-foi PASSAGE OF SALMONOIDS THROUGH A DARKENED FISHWAY Marine Biological Laboratory ; . 1 -1959 WOODS HOLE, MASS. SPECIAL SCIENTIFIC REPORT- FISHERIES No. 300 UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE EXPLANATORY NOTE The series embodies results of Investigations, usually of restricted scope, Intended to aid or direct management or utilization practices and as guides for administrative or legislative action . It is issued in limited quantities for Official use of Federal, State or cooperating agencies and in processed form for economy and to avoid delay in publication . Ikiited States Department of the Interior, Fred A. Seaton, Secretary Fish and Wildlife Service, Arnie J. Suomela, Commissioner PASSAGE OF SALMONOIDS THROUGH A DARKENED FISHWAY by Clifford W. Long Fishery Research Biologist Bureau of Commercial Fisheries United States Fish and Wildlife Service Special Scientific Report — Fisheries No. 300 Washington, D. C. May 1959 The Library of Congress catalogue card for this publication is as follows: Long, Clifford W Passage of salmonoids through a darkened fishway. Washington, U. S. Dept. of the Interior, Fish and Wildlife Service, 1959. iv, 9 p. illus., diagrs., tables. 27 cm. (U. S. Fish and Wildlife Service. Special scientific report — fisheries, no. 300) 1. Flshways. i. Title. [SH11.A335 no. 300] (Series) Int 59-61 V. S. Dept. of the for Library of Congress Interior. Library The Fish and Wildlife Service series, Special Scientific Report — Fisheries, is catalogued as follows: U. S. Fish and Wildlife Service. Special scientific report : fisheries, no. 1- iWashington, 1949- no. Illus., maps, diagrs. 27 cm. Supersedes In part the Service's Special sclentlflc report 1. Fisheries — Research. SH11.A335 639.2072 Library of Congress (2j 69-60217 11 TABLE OF CONTENTS Page Introduction 1 Fishway 1 Procedure 2 Results and discussion 4 Summary 5 Acknowledgment 5 Literature cited 5 Appendix 6 111 Entfonce Diversion Barrier Test Area (Fishwoy) i Flow Introduction Pool -Weir 60 Water flow —y Exi Fishwoy Fishway Introduction Pool Entrance Gate Figure 1. --Sketch showing principal units of research facility in plan view. IV PASSAGE OF SALMONOIDS THROUGH A DARKENED FISHWAY -' 1/ by Clifford W. Long U. S. Fish ahd Wildlife Service Seattle, Washington ABSTRACT An experiment to produce specific information on rate of ascent of salmonolds through a darkened fishway was conducted in a short, pool -and -overfall fishway without submerged orifices. The fish (98 percent steelhead - Salmo qairdneri) negotiated the 6-pool fishway significantly faster in near-total darkness than in light conditions approximating a bright, cloudy day. JNTRODUCTION In the construction of fishways, occa- sionally it is necessary to provide covering to protect against slides and debris. Also, it is not uncommon to find fishway channels covered for roadway crossings, decking, and other purposes. Such situations may result in dimly lighted fishway channels, some of which have been provided with artificial lighting to simulate natural light prevail- ing in outside fishways. Whether or not artificial lighting is necessary or even desirable, has not been fully demonstrated. Although experiments at Bonneville Dam (U. S. Army, Corps of Engi- neers, 1948) indicated that under suitable hydraulic conditions salmonoids will pass through a darkened fishway, specific infor- mation on rate of ascent was not obtained. To provide answers to these questions, an experiment designed to measure the effect of total or near-total dcirkness on the pas- sage of adult migrating salmonoids through a pool- and-overf all fishway Wcis conducted. Steelhead (Salmo gairdneri) comprised 98 percent of those fish tested. \/ Research financed by the U. S. Army Corps of Engineers cis a part of a broad program of fisheries-engineering re- search for the purpose of providing de- sign criteria for more economical and more efficient fish passage facilities at Corps projects on the Columbia River. FISHWAY The experiment was conducted in the Fisheries-Engineering Research Facility which adjoins the Washington shore fishway at Bonneville Dam on the Columbia River. A by-pass diverts a part of the Washington shore fishway flow through the facility and back into the fishway again. Each day a portion