Uence of Forest and Rangeland Management an Anadromous Fish Habitat in Western North America HABITAT REQUIREMENTS of ANADROMOUS SALMONIDS

General Technical Report PNW-96 October 1979

EDITOR'S

uence of Forest and Rangeland Management an Anadromous Fish Habitat in Western North America HABITAT REQUIREMENTS OF ANADROMOUS SALMONIDS

D.W. REISER and T.C. BJORNN

U.S. Department of Agriculture Forest Service Pacific Northwest Forest and Range Experiment Station ABSTRACT

Habitat requirements of anadromous and some resident salmonid fishes have been described for various life stages, including upstream migration of adults, spawning, incubation, and juvenile rearing.

Factors important in the migration of adults are water temperature, minimum water depth, maximum water velocity, turbidity, dissolved oxygen, and barriers.

Habitat requirements for successful spawning are suitable water temperature, water depth, water velocity, and substrate composition. Cover--riparian vegetation, undercut banks, and so on--is needed to protect salmonids waiting to spawn and may influence the selection of spawning locations.

Incubation requirements incorporate both extra- and intragravel factors. Extragravel factors are: dissolved oxygen, temperature, velocity, discharge, and biochemical oxygen demand of the stream. Intragravel factors are dissolved oxygen, temperature, permeability, apparent velocity, and sediment composition.

Important habitat components for juvenile rearing are fish food production areas, water quality, cover, and space. Good fish food production areas are mostly riffles with water depths of 0.15-0.91 m, water velocities of 0.30-0.46 m/s, and substrates of coarse gravel and rubble (3.2-30.4 cm). Good water quality for rearing salmonids includes mean summer water temperatures of 10.0'-14.0°C, dissolved oxygen at more than 80-percent saturation, suspended sediment less than 25 mg/liter, and fine sediment content of riffles less than 20 percent. Adequate cover--in the form of riparian vegetation, undercut banks, aquatic vegetation, and rubble-boulder areas--is needed to protect juvenile fish from predation and adverse physical factors.

KEYWORDS: fish habitat, anadromous fish, salmonids, habitat needs. Gen. Tech. Rep. PNW-96, "Influence of forest and rangeland management on anadromous fish habitat in Western North America--1. Habitat requirements of anadromous salmonids.

In Western North America many human activities, both commercial and recreational, take place on forest and range lands. These activities include timber harvest, livestock grazing, mining, hunting, fishing, camping, backpacking, and those associated with resource uses, such as road construction, urbanization, water development, and treatments to improve forest growth. The many streams, rivers, lakes, and estuaries encompassed by these forest and range lands are habitat for the valuable stocks of anadromous (sea-going) and resident salmon and trout.

The effects of human activities on the habitat of these salmonids has been of increasing concern to resource users and managers. Much has been learned about the responses of fish to changes in their habitat, but some of it is not widely known and the information is contained in a wide variety of sources. Scientific journals and other publications that discuss the results of fisheries research are numerous, and significant work is often published in a form that is not readily available to resource managers and to other scientists studying similar situations.

In 1976, the Forest Service of the U.S. Department of Agriculture initiated a cooperative program to define the potential problems associated with land uses in watersheds supporting anadromous fish populations, and to D apply this knowledge to managing forest and range lands. Three Forest Service experiment stations--Pacific Northwest, Pacific Southwest, and Intermountain, and five regions in the National Forest System--Region 1 (Northern), Region 4 (Intermountain), Region 5 (California), Region 6 (Pacific Northwest), and Region 10 (Alaska)--as well as many Federal, State, university, and private cooperators, are participating in the program.

The purpose of this series of reports is to assemble current knowledge on how management practices on forest and range lands influence anadromous fish habitat into one set of documents for resource managers, scientists, administrators, and interested citizens. Three general areas covered will be the habitat requirements of salmon and trout, the effects of various land uses on this habitat, and methods for restoration and enhancement of habitat.

Fourteen papers are presently planned for this series. They will be published irregularly, but most will be available within the next 2 years. Additional topics may be addressed later, as the need for information arises.

I would like to express my thanks not only to the authors of these reports, but. to the many technical reviewers, editors, illustrators, typists, and others whose efforts have made and will continue to make this compendium series a success.

