c.i5

Fishand WildlifeRelationships in Old-GrowthForests

Proceedingsof a Symposium Sponsoredby Alaska District, American Institute of FisheryResearch Biologists Northwest Section, The Wildlife Society AlaskaCouncil on Scienceand Technology Held in Juneau,Alaska, 12-15 April 1982

Symposium Editors

William R. Meehan TheodoreR. Merrell,Jr. ThomasA. Hanley

SuggestedCltatlon: (Eds.). 1984. Fish and ttilliam R., TheodoreR. Merrell, Jr. and Thornas^A' Hanlev lleehan, in Juneau,Alaska' ltiiaiiie-ietaiionstrips in 0ld-GrowthForests: Proceedingsof a syrnpoiiumheld 12-15April 1982. Ainer.Inst. Fish. Res.Biol' 425p'

Published by the American lnstitute of Fishery Research Biologists December 1984

Availablefrom John W. Reintjes,Rt. 4, Box 85, MoreheadCity, NC 28557 Price920. *'"'

&,,4 HABITATSAND SALMONIDDISTRIBUTION IN PRISTINE. E SEDIMENT-RICHRIVER VALLEY SYSTEMS: S. FORKHOH AND .€ ii OUEETSRIVER, OLYMPIC NATIONAL PARK € E JamesR. Sedell I USDA, ForestService. Corvallis, Oregon il ri Joseph E. Yuskaand RobertW. Speaker Oregon State University,Corvallis, Oregon :]:

ABSTRACT Four distinct running-water habitats are defined and examined on the South Fork Hoh River and Upper Queets River-main river channel, river off-channel areas, terrace tributaries, and valley-wall tributaries. Speciescompositions, densities, and total fish biomassesare distinctly different for each habitat examined. Habitat formed by the main river channel and its tributaries is controlled by the valley terrace structure and the modifyingeffects of large woody debris. Large woody debris is important to all habitats regardless of size of stream. Without large wood, spawning and rearing-habitat quality would be poorer, even in the large, sediment-rich main channel. large wood-capped side channels had eight times the coho salmon (Oncorhynchus kisutch) densities as side channels without debris. During late summer, the majority of juvenile salmonid rearing occurs in river side-channelareas and tributaries.

INTRODUCTION Stream ecologists have few benchmark descriptive terrace tributaries. and vallev-wall tributaries (Swanson studies for naturally sediment-rich river systems. We and Lienkaemper 1982; et ;1. lg82; Sedell et'al.1982). know very little about aquatic habitats and how they are Speciescompositions, densities,and total fish biomasses formed in pristine, sediment-rich river valley systems.We were defined for each habitat type. With each habitat also know very little about how a pristine old-growth type, pools were described and the role of large woody forest interacts with the river to produce different fish debris in the formation and stability of fish habitats was habitats. documented. Sedell et al. (1982) found terrace The rivers of the Olympic National Park representthe tributaries and side channels to have the higheststanding last pristine coastal systems of intermediate size in the crops of juvenile coho salmon. This present study western United States. As such, they can provide reexamined the sites on the South Fork Hoh River and important insights as to the summer salmonid habitats of examined the Upper Queets River in order to determine coastal rivers in their "native condition." For these whether the 1978 results were consistent through time rcasons, a description of two rivers in the Olympic (South Fork Hoh River) and held true for another river National Park provide a neededand significant baseline system (Upper Queets River). for streamecologists and fisheriesmanagers in the Pacific We thank Jeff Cederholm and Peter Bisson for Northwest. reviewing the draft manuscript. Our heartiest thanks to The 1978 South Fork Hoh River study examined late Judy Bufford for drawing the figures, and to Rose Davies summer frsh populations in relation to four general and Phyllis Taylor-Hill for typing the manuscript. habitat types: main riverchannel, river off

HABITAT DESCRIPTIONS Geomorphic processeshave created and maintained Main River Channel four broadly defined classesof aquatic habitat in the South Fork Hoh River and Upper Queets River valleys The main river channelsfor both the Queets River and (Swanson and Lienkaemper 1982). These are the main South Fork Hoh River (Sedell et al. 1982\are wide and channel, side channel or off

