharge averaged 99 kcfs, or approximately\n111% of the previous 10-year average daily flow of 89 kcfs at Lower Monumental Dam\n(1998-2007; Figure 4). Project operations included a mix of voluntary and involuntary\nspill throughout the study period. Two spill patterns (flat and bulk) were planned to be\nevaluated, however, at flows greater than approximately 100 kcfs, the two spill patterns\nconverge. Flow above 100 kcfs occurred for more than 25% of the time resulting in\ninsufficient replication of the treatment operations, and a lack of consistent adherence to\nthe treatment schedule for the experimental design (Appendix Table B9 and B10).\nTherefore, the operational treatments were ignored for analysis and data was grouped into\ndaily replicates. Daily project operations during the study averaged 98.7 kcfs total\ndischarge, 65.5 kcfs powerhouse discharge, 33.3 kcfs spillway discharge (34% of total\nproject discharge), and tailwater elevation of 440.7 ft msl (Table 6 and Figure 5). Flow\nthrough the RSW averaged 7.1 kcfs during the study. Water temperature during tagging,\nthe post-tagging holding period, and releases ranged from 9.1 to 12.0°C and averaged\n10.5°C.\n200\n180\n160\n140\n120\n100\n80\n60\n40\n20\n0\n2008\n10-year average (1998-2007)\nFigure 4. Average daily project discharge during passage and survival study of hatchery\nyearling Chinook salmon and juvenile steelhead at Lower Monumental Dam,\n2008. Ten-year average discharge during this period is also shown.\n19","2008.\nhatchery yearling Chinook salmon spillway and juvenile discharge, steelhead and tailwater at Lower elevation Monumental by date during\nDam,\n5. releases Average of daily radio-tagged project discharge, powerhouse discharge, Tailwater elevation\n450\n445\n440\n435\nSpill (kcfs)\nPowerhouse (kcfs)\n20\nTotal discharge (kcfs)\n200\n180\n160\n140\n120\n100\n80\n60\n40\n20\n0\nFigure","Table 6. Average daily conditions during evaluation of passage and survival of radio\ntagged hatchery yearling Chinook salmon and juvenile steelhead at Lower\nMonumental Dam, 2008.\nTotal\nTailwater\ndischarge\nPowerhouse\nWater temperature\nelevation\nRelease date\n(kcfs)\n(kcfs)\nSpill (kcfs)\nSpill (%)\n(C)\n(ft msl)\n28-Apr\n49.9\n25.4\n24.5\n53\n9.2\n438.1\n29-Apr\n62.1\n39.2\n22.9\n40\n9.6\n438.8\n30-Apr\n67.8\n46.3\n21.5\n32\n9.4\n439.3\n1-May\n65.3\n42.8\n22.5\n37\n9.1\n439.0\n2-May\n59.8\n36.0\n23.8\n42\n9.2\n438.4\n3-May\n60.8\n37.0\n23.8\n40\n9.6\n438.5\n4-May\n60.4\n36.6\n23.8\n40\n9.6\n438.6\n5-May\n70.2\n47.1\n23.1\n36\n9.8\n439.2\n6-May\n78.6\n58.0\n20.6\n27\n10.4\n439.5\n7-May\n85.7\n66.0\n19.7\n23\n11.0\n439.9\n8-May\n98.8\n77.1\n21.7\n23\n10.7\n440.9\n9-May\n93.4\n68.8\n24.6\n27\n10.5\n440.4\n10-May\n90.0\n63.4\n26.6\n30\n10.7\n440.2\n11-May\n84.2\n56.3\n27.9\n33\n11.0\n439.8\n12-May\n86.6\n60.5\n26.2\n31\n11.1\n440.0\n13-May\n82.6\n59.8\n22.8\n28\n11.1\n439.8\n14-May\n71.0\n47.0\n24.0\n34\n10.8\n439.1\n15-May\n77.2\n50.5\n26.8\n35\n10.6\n439.6\n16-May\n95.8\n68.5\n27.3\n29\n10.8\n440.4\n17-May\n116.0\n90.3\n25.6\n23\n11.0\n441.6\n18-May\n146.6\n113.9\n32.7\n22\n11.3\n443.5\n19-May\n182.0\n113.2\n68.8\n38\n11.6\n445.1\n20-May\n198.1\n112.4\n85.6\n42\n12.0\n445.8\n21-May\n196.3\n110.7\n85.7\n43\n11.6\n445.8\n22-May\n189.0\n109.7\n79.3\n42\n10.8\n445.4\nAverage\n98.7\n65.5\n33.3\n34\n10.5\n440.7\n21","Forebay Residence Time\nOf the 1,183 radio-tagged yearling Chinook salmon released above Lower\nMonumental Dam, 988 (84%) were detected on the forebay entrance line at the upstream\nend of the BRZ. Yearling Chinook salmon forebay entry at Lower Monumental Dam\nwas relatively consistent across all hours (Figure 6). Median forebay residence time was\n2.2 h (95% CI 1.6-2.7) and ranged from 0.2 to 98.3 h (Table 7). Median forebay\nresidence time of yearling Chinook salmon that passed through the JBS (5.9 h; 95% CI\n3.3-8.5) was significantly longer than for fish passing through the spillway (1.8 h; 95%\nCI 1.3-2.4) or turbines (1.0 h, no 95% CI calculated; P = 0.001).\n10%\n9%\n8%\n7%\n6%\n5%\n4%\n3%\n2%\n1%\n0%\n0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n12\n13\n14\n15\n16\n17\n18\n19\n20\n21\n22\n23\nHour\nFigure 6. Hour of first detection for radio-tagged yearling Chinook salmon released\nupstream from Lower Monumental Dam and detected in the forebay of Lower\nMonumental Dam, 2008.\n22","Table 7. Sample size, percentile distribution, minimum, mean, median, mode, and\nmaximum forebay residence time (elapsed time in hours from first detection on\nthe forebay entry line to time of passage) by passage route and overall for\nradio-tagged hatchery yearling Chinook salmon at Lower Monumental Dam,\n2008.\nForebay residence time (h)\nPassage percentile\nJBS\nSpillway\nRSW\nTurbine\nOverall\nN\n265\n586\n425\n56\n907\n10th\n1.2\n0.6\n0.7\n0.6\n0.7\n20th\n1.6\n0.8\n0.9\n0.7\n0.9\n30th\n2.6\n1.1\n1.2\n0.8\n1.2\n40th\n4.1\n1.3\n1.5\n0.8\n1.6\n50th\n5.9\n1.8\n2.1\n1.0\n2.2\n60th\n8.0\n2.5\n3.1\n1.2\n3.6\n70th\n10.9\n3.8\n4.6\n1.3\n5.8\n80th\n15.4\n6.8\n7.4\n1.6\n8.9\n90th\n33.0\n12.2\n14.3\n5.2\n16.3\n95th\n51.0\n19.5\n19.5\n6.1\n27.7\nMinimum\n0.6\n0.2\n0.3\n0.2\n0.2\nMean\n12.2\n4.8\n5.3\n1.9\n6.8\nMedian\n5.9\n1.8\n2.1\n1.0\n2.2\nMode\n1.2\n0.7\n0.9\n0.8\n0.8\nMaximum\n98.3\n81.0\n81.0\n19.3\n98.3\nOf the 1,187 radio-tagged juvenile steelhead released above Lower Monumental\nDam, 1,109 (93%) were detected on the forebay entrance line at the upstream end of the\nBRZ. Seventy-nine percent of the juvenile steelhead entered the forebay of Lower\nMonumental Dam between 0500 and 1900 PDT (Figure 7). Median forebay residence\ntime was 2.2 h (95% CI 1.8-2.5) and ranged from 0.2 to 146.3 h (Table 8). Median\nforebay residence time of steelhead that passed through the JBS (8.5 h; 95% CI 5.0-12.0)\nwas significantly longer than for fish passing through the spillway (1.8 h; 95% CI\n1.5-2.1) or turbines (2.9 h, no 95% CI calculated; P < 0.001).\nMedian gatewell residence time was 0.5 h for yearling Chinook salmon and 0.2 h\nfor juvenile steelhead that passed the dam through the JBS (Table 9). For yearling\nChinook salmon that passed via the JBS, median gatewell residence time accounted for\n24% of delay associated with forebay residence time. For juvenile steelhead that passed\nvia the JBS, median gatewell residence time accounted for 7% of the delay associated\nwith forebay residence time.\n23","10%\n9%\n8%\n7%\n6%\n5%\n4%\n3%\n2%\n1%\n0%\n0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10 11 12 13 14 15 16 17 18 19 20 21 22 23\nHour\nFigure 7. Hour of first detection for radio-tagged juvenile steelhead released upstream\nfrom Lower Monumental Dam and detected in the forebay of Lower\nMonumental Dam, 2008.\nTable 8. Sample size and forebay residence time (from first detection on forebay entry\nline to passage) statistics by passage route and overall for juvenile steelhead at\nLower Monumental Dam, 2008.\nForebay residence time (h)\nPassage percentile\nJBS\nSpillway\nRSW\nTurbine\nOverall\nN\n175\n851\n740\n14\n1,040\n10th\n1.7\n0.6\n0.6\n0.6\n0.6\n20th\n3.3\n0.8\n0.8\n0.8\n0.9\n30th\n4.4\n1.0\n1.0\n0.9\n1.2\n40th\n6.2\n1.3\n1.3\n1.1\n1.7\n50th\n8.5\n1.8\n1.8\n2.9\n2.2\n60th\n11.4\n2.3\n2.3\n4.4\n3.1\n70th\n14.9\n3.2\n3.2\n4.6\n4.4\n80th\n21.7\n4.7\n4.6\n5.4\n7.1\n90th\n44.5\n8.7\n8.4\n6.8\n13.1\n95th\n63.4\n12.8\n12.5\n10.2\n20.3\n0.7\nMinimum\n0.2\n0.2\n0.4\n0.2\n17.3\n3.5\n3.5\n3.8\n5.8\nMean\n8.5\n1.8\n1.8\n2.9\nMedian\n2.2\n1.1\n0.9\n1.0\nNA\n0.9\nMode\n146.3\n41.3\n41.3\n15.4\n146.3\nMaximum\n24","Table 9. Sample size, percentile distribution, minimum, mean, median, mode, and\nmaximum gatewell residence time (elapsed time in hours from first detection in\nthe gatewell to time of passage) for radio-tagged hatchery yearling Chinook\nsalmon and juvenile steelhead at Lower Monumental Dam, 2008.\nGatewell residence time (h)\nPassage percentile\nYearling Chinook salmon\nJuvenile steelhead\n234\n156\nn\n10th\n0.1\n0.1\n20th\n0.1\n0.1\n30th\n0.2\n0.1\n40th\n0.3\n0.1\n50th\n0.5\n0.2\n60th\n2.2\n0.2\n70th\n5.1\n0.3\n80th\n8.7\n0.6\n90th\n25.2\n2.8\n95th\n45.2\n8.4\nMinimum\n0.0\n0.0\nMean\n7.6\n1.3\nMedian\n0.5\n0.2\nMode\n0.1\n0.1\nMaximum\n88.1\n20.0\n25","Approach and Passage-Route Distribution\nA total of 979 yearling Chinook salmon entered the forebay of Lower\nMonumental Dam, and 93% of these fish (907) subsequently passed the dam. Seventy\npercent of the yearling Chinook salmon first approached the spillway portion of the dam,\nwith the majority of these (44%) approaching the RSW in Spillbay 8 (Figure 8).\nPassage-route distribution was 62, 28, and 6%, through the spillway, JBS, and turbines,\nrespectively. The remaining 4% passed through undetermined routes. The greatest\nproportion of yearling Chinook passed through the RSW in Spillbay 8 (45%; Figure 9).\ntotal of 1,088 juvenile steelhead entered the forebay of Lower Monumental\nA\nDam and 96% of these fish (1,040) subsequently passed the dam. Eighty-six percent of\njuvenile steelhead first approached the spillway portion of the dam, with the majority of\nthese (48%) approaching the RSW in Spillbay 8 (Figure 10). Passage-route distribution\nwas 80, 16, and 1% through the spillway, JBS, and turbines, respectively. The remaining\n2% passed via undetermined routes. The largest proportion of juvenile steelhead passed\nthrough the RSW in Spillbay 8 (70%; Figure 11).\n45%\n40%\n35%\n30%\n25%\n20%\n15%\n10%\n5%\n0%\nT1\nT2\nT3\nT4\nT5\nT6\nRSW\nS7\nS6\nS5\nS4\nS3\nS2\nS1\nFigure 8. Horizontal approach distribution (within 18 m of the dam) for radio-tagged\nyearling Chinook salmon released upstream from Lower Monumental Dam\nbased on first detection at individual turbine intakes (T), the RSW, or spillbays\n(S), 2008.\n26","50%\n45%\n40%\n35%\n30%\n25%\n20%\n15%\n10%\n5%\n0%\nU JBS T1\nT2\nT3\nT4\nT5\nT6 RSW S7\nS6\nS5\nS4\nS3\nS2\nS1\nTurbine (n = 56) N JBS (n = 265) Spillway (n = 586) Unknown (n = 33)\nFigure 9. Passage route distribution for radio-tagged yearling Chinook salmon released\nupstream from Lower Monumental Dam, 2008. Passage locations are U =\nunidentified route, JBS, T = individual turbine intakes, RSW, and S =\nindividual spillbays.