WILLIAM R. MEEHAN Technical Editor USDA FOREST SERVICE General Technical Report PNW-96

INFLUENCE OF FOREST AND RANGELAND MANAGEMENT ON ANADROMOUS FISH HABITAT IN THE WESTERN UNITED STATES AND CANADA William R. Meehan, Technical Editor

1. Habitat Requirements of Anadromous Salmonids

DmW. REISER AND T. C. BJORNN ldaho Cooperative Fishery Research Unit University of Idaho, Moscow

PACIFIC NORTHWEST FOREST AND RANGE EXPERIMENT STATION Forest Service, U.S. Department of Agriculture Portland, Oregon PREFACE

This, the first in a series of publications summarizing knowledge about the influences of forest and rangeland management on anadromous fish habitat in the Western United States, describes habitat requirements of anadromous salmonids--the valuable salmon and trout species that use both freshwater and marine environments. ~equironentsof these unique fish must be understood before we can explore the effects that natural events and human activities can have on their habitat, and on their ability to maintain productive populations with our increasing use of other forest and rangeland resources. Reports on the effects of natural watershed disturbances and various land use activities will follow.

We intend to present information in these publications that will provide managers and users of the forests and rangelands of the Western United States with the most complete infomation available for estimating consequences of various management alternatives. In this series of papers, we will summarize published and unpublished reports and data as well as observations made by resource scientists and managers made during years of experience in the West. These compilations will be valuable in planning management of forest and rangeland resources, and to scientists in planning future research. The extensive lists of references will serve as a bibliography on forest and rangeland resources and their use for this part of the United States.

KBERT F. TARRANT, Director Pacific Northest Forest and Range Experiment Station 809 NE Sixth Avenue Partland, OR 97232 TABLE OF CONTENTS

I~UCrI~~mm~m~m~m~m~mmm~m~~m~~~mmmmmmmmmmm1 UPS- MIGRATION CX' ADULTS ...... 2

~~RATURE~.m~.m~m.m~m.~.m~mmo.m~m~mm.mm.m~~~m~~~m.~mm~mm2 DISSOLVED OXYGE2N ...... 2 TURBIDITY.m.mm.m.mm.~m.~.~m.~~.~.mm~~~~~m~~mm.mmm.*~**mm*m 2 -Em...... 2 S~~~m~mmm~~~m~~m~m~~m~~mmmmmmmmmmm4

CX>VER...... 6 TEMPERATURE ...... 6 SUBSTRATE COP(IH)SITIa...... 6 fiEDD AREA ...... 8 WATER DEPTH AND VELOCITY ...... 8 S- S- ...... 9

SURF= STREAM=IMWG?AVEf, RELATION ...... 15 DISSOLVED O~~Nm.mmmm.~.mmmmm~~~~~mm~..m*rn*.m.. m.mmm*mm~m 16 ~~RA~m~m~mmm~mm~~mmmm~mmm~~mm~mm~~m~~mm~mmm~mm~mmmm~19 BI-ICAL OXYGEN DWm~mmmmm~mm~~mm~~mm~mmmmmm~~~m~~m 20 APP- VELOCITY ...... 20 SUBSTRATE MA^...... 21 S~~~mm~mm~mm~~m~~m~~~mmmmmmmmmmmmmmmmm22

FISH FOOD PRODUCTION AREAS ...... 24 VELOCITY ...... 24 DEPTH ...... 24 SUBSTRATE ...... 25 RIP= VJEIX;EITATION...... 25 WTER QvXIW...... 27 TmpraWe ...... 27 Dissolved Cbrygen ...... 28 Suspended and Deposited Sediment...... 29

LITERATURE CITED.m.~.m.~.m~m.m~.mmm~m.~mo ...... 41 Carmc>n nw Scientific nime

Pink salmon Oncorhynchus gorbuscha (Walbaum) Qxrm salmn Oncorhynchus keta (Walbaum) Cd20 salm Oncorhynchus kisutch (Walbaun) Sbdceye sdlmn (hkanee) Oncorhynchus nerka (Walbam) Chinadc dm Oncorhynchus tshmytscha (Walbaun) Cutthroat trmt SaZmo cZarki Richardson Rabbw (steelhed) trout SaZmo gairdneri Richardson Atlantic salmon Sa Zmo sa Zar Linnaeus Bmtrout SaZmo trutta Linnaeus Asctic char Salve Zinus alpinus (Linnaeus) Brock trout SaZveZinus frmtinalis (Miail1) m11y Vadn SaZveZinus maZma (Walbam) Ldce trmt SaZveZinus namaycush (Walbam)