33

&- sediments but riffle areas are relatively clean. The Terrace Tributaries channel gradient is 2-3 percentand is composed mainly of riffles and deeper runs, with some pools associatedwith Terrace tributaries result from spring networks on the debris. Riparian vegetation does not significantly flat valley floor and from tributaries draining the valley influence the course of the river; however, bank cutting side-slopesand continuing acrossthe terracesto the main causes inputs of large woody debris which can river on the South Fork Hoh River. Many terrace accumulate on bars and outsides of bends to deflect the tributaries parallel the secondary river channels that cut river flow (Swanson and Lienkaemper 1982). Debris through the lower terrace areas within the flood plain accumulations provide little cover for fish rearing in the before emptying into the main river. These streams are main river channels, but divert water through side- very stable and have low gradients, slow velocities, and channel overflow areas. Chinook salmon spawning channel widths from I to 5 m. These features are *wall habitat is provided by the big root wads and boles sometimes referred to as based streams." This functioning as scour agentsin the main channel. The tail- results from mainstream overflow of natural stream outs of these scour pools provide excellent cleaned and leveesin combination with collected side-slope runoff. sorted gravels. This habitat type is common in both glacial and non- glacial high-gradient streams. Where sediments have been deposited historically, this habitat type is often Side-Channel or Off-Channel Areas poorly developed and is usually considered a side- Side channelsare subsidiary channelsto the main river channel feature. ln glacial streams such as the Hoh and which are located within the active exposed lower flood Queets River systems,these features are well developed. plain. These channels are not the obvious braided The lower Mississippi River has a few of these terrace channels. Unlike a braid, they carry a very small systemsthat are 28-320km long and9Gl26km wide, e.g. percentage of the flow of the main channel. Some are Yazoo River Basin. caused by woody debris accumulations on bars in the Terrace tributaries were found to be the most main channel; river flow is diverted by debris through a homogeneous of the habitats examined. Most terrace cobble and gravel flood levee.Some sidechannels are the tributaries along the Upper Queets River appear to be result of channel migration of the point bar. As the spring- and seepage-fed, low-gradient streams. channel migrates it often leavesan array of "scroll bars" Generally, they arise from a marshy or spring area where or levees which are generally parallel with the main the terrace meetsthe side slope, and flow parallel to the channel and not long in length (P. Peterson, personal main river for a considerable distance before joining the communication). Water percolates through the flood main river. Terrace tributaries have a very small levee gravel berm and debris to create a side channel watershed and never had low-velocity flows running between the gravel berm and the bank opposite the main through them year:round. Depending on their distance river flow channel. Other off-channel areas are from the main river, terrace tributaries are affected by intermittent overflgw channels that receivegroundwater main channel floods in different ways, but do not scour as from the main rivei and nearby terrace. Moit are subject side channels often do. In most cases,terrace tributaries to direct flows during freshet periods; others become receive depositional "pulses" from main-river flood completely isolated during summer low-flow periods. flows, to the extent that the flood level of the main river Flow velocities are lower than the main river and water penetratesthe terrace tributary system. percolated through berm gravels carries reduced Terrace tributaries are composed predominantly of suspended sediment. Organic input from terrace pools and short sectionsof riffle. Pools accumulate large vegetation and overflow accumulations from main river amounts of riparian leaf litter from the dense forest floods collect on off-channel pool bottoms. In the canoopy, thus producing abundant aquatic insects absence of heavy shading and the scouring effects of (Ward et al. 1982). Pool substrate is primarily fine suspended glacial material, algal growth is promoted. sediments,although riffles are relatively clean. Banks are High invertebrate populations occur in theseorganically stabilizedby live vegetationand downed woody debris. rich areas(Ward et aL 1982)-Woody debrisand undercut bank vegetation provide cover for fish and create pool areas. Downstream tail-outs offer good chinook and Valley-Wall Tributaries coho salmon spawning locations. This type of habitat is characterized by second- or The "side channel" classification was found to be one third-order streams that drop rapidly off the side slopes of the most heterogeneoushabitat designations. Stable or valley wall and then into a large stream or river. side channels are protected at the upstream end by large Generally, just before entering the larger stream, these organic debris, boulders,bedrock, or living vegetation, valley wall tributaries have a short, low-gradient section which tends to make their structure and morphology running across the terrace of the larger stream. These stableduring flood flows of the main river. Unstableside streams are typified by high gradients with alternating channels lack these protective features. There is a wide sections of riffles and plunge pools over woody debris gradient as one goes from a stable to unstable side and boulder obstructions. The substrate rangesfromfine channel. Both stable and unstableside channelscan be materials deposited above some of the debris to large shadedor exposedcompletely to sunlight. bouldersand bedrock in the plunge pools. Lower valley- wall tributaries have clear water and high flow velocities and are subject to extremely high flows in the winter months. Summer rearing areasat the lowerend of valley-wall tributaries appear to be torrent areas in 34 winter. The wide differences in the physical and main channel of Tshletshy,Harlow, Paradise,Pelton, biologicalcharacteristics of eachstream section surveyed AIta, and Hee Hee Creeks represent this habitat. resultedin this being a habitat designationof great Generally,the majortributaries of the UpperQueets were heterogeneity. Organic material from the riparian largerbasins (4th- to 6th-orderstreams) than those in the vegetationis transporteddownstream or retainedby the south Fork Hoh (2nd- to 4th-order streams).Upper debrisand boulders.The banks are steep but stabledue to QueetsRiver major tributary basinswere between 5 and deeplyembedded large boulders and debris.Productivity 30 kmz, where South Fork Hoh River tributarieswere of algaeand aquaticinvertebrates is lower than in other lessthan 7 kmz.Because they were larger than the valley- streamsbecause the denseforest canopy limits light entry wall tributariessampled on the South Fork Hoh River, and scour forces of the rapidly moving water create we gavethem a classificationof their own. considerableshear stress (Ward et al. 1982).

