PASSAGE OF ADULT CIDNOOK SALMONTHROUGH BROWNLEE RESERVOIR, 1960-62

By PARKER S. TREFETHEN AND DoYLE F. SUTHERLAND, Fishery Biologists

BUREAU OF CoMMERCIAL FISHERIES BiOLoGICAL LABORATORY

SEATTLE, WASHINGTON 98102

ABSTRACT

Adult chinook slilmon (Oncorhynchus tshau'Ytscha)were tagged and released in Brownlee Ueservoir and up­streamin the Snake River todetermineifadults could passthrough the reservoir and reach spawning grounds.Experiments with Petersen disk tags were performed bythe Idaho Fish and Game Depart ment in 1960-6L and bythe Department and the Bureau of ConllnerciaL Fish­eries in 1962. In addition. the Bureau marked salmonwith sonic tags in 1961-62 to trace orientation andInOl-ement. Information was also obtained on the use oftributary streams for spawning and success of spawn-ing. "

Fish marked with Petersen disk tags and released inthe 92.5-km.-long reservoir reached their spawning areaas suceeilsfulJ)' as thOile transported abOl'e tIle impound-

Knowledge of the effect of impoundments onupstream migration is needed to plan the pas­sage of adult salmon (On,;orhynchus spp.) andsteelhead trout (Sal-mo" gai1'dne1'i) at highdams. If mortality is high in the reservoir, 01'

if delays or other factors associated with pas­sage impair the ability of survivors to spawn,the fish may have to be transported around theimpoundment. Transportation could prove cliffi­cult if spawners bound for several tributarieswere intermingled below the dam. Subpopula­tions would then have to be separated beforetheir release into respective tributaries-a dif­ficult or impossible task. On the other hand,if anadromous fish can migrate up through the

Published July 1968.FISHERY BULLETIN: VOL. 67, NO.1

ment and released in the river. Fish released duringperiods of constantly high water temperature in 1961-62suffered losses, which may have been caulled by stressduring tagging. Som~ salmon with sonic tags wereinitialJy disoriented when released in" the reservoir;those released in the river above the impoundmentquickly oriented to the flow and resumed migrationupstrealn.

Subpopulations oC spring- and fall-run chinooksallnon continued to use ancestral spawning areas instreams tributary to the impoundment after it wasCormed in 1958. No differences were noted betweenpercentages of totally spent Call-run fish on the spawn­ing grounds in the years before and after BrownleeReserl-oir was filled.

impoundment and spawn successfully, they canbe passed directly to the forebay of the dam tocontinue their natural migration upstream.

Neither Brownlee Dam nor Oxbow Dam,which is 19.3 km. downr~ver from Brownlee,has a fishway leading up to its impoundment.Migrating adults enter a collection facility atOxbow Dam where they are trapped and trans­ferred to a tank truck; they are then trans­ported 23.3 km., to a point 4.0 km. aboveBrownlee Dam, and released into BrownleeReservoir to resume their migration. Releaseof" fish in the reservoir' was discontinuedafter these studies were completed; all fish weretransported to hatcheries for artificial propa-

35

gation. A small hatchery for fall chinook sal­mon (0. tshu'W'Ytscha) , 1 km. downstream fromthe trapping site, has been operated at OxbowDam from 1960 to the present by the IdahoFish and Game Department.

Fishery agencies recognized that BrownleeReservoir posed a number of problems. Theimpoundment is 92.5 km. long; it has almost nocurrent except during periods of high ·riverdischarge and extreme drawdown; water tem­peratures are high and oxygen concelitra,tionsare low during SUmmel" and early fall whenspawning migrations occur.

To leal'll if adults co.uld pass successfullythrough Brownlee Reservoir and reach thespawning grounds, the Idaho Fish and GameDepartment tagged fall chinool{ salmon (withPetersen disk tags) in 1960-61. The Bureauof Commercial Fisheries, in cooperation withIdaho. continued the investigations in 1962.Petersen dis~ tags· were used in all years; theBureau· also used sonic tags in 1961-62 to tracethe ori~ntation and movement of fish. .

Thi's report summarizes the results of the1960-62 studies. It also contains informationon (1) orientatiqn and migratory behavior ofsonic-tagged salmon, (2) observations of totallyspent fish in the Snake River above Brownle~

Reservoir. and (3) use of tributary spawningstreams after completion of Brownlee Reser­voir.

METHODS AND MATERIALS

The general plan was to capture adult chi­nook salmon in a trap at Oxbow Dam and trans­port them upstream for release either inBrownlee Reservoir or in the Snake Riverabove the reservoir (fig. 1). Some of the fishreleased in the reservoir were either tagged orfin clipped; others were caught and released un­marked without additional handling. Therelative numbers recovered on ancestral spawn­ing grounds below Swan Falls provided data

.. that enabled us to measure the ability of mi­grants to pass through Brownlee Reservoir.Sonic tags were applied to 59 fish in 1961-62to obtain information on orientation and mi­gratory behavior in and above the -impound­ment. A summary of data on tagging andrelease is shown in table 1.

