{"Bibliographic":{"Title":"Descaling and orifice passage efficiency studies at McNary Dam, 1995","Authors":"","Publication date":"1997","Publisher":""},"Administrative":{"Date created":"08-16-2023","Language":"English","Rights":"CC 0","Size":"0000055697"},"Pages":["SH153\n.Mc25\nDescaling and\norifice passage\nefficiency studies\nat McNary Dam,\nCZES\n1995\nCoastal Zone and\nEstuarine Studies\nby\nDivision\nR. Lynn McComas, Benjamin P. Sandford,\nand Douglas B. Dey\nNorthwest Fisheries\nScience Center\nFebruary 1997\nNational Marine\nFisheries Service\nSeattle, Washington\nLibrary\nNorthwest\nFisheries\n2725 Montlake Boulevaid Science E.\nCenter\nSeattle,\nWA\n98112","NWFSC 117\nSH\n153\nDESCALING AND ORIFICE PASSAGE\nMc25\nEFFICIENCY STUDIES AT MCNARY DAM, 1995\n1995\nby\nR. Lynn McComas\nBenjamin P. Sandford\nand\nDouglas B. Dey\nReport of Research\nFunded by\nU.S. Army Corps of Engineers\nWalla Walla District\nDelivery Order E86910060\nand\nCoastal Zone and Estuarine Studies Division\nNorthwest Fisheries Science Center\nNational Marine Fisheries Service\nNational Oceanic and Atmospheric Administration\n2725 Montlake Boulevard East\nSeattle, Washington 98112-2097\nFebruary 1997","","CONTENTS\nPage\nEXECUTIVE SUMMARY\nvii\nINTRODUCTION\n1\nOBJECTIVE 1: EVALUATE THE EFFECTS OF TWO ALTERNATIVE BEAM\nEXTENSION DESIGNS (WITH NEWLY DESIGNED VERTICAL\nBARRIER SCREEN SYSTEMS, EXTENDED-LENGTH BAR SCREEN,\nAND INLET FLOW VANE) ON DESCALING FOR YEARLING\nAND SUBYEARLING CHINOOK SALMON\n5\n5\nApproach\nResults and Discussion\n8\n8\nSpring Outmigration\nSummer Outmigration\n8\nOBJECTIVE 2: EVALUATE YEARLING AND SUBYEARLING CHINOOK SALMON\nORIFICE PASSAGE EFFICIENCY (WITH NEWLY DESIGNED\nVERTICAL BARRIER SCREEN, EXTENDED-LENGTH BAR\nSCREEN, AND INLET FLOW VANE)\n9\n9\nApproach\n9\nOrifice Trap\nMark/Recapture Method\n11\n13\nResults and Discussion\n13\nSpring Outmigration\n14\nSummer Outmigration","","OBJECTIVE 3: COMPARE ORIFICE TRAP AND MARK/RECAPTURE\nMETHODS OF ESTIMATING ORIFICE PASSAGE\nEFFICIENCY FOR YEARLING AND SUBYEARLING\nCHINOOK SALMON\n16\nApproach\n16\nResults and Discussion\n16\nSpring Outmigration\n16\nSummer Outmigration\n16\nSUMMARY\n17\nACKNOWLEDGMENTS\n19\nREFERENCES\n20\nAPPENDIX\n22","","vii\nEXECUTIVE SUMMARY\nExtended-length submersible bar screens (ESBSs) have been tested at McNary Dam since\n1991 as alternatives to standard-length submersible traveling screens (STSs) for guiding downstream\nmigrating juvenile salmonids out of turbine intakes. During the 1995 spring and summer\noutmigration periods, the National Marine Fisheries Service conducted studies to evaluate the gatewell\norifice passage efficiency (OPE) for chinook salmon and steelhead using an ESBS with a newly\ndesigned vertical barrier screen and an inlet flow vane. An auxiliary study compared juvenile fish\ndescaling associated with two beam extension modifications in gatewells equipped with these new\nguidance devices.\nTwo methods were used to compare OPE between north and south orifices for each of the\noutmigration periods. First, orifice traps provided an absolute measure of the proportion of migrants\npassing through the test slot during a 22-hour period. Second, a mark/recapture method furnished an\nestimate of marked chinook salmon egress from the gatewell over 22 hours. Mean orifice passage\nefficiency was > 70% (range: 43-100%) for all salmonids using either method. Mark/recapture OPE\nestimates were significantly higher than orifice trap estimates for both yearling and subyearling\nchinook salmon.\nThere was no significant difference in OPE between north and south orifices for either\nyearling or subyearling chinook salmon using orifice traps, or for yearling chinook salmon using the\nmark/recapture method.\nThere was no significant difference in descaling for any species between gatewell and orifice\ntraps, or between beam extension types in ESBS test slots. Descaling in the gatewell of the STS\ncontrol slot (11.2% for yearling chinook salmon and 13.9% for steelhead) was significantly higher\nthan in either ESBS test slot for yearling chinook salmon (7.2 and 8.9%) and steelhead (9.1 and\n9.3%). There were no statistical differences in descaling for subyearling chinook salmon among the\nthree test slots.","INTRODUCTION\nThe National Marine Fisheries Service (NMFS) has been evaluating extended-length\nscreens for guiding juvenile salmonids (Oncorhynchus sp.) out of turbine intakes at McNary\nDam since 1991 (Brege et al. 1992;, McComas et al. 1993, 1994, 1995). Based on the\nresults of these studies, the extended-length submersible bar screen (ESBS), combined with a\nnewly designed vertical barrier screen (VBS), was chosen as the guidance system to replace\nstandard-length submersible traveling screens (STSs) and modified balanced-flow vertical\nbarrier screens (MBFVBSs).\nThe two VBS systems evaluated as replacements for the MBFVBS have been\ndescribed in detail by McComas et al. (1995). Briefly, VBS1 uses a turning vane, or inlet\nflow vane, to change the flow of water up into the gatewell which results in a reduction of\nflow separation and turbulence in the gate slot. However, use of the inlet flow vane requires\nlowering the guidance device into the turbine intake 0.61 m (2 ft) below the standard\nelevation, which creates a comparable increase in the gap between the intake ceiling and the\ndownstream end of the guidance screen. For testing in 1994, a beam extension was bolted to\nthe ceiling of the intake to eliminate the increased gap (McComas et al. 1995). In 1995\nNMFS, in partnership with the COE, conducted tests to determine whether an analogous\ndevice mounted on the frame of the guidance screen would function similarly without\nadversely affecting juvenile chinook salmon condition. The two alternative beam extension\ndesigns were compared using descaling as the evaluation criterion.\nThe juvenile fish bypass system at McNary Dam is typical of most facilities on the\nSnake and Columbia Rivers (Fig. 1). Migrant fish are guided into an upstream gatewell","2\nMcNary Dam cross section\nGatewell (bulkhead slot)\nOperating gate slot\nOrifice trap\nJuvenile fish\nbypass channel\nOperating gate\n0.\nVertical barrier screen\nInlet flow vane\nFLOW\nOutlet flow control device\nBeam extension\nExtended-length\nscreen\n80.\nFigure 1. Cross section of turbine unit at McNary Dam with extended-length bar screen,\ninlet flow vane, outlet flow control device, beam extension, and orifice trap in\nplace.","3\nfrom which an egress path to the juvenile fish bypass channel is provided through submerged\norifices in the upstream wall of the gatewell. Two 30.5-cm (12-in)-diameter orifices have\nbeen shown to provide effective orifice passage efficiency (OPE) for chinook salmon (O.