Major Tributary Habitat This habitat is representedby the main channel of major tributary streamsto the upper QueetsRiver. The

METHODS A 2-pass removal method was used to sample fish (D. Martin and L. Lestell personal communication.) populations in thirteen off-channel and tributary areasin Density, biomass,and speciesdistribution were related to the South Fork Hoh River in both September1978 and each habitat parameter and important relationships Septemberl-15, 1980(Fig. l), and in 80 off-channeland noted. Additional details can be found in Sedell el a/. tributary siteson the Upper Queets River from August to t982. September 1982 (Fig. 2). Fish collected from each site Along the main stem of the Upper Queets, 33 were anesthetized with MS 222 (tricaine electroshocking siteswere mapped. Fifteen of these were methanesulfonate), identified to species, measured for located on named tributaries: Harlow, Paradise, Hee fork length, and allowed to recover before release.Fish Hee, Pleton, and Alta Creeks (Fig. 2). The rest of the biomass estimates were calculated from length-weight electroshocking sites were located on side channels and relationships developed directly in the Upper Queetsand terrace tributaries which are unnamed streams. Maps corresponded well with data from the Bogachiel River

MAINRIVER 1-5 OFF CHANNEL 6 -10

TERRACE

LOWER VALLEY WALL 14-'16

UPPER VALLEY WALL 17-18

:f4rK_ q99Np4ry

'11

t I N

o t 2. 3 4 #Ml or_i___?__i___{4KM 'l Figure . Locationof fish samplesites on the South ForkHoh river and tributariesfor autumn 1978 and 198O. Main riverchannel sites 1.5 were not sampledin 1980.Additional terrace-tibutary sites around 13 and 14 and off-channelor side-channelsites around 8 and 1Owere sampledin 198O.

3s t{

I \

) Ifu,

nrIIa fuus

o MAIN CHANNEL OF OUEETS a MAIN CHANNEL OF TRIBUTARY I SIOE CHANNEL o TERRACE lRIBUTARY

A VALLEY WALL TRIBUTARY

A ISOLATEO POOL

Figure2. Locationof f ish samplesites on the UpperOueets River and tributaries,late summer/early fall 1981.

and data are on file at Oregon State University, Corvallis, out and pool, riffle, off-channel characteristics,overhead Oregon. cover, bank cover, and debris influence, frequency, and Location of the beginning and ending of a pool or riffle amounts wererecorded. The samewasdonefora 13.5km was recorded. Pools were classified according to the transect on the Upper Queets.Results were extrapolated rating criteria developed by the U. S. Forest Service to the rest of the basin accessibleto anadromous fish. On (Duff and Cooper 1976). Gradient at each the South Fork Hoh River, about 50 percent of the main electroshocking site, as well as substrate, riparian channel and side channels were inventoried. All terrace vegetation, and overhead canopy shading and debris tributaries were surveyed on the South Fork Hoh River. were recorded. The Queets River had about 40 percent of the main Side channels that contained extremely deep (greater channel, side channels, and terrace tributaries surveyed. than 1.5 m) pools andi or contained extremely large About 50 percent of the off-channel areas of the major amounts of large organic debris often had poor tributaries, like Sams River and Tshletshy Creek, were electroshocking sampling efficiency. The data from a mapped. number of these sites were not used becauseof sampling Physical habitat stations (describedearlier) were done problems. It was difficult to collect fish by either the on all named tributaries to the Upper Queets between Zippen 3-pass or mark-recapture method, as the cover Sams River and Kilkelly Rapids. In addition, physical was very denseand made capture of a reasonablenumber habitat stations were set up on all off-channel features of fish quite difficult. Electroshocking stations on from the Upper Queetsat Sams River to a point 12.3 km valley-wall tributaries were very closeto the mouth on the upstream of this point on the Upper Queets. short, low-gradient section of the tributary. Secondly, on other parts of the Sams River (but not Side-channel habitats and all tributary streams in the above the 4.5 km mark), physical habitat stations 30 m m of off-channel or upper Queets basin were surveyed to the anadromous long were inventoried every 300 blockage on each particular system,or the end of suitable tributary length. This gave a resolution of l0 percent (30 coho and steelhead habitat, whichever came first. m inventoried for everv 300-m linear section of habitat). On the South Fork Hoh River. a 5 km transectwas laid

36 SOUTHFORK HOH RIVER PHYSICAL HABITATAND SALMONIDPOPULATIONS*1 98O

Physical Habitat Salmonid Distribution In 1980 physical habitat inventory did not change The distribution of juvenile coho salmon and juvenile significantly from the 1978 inventory reported by Sedell steelhead trout (Salmo gairdneri) are shown in Figure 3. et al. 1982.Terrace tributaries had 90 percent or greater The mainstream appears to be accessibleto anadromous of the stream surface area as pools. Side channels were fish for a distance of I 1.65 km upstream of the National also 60 to 85 percent pools. Only valley-walltributaries Park boundaries. A series of cascades and a narrow had riffles occupying twice the area of pools (Table l). canyon appear to present a velocity and turbulence Bank cover along the edge and as a percent of the total barrier to fish passage.Small tributaries draining from stream area was always less than l0 percent of stream the north side very often become isolated from the length and affected lessthan 3 percent ofthe stream area mainstream in late summer. Water probably percolates (Table l). into the porous substrates of the tributary delta or Total habitat available for summer rearing in the mainstem terrace and enters the main river by a South Fork Hoh River is presentedin Table 2. The main subsurface route. The great majority of the terrace channel and unstable side-channelsand braids account tributaries and stable side+hannels are located on the for over 80 percent of the total habitat. Terrace north side of the river. The largest tributaries drain from tributaries and stable side-channelsaccount for 3 percent the south and provide excellent cutthroat (5. clarki) and each. Valley-wall tributaries provide slightly more than 7 steelheadhabitat. percent of the total, and one-third of that is marginal for fish rearing.