of adult salmonoids moving up the Washington fishway were diverted into the facility, and after passing through the experimental area, they continued their movement in the by-pass until they again entered the main fishway. Figure 1 shows schematically the elements of the facility (described by Collins — ) essential to the description of this experiment: neunely, the collection pool in which the test fish accumulated, the fishway introduction pool into which the fish were released, the test area (fishway), and the flow introduction pool into which the fish passed after ascending the fishway. The test area was a pool- and-overf all- type fishway without submerged orifices. The fishway was 4 feet wide by 96 feet long, and consisted of six 16-foot pools with a 1-foot rise between pools. Because of the sloped floor, water depth in each pool varied from 6.8 feet in the lower end to 5.8 feet 2/ Gerald B. Collins. Research in fish passage problems. U. S. Fish and Wild- life Service. Manuscript in prepara- tion. Canvas Light Baffles Plywood Cover \ V Plunging Flow Canvas Light Baffles / \ y, Figure 2. — Schematic illustration of test area (fishway) showing ply- wood co-'/er, canvas baffles, and plunging flow pattern in side view. in the upper end. Square crested weirs 7 1/2 inches wide were painted white on top to facilitate observing the fish as they passed in and out of the fishway. The head on each weir, measured four feet upstream of the weir, was 0.8 foot. The flow pattern was that generally described as "plunging flow" (figure 2). For the "dark" or test trials, the fishway was covered with plywood sheets and sealed with canvas strips (figure 3). To reduce the light entering the entrance and exit of the resulting fishway tunnel, canvas baffles were extended from the plywood cover to within two inches of the water surface in the center of both first and last pools (fig- ure 2). To further reduce the light enter- ing the fishway the laboratory was darkened. Light readings y foot candle in the co entry gate (figure 1) foot candle at the fi (the upstream end of and at the last weir observations made in the fishway indicated register in the humcin ielded values of 0.1 llection pool near the , and 0.01 and 0.02 rst weir of the fishway the introduction pool) of the fishway. Visual the central portion of insufficient light to eye. For the "light" or control trials, the plywood covering was removed and 1000-watt mercury-vapor lajnps were suspended six feet above the fishway (figure 4) and six feet apart (raecisured center to center) down the center of the fishway. These Isimps provided light intensities at the surface of the fishway pools ranging from 300 foot candles measured along the wall to 1000 foot ccuidles directly beneath the lights. This range of light intensities approximates outdoor con- ditions on a bright, cloudy day. Water temperatures varied from 65.5" F. to 66.0° F. on the two days the experi- ment was conducted — July 23 cuid 24, 1957. Turbidimeter and Secchi's disc readings yielded values of 10 (equal to 10 p. p.m. Si02) and 4.5 feet respectively on both days. PROCEDURE The experiment consisted of four con- trol and four tests trials. As only one fishway was used, the control and test trials were conducted alternately. Averages of 26 and 21 fish were utilized for each control and test trial respectively. The species composition for the four groups passed under the dark (test) condition WM 82 steelhead and 1 chinook, and for the four groups passed under the light (control) con- dition, 100 steelhead aind 3 chinook. About 10 to 15 minutes before begin- ning a test trial, we darkened the building to permit the observers to adapt their eyes to the limited light. At the end of this time, the observers could count the fish as they passed through the entry gate and over the white weir crests of the fishway. An observer stationed at the collec- tion pool initiated each test and each control trial by opening the entrance gate. Figure 3. — The dark fishway (on right) showing plywood and canvas covering. Building interior was darkened during trials. Figure h. — The lighted fishway. Upper five pools of fishway are shown on extreme right . The fish were then allowed to pass through the gate and commence their ascent of the fishway. When