\n27","50%\n45%\n40%\n35%\n30%\n25%\n20%\n15%\n10%\n5%\n0%\nT1\nT2\nT3\nT4\nT5\nT6\nRSW\nS7\nS6\nS5\nS4\nS3\nS2\nS1\nFigure 10. Horizontal approach distribution (within 18 m of the dam) for radio-tagged\njuvenile steelhead released upstream from Lower Monumental Dam based on\nfirst detections at either individual turbine intakes (T) or spillbays (S), 2008.\n70%\n60%\n50%\n40%\n30%\n20%\n10%\n0%\nU\nJBS\nT1\nT2\nT3\nT4\nT5\nT6 RSW S7\nS6\nS5\nS4\nS3\nS2\nS1\nTurbine (n = 14)\nJBS (n = 175)\nSpillway (n = 851)\nUnknown (n = 21)\nFigure 11. Passage distribution for radio-tagged juvenile steelhead released upstream\nfrom Lower Monumental Dam, 2008. Passage locations are U = unidentified\nroute, JBS, T = individual turbine intakes, RSW, and S = individual spillbays.\n28","Fish Passage Performance Metrics\nFor radio-tagged yearling Chinook salmon and steelhead with a known passage\nroute, fish passage metrics are summarized below:\nYearling Chinook Salmon\nSteelhead\n95% CI\n95% CI\nFGE\n0.826\n0.783-0.868\n0.926\n0.888-0.964\nFPE\n0.938\n0.922-0.954\n0.987\n0.979-0.994\nBPE\n0.292\n0.262-0.322\n0.168\n0.145-0.191\nSPE\n0.646\n0.614-0.677\n0.818\n0.794-0.842\nSOE\n0.469\n0.435-0.502\n0.712\n0.683-0.740\nSPS (mean spill of 34%)\n1.91 to 1\n2.43 to 1\nSOS (mean surface spill of 7%)\n6.51 to 1\n9.89 to 1\nTailrace Egress\nOverall median tailrace egress time was 6.6 min (95% CI, 5.7-7.6) for yearling\nChinook salmon and ranged from 1 to 9,756 min (Table 10). Median tailrace egress time\nwas significantly longer for yearling Chinook that passed through the powerhouse (JBS\n10.2 min, 95% CI, 4.5-15.8; turbines 10.3 min, no 95% CI calculated) than for those that\npassed through the spillway (5.1 min, 95% CI, 4.5-5.7; P = 0.013).\nOverall median tailrace egress for juvenile steelhead was 5.3 min (95% CI,\n4.7-5.8) and ranged from 1 to 3,167 min (Table 11). Median tailrace egress time was\nsignificantly longer for juvenile steelhead that passed through the powerhouse (JBS\n8.5 min, 95% CI 4.6-12.4; turbines 16.5 min, no 95% CI calculated) than for those that\npassed through the spillway (4.9 min, 95% CI, 4.3-5.4; P- = 0.045). The longer egress\ntimes for JBS passage of both yearling Chinook salmon and steelhead were likely related\nto the proximity of the powerhouse and strong clockwise eddy in the tailrace.\n29","Table 10. Sample size, distribution, minimum, mean, median, mode, and maximum\ntailrace egress time (elapsed time from last detection in a passage route to last\ndetection in the tailrace) by passage route and overall for radio tagged hatchery\nyearling Chinook salmon at Lower Monumental Dam, 2008.\nYearling Chinook tailrace egress time (min)\nPassage\npercentile\nJBS\nSpillway\nRSW\nTurbine\nOverall\n235\n463\n326\n42\n740\nn\n10th\n4.7\n2.0\n2.0\n6.4\n2.7\n20th\n6.2\n3.3\n3.4\n6.9\n3.7\n30th\n7.5\n3.8\n3.9\n7.6\n4.7\n40th\n8.5\n4.5\n4.5\n8.9\n5.5\n50th\n10.2\n5.1\n5.2\n10.3\n6.6\n60th\n13.6\n6.1\n5.8\n11.3\n7.8\n70th\n17.5\n6.9\n6.9\n11.8\n9.8\n80th\n23.0\n8.6\n8.5\n18.1\n16.2\n90th\n41.9\n22.5\n18.5\n146.4\n35.1\n95th\n373.5\n269.6\n124.8\n421.7\n328.8\nminimum\n1.0\n1.0\n1.0\n5.0\n1.0\n159.0\n183.0\n132.8\n140.9\n173.0\nmean\nmedian\n10.2\n5.1\n5.2\n10.3\n6.6\nmode\n0.0\n3.4\n3.4\n#N/A\n4.9\nmaximum\n9620.3\n9755.7\n9227.9\n3211.8\n9755.7\n30","Table 11. Sample size, percentile distribution, minimum, mean, median, mode, and\nmaximum tailrace egress time (elapsed time in minutes from last detection in a\npassage route to last detection in the tailrace) by passage route and overall for\nradio-tagged juvenile steelhead at Lower Monumental Dam, 2008.\nJuvenile steelhead tailrace egress time (min)\nPassage\npercentile\nJBS\nSpillway\nRSW\nTurbine\nOverall\n147\n628\n534\n11\n786\nn\n10th\n4.2\n2.0\n2.0\n4.8\n2.2\n20th\n5.2\n2.8\n2.9\n5.1\n3.1\n30th\n6.5\n3.6\n3.6\n11.1\n4.0\n40th\n7.5\n4.3\n4.3\n12.0\n4.6\n50th\n8.5\n4.9\n4.9\n16.5\n5.3\n60th\n10.0\n5.4\n5.4\n19.2\n6.0\n70th\n13.6\n6.1\n6.1\n24.2\n7.2\n80th\n19.9\n7.4\n7.2\n36.8\n9.3\n90th\n27.0\n10.8\n10.1\n120.0\n17.4\n95th\n44.8\n21.1\n20.0\n688.9\n30.6\nminimum\n1.0\n1.0\n1.0\n3.3\n1.0\n41.9\n9.8\n8.4\n137.4\n17.6\nmean\nmedian\n8.5\n4.9\n4.9\n16.5\n5.3\nmode\n0.0\n0.0\n0.0\n#N/A\n0.0\nmaximum\n3167.0\n449.7\n409.0\n1257.9\n3167.0\n31","Survival Estimates\nDetection Probability\nDetection histories used for survival estimates are presented in Appendix\nTables A1-A10. Detection probabilities at the primary survival array, 30 km downstream\nfrom Lower Monumental Dam, are presented for each species in Appendix Table A11.\nDaily survival estimates for paired treatment and reference fish groups are presented in\nAppendix Tables B1-B8.\nPool Survival\nFor yearling Chinook salmon, single-release pool survival (from release ~5 km\ndownstream of Little Goose Dam to ~500 m upstream from Lower Monumental Dam),\nwas estimated at 0.912 (geomean; SE = 0.038; 95% CI, 0.889-0.934). For juvenile\nsteelhead, single-release pool survival was estimated at 0.958 (geomean; SE = 0.026;\n95% CI, 0.946-0.968).\nProject Survival\nFor yearling Chinook salmon, relative dam survival (~500 m upstream to ~1 km\ndownstream from the dam) was estimated at 0.934 (geomean; SE = 0.016; 95% CI,\n0.902-0.968; Table 12). Relative concrete survival (all passage routes combined to\napproximately 1 km downstream from the dam) was estimated at 0.963 (geomean; SE =\n0.016; 95% CI, 0.929-0.997).\nFor juvenile steelhead, relative dam survival was estimated at 0.982 (geomean;\nSE = 0.011; 95% CI, 0.960-1.005; Table 13) and relative concrete survival at 1.006\n(geomean; SE = 0.009; 95% CI, 0.987-1.026).\nRoute-Specific Survival\nFor radio-tagged yearling Chinook salmon, relative survival (treatment/reference)\nwas estimated at 0.976 (geomean; SE = 0.016; 95% CI, 0.943-1.010) for fish passing via\nthe spillway, 0.936 (pooled; SE = 0.025; 95% CI, 0.886-0.985) for those passing via the\nJBS, and 1.012 (geomean; SE = 0.016; 95% CI, 0.979-1.046) for those passing via the\nRSW (Table 12). Insufficient numbers of yearling Chinook salmon passed through\nturbines to estimate survival with acceptable precision.\n32","Table 12. Sample sizes and mean estimates of survival for radio-tagged hatchery yearling Chinook salmon passing (treatment)\n0.902-0.968\n0.929-0.997\n0.943-1.010\n0.886-0.985\n0.979-1.046\n95% CI\nLower Monumental Dam relative to fish released into the tailrace (reference), 2008. Standard errors are in\nRelative\n0.934 (0.016)\n0.963 (0.016)\n0.976 (0.016)\n0.936 (0.025)\n1.012 (0.016)\nSurvival\n0.902-0.937\n0.902-0.937\n0.902-0.937\n0.903-0.939\n0.902-0.937\n95% CI\nYearling Chinook salmon\nReference\n0.919 (0.009)\n0.919 (0.009)\n0.919 (0.009)\n0.921 (0.009)\n0.919 (0.009)\nSurvival\n33\n930\n930\n930\n930\n930\nn\n0.834-0.887\n0.860-0.913\n0.871-0.926\n0.819-0.904\n0.906-0.958\n95% CI\n* Pooled estimate due to few replicates and limited sample sizes.\nTreatment\n0.860 (0.013)\n0.886 (0.013)\n0.899 (0.013)\n0.862 (0.021)\n0.932 (0.013)\nSurvival\n979\n907\n586\n265\n425\nn\nparenthesis.\nRoute-specific survival\nConcrete survival\nSpillway survival\nRSW survival\nProject survival\nJBS survival*\nDam survival","For radio-tagged juvenile steelhead passing Lower Monumental Dam, relative\nsurvival was estimated at 1.014 (geomean; SE = 0.011; 95% CI, 0.990-1.037) for fish\npassing via the spillway, 0.977 (pooled; SE = 0.023; 95% CI, 0.930-1.023) for fish\npassing via the JBS, and 1.026 (geomean; SE = 0.011; 95% CI, 1.004-1.048) for those\npassing via the RSW (Table 13).\nAvian Predation\nA total of 17 tags from radio-tagged yearling Chinook salmon released to evaluate\nLower Monumental Dam passage in 2008 were recovered from avian colonies on\nCrescent or Foundation Island in the McNary Dam Reservoir, Columbia River\n(Table 14). The majority of these fish (53%) were last detected between Ice Harbor Dam\nand the mouth of the Snake River. Only three tags from yearling Chinook salmon were\nlast detected above our primary survival array (30 km downstream from Lower\nMonumental Dam) prior to being recovered on Crescent Island.\nA total of 66 tags from radio tagged juvenile steelhead were recovered from avian\ncolonies on Crescent or Foundation Island (Table 15). The majority of these fish (76%)\nwere last detected between Ice Harbor Dam and the mouth of the Snake River. Only five\ntags from juvenile steelhead were last detected above our primary survival array prior to\nbeing recovered from Crescent Island.\n34","Table 13. Sample sizes and mean estimates of survival for radio-tagged hatchery juvenile steelhead passing (treatment) Lower\n0.960-1.005\n0.987-1.026\n0.990-1.037\n0.930-1.023\n1.004-1.048\n95% CI\nMonumental Dam relative to fish released into the tailrace (reference), 2008. Standard errors are in parenthesis.\nRelative\n0.982 (0.011)\n1.006 (0.009)\n1.014 (0.011)\n0.977 (0.023)\n1.026 (0.011)\nSurvival\n0.930-0.956\n0.930-0.956\n0.930-0.956\n0.839-1.003\n0.930-0.956\n95% CI\nReference\nJuvenile steelhead\n0.943 (0.006)\n940 0.943 (0.006)\n0.943 (0.006)\n0.943 (0.008)\n0.943 (0.006)\nSurvival\n35\n940\n940\n940\n940\nn\n0.907-0.947\n0.933-0.964\n0.939-0.973\n0.880-0.962\n0.951-0.984\n95% CI\n* Pooled estimate due to few replicates and limited sample sizes.\n0.927 (0.010)\n0.949 (0.007)\n0.956 (0.008)\n0.921 (0.021)\n0.967 (0.008)\nTreatment\nSurvival\n1,088\n1,040\n740\n851\n175\nn\nConcrete survival\nSpillway survival\nRSW survival\nProject survival\nJBS survival*\nDam survival\nRoute-specific\nsurvival","Table 14. Number and proportion of radio tags from yearling Chinook salmon recovered\nfrom avian colonies on Crescent or Foundation Island. Yearling Chinook were\nreleased to evaluate passage behavior and survival at Lower Monumental\nDam, 2008. Recoveries are grouped by location of the last telemetry\ndetection.