'1 TABLE . Summaryof habitatcharacteristics, South ForkHoh River,summer 1980.Debris jams arepartitioned on the basis of percentageof the stream width affected by the downed tree(s) Debrls laus Nunber Pool/rlffle Z slream Z strean n of debris/100m strean Habltat type sanpled ratlo Iength area u3 Ll2 213

Terrace trlbutaries z. J L.Z 3.1 7.6 L4

Side- channels (s 1 tab le ) 2.L o.7 .7 .7 .J L2

Side- channels (uns rab le) 3.7 1.0 t.3 2.5 5.8 1I ll 27

Va 11ey-wa11 trib ucaries n( z.) 4

debris jare spanning entire channel uidth. h total nunber/meters of debris ians.

TABLE 2. South Fork Hoh River within Olympic National Park anadromous salmonid habital

Habitat type Length (m) Area (m2) 7.(Area)

Main channel LL,652 233,O40 66.2

Braids, unstable side channels 8,835 70,777 20.L

Shaded stable side channels 594 933 0.3

Stable side channels L,824 11,028 3.1

Terrace t.ributaries 4,610 L0,579 3.0

VaIley-wal1 tributaries 5,1s6 25,775 7.3

TotaI 32,67L 352,132 r00.0

37 SOTJTHFORK HOH RIVER

COHO AND STEELHEAD DISTRIBUTION

I COHO AND STEELHEAD wll a!.atl STEELHEAD llrl Elil EXCELLENT COHO HAEITAT

)-'r 'i!:-.-l,,l

N

+Ml o1234 l-.-.nlKM

Figure 3. Distribution of coho salmon and steelhead trout in the South Fork Hoh River, late summer of 1978 and 1980. Excellent coho salmon habitat corresponds with terrace tributaries and stable side-channel areas.

Salmonid Densities and Biomass-198O Terrace tributaries contained the second highest densitiesand biomass, although they are essentially the The largest density and biomass of salmonidsoccurred same amounts as in the stable side-channels. Coho in the stable side-channel and terrace-tributary habitat salmon were the most abundant, with 94 percent of the (Table 3). Coho salmon juvenile densitiesand biomass density and 80 percent of the biomass. Steelhead trout were not significantly different betweenthese two habitat were not abundant or large. Cutthroat trout represented types. Coho salmon densitiesand biomassesin stable only 3 percent of the total density, yet due to two yearling side-channels and terrace tributaries were both trout provided 14 percent of the salmonid biomass. significantly different from unstable side-channelsand The lower valley-wall tributaries that were examined valley-wall tributaries ( p s 0.01 analysisof variance.) (two sites) were dominated by steelhead trout, with 97 Steelhead trout densities were much higher in the percent of the density and 96 percent ofthe total biomass. stable and unstable side+hannels and lower valley-wall The main stem was not examined with any degree of streamsthan in the terracetributaries (Table 3). The only vigor. However, both Dolly Varden (Salvelinus malma) siteswhere large steelheadjuveniles werefound was in the and mountain whitefish (Prosopium williamsoni) were lower valley-wall tributaries. caught by hook and line in the mainstreams. Cutthroat trout were exclusivelyfound in the upper Electroshocking of mainstem river margins yielded very valley-wall tributaries (Table 3). The salmonid few coho salmon (3 total in a l-km reach). Small biomassesin terrace tributaries and stable side-channels backwater pools and root wads and debris were sampled. were highly variable primarily becauseof small sample- size and (122 cutthroat one or two large mm) trout. Comparison of 1978 and 198O Fish Population In the stable side-channel habitat, coho salmon Data represented 74 percent of the total density. Steelhead young-of-the-year made up 25 percent of the total The trendswere very much the samein 1980asin 1978. density. Becausethey were so small relative to the coho Side channels and terrace tributaries dominated both salmon fry, steelheadfry amounted to only 6 percent of years as habitats for the greatest numbers and most the total biomass. Coho salmon represented80 percent of biomass (Table 3). The most significant change was the the biomass found in the side channels. Cutthroat trout large difference in both density and biomass between the were uncommon and represented I percent of the density two years. In 1980, coho dominated all of the quiet, but l4 percent of the biomass due to one large yearling. pooled water, especially in the side channels. Both

38 . € & numbers and biomass for all salmonids were 5-10 times escapementinto the Hoh River in 1977was less than half higher in 1980. the escapementof 1979(Table 4). The higher number Coho salmon sampled in the same sites on terrace found in 1980could havebeen the resultof bettercoho tributaries and stable side-channels in 1978 and 1980 seedingthe year before. In 1978the area and volume for were significantly (p 3 0.05, paired t-test) more numerous eachhabitat class was higher than in 1980because of the in 1980 than in 1978. Steelhead young-of-the-year rains during the sampling.However, this resultedin a residing in unstable side-channelsand lower valley-wall sampledhabitat area on only 1.5 times larger in 1978. reacheswere also significantly more numerous (p < 0.05, Densitiesand biomasswere still severaltimes higher in paired t-test) in 1980than in 1978.The averagesize of 1980,even taking a dilution effect into consideration. coho juvenies was 55 mm for 74 fish sampled in | 978and Winter storms have not yet been analyzed as to 59 mm for 240 fish sampled in 1980. magnitudeor timing with the spawningandincubation of We could not calculate variance around the 1978 the eggs.Two data pointsdo not allow us to talk about biomass means because the data were lost at whether the streams are underseededby being Weyerhauser Company. However, the fish were both underescaped.Several years' continuousdate will be bigger and more num€rous in 1980 and the biomass necessary.We can saythat the reducedrearing area in the differences,at least for the anadromous fishes, would be late summerof 1980was carrying more and largercoho significant. juvenilesthan in 1978and that the steelheadpopulation A number of factors could help explain the data. The waslarger in 1980as comparedto 1978.