-1/ Fron .A List of ComDn and Scientific Names of Fishes £ran the United States and Gmda," American Fisheries Society Special Publication No. 6, Third Edition, 1970, 150 p. INTRODUCTION

Habitat needs of anadromous salmonids ( sea-run salmon and trout) in streams vary with the season of the year and the stage o of their life cycle. Upstream migration of adults, spawning, incubation, juvenile rearing, and seaward migration of smolts are the major life stages for most anadromous salmonids . Insofar as possible, we have defined the range of habitat conditions for each life stage that will allow a population to thrive. Throughout this paper, we have included data for salmonids that are not anadromous because they illustrate the range of temperatures, velocities, and depths of waters preferred by salmonids, and these species are generally similar to the anadromous ones. stocks of anadromous salmonids have evolved with the temperature patterns of their home streams, and significant abrupt deviations from the normal pattern could adversely affect their survival.

DISSOLVED OXYGEN Reduced dissolved oxygen concentrations can adversely affect the swimming performance of migrating salmonids . Maximum sustained swimming speeds of juvenile and adult coho salmon at temperatures of lo0-20°C were adversely affected when oxygen was reduced from air-saturation --- \ levels (Davis et al.1963). A UPSTREAM sharp decrease in performance MIGRATION OF ADULTS was noted at 6.5-7.0 mg/l for all temperatures tested. A similar relation has been ob- Adult salmonids returning served by Graham (1949) for to their natal streams must brook trout. Low dissolved arrive at the proper time and in oxygen may also elicit avoidance good health if spawning is to be reactions as noted by Whitmore successful. Unfavorable dis- et al. (1960) and may cause charges, temperatures, tur- migration to cease. The oxygen bidity, and water quality could levels recommended for spawning delay or prevent fish from fish (at least 80 percent of completing their migration. saturation, with temporary levels no lower than 5.0 mg/l) TEMPERATURE should provide the oxygen needs of migrating fish. Selected salmonid fishes have successfully migrated upstream in water temperatures TURBIDITY ranging from 3O to 20°C (table Migrating salmon will avoid 1). Temperatures above the or cease migration in waters upper limits have been know with high silt loads (Cordone stop the migration of fish.- and Kelley 1961, Bell, see footnote 1). Bell cited a study Unusual stream temperatures in which salmonid fish would not can lead to disease outbreaks in move in streams where the sedi- migrating fish, altered timing ment content was more than 4 000 of migration, and accelerated or mg/l. The turbid water resulted retarded maturation. Most from a landslide, Turbid water will absorb more radiation than - Unpublished report, "Fisheries clear water and thus may in- handbook of engineering requirements directly result in a thermal and biological criteria. Useful barrier to migration. factors in life history of most common species," by M. C. Bell. Submitted to BARRIERS Fish.-Eng. Res. Prograin, Corps of Waterfalls, debris jams, Eng , , North Pac. Div., Portland, and excessive velocities may Oreg., 1973. also impede migrating fish. Falls that are insurmountable Table 1-Water temperature, depth, and velocity criteria for successful upstream migration of adult salmon and trout.

Species of Temperature Minimum Maxi mum fish range-1 / depth- velocity-2/ 1 I 1 -"C Meters Meters/second Fall chinook salmon Spring chinook salmon Summer chinook salmon Chum salmon Coho salmon Pink salmon Sockeye salmon Steel head trout Large trout Trout

-1/ From Bell (see text footnote 1). -2/ From Thompson (1972). -3/ Basedonfishsize. at one time of the year may bye Some logs, leaves, dams, passed by migrating fish at and so on, in streams are other times when flows have beneficial as cover for adult changed. Stuart (1962) deter- and juvenile fish. All debris mined in laboratory studies that jams should be evaluated care- ideal leaping conditions for fully before they are removed. fish are obtained with a ratio of a height of falls to depth of Water velocities may exceed pool of 1:1.25. Figure 1 from the swimming ability of migrating Eiserman et al. (1975) depicts fish at channel constrictions the leaping behavior of salmonids during snow melt and storm observed by Stuart. Given runoff. Migration resumes when suitable conditions, salmon and streamflows and associated steelhead can get past many velocities have decreased. The obstacles that appear to be swimming abilities of fish are barriers. Both Jones (1959) and usually described in terms of Stuart (1962) observed salmon cruising speed--the speed a fish jumping 2-3 m. can swim for an extended period of time (hours), usually ranging Debris jams, whether nat- from 2 to 4 body lengths per ural or caused by human activ- second; sustained speed--the ities, can prevent or delay speed a fish can maintain for a upstream migration. Chapman period of several minutes, (1962) cited a study in which a ranging from 4 to 7 body lengths 75-percent decrease in spawning per second; and darting or burst salmon in one stream was attrib- speed--the speed a fish can swim uted to debris blockage. Debris for a few seconds, ranging from barriers often form large pools 8 to 12 body lengths per second and sediment traps that, if (Bell, see footnote 1; Watts released, could adversely affect 1974; table 2). According to downstream spawning areas. Bell, cruising speed is used FLOW (CUBIC FEET PER SECOND)