CAl'1'llRE AND HANDLING

Adult chinook salmon used in the experi­ments were tal{en at different stages of thespawning run in the different years. In 1960and 1961 the flsh were obtained after the peakof the run. Hauck (1961) t, describing thework in 1960, mentioned "... that the selectionof fish for tagging was not on a random basis;that some selection was made for better fish onthe basis of appearance and physical vigor."

I Hauck, Forrest. 1961. Fall chinook salmon tagginll studies, SnakeRiver. 1960. Idaho Fish and Game Dept.. 7 pp. [Processed.]

TABLE I.-Summary of data on larminy alld release durino lests all pu.~8a(le of fall-run chinook salmon through Brownlee Reservoir,1960-fJ2

[[T"mar1<~d fis" u'~re re'eased ill the reBa""i,. durillg norm 111 Irallsporl '0 mllillllli" run; all fish ",ere t<l1<m from Ira,' at Oxbow D<lm (fig. 1)1

Year and kind Released in reservoirof mark

Number Anesthetized 1Date

1960NoPetersen tag Sept. 20-21 108

Do Oct. 4-7 253 NoNone Aug. 4-Dec. 12 4,282 No

1961YesPetersen tall Sept. IS-Oct. 31 686

None Aug. 9-Dec. 10 3,272 NoSonic t·all Sept. 20-0ct. 21 15 No

1962YesPetersen tal! Aug. 27--oct. 21 444

None Aug. 20-Dec. 11 342 NoFin clip Aug. 27--oct. 21 365 YesSonic tag -------- - -- -_ .... ----

I Anesthetized for tiL~ging. but not during transport to release site.

Date

Sept. 23-30

Sept. 18-0ct. 31

Aug. 27--ocl.. 21

Released in river

Number

267

688

340

Anesthetized I

No

Yes

Yes

36 U.S. FISH AND WILDLIFE SERVICE

FIGURE I.-Map showing trapping site helow Oxbow Dam.release sites in and above Brownlee Reservoir, weir site,and main spawning area of fall-run chinook salmon in theSnake River, 1960-·62.

In 1961, fish were c.ollected in the trap untilnumbers were sufficient for tagging. The trap­ping time ranged from a few hours, soon afterthe peak of the run (when the tests started),to 1 day in the later stages of the run. In 1962,the trapping to obtain fish for tagging and re­lease was scheduled by stage of migration. Inthe early and late stages (August 20 to Sep­tember 23 and October 15-21) fish were col­lected for 24 hours before they were removedto the tagging area, and during the. peak ofmigration (September 24 to October 14) fishwere removed from the trap for tagging afterabout 30 had accumulated.

Fish were transported in a tank truc.k (3,785­liter capacity): water was recirculated and,except for a few hauls in 1960, oxygenated.Ice was used to control water temperatures

IV

/o 10 20 KilometersI-+---l

Approximate Scole

Main spawnino area01 1011- run chinook

solman

during the 3%-hour drive to the release site atthe river, but not during the I-hour drive tothe release site at the reservoir.

All salmon were anesthetized (with tricainemethane sulfonate) for tagging in 1961-62,but not in 1960; none were anesthetized duringtransportation.

Prophylactic treatments, supervised by theFish Commission of Oregon, were used in 1962to attempt to minimize the transmission of dis­ease among fish during tagging and close con­finement in the tank trucks. Prophylacticsincluded tine.ture of iodine, roccal, ethanol, andmalachite green. Tagging equipment was ster­ilized in. a 70 percent solution of ethanol; thetagging area on the fish was treated withiodine. Wounds, abrasions, and infected 'areaswere treated by topical application of a 15 per­cent solution of malachite green. In addition,all fish were treated for 1 hour with 1 p.p.m.(parts per million) of malachite green whilebeing transported to the release sites. At theend of a day's operation, fish tanks on thehauling trucks were sterilized with roccal.

-Skin discoloration and formation of blistersearly in the experiment indicated that the io­dine treatment might be affecting the fish ad­versely. As a precautionary measure, a 15percent solution of malachite green was usedin lieu of the iodine after the third week oftagging. On one occasion the fish tank wasinadequately rinsed and the remaining roccalkilled a load of fish. Thereafter malachitegreen at a concentration of 2 p.p.m. was usedinstead of roccal for sterilization.