TABLE3. Comparisonof salmoniddensity and standingcrop from benchmarksites on the SouthFork Hoh River,1 978 and 1980. (+ 95% confidenceintervals)

Saluronid densi ties (no . /m2)

Habitat type Year Coho Steelhead Cutthroat Total

Terrace tributaries L978 0.22 + 0.20 0.01+ 0.02 0 0.23+ 0.20 1980 1.s5I o.s6 0.05 I 0 .09 0 .05 + 0.09 r..55I 0.5e Side channels (stable) 1978 0.19 t 0.08 0.28t 0.31 0 o.47+ 0.39 1980 1.40t 0.14 0.46t 0.10 o.02+ 0:03 r.88t 0.21

Side channels (unstable) L978 0.04+ 0.01 0.32T 0.07 0 0.36+ 0.06 1980 o.11! o.1r 0.22t 0.19 0 0.33t 0.42 Valley-wall tributaries t978 0 0.05 a 0 .03 0 .05 t 0 .08 0.09+ 0.04 1980 0.01t 0.01 0.64a 0.18 0 .01 I 0 .01 0.66+ 0.19

Salmonid bionass (g/m2)

Terrace tributaries L978 0.26 0.01 0.15 0.42 1980 3.80t 1.83 0 .08 + 0.15 0 .89 t 1.73 4.77 L 3.ss Side channels (stable) L978 0.33 0.23 o.02 0.59 1980 4.03t 0.60 0.62 ! 0.28 0.30 + 0.58 4.e5 ! L.46

Side channels (unstable) 1978 1980 0.33+ 0.29 0 .26t 0.19 0 0.59+ 0.36

Valley-wall tributaries r97 8 0.01 0 .08 0 .04 0.13 1980 0.04t 0.08 L.94+ 2.00 0.07+ 0.13 2.05+ 2.22

39 TABLE 4. Hoh Biver and Oueets River wild coho salmon adult returns and escapements,including jacks. Brood years for juvenilessampled in 1978, 198O,and 1981 are underlined.(Bill Woods, Washington Dept. Fisheries, Forks, Wash.. pers. comm.)

Hoh River Queets River

Year Total return Es caoement Total return Es capement

L977 3,430 2,298 3,387 2,223

L978 5,100 2,068 6,499 3,320

L979 8,770 5,160 L2,490 8,510

1980 3,860 2,100 11,800 5,836

1981 3,940 2,400 7 ,400 5,950

UPPEROUEETS RIVER BASIN PHYSICALHABITAT AND SALMONID POPULATIONS_1981

Physical Habitat

Micro-habitat data for the Upper Queets River was concentrate fish, we do not believe they represent a similar to that presentedfor the South Fork Hoh River in significant loss for the anadromous fisheries except Table l. Bank cover was not greater than l0 percent. during extreme drought. Terrace tributaries exhibited very little in the way of low, The overall contribution of the lower valley-wall overhanging riparian shrubbery. streams was less than 5 percent. The quiet-water shallow On a macro-scale,the total summer rearing habitat in margins along the mainstem extended out about I 1.0-1.5 the Upper Queets River is presented in Table 5. The m from the river edge. Big rearing pools around root Upper Queets River basin is a larger system with more wads and alcoves along the mainstem were about 0.5 extensive terrace development than the South Fork Hoh percent ofthe total area. This does not appear toprovide River. Side-channelsand terrace tributaries account for much quiet water for coho salmon juveniles. over 20 percent of the available habitat. As such, we The summer of l98l experiencedextremely low flows, expect more coho salmon production per kilometer of as the Olympic Mountains had only l0 percent of their river than in the South Fork Hoh. Isolated pools on the normal snowpack. Consequently, these July-through- floodplain only accounted for 0.3 percent of available September habitat surveysare probably conservative in rearing habitat. This is very low, considering historic estimating the amounts of summer coho and steelhead concerns over losses to the fishery when sloughs and rearing habitat. floodplain pools dry up. Even though they tend to

TABLE5. UpperOueets River(Sams Riverto KilkellyRapids) anadromous salmonid habitat. summer 1981

Habitat tvDe Surface atea (m2) Percent total area

Main channel 583,320 74.r Shallow margin habitat (32, 000) (4. 1) Alcoves/logjam side pools (4,010) (0.5)

Isolated floodplain pools 2,390 0.3

Side channels I18,130 15.0 Sheltered (i.e. through terrace) (68,410 ) (8.7) Unstable and exposed (36,360) (4.6) Intermediate (i.e. along terrace) (13,360) (1.7)