\ntshawytscha) and steelhead (0. mykiss) at most facilities (Long et al. 1977, Harmon and Park\n1980, Swan et al. 1984, Krcma et al. 1986). Backlighting orifices also improves OPE\n(Krcma et al. 1978, Krcma et al. 1983), and vertical barrier screen modifications that allow\nflow attraction near the orifices have been shown to aid fish passage (Swan et al. 1984,\nKrcma et al. 1985).\nOrifice submergence below the gatewell water surface may also affect OPE. For\nexample, Gessel et al. (1986) found that OPE values of up to 85% could be obtained with an\norifice submergence of 0.76 m (2.5 ft) at Bonneville Dam First Powerhouse. An OPE value\nof about 75% was attained at John Day Dam with 1.8-m (7.1-ft) orifice submergence (Krcma\net al. 1986). Brege et al. (1987) described variable OPE for orifices in test gatewells at John\nDay Dam (ranging from 45 to 89%) with a mean submergence of 1.2 m (4.0 ft). At\nMcNary Dam, Krcma et al. (1985) reported mean subyearling chinook salmon OPE values\n79% with 1.8 to 2.43-m (6 to 8-ft) orifice submergence.\nSeveral methods have been used to evaluate OPE. Where space permits, an orifice\ntrap can provide the absolute number of fish exiting within a specified time period.\nHowever, in addition to construction and installation constraints, traps require constant\nmonitoring during the sample period to ensure fish safety, and not all bypass facilities are\nlarge enough to accommodate traps and the necessary access to them. One alternative that\nhas been used as a direct estimate of OPE involves releasing a known number of marked fish\ninto the test gatewell, and recapturing those remaining after a given time interval","4\n(Krcma et al. 1986, Brege et al. 1987). This mark/recapture technique is easier to employ\nthan an orifice trap, but OPE values obtained using the two methods are not directly\ncomparable.\nExtended-length guidance screens create higher gatewell flows from the turbine intake\ninto the gatewell than STSs. Mean fish guidance efficiency is also higher with the ESBS and\nnewly designed vertical barrier screens, but little is known about the effects of these devices\non OPE. As a final phase in testing before installation of the new extended-length guidance\nsystems at McNary Dam, NMFS personnel conducted tests to evaluate OPE with the new\nsystems. Both orifice trap and mark/recapture methods were used to provide better estimates\nand to offer a basis for comparing results from the two techniques. Specific research\nobjectives for McNary Dam in 1995 were as follows:\n1)\nEvaluate the effects of two alternative beam extension designs (with newly designed\nvertical barrier screen systems, extended-length bar screen, and inlet flow vane) on\ndescaling for yearling and subyearling chinook salmon.\n2)\nEvaluate yearling and subyearling chinook salmon orifice passage efficiency (with\nnewly designed vertical barrier screen, extended-length bar screen, and inlet flow\nvane).\n3)\nCompare orifice trap and mark/recapture methods of estimating orifice passage\nefficiency for yearling and subyearling chinook salmon.","5\nOBJECTIVE 1: EVALUATE THE EFFECTS OF TWO ALTERNATIVE BEAM\nEXTENSION DESIGNS (WITH NEWLY DESIGNED VERTICAL\nBARRIER SCREEN SYSTEMS, EXTENDED-LENGTH BAR\nSCREEN, AND INLET FLOW VANE) ON DESCALING FOR\nYEARLING AND SUBYEARLING CHINOOK SALMON\nApproach\nThe use of inlet flow vanes requires lowering the ESBS 0.61 m (2 ft) below standard\nelevation. However, lowering the guidance screen increases the gap between the downstream\nend of the ESBS and the beam which forms the intake ceiling between the bulkhead and\noperating gate slots. To reduce this gap, a vertical continuation of the beam, called a beam\nextension, was used (Fig. 1). Gatewells 5B and 6B were used to compare fish condition\nusing two different beam-extension designs. The beam extension in Slot 6B was bolted to\nthe turbine intake ceiling, while the extension device used in Slot 5B was mounted to the\ndownstream side of the ESBS frame (Fig. 2). VBSI was installed in Slot 5B, and VBS2 was\nplaced in Slot 6B.\nBased on 1994 test results (McComas et al. 1995), inlet flow vanes were chosen for\ninstallation at McNary Dam, in place of expansion shapes, for minimizing the separation of\nflows entering the gatewell. The expansion shape previously used with VBS2 was therefore\nreplaced with an inlet flow vane identical to that used with VBS1. Vertically variable\nperforated plate panels, specific to each VBS type, were used as a downstream surface to\ndisperse flows evenly through the entire VBS surface.\nBoth test gatewells were equipped with ESBSs with a 30% porosity perforated plate\nand were lowered 0.61 m below standard elevation to adjust for the inlet flow vanes.\nExtended-length guidance screens (either ESBSs or extended-length submersible","Gatewell\nGatewell\n(bulkhead\n(bulkhead\nslot)\nslot)\nOperating\nOperating\ngate\ngate\nslot\nslot\nVertical\nVertical\nbarrier\nbarrier\nscreen\nscreen\n(VBS1)\n(VBS2)\nOutlet\nOutlet\nflow\nflow\ncontrol\ncontrol\nInlet\nInlet\nflow\nflow\nvane\nvane\nBeam\nESBS\nmounted\nmounted\nbeam extension\nbeam extension\nFlow\nFlow\nExtended-length\nExtended-length\nbar screen (ESBS)\nbar screen (ESBS)\nGatewell 5B\nGatewell 6B\n2. Cross section of test Gatewells 5B and 6B showing components evaluated di\nre\ndescaling and orifice passage efficiency studies at McNary Dam, 1995.","7\ntraveling screens) were also placed in Slots A and C of Turbine Units 5 and 6 to provide\nconsistent flows across all three intakes of each unit. The A and C slots did not contain inlet\nflow vanes and therefore the guidance screens in these slots were not lowered.\nSlot 7B was used as a control and represented the default guidance screen/VBS\nconfiguration for McNary Dam. This consisted of an STS at standard elevation with an\nMBFVBS, and a fully raised operating gate.\nNo operating gates were used in downstream gatewells of test slots, and all guidance\nscreen angles were fixed at 55° for both spring and summer outmigration test periods.\nFlows through test and control units were maintained at 360 m3/s (12,000 cfs), representing\nmaximum turbine efficiency for McNary Dam turbines, at turbine-unit loads of about\n70 MW. Outlet flow control devices were installed in test slots, but were not tested in 1995.\nFish condition was assessed by percent descaling according to Fish Transportation\nOversight Team descaling criteria (Ceballos et al. 1992). The descaling percentage was\ndefined by species as the number of fish identified as descaled divided by the total number of\nfish captured during the sample period.