TAGGING AND RELEASE

Petersen disk tags, sonic tags, and adiposefin-clips were used to mark adult chinook sal­mon before they were released. Personnel ofthe Idaho Fish and Game Department appliedall disk tags (fig. ·2), which were numbered ormulticolored for ide-ntifying.: individual fish.The Bureau of Commercial Fisheries attachedall sonic tags; only fish over 61 em. weretagged. The Bureau also excised the adiposefins.

CHINOOK SALMON PASSAGE THROUGH BROWNLEE R:ESERVOIIt 37

FIGURE 2.--Personnel of the ldaho Fish and Game Depart­ment attaching disk 1ag to ('hinook salmon. Fish is partiallysubmerged in water supplied by hose in left foreground.Canvas cover over head of salmon helps <luiel~ it duringtagging.

Petersen Disk Tag

Tagging and release of di k-tagged fish dif­fered in certain details during the 3 years ofthe study. In 1960, fish were tagged at theOxbow trap and transported directly to relea esites in the river or the reservoir. In 1961,untagged fish were transported to the releasesite and discharged into a holding pen; individ­ual fish were then removed, anesthetized,tagged, and released at the site. In 1962, fishwere taken from the Oxbow trap in groups I)fas many as 30, anesthetized en masse, tagged,put in a tank truck with fresh water to re­cover, hauled to the river 'Or reservoir releasesite, and discharged into an open-ended holdingpen. They swam over a submerged weir atthe open end of the pen to resume migration.Individuals that did not leave the pen in 24hours were eliminated from the experiment.

Releases of tagged and untagged fish in 1962varied between migration periods. During theearly and late stages 'Of migration, fish werereleased daily for 6 successive days at a singlesite. For example, tagged fish were released inthe Snake River on the first day of a week andin the reservoir on the next day. On the thirdday of the series, only untagged fish were re­leased in the reservoir. This sequence was re-

38

peated over the next 3 days. No tagging wasdone on the seventh day, but fish captured inthe trap at Oxbow Dam were transported andreleased in the reservoir by the Idaho PowerCompany as part of their usual fish-passagework. At the peak of migration (September24 to October 14), tagged fish were releaseddaily at both sites for 5 days a week. 0 morethan 30 fish with Petersen tags were releasedat either site on any day. (In this same period,fin-clipped fish were released in the reservoiralong with untagged fish that were excess tothe tagging needs.) On the other 2 days of theweek, only untagged fish were released in thereservoir.

Fin Clip

Fish marked by an adipose fin clip were re­leased at the reservoir site only in 1962. Thesefish had been anesthetized and inspected duringselection for spawn taking at the Oxbow hatch­ery but were not retained for that purpose.They were fin clipped to differentiate themfrom untagged fish that were released duringthe early stage of the 1962 experiment (Sep­tember 10-16), but most were released duringthe peak stage of migration (September 24 toOctober 14).

onic Tag

Each sonic tag, used in 1961-62, was fas­tened by a metal clip or hog-ring which wascrimped into the flesh behind the dorsal fin.The battery-powered tags emitted 132-kc. sig­nals, detectable by receiving equipment withina range of about 1 km.; the operational lifewas about 5 days.

Salmon bearing sonic tags were released onlyin the reservoir in 1961 and only in the SnakeRiver in 1962. In 1961, they were tagged atthe reservoir release site and allowed to resumetheir migration from an open-ended holdingpen. In 1962, the fish were tagged in groupsof 6 to 14 at the Oxbow trap, coincident withthe Petersen-disk tagging, and transported withthe other tagged fish to an open-ended holdingpen at the Snake River release site.

The sonic tags enabled us to obtain detailed

U.S. FISH A TD WILDLIFE SERVICE

FIGURE 3.-Boat following chinook salmon with sonic tagin Brownlee Reservoir. Electronic tracking equipmentprovided precise data on day and night movements oftagged fish.

information on movements of individual fish inthe reservoir by tracking them in a boatequipped with receiving equipment and plottingtheir positions on a chart at about 5-minuteintervals (fig. 3). In the Snake River, the dateand time of passage of fish with sonic tags pastspecific points was automatically recorded ontime-event charts connected to fixed monitors 2

placed along the shoreline (fig. 4). Informationon movement of individuals and groups oftagged fish between monitoring stations wasobtained with portable hydrophones on a skiffpropelled by an outboard motor.

RECOVERY

Marked and unmarked chinook salmon wererecovered from the spawning area in periodicsurveys from October to mid-January. Thesurveys were made monthly for the 1960spawning run by the Idaho Fish and Game De­partment and weekly for the 1961 and 1962runs, when the Bureau of Commercial Fisheriesassisted the Department.

During the surveys, observers drifted down­stream in a small boat or waded through shallowareas to search the entire known spawningarea for carcasses. The dead salmon were ex-

2 Johnson, James H. 1963. Development and use of sonic tracking as anaid to Pacific salmon conservation studies, 13 pp. [processed.]