\nNumber and proportion (%) of yearling Chinook tags\nrecovered on avian colonies\nLast location of telemetry detection\nTreatment\nReference\nUpstream of Lower monumental Dam forebay\n0 (0.0)\nN/A\nLower Monumental Dam forebay\n1 (0.1)\nN/A\nIce Harbor Dam pool\n0 (0.0)\n2 (0.2)\nIce Harbor forebay\n0 (0.0)\n0 (0.2)\nIce Harbor Dam to Snake River mouth\n6 (0.6)\n3 (0.3)\nMcNary Dam pool\n2 (0.2)\n3 (0.3)\nMcNary Dam forebay\n0 (0.0)\n0 (0.0)\nTotal\n9 (0.9)\n8 (0.9)\nTable 15. Number and proportion of radio tags from juvenile steelhead recovered from\navian colonies on Crescent or Foundation Island. Steelhead were released to\nevaluate passage behavior and survival at Lower Monumental Dam, 2008.\nRecoveries are grouped by location of the last telemetry detection.\nNumber and proportion (%) of juvenile steelhead tags\nrecovered on avian colonies\nLast location of telemetry detection\nTreatment fish\nReference fish\nUpstream of Lower monumental Dam\nforebay\n0 (0.0)\nN/A\nLower Monumental Dam forebay\n1 (0.1)\nN/A\nIce Harbor Dam pool\n2 (0.2)\n2 (0.2)\nIce Harbor forebay\n1 (0.1)\n0 (0.0)\nIce Harbor Dam to Snake River mouth\n24 (2.2)\n26 (2.8)\nMcNary Dam pool\n5 (0.5)\n3 (0.3)\nMcNary Dam forebay\n2 (0.2)\n0 (0.0)\nTotal\n35 (3.2)\n48 (3.3)\n36","DISCUSSION\nThis report summarizes the first year of study evaluating behavior and survival of\nvolitionally passing radio-tagged juvenile steelhead and yearling Chinook salmon at\nLower Monumental Dam with the new RSW installed. In 2006 and 2007, baseline\nstudies evaluated behavior and survival for volitionally passing radio-tagged juvenile\nsteelhead and yearling Chinook salmon. Spring flows during the baseline studies were\nconsiderably different between years, with high flows in 2006 and low flows in 2007.\nSnake River flows in spring 2007 at Lower Monumental Dam averaged 79 kcfs, or 74%\nof the 10-year average (107 kcfs from 1996 through 2005; Hockersmith et al. 2008a). In\ncontrast, Snake River flows in spring 2006 averaged 139 kcfs, or 130% of the 10-year\naverage (Hockersmith et al. 2008b). Although flow conditions were vastly different\nbetween years during the baseline studies, Lower Monumental Dam project operations\nwere relatively similar between years, with 26% of the river spilled in 2006 and 27% in\n2007. In 2008, flows at Lower Monumental Dam (99 kcfs average) were in between the\nflow conditions during the baseline studies, and the proportion spilled averaged 34%,\nwhich was 31% more than during the baseline studies.\nAs in the baseline study years of 2006 and 2007 the majority of our radio-tagged\nfish (yearling Chinook salmon and juvenile steelhead combined) approached and passed\nthe dam in the thalweg of the river near Spillbay 8. Johnson et al. (1998), using\nhydroacoustics, observed similar horizontal distribution patterns, where smolts\napproached Lower Monumental Dam at the midpoint of the thalweg. We observed\nsimilar proportions of yearling Chinook salmon passing via the spillway in 2008 with the\nRSW operating compared to the baseline studies in 2006 and 2007 (62% VS. 58 to 74%)\neven though the proportion of river spilled was higher in 2008 (34% VS. 26 to 27%). We\nobserved a higher proportion of juvenile steelhead passing via the spillway in 2008 with\nthe RSW operating compared to the baseline studies in 2006 and 2007 (80% VS. 48 to\n62%) and this may have been influenced by either the RSW operation, or the increased\nproportion of river spilled (34% VS. 26 to 27%).\nFor both species (yearling Chinook salmon and juvenile steelhead), the RSW\nappeared to reduce forebay delay during 2008 compared to results during pre-RSW years.\nMedian forebay residence time for yearling Chinook salmon during 2008 was slightly\nless than observed during the baseline studies of 2006 and 2007 (2.2 VS. 2.5 h). Median\nforebay residence times for juvenile steelhead were 2.5 to 8 times shorter during 2008\nwith the RSW operating than observed during the baseline studies (2.2 VS. 5.5 to 17.8 h).\n37","Median tailrace egress time during 2008 for both species (yearling Chinook\nsalmon and juvenile steelhead) was similar to the range of egress times observed during\nthe baseline studies of 2006 and 2007 (6.6 vs. 6.0-8.2 minutes). As observed during the\nbaseline studies, tailrace egress times were longer for fish passing via the powerhouse\n(JBS and turbines) compared to the spillway during 2008 for both yearling Chinook\nsalmon and juvenile steelhead.\nSpill effectiveness for yearling Chinook salmon was lower during 2008 compared\nto results during pre-RSW years of 2006 and 2007 (1.91 VS. 2.31-2.76). The lower level\nof spill effectiveness observed for yearling Chinook salmon was likely influenced by the\nincreased proportion of river spilled during 2008 compared to during the baseline studies\n(34% VS. 26 to 27%). Spill effectiveness for juvenile steelhead was towards the upper\nend of the range of spill effectiveness observed during pre-RSW years of 2006 and 2007\n(2.43 VS. 1.88 to 2.45). For juvenile steelhead, spill effectiveness remained high during\n2008 due to the increased proportion of fish passing via the RSW, even though the level\nof spill during 2008 was higher than during baseline studies.\nRelative dam, concrete, and spillway survival for yearling Chinook salmon were\nslightly higher in 2008 compared to results during pre-RSW years of 2006 and 2007\n(0.934 VS. 0.924 to 0.930; 0.963 VS. 0.943 to 0.952; and 0.976 VS. 0.925-0.959,\nrespectively). Relative bypass survival was slightly lower in 2008 compared to results\nduring pre-RSW years of 2006 and 2007 (0.936 VS. 0.941 to 0.987). For juvenile\nsteelhead, relative dam, concrete, and spillwa survival were higher in 2008 compared to\nresults during pre-RSW years of 2006 and 2007 (0.982 VS. 0.888 to 0.980; 1.006 VS.\n0.955 to 1.000; and 1.014 VS. 0.939-0.999, respectively). Relative bypass survival was\nslightly lower in 2008 compared to results during pre-RSW years of 2006 and 2007\n(0.977 VS. 0.986 to 1.010) for juvenile steelhead.\n38","RECOMMENDATIONS\nIn general, the RSW at Lower Monumental Dam appears to have increased the\nproportion of yearling Chinook salmon and juvenile steelhead passing the dam via the\nspillway, reduced delays associated with passing the dam, and increased survival. These\nresults however, are only for one year, and flows during 2008 were above average. At\nleast one additional year of evaluation should be conducted to confirm the findings from\n2008. In addition, it would be useful to evaluate operation of the RSW during low flows\nto capture a wider range of conditions that occur across multiple years.\nThe two-spill treatment test planned for 2008 was not evaluated due to high Snake\nRiver flows during the study, and a lack of consistent adherence to the treatment\nschedule. When conditions allow, this evaluation should be attempted again if there\ncontinues to be interest in alternative spill patterns by the regional fish management\nagencies.\nJuvenile bypass systems were first utilized to divert salmonid smolts around\nhydroelectric facilities on the lower Snake River in the 1970s (Marsh et al. 1995). At\nLower Monumental Dam, a PIT-tag detection system was added to the bypass system in\n1993. Operation of the RSW at Lower Monumental Dam has increased the proportion of\nfish passing via the spillway while decreasing the proportion passing via the JBS. The\ndecrease in JBS passage has reduced the PIT-tag detection probability at Lower\nMonumental Dam and reduced the precision of PIT-tag survival estimates. Active tags\nsuch as those used in radio or acoustic telemetry remain unsuitable for evaluating most\nwild yearling Chinook salmon stocks and Snake River sockeye passage and survival\nbecause of the size of the tag.\nIn 2008, 73% of the yearling Chinook salmon and 86% of the juvenile steelhead\npassed either through the JBS or the RSW. The development of PIT-tag detection in the\nRSW at Lower Monumental Dam would have provided increased PIT-tag detection of\nsmolts in 2008. The higher-than-average flows during 2008 likely lowered passage\nproportions through the RSW for some stocks and increased the proportion through the\nJBS. During a low-flow year like 2007, the proportion of fish passing through the JBS\nwould likely be even lower than observed in 2008, while the proportion passing through\nthe RSW would likely be higher. The addition of PIT-tag detection in the RSW could\nprovide information on surface passage use, behavior, and survival for sockeye, wild\nstocks, and for various ESUs; information which is currently very limited.\n39","ACKNOWLEDGMENTS\nWe express our appreciation to all who assisted with this research. We thank the\nUSACE who funded this research, particularly William Spurgeon, Lower Monumental\nDam Project Biologist, Mark Plummer, Ice Harbor Dam Project Biologist, and Ann\nSetter and Tim Wik, Walla Walla USACE District office for their help coordinating\nresearch activities. Monty Price, and the staff of the Washington Department of Fish and\nWildlife at Lower Monumental Dam provided valuable assistance with collecting and\nsorting of study fish. Carter Stein and staff of the Pacific States Marine Fisheries\nCommission provided valuable assistance in data acquisition.\nFor their ideas, assistance, encouragement, and guidance, we thank, Steve Brewer,\nTyler Conrad, Scott Davidson, Doug Dey, Nathan Dumdei, John Ferguson, Josh Gifford,\nNathan Jones, Byron Iverson, Bruce Jonasson, Mark Kaminski, Jesse Lamb, Esa Pecka\nMaenpaa, Ronald Marr, Jeffrey Moser, Matthew Nesbit, Sean Newsome, Sam Rambo,\nThomas Ruehle, Sam Rushing, Jim Simonson, Steve Smith, Scott Telander, William\nWassard, Alex Wentz, and Galen Wolf of the Fish Ecology Division, Northwest Fisheries\nScience Center, National Marine Fisheries Service.\n40","REFERENCES\nAdams, N. S., D. W. Rondorf, S. D. Evans, and J. E. Kelly. 1998. Effects of surgically\nand gastrically implanted radio transmitters on growth and feeding behavior of\njuvenile Chinook salmon. Transactions of the American Fisheries Society\n27:128-136.\nBeeman, J. W., C. Grant, and P. V. Haner. 2004. Comparison of three underwater\nantennas for use in radio telemetry. North American Journal of Fisheries\nManagement 24:275-281.\nBeeman, J. W., and A. G. Maule. 