\nDaily descaling samples were collected from test and control gatewells using a dip\nbasket similar to the one described by Swan et al. (1979). For Slots 5B and 7B, sample size\nwas limited to approximately 100 chinook salmon; for Slot 6B, however, sample size\nconsisted of the total number of fish present because of concurrent OPE testing in that\ngatewell. Samples with fewer than 25 fish were considered inadequate for statistical analysis\n(McComas et al. 1995); on days when fewer than 25 fish were captured, catches from 2 or\nmore successive days were combined.","8\nResults and Discussion\nSpring Outmigration\nDescaling was significantly higher in the control slot than in either of the beam\nextension test slots for yearling chinook salmon (F = 10.66, df = 3, 102, P < 0.0001) and\nsteelhead (F = 9.06, df = 3, 80, P < 0.0001). Sockeye salmon (O. nerka) descaling was\nsignificantly higher in the control slot than in the beam mounted beam extension test slot\n(6B), but not statistically different from the screen mounted condition (F = 6.78, df = 3,\n95, P = 0.0003). Mean descaling values for the beam mounted and screen mounted\nextensions were statistically similar for all three species, and there was no real difference in\nmean coho salmon (0. kisutch) descaling values among any of the three treatments\n(F = 2.19, df = 3, 25, P = 0.1140). Mean descaling values (and standard error) for each\ntreatment are summarized below.\nPercent descaling (SE)\nBeam\nextension\nYearling\nchinook\nSteelhead\ntreatment\nCoho\nSockeye\nScreen mounted\n8.9 (0.7)\n9.3 (1.5)\n7.4 (1.4)\n13.1 (1.7)\nBeam mounted\n7.2 (0.7)\n9.1 (1.1)\n1.7 (1.7)\n9.3 (1.3)\nControl\n11.2 (0.7)\n13.9 (1.3)\n4.9 (1.8)\n15.2 (1.5)\nSummer Outmigration\nNo significant difference in mean descaling values was found for subyearling chinook\nsalmon among the beam extension and control treatments (F = 1.79, df = 3, 100,\nP = 0.1536). Descaling means were 5.8 (SE = 0.9), 6.5 (SE = 0.8), and 5.6 (SE = 0.9)\nfor beam mounted, screen mounted, and control conditions, respectively.","9\nGatewell catch descaling data for individual replicates are presented in Appendix\nTable 1. Results of statistical comparisons among descaling treatments are summarized in\nAppendix Table 2.\nOBJECTIVE 2: EVALUATE YEARLING AND SUBYEARLING CHINOOK SALMON\nORIFICE PASSAGE EFFICIENCY (WITH NEWLY DESIGNED\nVERTICAL BARRIER SCREEN, EXTENDED-LENGTH BAR\nSCREEN, AND INLET FLOW VANE)\nApproach\nEach gatewell at McNary Dam is equipped with two backlit 30.5-cm (12-in) orifices\nto provide volitional fish passage into the juvenile fish bypass channel. Orifices are located\napproximately 1.1 m (3.5 ft) from the north and south ends of the gatewell, at 100 m (330 ft)\nelevation. The range of potential orifice submergence is from 3 m (10 ft) at high turbine\noperating pool, to 1.5 m (5 ft) at minimum operating pool.\nGatewell 6B was used for OPE testing. Orifice passage efficiency was estimated\nand\ncomparisons were made between north and south orifices using orifice trap and\nmark/recapture methods. The test period was set at 22 hours, from 1300 to 1100 the\nfollowing day. This allowed concurrent testing, using both methods in the same gatewell,\nwith 2 hours between replicates for fish handling.\nOrifice Trap\nTwo orifice traps were constructed on platforms suspended above the juvenile fish\nbypass channel to capture emigrants from either the north or south orifice of Gatewell 6B\n(Fig. 3). Each trap unit included dewatering, holding, fish handling, and recovery facilities.\nOne trap was operated continuously during each test period, alternating between north and","Figure 3. Plan view of a section of the juvenile fish bypass channel at McNary Dam showing the relationship between the north\nOrifice\n(6BN)\norifice of Gatewell 6B and components of the north orifice trap used during OPE studies at McNary Dam, 1995.\nFlow\nGatewell 6B\nbypass channel\nJuvenile fish\ndewatering sections\nOrifice trap\nWalkway\ngrating\nGatewell 6C\nholding tank\nOrifice trap\nGatewell 7A\nRecovery\ntank\nhandling\nstation\nFish","11\nsouth traps on successive replicates. Fish were removed as they accumulated, anesthetized,\nenumerated by species, and checked for descaling. Following recovery from anesthetic, all\nfish were released directly into the fish bypass channel.\nAt the end of the 22-hour sample period, the test orifice was closed and fish\nremaining in the trap and gatewell were removed, enumerated, and checked for descaling.\nFor each species, OPE using the orifice trap (OPET) method was defined as the ratio of the\nnumber of fish captured in the orifice trap to the total number of fish recovered from the\norifice trap and gatewell combined.\nwhere T = orifice trap captures during the sample period\nG = gatewell captures after the end of the sample period\nMark/Recapture Method\nUp to 100 chinook salmon obtained during gatewell cleanout each day were marked\nusing partial caudal fin clips. To minimize the risk of counting marks from previous\nreleases, clips were alternated between upper and lower lobes on successive replicates.\nTo begin testing, marked fish were released approximately 9 m (30 ft) below the\nwater surface in the center of the test gatewell between 15 and 30 minutes after orifices were\nopened. In addition to being approximately the midpoint between the intake ceiling and the\ngatewell water surface, the 9-m depth was selected as the point below orifice depth which\nwould provide realistic upward movement through the gatewell, without risking additional\nstress and possible injury associated with increased flows at a lower release point. To ensure\nthat all fish were released simultaneously and at the same depth, marked fish were carefully","12\nlowered and released into the gatewell using a release capsule designed specifically for the\npurpose.\nMarked fish and other residuals remaining in the gatewell at the end of the sample\nperiod were captured with a dip basket. Incidence of marks was noted, and orifice passage\nefficiency using the mark/recapture method (OPEM/R) was defined as the ratio of marked fish\nthat exited the gatewell by the end of the sample period to the total number of marked fish\nreleased at the beginning of the sample period.\nwhere M = number of marks released at time t\nR = number of marks recaptured at time t+1\nDip-basket efficiency (DBE) testing was conducted as in past FGE studies (Krcma\net al. 1985). Yearling chinook salmon and steelhead were marked with caudal clips and\nreleased into the gatewell of Slot 6B during the interval between OPE replicates. The DBE\ngroup remained in the gatewell for 1 hour, after which they were removed along with the\ngatewell catch during cleanout just prior to beginning the next replicate. Dip-basket\nefficiency was defined for each species as the number of recaptured caudal-clipped fish\ndivided by the total number of marked fish released:\nDBE Rx 100% =\nwhere R = caudal-clipped fish recaptured\nM = caudal-clipped fish released.","13\nResults and Discussion\nA list of non-salmonid species incidentally captured in orifice traps during both spring\nand summer sampling periods is presented by catch frequency in Appendix Table 3.\nDip-basket efficiency testing conducted 2 June resulted in 99% efficiency for chinook\nsalmon and 100% for steelhead.