• MONITOR

o 2 4 6 8I e-------3 l===:!

KILOMETERS

FIGURE 4.-Locations a,]ong Snake River between BrownleeReservoir and the mouth of Payette River where fixedmonitors recorded the passage of upstream-migratingchinook salmon carrying sonic tags.

amined for tags, fin clips, and spawning stagesand then marked with spaghetti-type tags toidentify them on future surveys. SCUBA div­ing was added in 1962 for investigation of deeppools where the spent fish might accumulateand remain unobserved. The greater recoveryeffort in 1962-plus experience gained insearching for fish in 1960-61-may have led tohigher rates of recovery of untagged fish in1962 (24.9 percent) than in 1960 (5.1 percent)or 1961 (14.3 percent). Water level and clarityappeared to be about the same for the 3 years.

PROPORTIONS OF FISHREACHL~G SPAWNING GROUNDS

In evaluating recoveries from both releasesites, we considered the possible effect of differ­ences in hauling time and post-release environ­ment on the eventual passage of chinook salmonto the spawning grounds. Differences in haul-

CHINOOK SALMON PASSAGE THROUGH BROWNLEE RESERVOIR 39

TAIIL~; 3.--NulIIl}('r8 4 ta(/(Ied fall-rull chillook salmon rCCU1Jl'l"cdon tht' spawnfng grounds altcl' relell.~e ahul'C Brownlee Dmn

fn WGf!, by week oJ r(/eas"

The'high temperature, however, apparentlywas not the direct cause of mortality. Thegood recovery of untagged fish in 1962 (highestof the 3 years) suggests that a fair number ofuntagged fish from the early releases must haveslirvived and reached the spawning grounds inspite .of the high water temperatures. Possiblythe additional stress on fish during handling,anesthetizing., and tagging produced themortalities.

Mortality from tagging was also indicatedin 1961 by the differences in percentage recov-

different years. In 1960, the percentages oftagged and untagged fish recovered in thespawning areas were closely similar; in 1961,

.more untagged than tagged fish were l'ecov-ered; and in 1962 the percentage recovery washigher for untagged fish than for either fin­clipped or tagged fish, and higher for fin-clippedthan for tagged fish (table 2).

A high mortality of tagged fish was apparentin the early pha~e of the 1962 experiment. Norecoveries were made of tagged fish released inthe reservoir or in the Snake River during thefirst 4 weeks of tagging, August 27 to Septem­ber 23 (table 3), and only one recovery wasmade from fish released in the first 5 days ofthe following week of tagging. This lack oftag recoveries coincided with a period of sus­tained high water temperature at both releasesites. The average temperature of surfacewater was 22.1" C. (range, 21.1" to 23.9°) inBrownlee Reservoir and 18.4° C. (range, 16.6°to 20.6°) in the Snake River.

ing time, however, did not appear to be animportant factor in survival. Although fishtransported to the Snake River were confinedin a tank truck about 2% hours longer thanthose transported to the reservoir, they ap­peared to be in excellent condition at release.Other investigators have also indicated thatprolonged transportation is not detrimental toadult c.hinook salmon. Parker and Hanson(19'44) suc.cessfully transported adult salmonfor 2 hours, and Fish and Hanavan (1948)reported hauls of about 4 hours without adverseeffects. Groves (personal communication3

)

transported adult chinook salmon for about 5hours to a test area in 1961 and followed thisat a later date by a 5-hour return haul to ahatchery. He reported no mortalities directlyattributable to the prolonged transportation.

Differences in postrelease environment alsohad no apparent effect on survival in the pres­ent experiments. Differences between recover­ies of tagged fish released in the reservoir andof those released in the river were not signifi­cant in any year (table 2) .

TABLE 2.-Numbers (~r II/urked a."/Id "nmarked fall-run chinooksalmon rclca.~ed in Rru1QlIlce R".~crl'oir a.ud the Snake RilleI'and lIl/.lIlbers rec(JIlel'e~1 on the spawning gronnds, 1060-6&

Fish recoveredYear and Mark' Fish onrelease site released spawning grounds

Number Number Perrrnt19601

Reservoir Tag 361 23 6.4None 4,282 218 5.1

River Tag 267 16 6.0

19611Reservoir Tag 686 70 10.2

None 3,272 467 14.3River Tall 688 83 12. I

1962Reservoir Tal!: 444 13 2.9

Fin" olip 365 31 8.5None 342 85 24.9

River Tag 340 11 3.2

I Tag indicates Perersen disk; nonc of the 59 fish tagl!:ed with sonic talll!werE' ftlcovered. .

• Hauck. Forrest. 1961. Fall chinook salmon tal!:l!:inll studies, SnakeRiver. 1960. Idaho Fish and Game Department. 7 pp. [Processed.]