2006. Migration depths of juvenile Chinook salmon\nand steelhead relative to total dissolved gas supersaturation in a Columbia River\nreservoir. Transactions of the American Fisheries Society 135:584-594.\nCormack, R. M. 1964. Estimates of survival from sightings of marked animals.\nBiometrika 51:429-438.\nHockersmith, E. E., G. A. Axel, M. B. Eppard, D. A. Ogden, and B. P. Sandford. 2005.\nPassage behavior and survival for hatchery yearling Chinook salmon at Lower\nMonumental Dam, 2004. Report of the National Marine Fisheries Service to the\nU.S. Army Corps of Engineers, Northwestern Division, Walla Walla,\nWashington. (Available from the Northwest Fisheries Science Center, 2725\nMontlake Blvd. E., Seattle, WA 98112-2097).\nHockersmith, E. E., G. A. Axel, D. A. Ogden, B. J. Burke, K. E. Frick, B. P. Sandford,\nand R. F. Absolon. 2008a. Passage behavior and survival for radio-tagged\nyearling Chinook salmon and juvenile steelhead at Lower Monumental Dam,\n2007. Report of the National Marine Fisheries Service to the U.S. Army Corps of\nEngineers, Northwestern Division, Walla Walla, Washington. (Available from\nthe Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA\n98112-2097).\nHockersmith, E. E., G. A. Axel, D. A. Ogden, B. J. Burke, K. E. Frick, B. P. Sandford,\nand R. F. Absolon. 2008b. Passage behavior and survival for radio-tagged\nyearling Chinook salmon and juvenile steelhead at Lower Monumental Dam,\n2006. Report of the National Marine Fisheries Service to the U.S. Army Corps of\nEngineers, Northwestern Division, Walla Walla, Washington. (Available from\nthe Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA\n98112-2097).\n41","Hockersmith E. E., W. D. Muir, S. G. Smith, B. P. Sandford, N. S. Adams, J. M. Plumb,\nR. W. Perry, and D. W. Rondorf. 2003. Comparison of migration rate and\nsurvival between radio-tagged and PIT-tagged migrant juvenile chinook salmon\nin the Snake and Columbia Rivers. North American Journal of Fisheries\nManagement 23:404-413.\nHolmes, H. B. 1952. Loss of salmon fingerlings in passing Bonneville Dam as\ndetermined by marking experiments. Unpublished manuscript, U.S. Bureau of\nCommercial Fisheries Report to U.S. Army Corps of Engineers, Northwestern\nDivision, Portland, Oregon.\nJohnson, G. E., N. S. Adams, R. L. Johnson, D. W. Rondorf, D. D. Dauble, and T. Y.\nBarila. 2000. Evaluation of the prototype surface bypass for salmonid smolts in\nspring 1996 and 1997 at Lower Granite Dam on the Snake River, Washington.\nTrans. Am. Fish. Soc. 129:381-397.\nJohnson, G. E., R. A. Moursund, and J. R. Skalski. 1998. Fixed location hydroacoustic\nevaluation of spill effectiveness at Lower Monumental Dam in 1997. Report of\nPacific Northwest National Laboratories to the U.S. Army Corps of Engineers,\nNorthwestern Division, Walla Walla, Washington.\nJolly, G.M. 1965. Explicit estimates from capture-recapture data with both death and\nimmigration-stochastic model. Biometika 52:225-247.\nKnight, A. E., G. Marancik, and J. B. Layzer. 1977. Monitoring movements of juvenile\nanadromous fish by radio telemetry. Progressive Fish-Culturist 39:148-150.\nMarsh, D. M., B. P. Sandford, and G. M. Matthews. 1995. Preliminary evaluation of the\nnew juvenile collection, bypass, and sampling facilities at Lower Monumental\nDam, 1993. Report to U.S. Army Corps of Engineers, Contract DACW68-84-H-\n0034, 48 p. plus Appendix. (Available from Northwest Fisheries Science Center,\n2725 Montlake Boulevard E., Seattle, WA 98112-2097.)\nMarsh, D. M., G. M. Matthews, S. Achord, T. E. Ruehle, and B. P. Sandford. 1999.\nDiversion of salmonid smolts tagged with passive integrated transponders from an\nuntagged population passing through a juvenile collection system. North\nAmerican Journal of Fisheries Management 19:1142-1146.\nMuir, W. D., S. G. Smith, J. G. Williams, and B. P. Sandford. 2001. Survival of juvenile\nsalmonids passing through bypass systems, turbines, and spillways with and\nwithout flow deflectors at Snake River Dams. North American Journal of\nFisheries Management 21:135-146.\n42","Nehlsen, W., J. E. Williams, and J. A. Lichatowich. 1991. Pacific salmon at the\ncrossroads: stocks at risk from California, Oregon, Idaho, and Washington.\nFisheries 16(2):4-21.\nNetboy, A. N. 1980. Columbia River salmon and steelhead trout: their fight for survival.\nUniversity of Washington Press, Seattle.\nNMFS (National Marine Fisheries Service). 1991. Endangered and threatened species:\nendangered status for Snake River sockeye salmon. Final Rule. Federal Register\n56:224 (20 November 1991):58619-58624.\nNMFS (National Marine Fisheries Service). 1992. Endangered and threatened species:\nthreatened status for Snake River spring/summer Chinook salmon, threatened\nstatus for Snake River fall Chinook salmon. Final Rule. Federal Register 57:78\n(22 April 1992):14563-14663.\nNMFS (National Marine Fisheries Service). 1995. Reinitiation of consultation on 1994-\n1998 operation of the federal Columbia River power system and juvenile\ntransportation program in 1995 and future years. Endangered Species Act,\nSection 7 consultation, Biological opinion. (Available from NMFS Northwest\nRegional Office, Hydropower Program, 525 NE Oregon Street, Suite 500,\nPortland, OR 97232.)\nNMFS (National Marine Fisheries Service). 1998. Endangered and threatened species:\nthreatened status for two ESUs for steelhead in Washington, Oregon, and\nCalifornia. Final Rule. Federal Register 63:53 (19 March 1998): 13347-13371.\nNMFS (National Marine Fisheries Service). 1999. Endangered and threatened species:\nthreatened status for three Chinook salmon ESUs in Washington and Oregon, and\nendangered status of one Chinook salmon ESU in Washington. Final Rule.\nFederal Register 64:56(24 March 1999):14307-14328.\nNMFS (National Marine Fisheries Service). 2000. Reinitiation of consultation on\noperation of the Federal Columbia River power system, including the juvenile fish\ntransportation program and 19 Bureau of Reclamation projects in the Columbia\nBasin. Endangered Species Act - Section 7 Consultation, Biological Opinion.\nwww.nwr.noaa.gov/1hydrop/hydroweb/docs/Final/2000Biop.html(April 2005).\nPeven, C., A. Giorgi, J. Skalski, M. Langeslay, A. Grassell, S. G. Smith, T. Counihan, R.\nPerry, S. Bickford. 2005. Guidelines and recommended protocols for\nconducting, analyzing, and reporting juvenile salmonid survival studies in the\nColumbia River Basin. Available at www.pnamp.org//web/workgroups/FPM\n/meetings/2007_0524/Guid_Sug_Prot_final.pdf(June 2008).\n43","Plumb, J. M., A. C. Braatz, J. N. Lucchesi, S. D. Fielding, J. M. Sprando, G. T. George,\nN. S. Adams, and D. W. Rondorf. 2003. Behavior of radio-tagged juvenile\nChinook salmon and steelhead and performance of a removable spillway weir at\nLower Granite Dam, Washington, 2002. Annual report to the U. S. Army Corps\nof Engineers, Contract W68SBV00104592, Walla Walla, Washington.\nPlumb, J. M., A. C. Braatz, J. N. Lucchesi, S. D. Fielding, A. D. Cochran, Theresa K.\nNation, J. M. Sprando, J.L. Schei, R. W. Perry, N. S. Adams, and D. W. Rondorf.\n2004. Behavior and survival of radio-tagged juvenile Chinook salmon and\nsteelhead relative to the performance of a removable spillway weir at Lower\nGranite Dam, Washington, 2003. Annual report the U.S. Army Corps of\nEngineers, Contract W68SBV00104592, Walla Walla, Washington.\nSeber, G. A. F. 1965. A note on the multiple recapture census. Biometrika 52:249-259.\nSkalski, J. R., R. Townsend, J. Lady, A. E. Giorgi, J. R. Stevenson, and R. D. McDonald.\n2002. Estimating route-specific passage and survival probabilities at a\nhydroelectric project from smolt radio telemetry studies. Canadian Journal of\nFisheries and Aquatic Sciences 59:1385-1393.\nSmith, S. G., J. R. Skalski, W. Schlechte, A. Hoffmann, and V. Cassen. 1994. Statistical\nsurvival analysis of fish and wildlife tagging studies. SURPH.1 Manual.\n(Available from University of Washington, School of Aquatic & Fisheries\nScience, 1325 Fourth Avenue, Suite 1820, Seattle, WA 98101-2509.)\nSnedecor, G. W., and W. G. Cochran. 1980. Statistical Methods. 7th Ed. Iowa St.\nUniv. Press, Ames, IA. 507 pp.\nWhitney, R. R., L. Calvin, M. Erho, and C. Coutant. 1997. Downstream passage for\nsalmon at hydroelectric projects in the Columbia River Basin: development,\ninstallation, and evaluation. U.S. Department of Energy, Northwest Power\nPlanning Council, Portland, Oregon. Report 97-15. 101 p.\n44","APPENDIX A\nEvaluation of Study Assumptions\nWe used the CJS single-release model (Cormack 1964, Jolly 1965, Seber 1965) to\nestimate survival of radio-tagged juvenile Chinook salmon and juvenile steelhead\nreleased above and below Lower Monumental Dam. Ratios of these survival estimates\n(treatment survival divided by reference survival) were calculated to determine relative\nsurvival. Evaluation of critical model and biological assumptions of the study are\ndetailed below.\nAl. All tagged fish have similar probabilities of detection at a detection location.\nOf the 979 radio-tagged yearling Chinook salmon released above Lower\nMonumental Dam and detected on the forebay entrance array, 821 (85.5% of those\nreleased) were detected either at or below our primary survival array 30 km downstream\nfrom Lower Monumental Dam. Of the 930 radio-tagged yearling Chinook salmon\nreleased into the tailrace of Lower Monumental Dam, 860 (92.5% of those released)\nwere\ndetected either at or below our primary survival array 30 km downstream from Lower\nMonumental Dam. Capture histories for survival analysis of yearling Chinook salmon\nare presented in Appendix Tables A1-A5.\nOf the 1,088 radio-tagged steelhead released above Lower Monumental Dam and\ndetected on the forebay entrance array, 1,009 (92.7% of those released) were detected\neither at or below our primary survival array 30 km downstream from Lower\nMonumental Dam. Of the 940 radio-tagged steelhead released into the tailrace of Lower\nMonumental Dam, 886 (94.3% of those released) were detected either at or below our\nprimary survival array 30 km downstream from Lower Monumental Dam. Capture\nhistories for survival analysis of juvenile steelhead are shown in Appendix Tables\nA6-A10.