\nSpring Outmigration\nReleative to the gatewell water surface, orifice submergence over the spring\noutmigration sample period ranged from approximately 1.6 to 2.1 m (5.3 to 7 ft), with a\nmean of 1.9 m (6.3 ft) (SE = 0.0620). Mean operating pool elevation during the spring test\nperiod was 101.69 m (338.95 ft). From 20 April through 7 June, a total of 36 replicates\nwere completed using the orifice trap, and 29 replicates were completed using the\nmark/recapture method. Yearling chinook salmon data from four orifice trap replicates\n(28 April; 2, 5, and 24 May) were omitted from analysis due to suspected enumeration\nerrors.\nUsing orifice traps, there was no significant difference in mean OPE values between\nnorth and south orifices for yearling chinook salmon (t = 0.05, df = 30, P = 0.9586),\nsteelhead (t = 0.62, df = 30, P = 0.5399), coho salmon (t = 0.47, df = 12, P = 0.6483),\nor sockeye salmon (t = 0.10, df = 26, P = 0.9241). Estimated mean OPE (with standard\nerrors) using orifice traps is summarized below for each species.\nPercent OPE (SE)\nYearling\nOrifice\nchinook\nSteelhead\nCoho\nSockeye\nNorth\n74 (2.2)\n93 (1.3)\n93 (2.5)\n87 (3.1)\nSouth\n74 (3.0)\n92 (1.0)\n94 (2.1)\n87 (2.5)","14\nMean mark/recapture OPE estimates for yearling chinook salmon were\n79% (SE = 3.1) and 78% (SE = 3.8) for the north and south orifices, respectively. The\ndifference was not significant (t = 0.06, df = 13, P = 0.9559).\nA paired t-test using successive 2-day blocks as pairs revealed no difference in mean\ndescaling values for yearling chinook salmon (t = 1.11, df = 16, p = 0.2846), steelhead\n(t = 0.27, df = 17, p = 0.7872), coho salmon (t = 0.56, df = 5, p = 0.5977), or sockeye\nsalmon (t = 1.17, df = 15, p = 0.2614) passing through the north and south orifices. For\neach species, mean descaling using north and south orifices is summarized below.\nPercent descaling (SE)\nYearling\nOrifice\nchinook\nSteelhead\nCoho\nSockeye\nNorth\n6.4 (0.7)\n6.0 (0.7)\n3.9 (0.8)\n7.8 (1.0)\nSouth\n7.3 (0.8)\n6.2 (0.8)\n4.6 (1.5)\n6.7 (0.8)\nFisher's Protected Least Significant Difference procedure detected no significant\ndifference in mean descaling between gatewell and orifice trap catches for any of these four\nsalmonid species.\nDaily orifice trap, mark/recapture, and OPE data for yearling chinook salmon are\npresented in Appendix Table 4, and statistical comparisons between OPE treatments are\nsummarized in Appendix Table 5. Orifice trap catch and OPE data for non-target salmonids\nare included in Appendix Table 6.\nSummer Outmigration\nOrifice submergence below the gatewell water surface ranged from approximately 1.5\nto 2.1 m (5 to 7 ft), with a mean of 1.9 m (6.3 ft) (SE = 0.0677). Mean operating pool","15\nelevation during the summer test period was 101.57 m (338.56 ft). Sampling for subyearling\nchinook salmon comprised 30 orifice trap replicates from 21 June through 1 August, and 18\nmark/recapture replicates beginning 28 June. Mark/recapture tests were terminated after\n22 July to minimize negative impacts on fish associated with elevated water temperatures and\nhigher levels of descaling in test gatewells.\nRespective mean OPE estimates for north and south orifices were 81 (SE = 2.7) and\n86% (SE = 2.6) using orifice traps, and 95 (SE = 1.9) and 99.6% (SE = 0.2) using the\nmark/recapture method. Estimates using orifice traps were not statistically different\n(t = 1.16, df = 28, P = 0.2555); however there was a significant difference between mean\nsubyearling chinook salmon OPE values for the north and south orifices using the\nmark/recapture method (t = 2.13, df = 7, P = 0.0706).\nAs with yearling chinook salmon during the spring series, there was no difference\nbetween gatewell and orifice trap descaling for subyearling chinook salmon. However, the\ndifference between mean descaling values for the north orifice (4.8%, SE = 0.4) and the\nsouth orifice (3.2%, SE = 0.4) was significant (t = 3.86, df = 14, P = 0.0017) for\nsubyearling chinook salmon.\nDaily orifice trap, mark/recapture, and OPE data for subyearling chinook salmon are\npresented in Appendix Table 7.","16\nOBJECTIVE 3: COMPARE ORIFICE TRAP AND MARK/RECAPTURE METHODS\nOF ESTIMATING ORIFICE PASSAGE EFFICIENCY FOR\nYEARLING AND SUBYEARLING CHINOOK SALMON\nApproach\nOrifice trap and mark/recapture methods of estimating OPE were compared using\npaired t-tests for yearling and subyearling chinook salmon. Comparisons were made only for\nthose days when both methods were used simultaneously.\nResults and Discussion\nSpring Outmigration\nThere was a significant 4% difference between the two methods of measuring OPE\nfor yearling chinook salmon (t = 2.56, df = 24, P = 0.0174). Combined mean OPE\nestimates for both orifices were 78% (SE = 1.4) using the mark/recapture method and 74%\n(SE = 1.8) using orifice traps.\nSummer Outmigration\nThe combined mean OPE estimates for both orifices were 83% (SE = 1.9) using\norifice traps and 97% (SE = 1.2) with the mark/recapture method. The 14% difference was\nsignificant (t = 6.14, df = 17, P < 0.0001).\nThere are two readily apparent factors contributing to the difference in mean OPE\nvalues between estimation techniques. The mark/recapture method relied on a point release\nat the beginning of the sample period, allowing nearly the entire 22-hour period for egress,\nwhile the orifice trap technique relied on migrants accumulating over the entire period. It is\npossible that fish entering the gatewell just prior to the end of the test period did not have\ntime to acclimate and find the exit point before the test terminated. In addition, orifice","17\npassage was bimodal; distinct peaks were generated during late evening and early morning\n(Fig. 4). The morning peak extended later into the replicate as the season progressed, with\nincreased numbers of fish exiting closer to the end of the sample period. This undoubtedly\nresulted in more fish in the gatewell at the end of the test, particularly during the subyearling\nchinook salmon outmigration, and may have contributed to the greater disparity in mean OPE\nvalues between the two methods in summer.\nThe result of this comparison indicates fundamental differences for the application of\nresults from the two approaches. The mark/recapture method furnishes a measure of\nindividual residence time in the gatewell. Orifice traps can be used to provide seasonal and\ndiel passage timing data, and can provide the opportunity to assess condition associated with\norifice passage. Methods selected for future investigations will depend on the goals of the\nstudy.\nSUMMARY\n1) There was no significant difference in mean descaling values for yearling and subyearling\nchinook salmon between beam and screen-mounted beam extensions used with extended-\nlength bar screens and inlet flow vanes.