1 Graban. James R. 1964. Evaluation of fish facilities. Brownlee andOxbow Dams, Snake River. Idaho Fish and Game Dept. 60 pp. [Processed.l

The effect of tagging on survival of fish re­leased in the reservoir apparently varied in

1 Alan B. Groves. 1963. Fishery Bioloe:ist, Biological LaboratoryBureau of COlllmercial Fisheries, Sesttl-e, Wssh. '

Week ofrelessc

Aug. 27-Bept. 2Scpt. 3-0Sept. 10-16Scpt. 17-23Sept. 24-30Oct. 1-7Oct. 8-14Oct. 15-21

Fish Fish Fish Fishreleased rec.overed released recovcred

in on in onreservoir spawning river spawning

grounds grounds

.Vumber Number lVIJmber Number

11 0 7 030 0 20 033 0 31 096 0 85 074 2 46 3

158 7 80 534 3 41 2

8 I 21 I

40 U.S. FISH AND WILDLIFE SERVICE

FIGURE 5.-Percentage of totally spent fall-run chinooksalmon recovered on spawning ground surveys in the SwanFalls area, Snake River, 1954-{):? Numerals in each barindicate 'number of fish. Brownlee Reservoir was filled in1958.

"60'";;:I- 50zle1/1 40 N=

j 3096 60 108 84 27 40 650242 177 147 253 96 171 75 195374 69 67

gI- 20

Eagle Creek; the Idaho Fish arid Game Depart­ment carried out simiJar spawning surveys up­stream from the impoundment in the Snakeand Weiser Rivers. Records of State fisheryagencies and of the Bureau of CommercialFisheries on the capture of juveniles migratingfrom these various spawning areas'also verifiedprevious spawning.

The formation of Brownlee Reservoir appar­ently did not affect the ability of anadromoussalmonids to use specific spawning areas. Fall­run chinook !!lalmon passed through the im­poundment after construction of BrownleeDam and spawned in their accustomed areanear Swan Falls. Because no tagged fall-runchinook salmon were observed in other spawn­ing streams in 1960-62, straying evidently wasslight or nil. Spring-run chinook salmon andsteelhead trout, as evidenced by surveys onspawning grounds and by catches of theirprogeny in sampling traps, continued to usewidely separated spawning areas after the res­,ervoir was filled. Some spring-run populationsentered the Powder River about 32 km. aboveBrownlee Reservoir and migrated into EagleCreek to spawn (fig. 1), whereas others passedthrough the entire length of the impoundmentand continued into spawning grounds in theWeiser River system.

o 1954 1955 "1956 19~7 19621958 1959 1960 1961YEAR

,OMALE"DFEMALE

70

90

10

so

100

SPAWNING SUCCESS

Annual surveys by Richards 5 and Pirtle andKeating (1955) r, provided percentages of to­tally spent fish on the spawning grounds frominspection of gonads and counts of eggs re­tained before and after the filling of BrownleeReservoir in 1958 (fig. 5). These observationsshowed that passage through the reservoir didnot affect the ability of fall-run chinook salmonto spawn successfully. The difference betweenpercentages of totally spent fish in the preim­poundment and postimpoundment years was notsignificant.

Information on the use of 'specific areas forspawning by various salmonids was obtainedfrom surveys before and after the impound­ment was formed and from discussions withpersonnel of the Oregon State Game Commis­sion, who annually surveyed spawning fish inthe Powder River and its major tributary-

• Grahan, James R. .1964. Evaluation of fish facilities. Brownlee andOxhow Dams. Snake River. Idaho Fish and Game Department. RO pp.[Processed.1 '

• Richards: Monte. 1956-62. Snake River fall-chinook spawningR'round surveys. Idaho Fish and Game Department. Various pa~ination.[Processed.] ,

• Pirtle. Ralph B., and .James Keating. 1055. Annual report: The sizeand timing of runs of anadromous species of fish in the Columbia andSnake Rivers and their tributarie. abo\'e the confluence of the Snake River1054. Idaho Fish Game Dept.. Contract. nA 35-026-eng-20608. for U.S:Army, Corps Engrs., 30 pp. [Processed.]

ery of tagged and untagged fish released in thereservoir. Graban (1964)4 observed that tag­ging mortality approached 30 percent. Al­though total recoveries of tagged and untaggedfish in the 1960 experiments did not differ 'ap­preciably-possibly because of the selection oflarge, healthy fish for tagging-Hauck (seefootnote 1) reported, "A decrease in survival(recovery) rates is indicated with increasingwater temperatures at release site...."