\nDetection probability for yearling Chinook salmon used in survival analysis was\n0.930 overall (Appendix Table A11), which was slightly lower than we have observed\npreviously. The detection probability for juvenile steelhead used in survival analysis was\nnear 100% (0.984 overall; Appendix Table A11), which is similar to detection probability\nobserved previously. Field testing of detection depth of radio transmitters at our entrance\nand survival arrays indicated tags were delectable to a depth of approximately 8 m;\nhowever, range from the receiving antenna decreased detection capability at depth.\n45","Beeman and Maule (2006) found that Chinook salmon smolts migrated at greater depths\nthan steelhead smolts. If Chinook salmon in 2008 were migrating at a greater depth than\njuvenile steelhead, they would likely have a slightly lower detection probability. In\ngeneral, detection probabilities were greater than 90% at our primary array, with few fish\ndetected downstream that were not detected at the primary array. With high detection\nprobabilities for all fish, there was likely no disparity between detection probabilities of\ntreatment and reference groups.\nAppendix Table A1. Detection histories of radio-tagged yearling Chinook salmon\nreleased above (treatment) and below (reference) Lower\nMonumental Dam to evaluate dam passage survival in 2008. The\nprimary survival array was 30 km downstream from the dam, and\ndetections downstream from the primary array are shown in\nFigure 1. Detection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array\nPost primary array\nn\nTreatment group (979)\n0\n0\n142\n1\n0\n16\n0\n1\n48\n1\n1\n773\nReference group (930)\n0\n0\n70\n1\n0\n16\n0\n1\n68\n1\n1\n776\n46","Appendix Table A2. Detection histories of radio-tagged yearling Chinook salmon\nreleased above (treatment) and below (reference) Lower\nMonumental Dam to evaluate concrete passage survival in 2008.\nThe primary survival array was 30 km downstream from the dam,\nand detections downstream from the primary array are shown in\nFigure 1. Detection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array\nPost primary array\nN\nTreatment group (907)\n0\n0\n107\n1\n0\n15\n0\n1\n45\n1\n1\n740\nReference group (930)\n0\n0\n70\n1\n0\n16\n0\n1\n68\n1\n1\n776\nAppendix Table A3. Detection histories of radio-tagged yearling Chinook salmon\nreleased above (treatment) and below (reference) Lower\nMonumental Dam to evaluate spillway passage survival in 2008.\nThe primary survival array was 30 km downstream from the dam,\nand detections downstream from the primary array are shown in\nFigure 1. Detection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array\nPost primary array\nn\nTreatment group (586)\n0\n0\n62\n1\n0\n10\n0\n1\n32\n1\n1\n482\nReference group (930)\n0\n0\n70\n1\n0\n16\n0\n1\n68\n1\n1\n776\n47","Appendix Table A4. Detection histories of radio-tagged yearling Chinook salmon\nreleased above (treatment) and below (reference) Lower\nMonumental Dam to evaluate JBS passage survival in 2008. The\nprimary survival array was 30 km downstream from the dam, and\ndetections downstream from the primary array are shown in\nFigure 1. Detection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array\nPost primary array\nn\nTreatment group (265)\n0\n0\n37\n1\n0\n4\n0\n1\n10\n1\n1\n214\nReference group (930)\n0\n0\n70\n1\n0\n16\n0\n1\n68\n1\n1\n776\nAppendix Table A5. Detection histories of radio-tagged yearling Chinook salmon\nreleased above (treatment) and below (reference) Lower\nMonumental Dam to evaluate RSW passage survival in 2008. The\nprimary survival array was 30 km downstream from the dam, and\ndetections downstream from the primary array are shown in\nFigure 1. Detection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array\nPost primary array\nn\nTreatment group (425)\n0\n0\n35\n1\n0\n8\n0\n1\n23\n1\n1\n359\nReference group (930)\n0\n0\n70\n1\n0\n16\n0\n1\n68\n1\n1\n776\n48","Appendix Table A6. Detection histories of radio-tagged juvenile steelhead released\nabove (treatment) and below (reference) Lower Monumental Dam\nto evaluate dam passage survival in 2008. The primary survival\narray was 30 km downstream from the dam and detections\ndownstream from the primary array are shown in Figure 1.\nDetection histories recorded as: 1, detected; 0, not detected.\nDetection history\nPrimary survival array Post primary array\nn\nTreatment group (1,088)\n0\n0\n79\n1\n0\n14\n0\n1\n18\n1\n1\n977\nReference group (940)\n0\n0\n54\n1\n0\n19\n0\n1\n11\n1\n1\n856\nAppendix Table A7. Detection histories of radio-tagged juvenile steelhead released\nabove (treatment) and below (reference) Lower Monumental Dam\nto evaluate concrete passage survival in 2008. The primary survival\narray was 30 km downstream from the dam and detections\ndownstream from the primary array are shown in Figure 1.\nDetection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array Post primary array\nn\nTreatment group (1,040)\n0\n0\n52\n1\n0\n13\n0\n1\n16\n1\n1\n959\nReference group (940)\n0\n0\n54\n1\n0\n19\n0\n1\n11\n1\n1\n856\n49","Appendix Table A8. Detection histories of radio-tagged juvenile steelhead released\nabove (treatment) and below (reference) Lower Monumental Dam\nto evaluate spillway passage survival in 2008. The primary survival\narray was 30 km downstream from the dam and detections\ndownstream from the primary array are shown in Figure 1.\nDetection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array\nPost primary array\nn\nTreatment group (851)\n0\n0\n38\n1\n0\n8\n0\n1\n11\n1\n1\n794\nReference group (940)\n0\n0\n54\n1\n0\n19\n0\n1\n11\n1\n1\n856\nAppendix Table A9. Detection histories of radio-tagged juvenile steelhead released\nabove (treatment) and below (reference) Lower Monumental Dam\nto evaluate JBS passage survival in 2008. The primary survival\narray was 30 km downstream from the dam and detections\ndownstream from the primary array are shown in Figure 1.\nDetection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array\nPost primary array\nn\nTreatment group (175)\n0\n0\n14\n1\n0\n6\n0\n1\n4\n1\n1\n151\nReference group (940)\n0\n0\n54\n1\n0\n19\n0\n1\n11\n1\n1\n856\n50","Appendix Table A10. Detection histories of radio-tagged juvenile steelhead released\nabove (treatment) and below (reference) Lower Monumental Dam\nto evaluate RSW passage survival in 2008. The primary survival\narray was 30 km downstream from the dam and detections\ndownstream from the primary array are shown in Figure 1.\nDetection histories are 1 = detected; 0 = not detected.\nDetection history\nPrimary survival array\nPost primary array\nn\nTreatment group (740)\n0\n0\n25\n1\n0\n8\n0\n1\n10\n1\n1\n697\nReference group (940)\n0\n0\n54\n1\n0\n19\n0\n1\n11\n1\n1\n856\nAppendix Table A11. Detections at the primary survival array and below, and the\nresulting detection probabilities at the primary survival array\n30 km downstream from the dam. These probabilities satisfied\nassumptions of the CJS model used in evaluating survival of\nyearling Chinook salmon and juvenile steelhead passing Lower\nMonumental Dam, 2008.\nDetection at primary\nDetection\nRelease group\narray or below\nbelow primary array\nDetection probability\nYearling Chinook salmon\nTreatment\n773\n821\n0.941\nReference\n776\n844\n0.919\nTotals\n1,549\n1,665\n0.930\nJuvenile steelhead\nTreatment\n977\n995\n0.982\nReference\n856\n867\n0.987\nTotals\n1833\n1,862\n0.984\n51","A2. Treatment and corresponding reference groups are evenly mixed and travel\ntogether through downstream reaches.\nThe difference in passage distribution of treatment and reference groups at the\nprimary survival array (30 km downstream from the dam) were examined to determine if\ngroups were evenly mixed and travel together through downstream reaches (Appendix\nTables A12 and A13). Mixing was compared for specific percentiles (10th, 50th, 90th)\nof the passage distribution with t tests for differences in passage distributions (Tables\nA14 and A15). For mixing analysis, the date of passage of treatment fish at Lower\nMonumental Dam was paired with the release date of reference fish.\nTests of homogeneity in passage distributions at the primary survival array\nshowed statistically significant differences for both species between treatment and\nreference groups used to calculate relative survival estimates (Appendix Tables A14 and\nA15). However the biological significance is small (-3.6 and -3.4 hours for yearling\nChinook salmon and steelhead, respectively), and is partly explained by the differential\npassage at Lower Monumental Dam of treatment (continuous) and control (systematically\nfor six hours in daylight and darkness). We concluded the overall survival estimates\nwere not biased regarding mixing through the common reach.\n52","Appendix Table A12. Differences in passage timing at the primary survival array (30 km\ndownstream from the dam) between treatment and reference\ngroups in hours for radio tagged hatchery yearling Chinook\nsalmon used for estimating survival at Lower Monumental Dam in\n2008. Standard errors are in parenthesis.\nPercentile\nDate\n10th\n50th\n90th\nn\n30\n-10.7\n-24.0\n-32.9\n30 Apr\n49\n-6.7\n-12.7\n-15.8\n1 May\n45\n17.3\n3.6\n22.3\n2 May\n62\n-2.6\n-2.1\n-19.6\n3 May\n68\n-5.7\n-1.1\n-1.6\n4 May\n60\n-2.6\n4.4\n-4.0\n5 May\n77\n-1.6\n-2.6\n-5.4\n6 May\n67\n0.1\n-3.3\n6.2\n7 May\n66\n-10.1\n-5.4\n-18.3\n8 May\n83\n-3.3\n-0.5\n5.8\n9 May\n79\n-2.9\n-3.5\n-17.0\n10 May\n76\n-2.7\n-0.7\n6.5\n11 May\n72\n4.1\n2.7\n-3.9\n12 May\n68\n-2.8\n-6.1\n0.5\n13 May\n86\n-5.8\n-6.6\n-20.8\n14 May\n71\n-3.5\n1.4\n-1.2\n15 May\n88\n-2.4\n-4.2\n-14.8\n16 May\n83\n-3.3\n-0.9\n1.2\n17 May\n79\n1.0\n-0.7\n-5.1\n18 May\n83\n0.6\n-4.2\n-5.1\n19 May\n94\n-0.7\n-4.0\n-3.3\n20 May\n85\n-1.5\n-2.7\n-4.3\n21 May\n86\n-6.2\n-8.7\n-12.2\n22 May\nMean\n-2.3 (1.1)\n-3.6 (1.2)\n-6.2 (2.4)\n53","Appendix Table A13. Differences in passage timing at the primary survival array (30 km\ndownstream from the dam) between treatment and reference\ngroups in hours for radio tagged juvenile steelhead used for\nestimating survival at Lower Monumental Dam in 2008.