\n2) Mean descaling for yearling chinook salmon was significantly higher with the control\nMBFVBS and a standard-length traveling screen than for either beam extension treatment\nused with extended-length bar screens and inlet flow vanes. Mean descaling differences\namong the three treatments for subyearling chinook salmon were not significant.\n3) Orifice passage efficiency was > 70% for both orifice trap and mark/recapture estimation\nmethods using an extended-length bar screen and VBS2 with an inlet flow vane.","1100\n05.0-10.0\n0800\n010.0-15.\n10.0-5.0\n015.0-20\n020.0-2\n0500\nPercent\nHour\n0200\n2300\n2000\n1700\n1400\n7/31\n7/25\nFigure 4. Chinook salmon diel orifice passage, McNary Dam, 1995.\n7/20\n7/15\n7/10\n7/5\n6/29\n6/24\n6/4\nTest Date\n5/30\n5/25\n5/20\n5/15\n5/10\n5/5\n4/30\n4/25\n4/20","19\n4) There was no significant difference between orifice passage efficiency values for the north\nand south orifices using orifice traps for yearling and subyearling chinook salmon or the\nmark/recapture method for yearling chinook salmon. Subyearling chinook salmon orifice\npassage efficiency was significantly higher for the south orifice than for the north orifice\nusing the mark/recapture method.\n5) Differences in mean descaling values between gatewell and orifice traps for yearling and\nsubyearling chinook salmon were not significant.\n6) Descaling was significantly higher for subyearling chinook salmon using the north orifice\nthan for those using the south orifice. Mean yearling chinook salmon descaling values\nwere statistically similar for both orifices.\n7) Orifice passage efficiency estimated using the mark/recapture method was significantly\nhigher than OPE estimated using orifice traps for both yearling and subyearling chinook\nsalmon.\nACKNOWLEDGMENTS\nWe express our appreciation to our seasonal employees for their interest and efforts\nduring this project. We extend special thanks to the Walla Walla District COE personnel,\nparticularly to Ms. Theresa Barila, and to Mr. Scott Ross who designed the orifice trap. At\nMcNary Dam, Mr. David Coleman, Mr. William Pruit, and the rigging crew provided\ninvaluable assistance and cooperation. We also extend special thanks to our maintenance\nstaff, especially Mr. Irvin Wilbert, Mr. Wayne Henry, and Mr. Wallace Iceberg for their\nefforts in this study.","20\nREFERENCES\nBrege, D. A., S. J. Grabowski, W. D. Muir, S. R. Hirtzel, S. J. Mazur, and B. P.\nSandford. 1992. Studies to determine the effectiveness of extended traveling screens\nand extended bar screens at McNary Dam, 1991. Report to U.S. Army Corps of\nEngineers, Contract DACW68-84-H-0034, 32 p. plus Appendixes. (Available from\nNorthwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112-\n2097.)\nBrege, D. A., D. R. Miller, and R. D. Ledgerwood. 1987. Evaluation of the rehabilitated\njuvenile salmonid collection and passage system at John Day Dam - 1986. Report to\nU.S. Army Corps of Engineers, Contract DACW57-86-F-0245, 37 p. plus Appendix.\n(Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E.,\nSeattle, WA 98112-2097.)\nCeballos, J. R., S. W. Pettit, and J. L. McKern. 1992. Fish Transportation Oversight\nTeam. Annual Report - 1991. Transportation operations on the Columbia and Snake\nRivers. NOAA Technical Memo. NMFS F/nwr-29. 77 p. plus Appendix.\nGessel, M. H., L. G. Gilbreath, W. D. Muir, and R. F. Krcma. 1986. Evaluation of the\njuvenile collection and bypass system at Bonneville Dam, 1985. Report to U.S.\nArmy Corps of Engineers, Contract DACW57-85-H-0001, 63 p. plus Appendix.\n(Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E.,\nSeattle, WA 98112-2097.)\nHarmon, J. R., and D. L. Park. 1980. Evaluation of a bypass system for juvenile\nsalmonids at Little Goose Dam. Marine Fisheries Review 42:25-28.\nKrcma, R. F., D. A. Brege, and R. D. Ledgerwood. 1986. Evaluation of the rehabilitated\njuvenile salmonid collection and passage system at John Day Dam - 1985. Report to\nU.S. Army Corps of Engineers, Contract DACW57-85-H-0001, 25 p. plus Appendix.\n(Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E.,\nSeattle, WA 98112-2097.)\nKrcma, R. F., C. W. Long, and C. S. Thompson. 1978. Research on the development of a\nfingerling protection system for low-head dams--1977. Report to U.S. Army Corps\nof Engineers, Contract DACW57-77-F-0307, 32 p. plus Appendix. (Available from\nNorthwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112-\n2097.)\nKrcma, R. F., M. H. Gessel, and F. J. Ossiander. 1983. Research at McNary Dam to\ndevelop and implement a fingerling protection system for John Day Dam, 1982.\nReport to U.S. Army Corps of Engineers, Contract DACW57-82-F-0373, 24 p. plus\nAppendix. (Available from Northwest Fisheries Science Center, 2725 Montlake\nBlvd. E., Seattle, WA 98112-2097.)","21\nKrcma, R. F., G. A. Swan, and F. J. Ossiander. 1985. Fish guiding and orifice passage\nefficiency tests with subyearling chinook salmon, McNary Dam, 1984. Report to\nU.S. Army Corps of Engineers, Contract DACW68-84-F-0034, 19 p. plus\nAppendixes. (Available from Northwest Fisheries Science Center, 2725 Montlake\nBlvd. E., Seattle, WA 98112-2097.)\nLong, C. W., R. F. Krcma, and T. E. Ruehle. 1977. Development of a system for\nprotecting juvenile salmonids at the Second Powerhouse at Bonneville Dam--Progress\n1976. Report to U.S. Army Corps of Engineers, Contract DACW57-76-F-0512,\n15 p. (Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E.,\nSeattle, WA 98112-2097.)\nMcComas, R. L., D. A. Brege, W. D. Muir, B. P. Sandford, and D. B. Dey. 1993.\nStudies to determine the effectiveness of extended-length submersible bar screens at\nMcNary Dam, 1992. Report to U.S. Army Corps of Engineers, Contract DACW68-\n84-H-0034, 34 p. plus Appendixes. (Available from Northwest Fisheries Science\nCenter, 2725 Montlake Blvd. E., Seattle, WA 98112-2097.)\nMcComas, R. L., B. P. Sandford, and D. B. Dey. 1994. Studies to evaluate the\neffectiveness of extended-length screens at McNary Dam, 1993. Report to U.S.\nArmy Corps of Engineers, Contract DACW68-84-H-0034, 25 p. plus Appendixes.\n(Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E.,\nSeattle, WA 98112-2097.)\nMcComas, R. L., B. P. Sandford, and D. B. Dey. 1995. Vertical barrier screen studies at\nMcNary Dam, 1994. Report to U.S. Army Corps of Engineers, Contract DACW68-\n84-H-0034, 25 p. plus Appendixes. (Available from Northwest Fisheries Science\nCenter, 2725 Montlake Blvd. E., Seattle, WA 98112-2097.)\nSwan, G. A., R. F. Krcma, and W. E. Farr. 1979. Dip basket for collecting juvenile\nsalmon and trout in gatewells at hydroelectric dams. Progressive Fish Culturist\n41:48-49.\nSwan, G. A., R. F. Krcma, and F. J. Ossiander. 