Terrace tributaries 46,250 5.9

Lower va1ley-wal1 tributaries 37,000 4.7

Total 787,060 100.0

40 fP I i Distribution of Coho Salmon and SteelheadTrout Winter utilization of these stream habitats does not i in the Upper Oueets River appear likely to any large extent. The major tributary 'aj. The distributionof coho salmonand steelheadtrout is streamsof the Upper Queets(except for Paradise)appear in Figure4. WashingtonDepartment of Fisheries to act as large valley-wall tributaries, with extreme flows shown being common. reports 14.4 km of Tshletshy Creek are open to The distribution anadromousfish, but we estimatethat only the lower 7.2 of side-channel and terrace-tributary habitats, prime km are available to anadromousfish, becauseof an which are coho salmon rearing areas,are generally apparentbarrier falls at that point. on the north side ofthe river, as theyare along the South Fork Hoh Kilkelly Rapidswas determined to bethe upper limit of River. The mainstem Upper Queets at the Sams River confluenceand the first 1.5km cohomigration. Two daysof electroshockingabove these of Sams River have particularly high-quality rapidsresulted in finding no coho juveniles. terrace-tributary As samplingcontinued upstream from the conlluence development and stable side-channels which make for excellent coho salmon habitat. of a tributary streamwith the Upper QueetsRiver, the percentageof salmonidsthat werecoho salmongenerally declined. Salmonid Densities and Biomass-l 981 In late summer, most major tributary streamsof the A detailed graphic presentation of salmonid densities had Upper Queets a tendencyto dry up for several and biomass, by habitat type, in the Upper Queetsbasin hundred m just before reachingthe Upper QueetsRiver. is found in Figures 5ad for density, and Figures 6a-d for Waterpercolated into the poroussubstrate of the major biomass. tributary and entered the Queetsby a subsurfaceroute. Unlike the South Fork Hoh River, the highestdensities This wasseen on Harlow, Bob, Alta, HeeHee, and Coal and greatest biomass of salmonids were found in the Creeks.Summer rearing habitat in the lowerend of these lower valley-wall tributaries and not in the stable side- streamsis ephemeral,and utilization of these low- channels(Table 6). In this habitat type, over 90 percent of gradient,pool-rich areasby rearing salmonidsusually the salmonid density were steelheadtrout and 80 percent resultedin fish beingtrapped in isolatedpools which later of the total salmonid density were 0-age steelhead.These driedup or appearedto beheavily exploited by avianand high-gradient valley-wall streams were prime steelhead mammalianpredators. nursery areas. Seventy-five percent of the salmonid

H

ffil .o"o ANo'TEELHEA'

Nl ,r.ELHEAo

El ."...rrNr coHo

Figure 4. Distribution of coho salmon and steelhead trout in the upper oueets River, late summer of j 9g1 . Excellent coho salmon habitat corresponds with terrace-tributary and stable side-channel areas.

4r biomass was also steelhead trout. The contribution of of habitat sampled in 1981. Isolated pools were not cutthroat trout was from a few Z+-agefish. Coho salmon included, since populations of fish were artificially high were a minor participant in this habitat. due to habitat shrinkage. Major tributaries were also All valley-wall tributary sites had at least 90 percent of dominated by steelhead biomass (68V0) and density the salmonid density as cutthroat and steelheadtrout, (86%o),and the individual coho salmon were relatively and no more than l0 percent coho salmon. The only Iarge. valley-wall tributary with any appreciable number of Side

coHo O.8= 89%

STEE LHEAD = 206 O.O4 = 4% O.O1

CUT THROAT + STE E LHEAO O.2 = 32% CUTTHBOAT + STEELHEAD A.2 =16% coHo O.O3=3% Figure5- Relativedensities of salmonidspecies (#/mz) in the UpperQueets Riverforthe{our major habitattypes: (a)terracetributaries; (b) side channels; (c) major tributaries (Sams River, Tshletshy Creek, etc.); (d) lower valley- wall tributary.

42 , E 4 t; ,g coHo O.8=78% 3 2.5 = A4%

O+ TROUT o.1 = 13%

CUTTHROAT CUTTHROAI =7% TEELHEAD O.4=13% STEE LHEAO O.O7 O.Ol= <196 O.O3:3%

CUTTHBOAT CUTTHROAT = O.O3=l% O.9 21% STEELHEAD STEE LHEAO 1.6 = 39%

O+ TROUT O+ TROUT O.5= 20% 1.5=36%

TABLE 6. Density and biomass of salmonid species collected in stream habitats of Upper Oueets River, late summer and autumn.1981

Salmonid densities Total Habitat type S tee the ad Cutthroat

0.89 0.29 Terrace tributaries 0.79! 0.28 0.06 + 0.06 0.002t 0.002 0.04t 0.04 t 0.13 Si& dranrpls 0.21+ 0.10 0.L2 + 0.L2 0.004t 0.004 0.004I o.o2 0.34-t 0.91 I"o^rer valley-wall tributaries 0.03 + 0.05 0.83 t 0.94 0.12+ 0.07 0.05+ 0.06 r.03t + 0.31 l4ajor rributary' drsrrels, 0.06+ 0.05 0.38 + 0.22 0.18+ 0.09 0.001+ 0.001 0.65

ncrr-glacial n Salnrnid biormss (cJm') + O.91 Terrace tributaries 2.46+ 0.8L 0.133t 0.23 0.0rt 0.01 0.37t 0.32 2.97