Recoveries of fish from the fin-clipped groupin 1962 also give evidence of stress from han­dling :' the percentage of returns was onlyabout one-third that of returns from untaggedsalmon (table 2). The percentage of-recoverieswas higher from fin-clipped "fish than fromtagged fish (even though handling procedureswere about the same for both lots), but mostof the fin-clipped fish were released when watertemperatures were declining and, hence, be­coming more favorable for survival.

CHINOOK SALMON PASSAGE THROUGH TROWNLEE RESERVOIR 41

RATES OF MIGRATION OF FISHMARKED WITH PETERSEN TAGS

The rate of movement of chinook salmon inBrownlee Reservoir in 1960 was estimated byHauck (see footnote 1) from tagged fish thatsport fishermen recovered on the spawninggrounds. Eight fish released in the reservoirand five released in the river were recovered;the elapsed time from release to recovery aver­aged 32.0 days (range, 17 to 42) for fish re­leased in the reservoir and 25.8 days (range,18 to 30) for those released in the river 16 km.above the reservoir. On the basis of the dif­ference between the averages (6.2 days) and.the distance between the reservoir and the riverrelease sites (104.5 km.), he estimated the av­erage rate of movement in the reservoir as 16.8km. per day.

Rates of migration were not studied in 1961,but in 1962 the rate of movement through thereservoir was estimated from data on fivetagged fish that were identified ·as they mi­grated through a gate in a weir in the SnakeRiver (fig. 6). The weir was 20 km. above thereservoir and 1 km. above the river release site,which was 19 km. above the reservoir in 1962.(Midway through the experiment, it becameevident that the weir was delaying upstreammigration; the structure was removed at theend of September to allow free passage of adult

-"- ..-. - ..__ . ~ .. _"":-r. '.

I

.~~I~ilfij&ii*l-f-: .

FIGURE 6.-Snake River weir (upstream view) wit.h fish trapsfor identification and release of migrating salmon. Site isabout 20 km. above Brownlee Reservoir.

42

migrants.) The total elapsed time between re­lease of the five fish above Brownlee Dam andrecapture at the weir (108.5 km. upstream)ranged from 3.2 to 9.9 days and averaged 6.7days. Thus, the average rate of upstreammovement from release to passage through theweir was 16.1 km. per day. The true rate ofmovement may have been somewhat fasterthan indicated because the calculation does nottake into account any possible delay'~ at theweir.

Thirteen tagged salmon released in the SnakeRiver in 1962 were observed passing throughthe weir, 1 km. upstream, in elapsed time thatranged from 2.2 hours to 6.6 days and averaged2.8 days (or about 0.36 km. per day). The.de­laying effect of the weir undoubtedly accountedfor the low rate of movement in this stretchof river. As is shown in the next section,more than half of the sonic-tagged fish reachedthe weir in less than 1 hour; hence, they movedup this short section of stream at about 19 km.per day.

ORIENTATION AND MOVEMENTOF SONIC-TAGGED FISH

Because the sonic tags we used transmittedidentifiable signals for only about 5 days, ourexperiments were limited to a study 01 initialbehavior after release. In such a study, it isessential that the attachment of the tag notaffect the behavior of the fish. We were un­able to detect any immediate effect of the tagfrom visual observations of tagged and un­tagged fish released in the same area. Al­though the long-term effect on behavior isunknown, previous work by the Bureau ofCommercial Fisheries during the past 10 yearssuggests that the effect may be slight (Johnson,1957) .

RROWNLEE RESERVOIH

Most of the chinook salmon with sonic tagsreleased in Brownlee Reservoir in 1961 wereinitially disoriented and spent considerable timein the lower end of the reservoir before re­suming migration upstream. The movement

U.S. FISH AND WILDLIFE SERVICE

upstream. Distributions that show the delay­ing effect of the weir are given in figure 9.

FIGURE S.-Chronological record (dingrammatic) of a i7­hour track of well-oriented arlult. l'hinrlllk salmon moving81 kill. IIp,,,tream in Brownlee Re;;eryoir. Fi8h carried) asonic tag.

of an obviously disoriented fish is shown infigure 7. A track of one fish that resumedmigration upstream soon after release is shownin figure 8.

The initial aimless wandering of most of thesonic-tagged fish may also have been character­istic of untagged fish released in the reservoir;it so, they eventually recovered because a highpercentage of fish arrived on the spawninggrounds from releases in the reservoir. In1962, for example, nearly 25 percent of the un­tagged fish released in the reservoir were re­~overed in the spawning areas. In view ofthe size of the Snake River (flow more than365 c.m.s.) and the extent of spawning grounds(over 25 river km.), we can be certain the per­centage of fish that reached the spawninggrounds was far greater than the percentagerecovered.

SNAKE RIVER

More than half of the 44 fish with sonic tagsthat were released in the Snake River coveredthe 1.0 km. stretch to the weir in less than anhour. Other fish moved more slowlr. A fewfish remained in the release area up to 24 hours,and one stayed 4 days before moving upstream.Only one fish moved downstream; this salmondrifted 2.4 km. below the release site, lingeredabout 2 hours. and then resumed its migration.