1984. Research to develop an improved\nfingerling protection system for Lower Granite Dam. Report to U.S. Army Corps of\nEngineers, Contract DACW68-78-C-0051, 20 p. plus Appendixes. (Available from\nNorthwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112-\n2097.)","22\nAPPENDIX","25.0\n0.0\n0.0\n0.0\n14.3\n0.0\n13.0\n4.7\n0.0\n33.3\n0.0\n13.3\n24.7\n20.0\n12.1\n8.3\n10.0\n100.0\n19.1\n6.9\n4.0\n100.0\n28.6\n14.6\n11.8\n16.7\nGatewell catch descaling data from orifice passage efficiency and\nSockeye\nCatch Desc\n1\n1\n3\n5\n3\n2\n21\n1\n19\n1\n11\n3\n9\n2\n1\n2\n4\n7\n2\n3\n4\n4\n4\n3\n7\n13\n23\n106\n10\n9\n1\n15\n85\n5\n157\n12\n110\n3\n47\n29\n25\n2\n14\n48\n17\n18\n0.0\n0.0\n0.0\n0.0\n7.7\n20.0\n11.8\n3.6\n9.2\n9.1\n0.0\n6.8\n15.0\n0.0\n50.0\n0.0\n0.0\nCatch Desc.\nCoho\n1\n1\n10\n1\n9\n1\n4\n3\n1\n11\n6\n10\n15\n13\n5\n85\n28\n98\n2\n11\n9\n59\n20\n2\n1\n2\ndescaling tests at McNary Dam, 1995.\n0.0\n0.0\n0.0\n4.8\n0.0\n0.0\n0.0\n0.0\n28.6\n0.0\n0.0\n10.8\n0.0\n16.7\n10.5\n4.4\n0.0\n50.0\n10.5\n15.0\n0.0\n0.0\n0.0\n15.0\n16.7\n23.1\n%\nSteelhead\nDesc\n2\n2\n11\n1\n2\n5\n1\n4\n3\n3\n1\n3\nCatch\n1\n5\n5\n42\n2\n1\n1\n18\n7\n2\n1\n102\n8\n6\n19\n113\n12\n2\n38\n20\n3\n2\n3\n20\n6\n13\nPercent descaling [ (number descaled/total gatewell catch) x 100]\n4.0\n3.1\n4.3\n1.8\n1.0\n1.8\n2.0\n1.7\n4.5\n3.6\n10.9\n3.5\n6.3\n6.5\n5.9\n10.2\n11.3\n7.8\n12.6\n8.7\n3.6\n8.3\n12.8\n7.8\n6.4\n1.4\n10.6\n12.0\n8.0\n13.1\n10.7\nNumber of descaled fish captured by dip net from gatewell.\n%\nchinook\nYearling\nCatch Desc.\n1\n1\n2\n2\n1\n20\n2\n2\n5\n4\n11\n3\n7\n7\n6\n11\n6\n8\n13\n9\n4\n9\n14\n8\n7\n2\n12\n12\n12\n13\n11\n25\n32\n46\n114\n102\n1102\n101\n115\n112\n111\n101\n85\n111\n107\n101\n108\n53\n102\n103\n103\n103\n109\n109\n103\n110\n141\n113\n100\n150\n99\n103\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n2.4\n3.4\n5.6\nqc\nSubyearling\nchinook\nb\nAppendix Table 1.\nCatch Desc.\n2\n1\n7\nTotal gatewell catch.\n1\n2\n6\n1\n3\n8\n2\n25\n27\n8\n7\n16\n84\n29\n124\nUnit 5, Slot B\n17 April\n18 April\n19 April\n21 April\n22 April\n25 April\n26 April\n27 April\n28 April\n29 April\n2 May\n3 May\n4 May\n5 May\n6 May\n9 May\n10 May\n11 May\n12 May\n13 May\n16 May\n17 May\n18 May\n19 May\n20 May\n23 MAY\n24 May\n25 May\n26 May\n27 May\n29 May\nTest\ndate\na\nb\nC","7.1\n37.5\n2.9\n16.2\n12.7\n11.9\n16.0\n0.0\n%\nSockeye\nCatch Desc.\n2\n9\n1\n6\n7\n5\n4\n28\n24\n34\n37\n55\n42\n25\n1\n%\nCatch Desc.\nCoho\n33.3\n0.0\n17.3\n0.0\n11.1\n16.7\n0.0\n%\nSteelhead\nDesc.\n1\n9\n2\n2\nCatch\n3\n8\n52\n12\n18\n12\n19\n8.5\n17.6\n12.1\n19.4\n20.3\n17.0\n21.9\n0.0\n0.0\n14.3\n0.0\n0.0\n0.0\n10.5\n0.0\n9.1\n0.0\n25.0\n0.0\n16.7\n50.0\n6.3\n14.3\n36.4\n18.2\n9.5\n14.3\n33.3\n0.0\n%\nYearling\nchinook\nDesc.\n6\n9\n11\n12\n12\n26\n14\n1\n2\n1\n1\n1\n1\n2\n3\n4\n2\n2\n1\n2\nCatch\n71\n7\n51\n91\n62\n59\n153\n64\n6\n1\n9\n12\n15\n19\n19\n11\n4\n4\n1\n6\n2\n32\n21\n11\n11\n21\n7\n6\n4\nContinued.\n1.2\n8.7\n3.4\n2.1\n2.9\n10.8\n6.8\n9.3\n13.9\n1.6\n5.0\n2.5\n4.5\n3.1\n5.6\n5.2\n0.0\n7.6\n1.9\n5.0\n1.6\n2.4\n2.3\n3.3\n7.5\n5.0\n8.7\n2.8\n11.0\n27.0\n%\nSubyearling\nchinook\nDesc.\n2\n18\n14\n5\n8\n27\n35\n17\n14\n3\n7\n6\n5\n4\n10\n8\n9\n2\n5\n4\n3\n3\n10\n9\n6\n11\n3\n11\n41\nAppendix Table 1.\nCatch\n161\n208\n414\n233\n278\n251\n517\n183\n101\n182\n139\n236\n112\n129\n117\n115\n115\n118\n104\n100\n250\n124\n133\n304\n120\n120\n127\n106\n100\n152\nUnit 5, Slot B\n1 June\n2 June\n3 June\n4 June\n5 June\n6 June\n7 June\n22 June\n24 June\n27 June\n28 June\n29 June\n30 June\n1 July\n6 July\n7 July\n8 July\n9 July\n10 July\n11 July\n12 July\n13 July\n14 July\n15 July\n18 July\n19 July\n20 July\n21 July\n22 July\n31 May\nTest\ndate","50..0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n2.4\n2.2\n3.0\n1.3\n3.2\n4.1\n1.5\n16.7\n16.8\n9.9\n6.0\n8.3\n14.9\n20.1\n10.8\n11.9\n29.6\n2.6\n17.9\n5.6\n23.1\n0.0\n23.3\n5.6\n0.0\n10.0\n4.0\n7.7\n11.1\n%\nSockeye\nCatch Desc.\n1\n2\n8\n3\n6\n2\n1\n6\n19\n13\n3\n4\n10\n35\n23\n5\n21\n1\n7\n2\n3\n7\n3\n0\n2\n1\n1\n1\n1\n1\n2\n2\n3\n8\n10\n33\n42\n89\n268\n228\n190\n49\n68\n36\n113\n131\n50\n48\n67\n174\n212\n42\n71\n39\n39\n36\n13\n2\n30\n54\n3\n20\n25\n13\n2\n9\n6.25\n0.0\n0.0\n0.0\n0.0\n0.0\n16.7\n11.1\n0.0\n0.0\n0.0\n9.1\n0.0\n0.0\n0.0\n0.0\n%\nCatch Desc.\nCoho\n1\n1\n1\n1\n8\n4\n2\n21\n10\n6\n9\n28\n16\n5\n7\n11\n4\n1\n1\n1\n0.0\n0.0\n0.0\n0.0\n5.3\n0.0\n9.1\n0.0\n0.0\n5.9\n10.7\n6.1\n5.7\n3.7\n6.4\n6.4\n10.8\n5.9\n2.3\n7.2\n5.6\n9.8\n7.6\n16.7\n6.8\n25.0\n20.0\n7.1\n13.3\n50.0\n50.0\n26.7\n40.0\n33.3\n0.0\n%\n14\nSteelhead\nDesc.\n1\n1\n1\n3\n2\n2\n1\n2\n5\n8\n3\n1\n9\n30\n7\n11\n9\n13\n3\n3\n3\n1\n2\n2\n2\n8\n2\n1\nCatch\n7\n6\n3\n2\n19\n35\n11\n14\n12\n17\n28\n33\n35\n27\n30\n78\n74\n51\n43\n125\n210\n126\n112\n119\n78\n44\n12\n15\n14\n15\n4\n4\n30\n5\n3\n2\n6.7\n3.8\n2.6\n2.6\n2.5\n1.5\n3.6\n3.1\n2.8\n2.6\n6.8\n3.4\n4.7\n4.9\n2.7\n6.6\n11.0\n6.9\n10.6\n5.5\n8.0\n5.8\n6.1\n7.2\n4.5\n3.5\n19.8\n1.3\n4.1\n8.5\n10.4\n20.0\n10.6\n9.9\n12.5\n19.0\n18.9\n16.7\n18.8\n9.1\n0.0\n%\nYearling\nDesc.\nchinook\n2\n2\n2\n10\n15\n10\n27\n9\n15\n11\n20\n8\n19\n19\n16\n40\n89\n54\n66\n38\n67\n39\n41\n58\n34\n10\n89\n1\n5\n20\n5\n1\n5\n14\n1\n8\n10\n5\n3\n4\nCatch\n30\n52\n76\n381\n592\n655\n749\n287\n541\n419\n294\n234\n407\n387\n597\n610\n808\n780\n623\n690\n840\n671\n669\n807\n755\n283\n449\n76\n123\n235\n48\n5\n47\n141\n8\n42\n53\n30\n16\n44\n2\nContinued.\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n1.0\n0.0\n1.0\n6.6\n1.3\n0.0\n0.0\n1.6\n0.0\n10.2\n1.5\n0.0\n4.4\n3.1\n4.6\n13.4\n10.6\n6.6\n%\nSubyearling\nchinook\nCatch Desc.\n2\n1\n6\n1\n1\n25\n5\n8\n4\n13\n33\n45\n25\nAppendix Table 1.\n1\n1\n2\n2\n2\n9\n4\n5\n3\n6\n2\n1\n6\n9\n17\n25\n79\n196\n71\n102\n91\n80\n59\n97\n64\n15\n244\n332\n39\n182\n129\n280\n246\n424\n379\nUnit 6, Slot B\n17 April\n18 April\n19 April\n21 April\n22 April\n25 April\n26 April\n27 April\n28 April\n29 April\n1 June\n2 June\n3 June\n4 June\n5 June\n6 June\n7 June\n22 June\n23 June\n2 May\n3 May\n4 May\n5 May\n6 May\n9 May\n10 May\n11 may\n12 May\n13 May\n16 May\n17 may\n18 May\n19 May\n20 May\n23 May\n24 May\n25 May\n26 May\n27 May\n29 May\n31 May\nTest\ndate","0.0\n1 100.0\n0.0\n0.0\n0.0\n%\n%\nSockeye\nSockeye\nCatch Desc.\nCatch Desc.\n0\n8\n1\n1\n1\n1\n%\n%\nCoho\nCatch Desc.\nCatch Desc.\nCoho\n0.0\n0.0\n%\n%\nSteelhead\nSteelhead\nDesc.\nDesc.\nCatch\nCatch\n1\n2\n0.0\n4.0\n0.0\n0.0\n4.9\n6.2\n6.3\n3.7\n9.1\n7.4\n12.9\n20.0\n85.7\n0.0\n16.7\n5.9\n0.0\n33.3\n13.2\n33.3\n40.0\n11.5\n25.0\n30.0\n0.0\n8.0\n7.0\n11.0\n3.9\n2.9\n6.5\n%\n%\nYearling\nYearling\nchinook\nDesc.\nDesc.\nchinook\n1\n7\n6\n5\n1\n16\n2\n4\n1\n6\n1\n1\n5\n5\n16\n2\n3\n5\n3\n2\n7\n11\n4\n3\n7\nCatch\nCatch\n13\n25\n121\n73\n144\n97\n80\n27\n175\n27\n31\n5\n7\n5\n6\n17\n19\n15\n38\n48\n5\n26\n20\n10\n14\n25\n100\n100\n103\n103\n107\nContinued.\n3.6\n4.1\n3.8\n4.4\n1.8\n3.7\n4.4\n1.8\n5.0\n7.8\n7.3\n4.0\n2.9\n17.9\n0.0\n10.0\n4.7\n12.9\n8.7\n14.7\n11.1\n16.3\n2.0\n1.6\n1.8\n0.0\n7.9\n11.5\n0.0\n0.0\n%\nof\nSubyearling\nSubyearling\nchinook\nchinook\nDesc.\nDesc\n23\n57\n93\n73\n28\n29\n67\n11\n157\n15\n53\n28\n16\n10\n12\n8\n4\n25\n60\n91\n17\n2\n1\n1\n3\n3\nAppendix Table 1.