an adequate sample of fish had entered, the entrance gate was closed. Each trial was terminated when all fish entered had passed through the fishway. The opening of the entrance gate signaled the start of each trial. Observers stationed at the first weir (54 2^) and the last weir (60 2/) were equipped with push- button switches that activated recording pens in an operations recorder. The moment a fish passed weir 54 or weir 60 the corre- sponding switch was pressed and a recording 3/ The numbers 54 and 60 refer to the "" elevation of the weir crests in feet above mean sea level. pen marked the time of passage (as related to the start) on a continuous paper tape. RESULTS AND DISCUSSION The results of the four control and four test trials are presented in figure 5 (see Appendix 1 for origincil data). The median entry (at weir 54) and median exit (at weir 60) times for the grouped control (n = 103) and grouped test trials (n = 83) correspond to the intersection of the median or 50 percent line sind the respective cumu- lative percent lines. Examination of these median times reveals two main points: (1) the fish were slower in entering the fishway under the dark condition thein under the light condition, as evidenced by the differ- ence in the respective median entry times at weir 54,aand (2) the length of time Z U) o tc tu Q. > < _J ID O 100 90 80 70 60 50 40- 30- 20 10 Light"entry 0° "Dark"entry ^j'^ / •r.~' ■ 0 "Dork" exit-,.. .••/ .••/ /^■Lighf"exlt / ._LJ__i. / o • I I • ' o • I % •! 0 . I ::/ :/ 50 60 — I 65 — t— 5 — I — 10 15 20 1 25 TIME — I — 30 IN 1 1 — 35 40 MINUTES 45 55 Figure 5. --Cumulative entry and exit (percent) in minutes during light and dark fishway trials. 4 (median elapsed time) -' required by the fish to negotiate the fishway was less under the dark thcin under the light condition. The slower median entry time at weir 54 under the dark condition can be at least partially explained by the fact that the fish were observed to hesitate more before passing through the small entrance gate (10 inches wide) in the dark condition than in the light. Table 1 lists the median elapsed times for the four control and four test trials. The average median elapsed time under the dark condition was 2.0 minutes and the aver- age median elapsed time under the light con- dition was 8.5 minutes. A "t" test indi- cates that passage through the fishway was significantly faster in the dark condition. Tcible 1. — Summary of light and dark fishway trials showing effect of lighting condi- tion upon passage time. C o nd i t ion 1 ight Dark Median Median Trial elapsed elapsed number N time (minutes) N time (minutes) 1 30 6.13 22 1.28 2 24 7.32 19 2.18 3 23 11.93 20 2.75 4 26 8.53 22 1.78 The degree to which the results of this limited experiment may be safely ap- plied is a matter of conjecture. Additional experiments are necessary to determine the relationship between fishway dimension and design and the degree to which the behavior of salmonoids is affected by low light in- tensities. As the present experiment applies almost exclusively to steelhead, it will be of interest to examine the behavior of other salmonoids under similar test conditions. £/ The mediein elapsed time is defined as the difference between the median entry (at weir 54) and median exit (at weir 60) time. SUMMARY The experiment was designed to deter- mine the effect of low light intensities upon the rate of passage of adult migrating salmonoids through a pool-and-overf all-type fishway without submerged orifices. The fishway, 4 feet wide by 96 feet long, con- sisted of six 16-foot pools with a 1-foot rise between pools. Average water depth in the pools was 6.3 feet and the head on each weir was 0.8 foot. The fishway was darkened for four test trials aind lighted for four control trials. A total of 82 steelhead and 1 chinook were passed through the darkened fishway and 100 steelhead and 3 chinook through the lighted fishway. Light measurements taken during the dark condition yielded values between 0.1 foot candle downstream of the fishway and near-total darkness in the central por- tion of the fishway. Light readings taken at the surface of the fishway pools during the lighted condition yielded values ranging from 300 to 1000 foot candles. The average mediaui elapsed