OREGON tv

/IDA H 0

LOST CONTACT

ELAPSED TIME ___ IHOUR 2HOURS 5 HOURS 19HOURSFOLLOWING 12P.MJ (4 P.M.) (6P.M"J I B A.M.)RELEASE r0 0.0 ,.0

r- r~"'~'I..M.

.".11'~111111111I11 WEIR TRAP '111111111

Imomller. -. OPENED

RELEASE POI~ °0° °0 °I(2 AMI

°0 0 02..4KM

~1 00I

~oISLANDS

NUMBER OF FISH • •ACCOUNTED FOR

OREGON

.••••... ACIUllillftlln1llMl- Awlrql,,","ment

FIllUKE i.-Di80rienled movement of an adult "hinooksalmon tagged with a ;;onie· tag and relca~ed in BrownleeReservoir. This fi~h. tracked for 106 hour~, moved almost·cont.inuousl~· da.\' and night ami tra\'eled about 81 km.Travel was confined to area wit·hin :3.3 km. of the releasepoint..

FIGURE ll.-Diagralll of the changing di~t.rihlltilJn nf a groupof nine chinook ~alnllll1 tagged with sonic tag~ and releasedin the Snake River ahoye Brownlee Resen'oir. Two fishpresumahly pas~ed through the weir between -1 and 6 p.m.No fish were found fart her than 2.4 km. downstream fromt·he weir.

CHINOOK SALMOX PASSAGE THltOUGH BRO\V:\'LEE RESERVOIR 43

In a similar, earlier release from the samesite, all but one of seven fish move.d up to theweir during the afternoon. Some fish thendropped downstream about 1 km. after darkbut returned to the weir in the morning, atwhich time only two were counted through thegates. In three releases (total of 25 fish)after the weir was removed, the fish movedpast the vacated site without hesitation.

Sonic tags provided additional informationon rates of movement in the river. Fish tookfrom 26 to 120 hours to move upstream fromthe release point to the monitor at the PayetteRiver mouth, which was 24 km. upstream. Themaximum rate of m~vement for the distancewas, therefore, slightly more than 0.8 km. perhour, or 19 km. per day. The slowest fishrecorded by the monitor moved 13. km. up­stream in 6 days; this was the same fish men­tioned earlier, which had spent 4 days in therelease area before resuming migration.

EXAMPLES· OF PASSAGETHROUGH LARGE NATURAL LAKES

Because Brownlee Reservoir provides theonly evidence ·of chinook salmon passagethrough It long, deep impoundment, we searchedfor other examples of their passage capabilitiesunder comparable conditions. Passage of chi­nook salmon through large, shallow impound­ments, such as those formed by low-head damson the Columbia River, has long been estab­lished. These impoundments pass tremendousvolumes of water and normally provide strongdirectional currents that are usually absent inlarge, deep reservoirs, such as Brownlee. Whatwas needed were examples of passage throughlarge bodies of water having low or no direc­tional currents. Although large lakes withinlets and outlets may differ from reservoirs,the flow of water and limnological conditionscan be similar to those in large, deep impound­ments.

We discussed the passage of adult chinooksalmon through large, natural bodies of waterwith biologists familiar with chinook salmonruns in Alaska, British Columbia, and theYukon Territory. They estimated the sizes of

44

sustained runs and provided data on tl:J.e sizesof lakes through whkh the' species migrates toreach spawning ar~as. .

We concluded that the size of a body of watermay not influence greatly the upstream migra­tion of this species. In Bristol Bay, Alaska,.chinook (king) salmon have been observed inthe ullper Wood River Lakes (Burgner, per­sonal communication7

). To reach this area, thefish migrate through three connecting lakes­about 30 km. through Aleknagik Lake, about56 km. through Lake Nerka, and about 24 km.thro~gh La.ke Beverly. An average of 5,000adults e~tered in 1957-62 and spawned intributaries. to Naknek Lake (about 64 km.long) (Jaenicke, personal communication8

).

Some of these fish were observed at the Brooks.. .Lake weir in a tributary. stream about 48 km.above the outlet of Naknek Lake.

In British Columbia (Fraser River system),researchers 9 estimated that 500 to 1,000 adultchinook salmon pass throug'h Harrison Lake(80 km.) into the Birkenhead River; about5,000 migrate through Kamloops Lake (24km.) and continue for 72 km. through Shuswap,Eagle, and Mara Lakes to spawn. Some chi­nook salmon pass 72 km. through Quesnel "Lakeinto the Mitchell River.' Before Coulee Damwas constructed on the Columbia River, largeruns of chinook salmon were reported by localresidents (Bryant and Parkhurst; 1950) tohave migrated through the lower Arrow Lake(72 km.). and upper Arrow Lake (56.. km.) tospawn below Windermere Lake, 128 'km. far­ther upriver..