\nCatch\nCatch\n645\n1392\n2419\n1656\n1515\n783\n1537\n610\n3157\n193\n731\n707\n556\n565\n17\n120\n172\n31\n288\n409\n819\n104\n102\n61\n56\n55\n38\n26\n2\n2\nUnit 6, Slot B\nUnit 7, Slot B\n1 August\n17 April\n18 April\n19 April\n21 April\n22 April\n24 June\n27 June\n28 June\n29 June\n30 June\n1 July\n6 July\n7 July\n8 July\n9 July\n10 July\n11 July\n12 July\n13 July\n14 July\n15 July\n18 July\n19 July\n20 July\n21 July\n22 July\n25 july\n26 July\n27 July\n28 July\n29 July\n30 July\nTest\ndate\nTest\ndate","11.1\n33.3\n0.0\n5.4\n6.1\n7.3\n6.3\n9.8\n0.0\n36.0\n18.2\n0.0\n25.0\n6.5\n71.4\n11.1\n9.2\n18.7\n12.7\n20.0\n76.9\n10.3\n15.5\n33.3\n35.0\n18.3\n10.0\n17.6\n30.0\n21.4\n2.7\n36.4\n50.0\n%\nSockeye\nCatch Desc.\n1\n1\n3\n2\n9\n13\n4\n9\n2\n4\n4\n5\n18\n22\n17\n21\n4\n10\n4\n13\n6\n7\n11\n1\n6\n9\n9\n1\n4\n1\n9\n3\n16\n56\n33\n123\n208\n41\n15\n25\n11\n21\n16\n62\n7\n162\n240\n91\n165\n20\n13\n39\n84\n18\n20\n60\n10\n34\n30\n42\n37\n11\n2\n25.0\n0.0\n0.0\n9.1\n0.0\n14.3\n0.0\n33.3\n4.2\n0.0\n0.0\n0.0\n0.0\n%\nCatch Desc.\nCoho\n1\n1\n1\n1\n1\n4\n5\n3\n11\n3\n7\n13\n3\n24\n2\n1\n5\n1\n0.0\n100.0\n20.0\n12.5\n11.8\n0.0\n0.0\n11.1\n0.0\n14.3\n0.0\n16.7\n0.0\n8.2\n16.3\n15.8\n6.3\n22.0\n3.6\n14.3\n8.3\n12.3\n25.0\n11.8\n21.4\n20.0\n17.1\n16.7\n21.3\n10.8\n21.4\n100.0\n%\nSteelhead\nDesc.\n1\n1\n1\n2\n1\n7\n1\n29\n16\n15\n1\n11\n1\n4\n2\n8\n1\n2\n3\n1\n22\n8\n13\n4\n3\n3\nCatch\n2\n1\n5\n8\n17\n11\n9\n9\n6\n58\n6\n6\n2\n355\n98\n95\n16\n50\n28\n28\n24\n65\n4\n17\n14\n5\n129\n48\n61\n37\n14\n3\n5.0\n9.8\n4.0\n8.5\n7.8\n15.7\n13.3\n6.9\n9.3\n11.0\n27.0\n10.6\n9.2\n8.4\n2.6\n10.3\n9.6\n11.0\n9.4\n6.8\n5.0\n13.3\n5.0\n8.0\n23.5\n11.0\n13.0\n3.8\n15.0\n18.3\n36.5\n15.5\n19.6\n22.2\n0.0\n10.0\n5.9\n8.3\n%\nYearling\nchinook\nDesc.\n11\n13\n4\n9\n8\n16\n14\n7\n11\n11\n27\n11\n10\n9\n3\n12\n10\n10\n12\n7\n5\n16\n5\n9\n24\n11\n13\n2\n12\n19\n31\n11\n10\n2\n1\n1\n1\nCatch\n222\n132\n100\n106\n102\n102\n105\n102\n118\n100\n100\n104\n109\n107\n115\n116\n104\n91\n127\n103\n101\n120\n100\n113\n102\n100\n100\n52\n80\n104\n85\n71\n51\n9\n7\n10\n17\n12\nContinued.\n0.0\n0.0\n100.0\n0.0\n0.0\n0.0\n0.0\n3.1\n5.3\n0.0\n45.5\n0.0\n6.0\n4.8\n11.5\n13.0\n7.2\n16.9\n9.5\n10.7\n10.0\n14.9\n10.7\n4.2\n3.5\n1.6\n1.9\n1.4\n6.6\n%\nSubyearling\nchinook\nCatch Desc.\n1\n1\n1\n5\n3\n1\n3\n10\n13\n40\n24\n28\n28\n23\n12\n5\n3\n2\n3\n5\n7\nAppendix Table 1.\n2\n2\n1\n3\n1\n15\n8\n32\n19\n9\n11\n35\n50\n21\n26\n77\n180\n236\n253\n262\n279\n154\n112\n120\n120\n124\n155\n142\n106\nUnit 7, Slot B\n25 April\n26 April\n27 April\n28 April\n29 April\n1 June\n2 June\n3 June\n4 June\n5 June\n6 June\n7 June\n22 June\n23 June\n24 June\n27 June\n28 June\n29 June\n30 June\n2 May\n3 May\n4 May\n5 May\n6 May\n9 May\n10 May\n11 May\n12 May\n13 May\n16 May\n17 May\n18 May\n19 May\n20 May\n23 MAY\n24 May\n25 May\n26 May\n27 May\n29 May\n31 May\nTest\ndate","%\nSockeye\nDesc.\nCatch\n%\nCatch Desc.\nCoho\n%\nSteelhead\nDesc.\nCatch\n20.0\n0.0\n11.1\n0.0\n57.1\n0.0\n0.0\n33.3\n3.7\n4.3\n5.4\n0.0\n6.0\n5.6\n0.0\n0.0\n%\nYearling\nchinook\nDesc.\n1\n3\n4\n1\n1\n1\n2\n5\n1\nCatch\n9\n9\n15\n7\n5\n2\n2\n3\n27\n23\n37\n4\n84\n18\n22\n3\nAppendix Table 1. Continued.\n6.9\n8.3\n6.5\n5.1\n2.6\n4.3\n3.5\n4.0\n4.1\n0.8\n9.6\n2.8\n5.1\n2.0\n14.1\n19.5\n%\nSubyearling\nchinook\nDesc.\n10\n9\n14\n7\n3\n5\n5\n4\n5\n1\n26\n3\n13\n2\n39\n23\nCatch\n145\n108\n215\n137\n114\n117\n142\n100\n121\n121\n271\n106\n257\n101\n276\n118\nUnit 7, Slot B\n1 July\n6 July\n7 July\n8 July\n9 July\n10 July\n11 July\n12 July\n13 July\n14 July\n15 July\n18 July\n19 July\n20 July\n21 July\n22 July\nTest\ndate","<0.0001\n<0.0001\n0.1140\n0.0003\n<0.0001\n<0.0001\n0.1140\n0.0003\n0.2846\n0.7872\n0.5977\n0.2614\n<0.1536\n<0.1536\n0.0017\nP\npassage efficiency (OPE) studies at McNary Dam, 1995. Asterisks indicate\nAppendix Table 2. Statistical analyses of mean descaling estimates obtained during orifice\n3,95\n16\n3,102\n3,80\n3,25\n3,95\n3,102\n3,80\n3,25\n17\n5\n15\n3,100\n3,100\n14\ndf\nF = 10.66*\nF = 9.06*\nt = 3.86*\nF = 6.78*\nCalculated\nF = 10.66\nF = 9.06\nF = 2.19\nF = 6.78\nF = 2.19\nt = 1.11\nt = 0.27\nt = 0.56\nt = 1.17\nF = 1.79\nF = 1.79\nstatistic\ntest\nScreen mounted beam extension vs.\nbeam mounted beam extension vs.\nScreen mounted beam extension vs.\nbeam mounted beam extension vs.\nstatistically significant differences between means.\nNorth orifice vs. south orifice\nNorth orifice vs. south orifice\nOrifice trap vs. gatewell\nOrifice trap vs. gatewell\nAnalysis\nsource\ncontrol\ncontrol\npaired t-test\npaired t-test\npaired t-test\npaired t-test\npaired t-test\nRBANOVA\nRBANOVA\nPaired sample Student's t-test using 2-day block pairing.\nAnalysis\nANOVA\nANOVA\nANOVA\nANOVA\nANOVA\nANOVA\nANOVA\nANOVA\ntype\nSubyearling chinook\nSubyearling chinook\nSubyearling chinook\nYearling chinook\nYearling chinook\nYearling chinook\nRandomized block analysis of variance.\nSingle factor analysis of variance.\nSpecies\nSteelhead\nSteelhead\nSteelhead\nSockeye\nSockeye\nSockeye\nCoho\nCoho\nCoho\n1 August\n1 August\n1 August\n21 - 29 April\n21 - 29 April\n21 - 29 April\n21 - 29 April\n1 - 6 June\n1 - 6 June\n1 - 6 June\n22 - 30 June\n1 - 31 July\n1 - 31 July\n22 - 30 June\n1 - 31 July\n1 - 31 May\n1 - 31 May\n1 - 31 May\ndates\nTest\nseries\nTest\n1b\n1a\nla\n2a\n2a\n2b\na\nb\nC","30\nAppendix Table 3. Nonsalmonid species incidentally captured in\norifice traps at McNary Dam, 1995. Species\nare listed in order of total catch.\nTotal\nScientific name\nCommon name\ncatch\nEntosphenus tridentata\nlamprey\n1,136\nAlosa sapidissima\nshad\n214\nProsopium williamsoni\nwhitefish\n170\nsucker\nCatostomus spp.\n96\nAcrocheilus alutaceus\nchiselmouth\n83\nPerca flavescens\nyellow perch\n77\nMylocheilus caurinus\npeamouth\n68\nMicropterus spp.\nbass\n34\nRichardsonius balteatus\nredside shiner\n32\nPtychocheilus oregonensis\nsquawfish\n7\nGasterosteus aculeatus\nstickleback\n6\nPomoxis nigromaculatus\nblack crappie\n4\nCyprinus carpio\n4\ncarp\nchannel catfish\nIctalurus punctatus\n3\nColumbia transmontanus\nsand roller\n2\nLepomis macrochirus\nbluegill\n2\nStizostedion vitreum\nwalleye\n1","31\nAppendix Table 4.\nDaily yearling chinook orifice passage\nefficiency (OPE) estimates obtained using\norifice traps (Trap OPE) and mark/recapture\n(M/R OPE) estimation methods, McNary Dam,\n1995.