Si& drarels 0.80+ 0.3B 0.13+ 0.11 0.03+ 0.03 0.07+ 0.06 1.03t 0.3s 4.11r- 0.67 Iower walley-wall Eributaries 0.20! 0.25 1.47t r..58 r.57 t 1.14 0.87t 1.34 + 2.66+ 1.15 Major tributary drarrels, 0.3L + 0.22 0.53! 0.23 r.81 t 0.90 0.01 0.02

rnn-glaeial

43 2. Side-channels in which 90 percent or more coho In the South Fork Hoh River in 1980, we found a were found (out of the total number of estimate progressive decrease in size the farther away from the salmonids in the population) were always side-channels main channel we got. This fact held for valley-wall which: (ul approached terrace-tributary habitat tributaries and terrace tributaries. characteristics, (b) or were stable and plugged at the Differences in size ofjuvenile coho salmon between the upstream end. South Fork Hoh River and Upper River reflect in 3. Side-channels Queets which approached isolated pool_ part the terrace extent in the two basins-The terracesare habitat characteristics had a species composition of extensiveand welldeveloped in the Upper Queets Rive r. salmonids which reflected what ihe percentage of pool The valley bottoms are wider in the Upper than in and riffle surface Queets area was before dry-up occurred. the South Fork Hoh River. A world-wide principle The averagelength ofjuvenile coho-salmonvaried with applied to fisheries production by FAO scientisls is that habitat type (Figs. 7 and 8). Those habitats which had the more extensive the interaction of flood waters with clear water, like the major tributaries, and had at least90 the flood plain, the more productive the fisheries percent riffles contained larger individuals. While terrace (Welcome 1979). The Upper River has a great tributaries juvenile Queets are the Coho salmon rearing areas in diversity of habitats and more extensive flood plains the .Upper Queets River, the mean fish-l-ength-major is which are inundated by floods. From this point ol view significantly than those found _smaller in the we should expect the Upper QueetsRiver to consistently, tributaries (Fig. 8). This is a highly significant differerice. from year to year, be more productive than the Souitr Instream food availability may be an important factor Fork Hoh River. contributing to this difference- That bigger streams yield bigger individual juvenile The number of sites and fish sampled in the Upper coho salmon has been documented in Oregon by Queets River was not small. Twelve terrace-tribuiirv Skeesick (1970) for the Wilson River, Oregon and by sites were sampled and 1,415 coho juvenil"r -""ru."d. Fred Everest, Corvallis, Oregon (personal Eighteen side-channel reaches weri sampled and 915 communication) for Knowles Creek, a tributary of the coho measured. Five major tributary siteswere sampled Siuslaw River on the central Oregon coast. Whether and 165 coho measured. Fourteen valley-wall tribuiary there is a bimodal distribution of smolts in the spring sites were sampled and 155 coho measuied. In the main which reflects the observed growth pattern by habitat channel of the Upper Queets River, the mean tength of type as shown in Figures 7 and 8, is unknown. coho salmon was derived from l5 individuals locatJd ina Iog jam on the channel pelton edge near Creek Shelter. We do not know whether the smaller fish delav In I 978, coho salmon found in terracetributaries of the smolting until they reach a larger sizeand drop down into South Fork Hoh River were significantly smaller than the lower parts of the basin to rear, or smoli when they individuals found g). in the side-channel haLitats (Fig. are small and have a different migration pattern when The trend held up in 1980although the differences were they reach the ocean. We do not know much about the not significant. Size differences between the two vears size requirements of wild fish for smoltification. Most of may reflect the different summer rearing area avai[able. the work on optimum size of smolts has been done on The. month of August was dry in 1980, thus limiting hatchery fish. rearing volume and area in both habitat types.

E c J J

- I F c, F z (, u z J -- o I o o I o o o u o (,U c t! E u

To;rac€ Sidc Lower Valley Non- Mrin Tribularios Channols Wail gtacial Ghannel Totraca Side Tributalies Stl€am Tributarios Channels

HAEITAT TYPE HABITATTYPE

Figure7. Averagelength (mm) of juvenilecoho salmon varied with Figure8. Average length of juvenile coho salmon varied between habitat type in th€ Upper Oueets River, Bars represent9b% terrace-tributary and stable side-channel habitaf types in the confidence intervals South Fork Hoh River. Bars represent 95% confidence intervals

44 ti"