\nStandard errors are in parenthesis.\nPercentile\nDate\n10th\n50th\nn\n90th\n65\n-1.1\n-11.4\n1 May\n-3.0\n64\n1.9\n-4.2\n2 May\n0.0\n66\n0.3\n-0.6\n3 May\n-3.1\n85\n3.4\n-3.5\n4 May\n-14.3\n84\n-1.5\n0.0\n5 May\n-4.4\n102\n-5.3\n-2.8\n6 May\n-8.2\n86\n5.8\n1.5\n7 May\n0.1\n85\n2.6\n0.7\n8 May\n-4.9\n87\n4.3\n1.6\n9 May\n-1.5\n72\n1.4\n0.8\n10 May\n-2.9\n92\n0.9\n0.7\n11 May\n-5.1\n88\n0.7\n-8.7\n12 May\n-4.4\n71\n5.0\n-7.1\n13 May\n-5.3\n72\n2.3\n2.1\n14 May\n-1.7\n90\n-0.1\n-3.9\n15 May\n2.2\n93\n-0.8\n-1.3\n16 May\n-7.5\n87\n-0.4\n1.6\n17 May\n-5.9\n95\n1.2\n-4.6\n18 May\n-5.7\n92\n0.9\n-6.3\n19 May\n-7.9\n82\n1.9\n-2.3\n20 May\n-9.6\n86\n-2.3\n-6.7\n21 May\n-5.7\n72\n0.7\n-5.2\n-10.8\n22 May\nMean\n0.8 (0.6)\n-3.4 (1.1)\n-4.9 (0.8)\n54","Appendix Table A14. Mean difference and tests of homogeneity of passage timing at the\nprimary survival array (30 km downstream from the dam) for\ntreatment groups and reference groups of radio tagged hatchery\nyearling Chinook salmon used for estimating survival at Lower\nMonumental Dam in 2008. Significant differences in passage\ntiming among tests was determined for a = 0.05.\nPassage percentile\nMean difference in timing (hours)\ndf\nP\nt\n10th\n-2.3\n-1.99\n23\n0.059\n50th\n-3.6\n-2.88\n23\n0.008\n90th\n-6.2\n-2.55\n23\n0.018\nAppendix Table A15. Mean difference and tests of homogeneity of passage timing at the\nprimary survival array (30 km downstream from the dam) for\ntreatment groups and reference groups of radio tagged steelhead\nused for estimating survival at Lower Monumental Dam in 2008.\nSignificant differences in passage timing among tests was\ndetermined for a = 0.05.\nPassage percentile\nMean difference in timing (hours)\ndf\nP\nt\n10th\n0.8\n1.35\n23\n0.191\n50th\n-3.4\n-3.22\n23\n0.004\n90th\n-4.9\n-6.23\n23\n<0.000\n55","A3. Individuals tagged for the study are a representative sample of the population of\ninterest.\nRiver run, hatchery yearling Chinook salmon and juvenile steelhead were\ncollected at the Lower Monumental Dam smolt collection facility from 1 to 26 May.\nOnly fish not previously PIT tagged, without any visual signs of disease or injuries, and\n12 g or larger were used. Tagging comprised the period between the 3rd and 82nd passage\npercentile for yearling Chinook salmon and between the 2nd and 84th passage percentile\nfor juvenile steelhead at Lower Monumental Dam in 2008 (Figure 3). Overall mean fork\nlengths for yearling Chinook salmon were 141.9 mm (SD = 13.1) and 142.9 mm (SD =\n12.3) for fish released into the forebay and tailrace of Lower Monumental Dam,\nrespectively (Table 2). Overall mean fork lengths for juvenile steelhead were 206.1 mm\n(SD = 21.7) and 208.4 mm (SD = 21.8) for fish released into the forebay and tailrace of\nLower Monumental Dam, respectively (Table 4).\nA4. The tag and/or tagging method do not significantly affect the subsequent behavior\nor survival of the marked individual.\nAssumption A4 was not tested for validation in this study. However, the effects\nof radio tagging on survival, predation, growth, and swimming performance of juvenile\nsalmonids have previously been evaluated by Adams et al. (1998) and Hockersmith et al.\n(2003). Based on their conclusions, we assumed that behavior and survival were not\nsignificantly affected over the length of our study area.\nA5. Fish that die as a result of passing through a passage route are not subsequently\ndetected at a downstream array that is used to estimate survival for that passage\nroute.\nIn 2008, we conducted a very limited test of the assumption that fish that die as a\nresult of passing through a passage route are not subsequently detected at a downstream\narray that is used to estimate survival for that passage route because past studies at Lower\nMonumental Dam have not observed a violation of this assumption. We released 52 dead\nradio tagged hatchery yearling Chinook salmon and 33 dead juvenile steelhead into the\ntailrace of Little Goose Dam and the tailrace of Lower Monumental Dam to test\nAssumption A5 (Appendix Table A16). Forebay releases were 41 km upstream from the\nforebay entrance array. The distance between release at Lower Monumental Dam and the\nfirst downstream telemetry array used to estimate survival was 30 km. Similar to past\nfindings, no dead radio tagged fish were detected at any downstream telemetry arrays.\n56","Appendix Table A16. Numbers of dead fish released and subsequent detections\ndownstream from release locations. These releases were used to\ntest the study assumption that fish that die as a result of passing\nthrough a passage route at Lower Monumental Dam are not\nsubsequently detected on downstream survival arrays.\nDead fish releases\nJuvenile steelhead\nYearling Chinook salmon\nTreatment Reference\nOverall\nTreatment Reference\nOverall\nNumber released\n31\n21\n52\n21\n13\n33\nPercent of total released (%)\n3.2\n2.3\n2.7\n1.9\n1.4\n1.7\nNumber detected below release site\n0\n0\n0\n0\n0\n0\nA6. The radio transmitters functioned properly and for the predetermined period of\ntime.\nAll transmitters were checked upon receipt from the manufacturer, prior to\nimplantation into a fish and prior to release, to ensure that the transmitter was functioning\nproperly. Of 4,545 tags allocated for the evaluation of passage and survival at Lower\nMonumental Dam 9 (0.2%) could not be activated and were therefore not used. A total\nof 4,467 tags were implanted in either hatchery yearling Chinook salmon of juvenile\nsteelhead of which 2 (0.04%) were not working 24 h after tagging. An additional 28 tags\nwere not used in the study because of duplicate tag codes. Of the live fish released with\nfunctional tags, a total of 4 fish (0.1% of those released) (2 yearling Chinook salmon\nreleased upstream and 1 yearling Chinook salmon and 1 juvenile steelhead released\nbelow Lower Monumental Dam) were subsequently detected at downstream PIT tag\ndetection facilities and not detected on any radio telemetry arrays. The transmitters in\nthese fish likely malfunctioned. All fish with tags that were known to be not functioning\nproperly were excluded from the study.\nIn addition, a total of 69 radio transmitters throughout the study were tested for\ntag life by allowing them to run in river water and checking them daily to determine if\nthey functioned for the predetermined period of time. Ten tags (14.5%) failed prior to the\npreprogrammed shut down after 10 d (Appendix Table A17). Of these, no tags failed in\nless than 9 d. Ninety-nine percent of the fish had travel times to the primary array of less\nthan 9 d, and the maximum travel time from release to our primary survival array was\n13.4 d (Appendix Table A18). Although we documented transmitter failures during our\nstudy, the short travel times to our survival array and the relatively low failure rate were\nsuch that they would not have significantly changed our findings.\n57","Appendix Table A17. Transmitter battery life testing, 2008.\nTags (n)\nTags (%)\nBattery life (d)\n0\n0.0\n1\n0\n0.0\n2\n0\n0.0\n3\n0\n0.0\n4\n0\n0.0\n5\n0\n0.0\n6\n0\n0.0\n7\n0\n0.0\n8\n10\n14.5\n9\n59\n85.5\n10\nAppendix Table A18. Travel time from release to detection at the primary survival array\nfor radio tagged hatchery yearling Chinook salmon and juvenile\nsteelhead released into the forebay and tailrace of Lower\nMonumental Dam, 2008.\nTravel time (d) to primary survival array by release location and species\nYearling Chinook salmon\nJuvenile steelhead\nPercentile\nForebay\nTailrace\nForebay\nTailrace\n10\n1.7\n0.8\n1.6\n0.7\n20\n2.2\n1.1\n1.9\n0.9\n30\n2.6\n1.2\n2.1\n1.0\n40\n2.9\n1.4\n2.2\n1.1\n50\n3.2\n1.5\n2.5\n1.2\n60\n3.5\n1.7\n2.8\n1.3\n70\n3.9\n2.0\n3.0\n1.4\n80\n4.3\n2.3\n3.1\n1.5\n90\n5.1\n2.7\n3.6\n1.8\nMax\n13.4\n7.4\n13.3\n7.9\nTime > 9 d\n2 (0.2%)\n0 (0.0%)\n1 (0.1%)\n0 (0.0%)\n836\n858\n1,013\n887\nn\n58","APPENDIX B\nTreatment and Reference Release Groups for Estimating Survival\nAppendix Table B1. Daily dam survival estimates and replicate group sizes for yearling\nChinook salmon passing Lower Monumental Dam, 2008. Standard\nerrors are in parenthesis.\nTreatment\nReference\nRelative survival\nDate\nSurvival\nSurvival\nn\nn\n30 April\n11\n0.909 (0.087)\n24\n0.875 (0.068)\n1.039 (0.127)\n1 May\n22\n0.925 (0.065)\n33\n0.884 (0.058)\n1.047 (0.100)\n2 May\n16\n0.859 (0.112)\n35\n0.951 (0.040)\n0.903 (0.124)\n3 May\n35\n0.919 (0.048)\n36\n0.889 (0.052)\n1.033 (0.081)\n4 May\n49\n0.860 (0.050)\n34\n0.869 (0.063)\n0.990 (0.092)\n5 May\n39\n0.872 (0.054)\n35\n0.914 (0.047)\n0.954 (0.077)\n6 May\n62\n0.760 (0.055)\n42\n0.842 (0.059)\n0.903 (0.090)\n7 May\n38\n0.847 (0.060)\n43\n0.886 (0.049)\n0.956 (0.086)\n8 May\n42\n0.791 (0.064)\n39\n0.872 (0.054)\n0.907 (0.092)\n9 May\n51\n0.877 (0.050)\n43\n0.935 (0.039)\n0.938 (0.066)\n10 May\n47\n0.791 (0.060)\n44\n0.987 (0.024)\n0.801 (0.064)\n11 May\n46\n0.828 (0.056)\n41\n0.978 (0.024)\n0.847 (0.061)\n12 May\n38\n0.790 (0.066)\n43\n0.978 (0.023)\n0.808 (0.070)\n13 May\n33\n0.758 (0.075)\n46\n0.935 (0.036)\n0.810 (0.086)\n14 May\n63\n0.778 (0.052)\n44\n0.865 (0.052)\n0.899 (0.081)\n15 May\n37\n0.811 (0.064)\n44\n0.934 (0.038)\n0.868 (0.078)\n16 May\n54\n0.870 (0.046)\n45\n0.936 (0.037)\n0.930 (0.061)\n17 May\n48\n0.917 (0.040)\n43\n0.939 (0.040)\n0.977 (0.059)\n18 May\n50\n0.881 (0.046)\n41\n0.902 (0.046)\n0.976 (0.071)\n19 May\n44\n0.932 (0.038)\n45\n0.956 (0.031)\n0.975 (0.051)\n20 May\n61\n0.918 (0.035)\n41\n0.951 (0.034)\n0.965 (0.050)\n21 May\n45\n0.956 (0.031)\n44\n0.955 (0.031)\n1.001 (0.046)\n22 May\n48\n0.938 (0.035)\n45\n0.9111(0.0424)\n1.028 (0.061)\nOverall\n979\n0.860 (0.013)\n930\n0.919 (0.009)\n0.934 (0.016)\n59","Appendix Table B2. Daily concrete survival estimates and replicate group sizes for\nyearling Chinook salmon passing Lower Monumental Dam, 2008.\nStandard errors are in parenthesis.