\nOrifice trap estimation method\nTest\nOrifice\nMark/recapture estimation method\ndate\nGatewell\ntrap\nTrap\nTrap OPE\nMarked\nMarked\nM/R OPE\ncatch\ncatch\nrecaptured\nestimate\nreleased\nestimate\n21 April\nSe\n381\n720\n65.4\nN°\n22 April\n592\n636\n51.8\n25 April\nS\n655\n1067\n62.0\n26 April\nN\n749\n1296\n63.4\n27 April\nS\n287\n788\n73.3\n28 April\nN\n100\n57\n43.0\n29 April\nS\n419\n741\n63.9\n100\n38\n62.0\n1 May\nN\n100\n26\n74.0\n2 May\nS\n234\n1003\n81.1\n73\n18\n75.3\n4 May\nN\n407\n1657\n80.3\n82\n13\n84.1\n5 May\nS\n100\n31\n69.0\n6 May\nN\n597\n1966\n76.7\n100\n16\n84.0\n9 May\nS\n610\n1983\n76.5\n100\n29\n71.0\n10 May\nN\n808\n1450\n64.2\n100\n36\n64.0\n11 May\nS\n780\n3000\n79.4\n100\n20\n80.0\n12 May\nN\n623\n1402\n69.2\n100\n32\n68.0\n13 May\nS\n690\n1951\n73.9\n100\n13\n87.0\n16 May\nN\n840\n1814\n68.3\n95\n26\n72.6\n17 May\nS\n671\n2056\n75.4\n100\n3\n97.0\n18 May\nN\n669\n4462\n87.0\n100\n14\n86.0\n19 May\nS\n807\n1595\n66.4\n100\n24\n76.0\n20\nMay\nN\n755\n1193\n61.2\n100\n15\n85.0\n23 May\nS\n283\n718\n71.1\n100\n40\n60.0\n24\nMay\nN\n100\n36\n64.0\n25\nMay\nS\n76\n418\n84.6\n100\n14\n86.0\n26\nMay\nN\n123\n269\n68.6\n27 May\nS\n235\n561\n70.5\n100\n12\n88.0\n29 May\nN\n48\n426\n89.9\n100\n8\n92.0\n31 May\nS\n5\n272\n98.2\n97\n3\n96.9\n1 June\nN\n47\n130\n73.4\n99\n13\n86.9\n2 June\nS\n141\n269\n65.6\n98\n35\n64.3\n3 June\nN\n8\n125\n94.0\n4 June\nS\n42\n112\n72.7\n103\n24\n76.7\n5 June\nN\n53\n328\n83.8\n100\n17\n83.0\n6 June\nS\n30\n153\n83.6\n100\n12\n88.0\n7 June\nN\n16\n66\n80.5\n95\n1\n98.9\na\nFraction captured from gatewell using dip baskets at the end of the test.\nb\nFraction enumerated from orifice trap during the test.\nC\nNumber of marked fish released at the beginning of the test, time t.\nd\nNumber of marked fish recaptured at the end of the test, time t+1.\ne\nSouth orifice trap.\na\nNorth orifice trap.","Statistical analyses of mean orifice passage efficiency estimates for tests at\n0.9586\n0.5399\n0.6483\n0.9241\n0.9559\n0.0174\n0.2555\n0.0706\n<0.0001\nP\nMcNary Dam, 1995. Asterisks indicate statistically significant differences\n30\n30\n12\n26\n13\n24\n28\n7\n17\nstatistic df\nCalculated\n2.56*\n2.13*\n6.14*\n0.05\n0.62\n0.47\n0.10\n0.06\n1.16\ntest\nNorth orifice trapb vs. south orifice trap\nNorth orifice trap vs. south orifice trap\npaired t-test North orifice M/Rd vs. south orifice M/R\nNorth orifice M/R vs. south orifice M/R\nOrifice trap method vs. M/R method\nOrifice trap method vs. M/R method\nAnalysis\nsource\npaired t-test\nMark/recapture orifice passage efficiency estimation method.\npaired t-test\npaired t-test\n2 t-testa\nOrifice trap orifice passage efficiency estimation method.\nbetween treatment means.\nAnalysis\n2 t-test\n2 t-test\n2 t-test\n2 t-test\nPaired sample Student's t-test using 2 day block pairing.\ntype\nSubyearling chinook\nSubyearling chinook\nSubyearling chinook\nYearling chinook\nYearling chinook\nYearling chinook\nSpecies\nSteelhead\nSockeye\nTwo sample Student's t-test.\nCoho\nAppendix Table 5.\n1 August\n21 - 30 April\n28 - 29 April\n28 - 29 April\n1 - 6 June\n1 - 6 June\n1 - 6 June\n22 - 30 June\n1 - 31 July\n28 - 30 June\n1 - 22 July\n28 - 30 June\n1 - 22 July\n1 - 31 May\n1 - 31 May\n1 - 31 May\ndates\nTest\nseries\nTest\nla\n1b\n1c\n2a\n2b\n2c\na\nb\nC\nd","Trap OPE\nestimate\n50.0\n89.9\n90.3\n90.9\n87.7\n90.0\n93.0\n90.6\n81.7\n93.5\n87.4\n94.5\n88.9\n93.4\n91.7\n89.4\n94.5\n94.4\n96.4\n98.2\n90.5\n85.4\n89.9\n72.6\n85.9\n75.5\n82.0\nAppendix Table 6. Daily non-target salmonid orifice passage efficiency (OPE) estimates\nobtained using the orifice trap (Trap OPE) estimation method, McNary\nSockeye\ncatch\n2\n17\n28\n80\n71\n289\n557\n856\n1200\n3303\n1320\n835\n547\n513\n1244\n1102\n858\n679\n1279\n3667\n1655\n1454\n373\n188\n238\n120\n164\nTrap\nGatewell\ncatch\n2\n2\n3\n8\n10\n33\n42\n89\n268\n228\n190\n49\n68\n36\n113\n131\n50\n40\n48\n67\n174\n212\n42\n71\n39\n39\n36\nTrap OPE\nestimate\n100.0\n83.3\n95.3\n93.9\n79.4\n96.9\n98.4\n99.0\n95.9\n98.8\n97.1\n95.8\n96.0\n91.7\n88.9\n88.9\n50.0\n100.0\n80.0\nFraction captured from gatewell using dip baskets at the end of the test.\ncatch\nCoho\nTrap\n14\n40\n82\n31\n81\n312\n369\n882\n656\n1361\n134\n115\n167\n121\n32\n8\n1\n5\n5\nGatewell\ncatch\n8\n4\n2\n21\n10\n6\n9\n28\n16\n4\n5\n7\n11\n4\n1\n1\n1\nFraction enumerated from orifice trap during the test.\nTrap OPE\nestimate\n98.8\n92.1\n91.4\n93.5\n92.9\n93.7\n94.6\n92.5\n92.7\n94.5\n95.2\n96.4\n91.7\n90.5\n93.7\n92.4\n91.6\n91.9\n91.6\n93.4\n89.2\n86.6\n82.8\n92.4\n90.1\n80.6\n85.4\nSteelhead\nDam, 1995.\ncatch\nTrap\n167\n220\n373\n159\n183\n177\n300\n347\n416\n599\n540\n805\n866\n742\n754\n524\n1364\n2384\n1374\n1576\n979\n502\n212\n146\n137\n58\n88\nGatewell\ncatch\n2\n19\n35\n11\n14\n12\n17\n28\n33\n35\n27\n30\n78\n74\n51\n43\n125\n210\n126\n112\n119\n78\n44\n12\n15\n14\n15\nSouth orifice trap.\nNorth orifice trap.\nOrifice\ntrap\nSc\nNd\nS\nN\nS\nN\nS\nN\nS\nN\nS\nN\nS\nN\nS\nN\nS\nN\nS\nN\nS\nN\nS\nN\nS\nN\nS\n21 April\n22 April\n25 April\n26 April\n27 April\n28 April\n29 April\nTest\ndate\n1 May\n2 May\n4 May\n5 May\n6 May\n9 May\n10 May\n11 May\n12 May\n13 May\n16 May\n17 May\n18 May\n19 May\n20 May\n23 May\n24 May\n25 May\n26 May\n27 May\na\nb\nC\nd","30\nTrap OPE\nestimate\n89.0\n97.6\n58.3\n57.1\n95.5\n81.1\n74.2\n78.7\n88.2\nSockeye\ncatch\n105\n80\n42\n72\n63\n86\n72\n48\n15\nTrap\nGatewell\ncatch\n13\n2\n30\n54\n3\n20\n25\n13\n2\nTrap OPE\nestimate\n100.0\n100.0\n100.0\n100.0\n100.0\n100.0\n100.0\n100.0\n100.0\ncatch\nCoho\nTrap\n16\n3\n4\n2\n1\n1\n2\n3\n1\nGatewell\ncatch\nTrap OPE\nestimate\n96.9\n100.0\n95.6\n90.1\n100.0\n94.6\n94.2\n96.8\n100.0\nSteelhead\nContinued.\ncatch\nTrap\n123\n46\n86\n273\n89\n88\n49\n60\n58\nGatewell\ncatch\n4\n4\n30\n5\n3\n2\nAppendix Table 6.\nOrifice\ntrap\nN\nS\nN\nS\nN\nS\nN\nS\nN\n1 June\n2 June\n3 June\n4 June\n5 June\n6 June\n7 June\n29 May\n31 May\nTest\ndate","35\nAppendix Table 7.\nDaily subyearling chinook orifice passage\nefficiency (OPE) estimates obtained using\norifice traps (Trap OPE) and mark/recapture\n(M/R OPE) estimation methods, McNary Dam,\n1995.\nMark/recapture estimation method\nTest\nOrifice\nOrifice trap estimation method\ndate\nGatewell\nTrap\nMarked\nM/R OPE\nTrap OPE\nMarked\ntrap\ncatchb\nrecaptured\ncatch\nestimate\nestimate\nreleased\n22 June\nNe\n424\n5504\n92.8\nS\n23 June\n379\n701\n64.9\n24 June\n68.4\nN\n645\n1393\n27 June\nS\n1392\n3434\n71.2\n28 June\nN\n2419\n5242\n68.4\n100\n100.0\n1\n99.0\n29 june\nS\n1656\n3973\n70.9\n100\n30 June\n100\n2\n98.0\nN\n1515\n5275\n77.7\n100.0\n1 July\nS\n783\n7161\n90.1\n100\na\n6 July\n16151\n91.3\n100\n13\n87.0\nN\n1537\n7 July\n5482\n100.0\nS\n610\n90.0\n100\n8 July\n5440\n63.3\nN\n3157\n100\n17\n83.0\n9 July\nS\n193\n2355\n92.4\n100\n100.0\n100.0\n10 July\nN\n731\n2020\n73.4\n100\n11 July\nS\n707\n9710\n100.0\n93.2\n100\n12 July\nN\n556\n2731\n83.1\n100\n4\n96.0\n13 July\nS\n56\n803\n93.5\n100\n1\n99.0\n100.0\n14 july\nN\n17\n477\n96.6\n100\n100.0\n15 July\nS\n120\n1679\n93.3\n100\n98.0\n18 July\nN\n172\n984\n85.1\n100\n2\n19 July\nS\n31\n1027\n97.1\n20 July\nN\n288\n970\n77.1\n100\n7\n93.0\n21 July\nS\n409\n1459\n78.1\n100\n1\n99.0\n100.0\n22 July\nN\n819\n1971\n70.6\n100\n25 July\nS\n104\n742\n87.7\n26 July\nN\n102\n812\n88.8\n27 July\nS\n61\n288\n82.5\n28 July\nN\n56\n6672\n92.3\n29 July\n84.3\nS\n55\n296\n30 July\n297\n88.7\nN\n38\n1 August\nS\n26\n436\n94.4\na\nFraction captured from gatewell using dip baskets at the end of the test.\nb\nFraction enumerated from orifice trap during the test.\nC\nNumber of marked fish released at the beginning of the test, time t.\nd\nNumber of marked fish recaptured at the end of the test, time t+1.\ne\nNorth orifice trap.\nf\nSouth orifice trap."]}