More than 3,600 chinook salmon are esti­mated by Elliott (personal communication10

)

to enter LaBerge Lake on the Yukon River,Yukon Territory. A small number enter atributary about halfway through the 56-km.lake, but most continue through the lake to theTakhini and McKlintock Rivers. Another run

7 Robert L. Burl!ner, 1963. Fisheries Research Institute, University ofWashington. Seattle. Wash. .

• Herbert W. Jaenicke, 1964. Fishery Biolog;st,.Bureau of CommercialFisheries, Auke Bay, Alaska. .

• J. R. Brett. Fishery Research Board of Canada, Nanaimo, B. C.; andW. R. Hourston. D. McKinnon, and B. M. Chatwin. Department of Fisb­eries. Canada. Vanco\l\'er, R. C.

10 W. K. Elliot. 1964. Fishery Officer, Department of Fisheries, Canada,Whitehorse. Yukon Territory.

U.S. FISH AND WILDLIFE SERVICE

of 2,000 fish migrate up the Teslin River, trib­utary to the Yukon River below LaBerge Lake,and continue 72 km. into Teslin Lake beforeentering the Nisutlin River; from here the fishcontinue for another 153 km. to a spawningarea at the outlet of Nisutlin Lake.

IMPLICATIONS OF PRESENT RESEARCH

Our experiments indicated that adult fall­run chinook salmon can migrate through largeimpoundments. This ability apparently doesnot require previous reservoir experience inthe juvenile stage; adult salmon returning up­stream through Brownlee Reservoir in 1958-60had passed downstream through this area asjuveniles when it was still a river. The resultspoint to the feasibility of passing adult chinooksalmon directly through large storage reser­voirs, thus eliminating the need for extendedtransport around impoundments.

The successful passage of fall chinook sal­mon through Brownlee Reservoir has specialsignificance because the environment for thesurvival of upstream migrants is perhaps aspoor as any found in the present freshwaterrange of this species. Surface temperaturesover 21 0 C. are common in the reservoir untilmid-September, and oxygen concentrations inthe deeper, cooler water generally are 4 p.p.m.or less 11 during the fall migration. Despitethe marginal environment for survival of sal­monids in the reservoir, adult migrants appar­ently suffered no greater losses than the fishbypassed upstream to the river, where watertemperatures and oxygen concentrations weremuch more favorable.

II Ebel. Wesley J., and Charles H. Koski. Physical and chemical lim­nology of Brownll"e Resen·oir. Bureau of Commercial Fisherifls Biolo~icalLaboratory, Seatt>le, Wash. Manuscri"t in preparation.

CONCLUSIONSThe studies on chinook salmon in the Brown­

lee Reservoir area support the followingconclusions:

1. Evidence of successful passage by chinooksalmon through Brownlee Reservoir and oftheir sustained migration through large lakesin Alaska, BritiSh Columbia, and Yukon Terri­tory suggests that the large size of an im­poundment may not be detrimental to upstreammigration of this species.

2. Despite initial disorientation, chinook sal­mon released in the reservoir were able to reachspawning areas as successfully as those trans­ported and released in the river above the im­poundment. In the river, fish resumed migra­tion shortly after release.

3. The ability of fish to spawn successfullywas not affected by passage through thereservoir.

4. Ancestral spawning grounds in the SnakeRiver above the reservoir continued to be usedafter the impoundment was formed.

LITERATURE CITEDBRYANT, FLOYD G., and ZELL E. PARKHURST.

1950. Survey of the Columhia River and its tributaries-Part IV. Area III Washington streams from theKlickitat and Snake Rivers to Grand Coulee Dam,with notes on the Columbia and its tributaries aboveGrand Coulee Dam. [U.S.] Fish Wild!. Serv., Spec.Sci. Rep. Fish. 37, 108 pp. .

FISH, FREDERICK F., and MITCHELl, G. HANAVAN.1948. A report upon the Grand Coulee fish-maintenance

Proil'ct, 1939-47. [U.S.] Fish Wildl. Serv., Spec.Sci. Rep. 55, 63 pp.

JOHNSON, JAMES H.1957. Sonic tracking of adult. salmon at Bonneville

Dam, 1957. U.S. Fish Wildl. Serv., Fish. Bull. 60:471-485.

PARKER, LEWIS P., and HARRY A. HANSON.1944. Experiments on transfer of adult. salmon into

Deer Creek, California. J: Wild!. Manage. 8: HI2-198.

CHINOOK SALMON PASSAGE THROUGH BROWNLEE RESERVOIR 45