THEROLE OF ORGANIC DEBRIS IN THE MAINTENANCEOF FISHHABITAT

I-arge woody debris in streams of the old-growth the very productive off-channel areas would maintain spruce, hemlock, and Douglas-fir forests have profound levels of invertebrate and fish densities and biomasses effects on channel form and fluvial processeson all-sized much lower than they now have. streams. Woody debris ( l0 cm diameter) play different large trees or wood in streams do not have to roles in each of the habitat typesdescribed. We examined completely dam a stream channel to have a major the extend to which debris intervened in the stream influence on fish habitat. The majority of debris channel on the South Fork Hoh River and we grouped intervening on channels only influences I / 3 or lessof the debris interventions into four categories, depending on channel width. This is enough to create diverse stream the extent of direct influence within the channel width. velocities,pocket pools, and cover, which resultsin stable The categories were (l) influences of l/3 or less of the and diverse fish-habitat conditions. channelwidth, (2) | l3to l/2of thechannelwidth,(3')l l2 Fish populations also responded to debris in side- to 213 of the channel width, and (4) complete channel channels.In general,side-channels which were plugged at dams, bridges or other direct interventions. the upstream end by organic debris and cobbles had We also determined the length of stream influenced by significantly greater salmonid densities (p ( 0.01) than debris. Thus, we had a frequency or number per 100m of unplugged sites (Fig. 9.) habitat type and a percentage of stream length which was debris-influencedper 100 m of stream. In 1978, debris was found to intervene on all habitat channels 16-18 times per 100 m of stream (Sedell el a/. 1982). Between 60 and 70 percent ofthe debris influence was caused by wing jams and single piecesof large debris which influenced less than I / 3 of the channel. These important structural features caused lateral and vertical deflection of the current at high flows which resulted in i =.53 ! .13 high-quality pools and clean spawning gravelsin the pool i=.5O!.32 tail-outs. In 1980, the frequency of debris interventions went down considerably (Table l). This was primarily due to the way we reported the data. In 1978, every piece was counted as an intervention. In 1980, clumps of debris were considered as one jam and pieceson the side were not included in the tally unless it was obvious that the Plugged Unplugged Othor n = ll n= 8 channel was influenced by it. As a result, the frequency of n=9 debris interventions dropped by half. In 1980,there were Sampl€ Sites no distinct differences among major habitat types as to in UpperQueets River channels the extont to which the channel was influenced by debris Figure9. Densitieso{ coho salmon which are cappedor pluggedat the head by cobbleand organic jams. debris.Pluggedside-channel areas represent 58% ol total side- In 1980,the length of channel which was influenced by channefhabitat, unplugged side channels 31o/", and inlermediate debris was estimated to be between 20 and 30 percent for 1 17o.Bars represent 95% confidenceintervals. all habitat channels except stableside-channels (Table l). These stable side-channelsmeasured about l2 percent of the channel length influenced by debris. Most of this influence was at the head of the side-channel.Debris also accounted for much of the bank cover along the channels. Debris-plugged side-channels had 6 times the In general, the main channel and off-channel areas salmonids/m2 and 3.6 times the salmonids/m3 as the utilized trees and large piecesof wood which originated unplugged sites. There were no significant differences in upstream from where the accumulations were found. The the length of coho salmon juveniles rearing in debris- adjacent forest along terrace tributaries and valley-wall plugged or unplugged habitats. tributaries contributed the wood which was usually Plugged sites were those which had an accumulation of found in thesestreams. Debris was a major contributor to material at the upstream end of the side-channel, fish habitat for both spawning and rearing requirements protecting the majority of the side-channelhabitat from of the different fish's life cycles. While we tend to ignore scouring due to flood flows of the main river. The debris influence to the physical channel oflarge rivers, its material was usually large organic debris, but could also role in forming and maintaining anadromous fish be boulders, stable cobble bars, living vegetation, or habitats is very important, regardlessof size of streams combinations of these three. Unplugged side-channels (Sedell and Luchessa 1982). Without large trees being were those subjected to scouring by flood flows of the transported to the off-channel areasby the main channel, main river.

45 coNcLUstoNs

Salmonidhabitat formed by the main-riverchannels of tributaries. Floodplain habitats which represent the South Fork Hoh and Upper 6-23 eueetsRiver tributaries percent of summer rearing habitat available can account is controlled by the valleyterrice structure and the for 55-70 percent of the summer standing crop of effectsof large, woody coho T$ifyi"g debris. I-arge,woody salmonjuveniles rearing in the two river basins. debris is important to While the all habitais,regardless of sire oi majority of coho salmon were found Without large rearing there, they ,rt.."l-. wood, spawning- and rearing_ were significantly smaller than coho juveniles habitat quality would be poorer,iven rearing on inlarge sedimenf_ the edges or in the main channel. The role rich main channels.I-arge-wood-plugged these smiller side-channels coho play in the smolt production from the basin remains had 8 times the coho salmonaeniitiJJas side-channels to be investigated. without debris. The Upper Queets River terraces are more extensive During the late summer the juvenile majority of and provide greater diversity and abundance of salmonid salmonidrearing occurs in river side-channelaieas and habitats than the South Fork Hoh River.

LITERATURECITED

Duff, D.A., and J.L. Cooper. 1976. Techniques for Swanson, F.J., and G.W. Lienkaemper. lgg2- conducting stream habitat survey on natural iesource Interactions among fluvial procesJes, forest land. U.S. Dept. Int., BLM TechnicalNote 2g3,72pp,. vegetation,and aquatic ecosysteml,South Fork Hoh Sedell, J.R., and K.J. Luchessa. lgg2. Using ihe OlVmpic National Park, Washington.-Confereice pages23- historical record as an aid to salmonid nlUitat $]v-e1, 34, Vol. 7 in Proceedingsof the Second on enhancement. Pages 2lG223 r? N.B. Armantout (ed) Scientific Research of National parks. National park Aquisition and Utilization of Aquatic Habitai Service,NPS/ST-80/02-7, Washington, D.C. Inventory Information. proceedingsof a Symposium, Ward, G.M., K.W. Cummins, 28-30 October 1981,portland, S.V. Gregory, R.W. Ore. West Div., emer. Speaker,T.L. Fish. Soc. Dudley, and A.K. Ward. tglZ. UaUitat and food resources for invertebrate communities in - P.A. Bisson,and J.A. June. 19g2.Ecology South Fork Hoh River, Olympic National park, and habitat requirements of fish populations in Souiir Washington. Pages35-46, Vol. 7 in proceedings of the Fork Hoh River, Olympic National park. pages 47_63, Second Conference on Scientific Researchin National Vol. 7 lrz Proceedings of the Second ConfJrence on Parks. National Park Service, NpS/ST-g0/02-7. Scientific Research parks. park in National National Wash.,D.C. Service,NPS/ ST-80/02-7,Wash., D.C. Welcomme, R. 1979. Fisheriesecology of floodplain Skeesick, D.G. 1970.'The fall immigration juvenile of rivers. London, Longmans. 317 pp. coho salmon into a small tributary. Res. Reps. Fish Comm. of Oregon 2:90-95.

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