passage time through the dark fishway was 2.0 min- utes and through the light fishway 8.5 minutes. A significantly faster rate of passage through the dark fishway is indi- cated. ACKNOWLEDGMENT Personnel participating in the experi- ment included Dr. Gerald B. Collins, Carl H. Elling, Joseph R. Gauley, Charles R. Weaver, Clark S. Thompson, Robert J. Hol- corab, James S. Johnson, and D. Lee Ellison. The manuscript was reviewed and suggestions were offered by the Biometrics Unit of the Pacific Salmon Investigations and Milo C. Bell. The author gratefully acknowledges this assistance. LITERATURE CITED S. ARMY, CORPS OF ENGINEERS 1948 Passage of fish over Bonneville Dam, Columbia River, Oregon and Washington. Ann. Rep. Corps of Engineers, U. S. Army, Office of the District Engineer, Portland, Oregon. 21 p. afpe:!dix Tr.ble 2»— Entrj' and exit observations (time in Tninutes from start) of fish passage during lij:ht and dark fishv.'ny conditions, trial number 1, July 23, 1957. Observation Light fishway (control) Dark fishwa. / (test) numbe r Entry time Exit time Entrj' tim.e Exit time (Vfeir 54) (Weir 60) (Weir 54) Yfeir 60) 1 0.25 1.77 0.33 1.46 2 0.30 2.22 0.52 2.23 3 0.32 2.60 0.75 2.50 4 0.33 3.15 1.03 2.83 5 0.35 3.25 1.18 3.13 6 0.37 3.38 1.40 7 C.38 3.46 1.63 3.32 8 0.46 3.50 1.92 3.37 9 0.46 3.80 1.97 3.73 10 0.48 3.83 2,30 4.00 11 0.50 5.90 2.70 4.23 12 0.57 4.46 2.72 4.58 13 0.60 4.57 2.75 4.67 14 0.67 6.12 2.77 4.82 15 0.68 6.80 2.77 5.13 16 0.70 6.83 3.46 6.28 17 0.77 7.73 3.60 12.46 18 0.80 7.7B 3.63 13.68 19 0.87 8.83 3.83 21.10 20 0.90 8.87 4.02 23.90 21 0.93 8.92 4.30 27.67 22 1.20 9.07 12.30 45.17 23 1.43 9.87 24 1.53 11.07 25 1.65 14.60 26 1.78 15.10 27 1.98 22.50 28 O TO 29.00 29 2.70 64.58 30 4.13 64.75 Table 3. — Entrj' and exit observations (time in ninutes fror. start) of fish passage during li;ht ind dark fishway conditions, trial number 2, July 23, 1957. Observation Light fishway (control) Dark fishway ' (test) nunbe r Entry time Exit time Entry time Exit time ('/Yeir 54) (Weir 60) (Weir 54) (Weir 60) 1 0.18 2.02 0.25 1.05 2 0.20 2.05 0.73 1.83 3 0.28 2.57 0.77 2.77 4 0.37 2.73 1.02 4.00 5 0.38 2.90 1.13 4.30 6 0.42 3.27 1.93 4,43 7 0.4C 3.82 2.23 4.52 8 0.48 3.85 2.53 4.97 9 0.52 5,40 2. 67 5.22 10 0.53 5.53 2.87 5.43 11 0.58 7.18 2.98 5.68 12 0.58 7.90 3.03 8.83 13 0.68 8.00 3.05 9.18 14 0.73 8.02 3.07 10.13 15 0.75 8.82 3.50 11.38 16 0.78 9.53 3.78 11.43 17 0.92 9.77 3.90 12.28 18 1.63 9.80 3.92 13.38 19 1.78 11.72 4.57 14.73 20 1.92 13.53 21 1.93 15.03 22 2.03 15.15 23 3.63 17.60 24 10.13 20.16 Table 4,~Entrj'' and exit observations (tine in ninutes from start) of fish passage during light and dark fishvmy conditions, trial number 3, July 23, 1957. Observation Light fishwa; r (control) Dark fishway (test) number Entry time Exit time Entry tine Exit time (Weir 54) (lYeir 60) (Weir 54) (y/eir 60) 1 0.28 3.63 0.25 1.72 2 0.32 6.27 0.63 2.17 3 0.50 6.72 0.87 2,28 4 0.50 7.37 0.93 2.55 5 0.53 7.43 0.97 3.05 6 0.68 7.50 1.33 3.12 7 0.73 9.12 1.35 3.33 8 0.88 9.18 1.42 3,33 9 0.97 10.18 1.46 3.35 10 0.98 10.48 1.55 3.40 11 1.00 11.55 1.65 4.77 12 1.02 12.95 1.67 5.00 13 1.13 12.98 1.72 5.92 14 l.P.O 13.12 1..90 6.40 15 1.23 14.60 2.58 9.27 16 1.40 14.75 3.25 9.63 17 1.50 15.18 3.37 18.10 18 2.45 18.03 3.63 19.78 19 2.46 18.83 3.70 21.53 20 2.48 20.46 4.12 21.73 21 3.15 21.97 22 3.43 •'7.55 23 3.60 34.08 Table 5. — Entry and exit observations (tine in minutes from start) of fish passage during li^ht and dark fishway conditions, trial number 4, July 24, 1957. Observation Lir;ht fishway (control) Drrlc fishrre.; ' (te?t) number Entry time Kxit time Entry tir.e Exit tim.6 ("feir 54) C.Yeir eo) (Vfeir 54) (-.Teir 60) 1 0.25 1.82 0.25 1.10 2 0.30 5.32 0.30 1.83 3 0.32 3.37 0.52 1.90 4 0.32 3.83 0.98 2.37 5 0.33 5.97 1.05 2.53 6 0.33 3.98 1.40 2.70 7 0.35 6.70 1.42 2.82 8 0.37 7.57 1.46 3.08 9 0.37 7.G7 1.57 3.23 10 0.42 8.32 1.62 3.37 11 0.48 8.57 1.95 3.57 12 0.57 8.72 1.97 3.90 13 0.50 8.90 1.98 4.15 14 0.G3 9.37 2.07 5.37 15 0.72 9.50 2.15 7.50 16 0.82 9.60 9 91 12.62 17 0.85 10.42 15.52 18 0.85 10.70 0 ■r'-i 18.20 19 0.95 11.77 2.58 19.30 20 0.97 12.13 3.10 24.78 21 1.05 12.27 3.50 33.27 22 1.25 12. "0 G.OO 36.48 23 1.32 1-1. ".0 24 1.45 M.A5 25 1.80 1C.02 26 0.33 21.03 INT.DUP.,D.C.59- 5*0 M Ml I i 5 WHSE 01297