\nTreatment\nReference\nDate\nSurvival\nN\nSurvival\nn\nRelative survival\n30 April\n10\n0.900 (0.095)\n24\n0.875 (0.068)\n1.029 (0.134)\n1 May\n21\n0.969 (0.051)\n33\n0.884 (0.058)\n1.097 (0.092)\n2 May\n14\n0.884 (0.101)\n35\n0.951 (0.040)\n0.929 (0.114)\n3 May\n33\n0.914 (0.051)\n36\n0.889 (0.052)\n1.028 (0.083)\n4 May\n44\n0.867 (0.052)\n34\n0.869 (0.063)\n0.998 (0.094)\n5 May\n32\n0.875 (0.059)\n35\n0.914 (0.047)\n0.957 (0.081)\n6 May\n52\n0.790 (0.057)\n42\n0.842 (0.059)\n0.938 (0.094)\n7 May\n32\n0.913 (0.052)\n43\n0.886 (0.049)\n1.031 (0.082)\n8 May\n34\n0.919 (0.049)\n39\n0.872 (0.054)\n1.054 (0.086)\n9 May\n50\n0.872 (0.050)\n43\n0.935 (0.039)\n0.932 (0.067)\n10 May\n43\n0.841 (0.057)\n44\n0.987 (0.024)\n0.852 (0.061)\n11 May\n42\n0.859 (0.054)\n41\n0.978 (0.024)\n0.878 (0.059)\n12 May\n36\n0.834 (0.062)\n43\n0.978 (0.023)\n0.853 (0.067)\n13 May\n33\n0.758 (0.075)\n46\n0.935 (0.036)\n0.810 (0.086)\n14 May\n60\n0.800 (0.052)\n44\n0.865 (0.052)\n0.925 (0.081)\n15 May\n37\n0.811 (0.064)\n44\n0.934 (0.038)\n0.868 (0.078)\n16 May\n53\n0.868 (0.047)\n45\n0.936 (0.037)\n0.928 (0.062)\n17 May\n46\n0.935 (0.036)\n43\n0.939 (0.040)\n0.996 (0.057)\n18 May\n45\n0.934 (0.037)\n41\n0.902 (0.046)\n1.035 (0.067)\n19 May\n41\n0.976 (0.024)\n45\n0.956 (0.031)\n1.020 (0.041)\n20 May\n57\n0.947 (0.030)\n41\n0.951 (0.034)\n0.996 (0.047)\n21 May\n44\n0.977 (0.023)\n44\n0.955 (0.031)\n1.024 (0.041)\n22 May\n48\n0.938 (0.035)\n45\n0.9111(0.0424)\n1.029 (0.061)\nOverall\n907\n0.886 (0.013)\n930\n0.919 (0.009)\n0.963 (0.016)\n60","Appendix Table B3. Daily spillway survival estimates and replicate group sizes for\nyearling Chinook salmon passing Lower Monumental Dam, 2008.\nStandard errors are in parenthesis.\nTreatment\nReference\nSurvival\nSurvival\nRelative survival\nDate\nn\nn\n30 April\n7\n0.857 (0.132)\n24\n0.875 (0.068)\n0.980 (0.169)\n1.032 (0.036)\n33\n0.884 (0.058)\n1.167 (0.086)\n1 May\n14\n2 May\n11\n0.955 (0.106)\n35\n0.951 (0.040)\n1.003 (0.119)\n0.897 (0.062)\n36\n0.889 (0.052)\n1.009 (0.091)\n3 May\n27\n0.869 (0.063)\n1.034 (0.095)\n4 May\n38\n0.899 (0.050)\n34\n0.846 (0.071)\n35\n0.914 (0.047)\n0.926 (0.091)\n5 May\n26\n6 May\n29\n0.831 (0.071)\n42\n0.842 (0.059)\n0.987 (0.108)\n0.864 (0.073)\n43\n0.886 (0.049)\n0.975 (0.099)\n7 May\n22\n0.872 (0.054)\n1.099 (0.086)\n8 May\n21\n0.958 (0.047)\n39\n43\n0.935 (0.039)\n0.933 (0.075)\n9 May\n31\n0.872 (0.060)\n0.896 (0.065)\n44\n0.987 (0.024)\n0.908 (0.069)\n10 May\n26\n11 May\n26\n0.885 (0.063)\n41\n0.978 (0.024)\n0.905 (0.068)\n0.978 (0.023)\n0.837 (0.086)\n12 May\n22\n0.818 (0.082)\n43\n46\n0.935 (0.036)\n0.815 (0.104)\n13 May\n21\n0.762 (0.093)\n0.861 (0.053)\n44\n0.865 (0.052)\n0.995 (0.085)\n14 May\n43\n15 May\n28\n0.893 (0.059)\n44\n0.934 (0.038)\n0.956 (0.074)\n0.896 (0.044)\n0.957 (0.061)\n16 May\n48\n45\n0.936 (0.037)\n17 May\n34\n0.971 (0.029)\n43\n0.939 (0.040)\n1.034 (0.054)\n0.864 (0.073)\n41\n0.902 (0.046)\n0.957 (0.095)\n18 May\n22\n19 May\n23\n0.957 (0.043)\n45\n0.956 (0.031)\n1.000 (0.055)\n1.000 (0.000)\n1.051 (0.037)\n20 May\n22\n41\n0.951 (0.034)\n0.955 (0.031)\n1.007 (0.052)\n21 May\n26\n0.962 (0.038)\n44\n22 May\n19\n0.895 (0.070)\n45\n0.9111(0.0424)\n0.982 (0.090)\nOverall\n586\n0.899 (0.013)\n930\n0.919 (0.009)\n0.976 (0.016)\n61","Appendix Table B4. Daily estimates of survival through the RSW in Spillbay 8 for\nyearling Chinook salmon passing Lower Monumental Dam, 2008.\nStandard errors are in parenthesis.\nTreatment\nReference\nRelative survival\nDate\nN\nSurvival\nSurvival\nn\n30 April\n4\n1.000 (0.000)\n24\n0.875 (0.068)\n1.143 (0.088)\n1 May\n13\n1.039 (0.044)\n33\n0.884 (0.058)\n1.175 (0.091)\n2 May\n8\n0.938 (0.148)\n35\n0.951 (0.040)\n0.985 (0.161)\n3 May\n20\n0.900 (0.067)\n36\n0.889 (0.052)\n1.012 (0.096)\n4 May\n26\n0.853 (0.072)\n34\n0.869 (0.063)\n0.981 (0.109)\n5 May\n19\n0.895 (0.070)\n35\n0.914 (0.047)\n0.979 (0.092)\n6 May\n24\n0.877 (0.068)\n42\n0.842 (0.059)\n1.042 (0.108)\n7 May\n13\n0.923 (0.074)\n43\n0.886 (0.049)\n1.042 (0.101)\n8 May\n20\n1.006 (0.007)\n39\n0.872 (0.054)\n1.154 (0.071)\n9 May\n30\n0.901 (0.055)\n43\n0.935 (0.039)\n0.964 (0.071)\n10 May\n21\n0.952 (0.047)\n44\n0.987 (0.024)\n0.965 (0.053)\n11 May\n18\n0.833 (0.088)\n41\n0.978 (0.024)\n0.852 (0.092)\n12 May\n17\n0.882 (0.078)\n43\n0.978 (0.023)\n0.902 (0.083)\n13 May\n14\n0.857 (0.094)\n46\n0.935 (0.036)\n0.916 (0.106)\n14 May\n32\n0.844 (0.064)\n44\n0.865 (0.052)\n0.976 (0.094)\n15 May\n26\n0.923 (0.052)\n44\n0.934 (0.038)\n0.988 (0.069)\n16 May\n36\n0.917 (0.046)\n45\n0.936 (0.037)\n0.980 (0.063)\n17 May\n24\n0.958 (0.041)\n43\n0.939 (0.040)\n1.021 (0.061)\n18 May\n14\n0.929 (0.069)\n41\n0.902 (0.046)\n1.029 (0.093)\n19 May\n10\n1.000 (0.000)\n45\n0.956 (0.031)\n1.046 (0.034)\n20 May\n10\n1.000 (0.000)\n41\n0.951 (0.034)\n1.051 (0.037)\n21 May\n17\n1.000 (0.000)\n44\n0.955 (0.031)\n1.048 (0.034)\n22 May\n9\n1.000 (0.000)\n45\n0.9111(0.0424)\n1.098 (0.051)\nOverall\n425\n0.932 (0.013)\n930\n0.919 (0.009)\n1.012 (0.016)\n62","Appendix Table B5. Grouping, samples sizes, and estimated dam survival for juvenile\nsteelhead passing Lower Monumental Dam, 2008. Standard errors\nare in parenthesis.\nTreatment\nReference\nSurvival\nRelative survival\nDate\nN\nSurvival\nn\n30 Apr\n36\n0.973 (0.027)\n29\n0.966 (0.034)\n1.008 (0.045)\n0.944 (0.038)\n1 May\n36\n34\n0.912 (0.049)\n1.036 (0.069)\n2 May\n35\n0.972 (0.028)\n32\n0.938 (0.043)\n1.037 (0.056)\n0.892 (0.051)\n3 May\n37\n36\n0.972 (0.027)\n0.917 (0.058)\n0.946 (0.037)\n4 May\n56\n0.893 (0.041)\n37\n0.944 (0.057)\n5 May\n61\n0.967 (0.023)\n33\n0.939 (0.042)\n1.030 (0.052)\n6 May\n61\n0.969 (0.023)\n45\n0.978 (0.022)\n0.991 (0.032)\n7 May\n46\n0.935 (0.036)\n45\n0.981 (0.022)\n0.953 (0.043)\n8 May\n56\n0.875 (0.044)\n46\n0.935 (0.036)\n0.936 (0.060)\n9 May\n47\n0.957 (0.029)\n43\n0.954 (0.032)\n1.004 (0.046)\n10 May\n36\n0.917 (0.046)\n42\n0.929 (0.040)\n0.987 (0.065)\n11 May\n61\n0.803 (0.051)\n45\n0.935 (0.037)\n0.859 (0.064)\n12 May\n49\n0.920 (0.039)\n45\n0.979 (0.022)\n0.940 (0.045)\n13 May\n37\n0.892 (0.051)\n44\n0.886 (0.048)\n1.006 (0.079)\n14 May\n40\n0.825 (0.060)\n44\n0.886 (0.048)\n0.931 (0.084)\n15 May\n50\n0.940 (0.034)\n45\n0.957 (0.031)\n0.983 (0.047)\n16 May\n53\n0.962 (0.026)\n43\n0.954 (0.032)\n1.009 (0.044)\n0.978 (0.022)\n17 May\n47\n0.915 (0.041)\n45\n0.936 (0.047)\n18 May\n55\n0.982 (0.018)\n44\n0.932 (0.038)\n1.053 (0.047)\n19 May\n59\n0.952 (0.029)\n40\n0.902 (0.048)\n1.056 (0.064)\n0.959 (0.028)\n1.069 (0.066)\n20 May\n49\n39\n0.897 (0.049)\n0.978 (0.023)\n21 May\n44\n0.955 (0.031)\n44\n0.976 (0.039)\n22 May\n37\n0.919 (0.045)\n40\n0.950 (0.035)\n0.967 (0.059)\nOverall\n1,088\n0.927 (0. 010)\n940\n0.943 (0.006)\n0.982 (0.011)\n63","Appendix Table B6. Grouping, samples sizes, and estimated concrete survival for\njuvenile steelhead passing Lower Monumental Dam, 2008.\nStandard errors are in parenthesis.\nTreatment\nReference\nDate\nN\nSurvival\nSurvival\nRelative survival\nn\n30 Apr\n36\n0.973 (0.027)\n29\n0.966 (0.034)\n1.008 (0.045)\n1 May\n35\n0.971 (0.028)\n34\n0.912 (0.049)\n1.065 (0.065)\n2 May\n34\n1.001 (0.001)\n32\n0.938 (0.043)\n1.068 (0.049)\n3 May\n34\n0.912 (0.049)\n36\n0.972 (0.027)\n0.938 (0.057)\n4 May\n55\n0.891 (0.042)\n37\n0.946 (0.037)\n0.942 (0.058)\n5 May\n55\n0.964 (0.025)\n33\n0.939 (0.042)\n1.026 (0.053)\n6 May\n59\n0.985 (0.017)\n45\n0.978 (0.022)\n1.007 (0.029)\n7 May\n43\n0.954 (0.032)\n45\n0.981 (0.022)\n0.972 (0.039)\n8 May\n47\n0.894 (0.045)\n46\n0.935 (0.036)\n0.956 (0.061)\n9 May\n47\n0.957 (0.029)\n43\n0.954 (0.032)\n1.004 (0.046)\n10 May\n35\n0.943 (0.039)\n42\n0.929 (0.040)\n1.015 (0.061)\n11 May\n55\n0.891 (0.042)\n45\n0.935 (0.037)\n0.953 (0.059)\n12 May\n48\n0.918 (0.040)\n45\n0.979 (0.022)\n0.938 (0.046)\n13 May\n35\n0.914 (0.047)\n44\n0.886 (0.048)\n1.031 (0.077)\n14 May\n37\n0.892 (0.051)\n44\n0.886 (0.048)\n1.006 (0.079)\n15 May\n48\n0.979 (0.021)\n45\n0.957 (0.031)\n1.024 (0.039)\n16 May\n53\n0.962 (0.026)\n43\n0.954 (0.032)\n1.009 (0.044)\n17 May\n45\n0.956 (0.031)\n45\n0.978 (0.022)\n0.977 (0.038)\n18 May\n54\n1.000 (0.001)\n44\n0.932 (0.038)\n1.073 (0.044)\n19 May\n57\n0.985 (0.018)\n40\n0.902 (0.048)\n1.093 (0.061)\n20 May\n49\n0.959 (0.028)\n39\n0.897 (0.049)\n1.069 (0.066)\n21 May\n43\n0.977 (0.023)\n44\n0.978 (0.023)\n0.999 (0.033)\n22 May\n36\n0.944 (0.038)\n40\n0.950 (0.035)\n0.994 (0.054)\nOverall\n1,040\n0.949 (0.007)\n940\n0.943 (0.006)\n1.006 (0.052)\n64","Appendix Table B7. Grouping, samples sizes, and estimated spillway survival for\njuvenile steelhead passing Lower Monumental Dam, 2008.\nStandard errors are in parenthesis.\nTreatment\nReference\nRelative survival\nDate\nN\nSurvival\nSurvival\nn\n30 Apr\n33\n0.970 (0.030)\n29\n0.966 (0.034)\n1.004 (0.047)\n1 May\n32\n0.969 (0.031)\n34\n0.912 (0.049)\n1.063 (0.066)\n2 May\n31\n1.000 (0.000)\n32\n0.938 (0.043)\n1.067 (0.049)\n3 May\n31\n0.936 (0.044)\n36\n0.972 (0.027)\n0.962 (0.053)\n4 May\n54\n0.889 (0.043)\n37\n0.946 (0.037)\n0.940 (0.058)\n5 May\n51\n0.980 (0.019)\n33\n0.939 (0.042)\n1.044 (0.051)\n6 May\n53\n0.983 (0.019)\n45\n0.978 (0.022)\n1.005 (0.030)\n7 May\n35\n0.971 (0.028)\n45\n0.981 (0.022)\n0.991 (0.037)\n8 May\n42\n0.881 (0.050)\n46\n0.935 (0.036)\n0.942 (0.065)\n9 May\n37\n0.946 (0.037)\n43\n0.954 (0.032)\n0.992 (0.051)\n10 May\n29\n0.931 (0.047)\n42\n0.929 (0.040)\n1.003 (0.066)\n11 May\n46\n0.891 (0.046)\n45\n0.935 (0.037)\n0.953 (0.062)\n12 May\n41\n0.953 (0.034)\n45\n0.979 (0.022)\n0.973 (0.041)\n13 May\n25\n1.000 (0.000)\n44\n0.886 (0.048)\n1.128 (0.061)\n14 May\n28\n0.929 (0.049)\n44\n0.886 (0.048)\n1.048 (0.079)\n15 May\n43\n0.977 (0.023)\n45\n0.957 (0.031)\n1.021 (0.041)\n16 May\n50\n0.960 (0.028)\n43\n0.954 (0.032)\n1.007 (0.045)\n17 May\n35\n1.000 (0.000)\n45\n0.978 (0.022)\n1.023 (0.023)\n18 May\n44\n1.001 (0.001)\n44\n0.932 (0.038)\n1.073 (0.044)\n19 May\n39\n0.977 (0.026)\n40\n0.902 (0.048)\n1.084 (0.064)\n20 May\n33\n1.000 (0.000)\n39\n0.897 (0.049)\n1.114 (0.060)\n21 May\n21\n0.952 (0.047)\n44\n0.978 (0.023)\n0.974 (0.053)\n22 May\n18\n0.889 (0.074)\n40\n0.950 (0.035)\n0.936 (0.085)\nOverall\n851\n0.956 (0.008)\n940\n0.943 (0.006)\n1.014 (0.011)\n65","Appendix Table B8. Grouping, samples sizes, and estimated survival for juvenile\nsteelhead passing Lower Monumental Dam via the RSW in\nSpillbay 8, 2008. Standard errors are in parenthesis.\nTreatment\nReference\nRelative survival\nDate\nN\nSurvival\nSurvival\nn\n30 Apr\n31\n1.000 (0.000)\n29\n0.966 (0.034)\n1.036 (0.036)\n1 May\n30\n0.967 (0.033)\n34\n0.912 (0.049)\n1.060 (0.067)\n2 May\n25\n1.000 (0.000)\n32\n0.938 (0.043)\n1.067 (0.049)\n3 May\n25\n0.920 (0.054)\n36\n0.972 (0.027)\n0.946 (0.062)\n4 May\n48\n0.896 (0.044)\n37\n0.946 (0.037)\n0.947 (0.060)\n5 May\n46\n0.978 (0.022)\n33\n0.939 (0.042)\n1.041 (0.051)\n6 May\n48\n1.002 (0.002)\n45\n0.978 (0.022)\n1.025 (0.023)\n7 May\n31\n0.968 (0.032)\n45\n0.981 (0.022)\n0.987 (0.039)\n8 May\n38\n0.868 (0.055)\n46\n0.935 (0.036)\n0.929 (0.069)\n9 May\n36\n0.944 (0.038)\n43\n0.954 (0.032)\n0.990 (0.052)\n10 May\n26\n0.962 (0.038)\n42\n0.929 (0.040)\n1.035 (0.060)\n11 May\n41\n0.951 (0.034)\n45\n0.935 (0.037)\n1.017 (0.054)\n12 May\n37\n1.000 (0.000)\n45\n0.979 (0.022)\n1.022 (0.023)\n13 May\n21\n1.000 (0.000)\n44\n0.886 (0.048)\n1.128 (0.061)\n14 May\n28\n0.929 (0.049)\n44\n0.886 (0.048)\n1.048 (0.079)\n15 May\n41\n1.000 (0.000)\n45\n0.957 (0.031)\n1.045 (0.034)\n16 May\n41\n0.976 (0.024)\n43\n0.954 (0.032)\n1.023 (0.043)\n17 May\n32\n1.000 (0.000)\n45\n0.978 (0.022)\n1.023 (0.023)\n18 May\n39\n1.001 (0.001)\n44\n0.932 (0.038)\n1.073 (0.044)\n19 May\n29\n0.971 (0.035)\n40\n0.902 (0.048)\n1.077 (0.069)\n20 May\n20\n1.000 (0.000)\n39\n0.897 (0.049)\n1.114 (0.060)\n21 May\n15\n1.000 (0.000)\n44\n0.978 (0.023)\n1.023 (0.024)\n22 May\n12\n0.917 (0.080)\n40\n0.950 (0.035)\n0.965 (0.091)\nOverall\n740\n0.967 (0.008)\n940\n0.943 (0.006)\n1.026 (0.011)\n66","Appendix Table B9. Planned treatment operations for spring 2008 at Lower Monumental\nDam of a 4-d random block schedule with each pattern operated for\n2 d. The operational treatment included two spill patterns (flat and\nbulk spill patterns) with both treatments utilizing the RSW. In\ngeneral, the maximum difference in gate openings for spillbays 1\nthough 6 was less than 2 stops during the flat spill pattern and more\nthan 2 stops for the bulk spill pattern.\nBlock\nTreatment\nStart\nEnd\nDuration (days)\n1\nBulk spill\n27 April 0500\n29 April 0459\n2.0\n1\nFlat spill\n29 April 0500\n1 May 0459\n2.0\n2\nBulk spill\n1 May 0500\n3 May 0459\n2.0\n2\nFlat spill\n3 May 0500\n5 May 0459\n2.0\n3\nBulk spill\n5 May 0500\n7 May 0459\n2.0\n3\nFlat spill\n7 May 0500\n9 May 0459\n2.0\n4\nBulk spill\n9 May 0500\n11 May 0459\n2.0\n4\nFlat spill\n11 May 0500\n13 May 0459\n2.0\nFlat spill\n5\n13 May 0500\n15 May 0459\n2.0\n5\nBulk spill\n15 May 0500\n17 May 0459\n2.0\n6\nFlat spill\n17 May 0500\n19 May 0459\n2.0\n6\nBulk spill\n19 May 0500\n21 May 0459\n2.0\n7\nBulk spill\n21 May 0500\n23 May 0459\n2.0\n7\nFlat spill\n23 May 0500\n25 May 0459\n2.0\n8\nBulk spill\n25 May 0500\n27 May 0459\n2.0\n8\nFlat spill\n27 May 0500\n29 May 0459\n2.0\nFlat spill\n9\n29 May 0500\n31 May 0459\n2.0\n9\nBulk spill\n31 May 0500\n2 June 0459\n2.0\n67","Appendix Table B10. Actual treatment operations for spring 2008 at Lower Monumental\nDam. The treatments utilized two spill patterns (flat and bulk spill\npatterns) with both treatments utilizing the RSW.\nDuration\nTreatment\nStart\nEnd\n(d)\nDeviation from scheduled plan\nBulk spill\n27 April 0500\n30 April 0605\n3.0\nTreatment 1 d long\nFlat spill\n30 April 0605\n2 May 0555\n2.0\nIncluded unscheduled bulk spill for 1.5 h\nBulk spill\n2 May 0555\n4 May 0650\n2.0\nFlat spill\n4 May 0650\n6 May 0540\n1.9\nBulk spill\n6 May 0540\n8 May 0600\n2.0\nFlat spill\n8 May 0600\n10 May 0600\n2.0\nFlat spill\n10 May 0600\n12 May 0635\n2.0\nBulk spill\n12 May 0635\n14 May 0550\n2.0\nFlat spill\n14 May 0550\n16 May 0645\n2.0\nIncluded unscheduled bulk spill for 1 h\nTreatment 1 d long and included\nBulk spill\n16 May 0645\n19 May 0720\n3.0\nunscheduled flat spill for 2.5 h\nTreatment 1.7 d long and included\nFlat spill\n19 May 0720\n22 May 2335\n3.7\nunscheduled bulk spill for 2 h\nBulk spill\n22 May 2335\n24 May 0110\n1.1\nTreatment 0.9 d short\nFlat spill\n24 May 0110\n26 May 0335\n2.1\nFlat spill\n26 May 0335\n28 May 0600\n2.1\nBulk spill\n28 May 0600\n30 May 0100\n1.8\nIncluded unscheduled flat spill for 5 h\nBulk spill\n30 May 0100\n31 May 2355\n2.0\nIncluded unscheduled flat spill for 5 h\n68","APPENDIX C: Telemetry Data Processing and Reduction\nData Collection and Storage\nData from radio telemetry studies are stored in the Juvenile Salmon Radio\nTelemetry project, an interactive database maintained by staff of the Fish Ecology\nDivision at the NOAA Fisheries Northwest Fisheries Science Center. This project tracks\nmigration routes and passage of juvenile salmon and steelhead past dams within the\nColumbia and Snake Rivers using a network of radio receivers to record signals emitted\nfrom radio transmitters (\"tags\") implanted into the fish. Special emphasis is placed on\nroutes of passage and on survival for individual routes at hydroelectric dams on the lower\nColumbia and Snake Rivers. The database includes observations of tagged fish and the\nlocations and configurations of radio receivers and antennas.\nThe majority of data supplied to the database are observations of tagged fish\nrecorded at the various radio receivers, which the receivers store in hexadecimal format.\nThe files are saved to a central computer four times daily and placed on an FTP server\nautomatically once per day for downloading into the database.\nIn addition, data in the form of daily updated tagging files were collected. These\nfiles contain the attributes of each fish tagged, along with the channel and code of the\ntransmitter used and the date, time, and location of release after tagging.\nData are consolidated into blocks in a summary form that lists each fish and the\nreceiver on which it was detected. This summary includes the specific time of the first\nand last detection and the total number of detections in each block, with individual blocks\ndefined as sequential detections having no more than a 5 min gap between detections.\nThese summarized data were used for analyses.\nThe processes in this database fall into three main categories or stages in the flow\nof data from input to output: loading, validation, and summarization. These are\nexplained below and summarized in Appendix Figure C1.\nThe loading process consists of copying data files from their initial locations to\nthe database server, converting the files from their original format into a format readable\nby SQL, and having SQL read the files and stores the data in preliminary tables.\n69","Data Validation\nDuring the validation process, the records stored in the preliminary tables are\nanalyzed. We determine the study year, site identifier, antenna identifier, and tag\nidentifier for each record, flagging them as invalid if one or more of these identifiers\ncannot be determined. Records are flagged by storing brief comments in the edit notes\nfield. Values of edit notes associated with each record are as follows:\nNull: denotes a valid observation of a tag\nNot Tagged: denotes an observation of a channel code combination that was not in use at\nthe time. Such values are likely due to radio frequency noise being picked up at an\nantenna.\nNoise Record: denotes an observation where the code is equal to 995, 997, or 999.\nThese are not valid records, and relate to radio frequency noise being picked up at\nthe antenna.\nBeacon Record: hits recorded on channel = 5, code = 575, which indicate a beacon being\nused to ensure proper functioning of the receivers. This combination does not\nindicate the presence of a tagged fish.\nInvalid Record Date: denotes an observation whose date/time is invalid (occurring before\nwe started the database, i.e., prior to 1 January 2004, or some time in the future).\nDue to improvements in the data loading process, such records are unlikely to arise.\nInvalid Site: denotes an observation attributed to an invalid (non existent) site. These are\ntypically caused by typographical errors in naming hex files at the receiver end.\nThey should not be present in the database, since they should be filtered out during\nthe data loading process.\nInvalid Antenna: Denotes an observation attributed to an invalid (non existent) antenna.\nThese are most likely due to electronic noise within the receiver.\nLt start time: Assigned to records occurring prior to the time a tag was activated (its start\ntime). Note: these records are produced by radio frequency noise.\nGt end time: Assigned to records occurring after the end time on a tag (tags run for 10 d\nonce activated). Note: these records are produced by radio frequency noise.\n70","In addition, duplicate records (records for which the channel, code, site, antenna,\ndate and time are the same as those of another record) are considered invalid. Finally, the\nrecords are copied from the preliminary tables into the appropriate storage table based on\nstudy year. The database can accommodate multiple years with differing sites and\nantenna configurations. Once a record's study year has been determined, its study year,\nsite, and antenna are used to match it to a record in the sites table.\nGeneration of the Summary Tables\nThe summary table summarizes the first detection, last detection, and count of\ndetections for blocks of records within a site for a single fish where no two consecutive\nrecords are separated by more than a specified number of minutes (currently using\n5 min).\n71","Determine values for\nFTP data from receivers--Uses\n'Edit Notes' field\nTracker software - 4 times daily\nConvert data from\nhexadecimal to ASCII text\nRemove duplicate records\nLoad records into a temporary table in\nInsert records into a permanent table in\nthe Oracle database\nthe Oracle database\nFish N\nFish 2\nFish 1\nDivide records for each fish into blocks (where no 2 records\nare separated by more than 5 min)\nRemove blocks that have too few records\n(threshold depends on the particular site) - these\nare likely noise records\nSummarize data in each block by inserting the first record, last\nrecord, and count of records into a summary table\nAppendix Figure C1. Flowchart of telemetry data processing and reduction used in\nevaluating behavior and survival at Lower Monumental Dam for\nyearling Chinook salmon, 2008.\n72"]}