Figure 2-Salmonid passage flow determination (from Thompson 1972).

during migration, sustained speed for passage through difficult areas, and darting speed for escape and feeding. Velo- cities of 3-4 m/s approach the Figure 1-Leaping ability of salmonids (from Eiserman et al. 1975, diagrams drawn after Stuart 1962): A. Falling upper swimming ability of salmon water enters the pool at nearly a 90" angle. A standing and steelhead and may retard up- wave lies close to the waterfall where trout use its stream migration. upward thrust in leaping. Plunge-pooldepth is 1.25 times the distance (h) from the crest of the waterfall to the water level of the pool. B. The height of fall is the same, but pool depth is less. The standing wave is STREAMFLOW formed too far from the ledge to be useful to leaping trout. C. Flow down a gradual incline is slow enough to Migration can also be allow passage of ascending trout. D. Flow over a steeper hampered by too little streamflow incline is more than trout can swim against for much and resulting shallow water. distance. Trout may even be repulsed in the standing wave at the foot of the incline. They sometimes leap Thompson (1972) established futilely from the standing wave. E. A shorter barrier with passage criteria for various outflow over steep incline may be ascended by trout salmonids based on minimum depth with difficulty. and maximum velocities (table 1). Stream discharges that will provide suitable depths and velocities for adult passage ( figure 2) can be determined from the criteria and techniques described by Thompson (1972): 1/ Table 2-Swimming abilities of average size adult salmonids-

Species of I fish Cruising speed Sustained speed Darting speed

I 1 I _--______Meters per second------

Chinook Coho Sockeye Steel head Trout Brown trout

-1/ From Bell (see text footnote 1).

...shallow bars most critical to passage of adult fish are located and a linear transect marked which £01 lows the shal- lowest course from bank to bank. At each of several flows, the total width and longest continuous portion of the transect meeting minimum depth and maximum velocity criteria are measured. For each transect, the flow is selected that meets the criteria on at least 25 percent of the total transect width and a continuous portion equal- ling at least 10 percent of its total width.

The mean selected flow from all transects is recommended as the minimum flow for passage. Thompson (1972) noted that maximum acceptable passage flows could theoretically be defined, but we have not attempted to do so in this paper. Baxter (1961) reports that salmon need 30-50 percent of the average annual flow for passage through the lower and middle reaches in Scottish rivers and up to 70 percent for headwater streams. Reiser and Wesche (1977) noted that many spawning brown trout selected areas adjacent to undercut banks and overhanging vegetation. Reiser and Wesche (1977) speculated that the early spawners and large dominant fish may select areas by cover. As these areas become occupied, the late spawners and small fish are forced to use relatively un- protected sites. Given a choice between two spawning areas, one with cover and one without, the fish would select the area with cover.

TEMPERATURE Successful spawning of salmonids has occurred in water temperatures ranging from 2.2 to 20. O°C (table 3 ) . A sudden drop in temperature may cause all spawning activity to cease, Cover, substrate composition, and water quality and resulting in lowered nest build- quantity are important habitat ing activity and reduced pro- elements for anadromous sal- duction (see footnote 1). monids before and during spawning. SUBSTRATE COMPOSITION COVER The suitability of a parti- Cover for fish can be cular size gravel substrate depends mostly on fish size. provided by overhanging vege- Large fish can build redds in tation, undercut banks, submerged vegetation, submerged large substrate. To determine objects--e.g. logs and rocks, the substrate composition floating debris, and water depth preferred by various salmonids, and turbulence (Giger 1973). many investigators (Burner 1951, Cover can protect the fish from Cope 1957, Warner 1963, Orcutt disturbance and predation and et al. 1968, Hunter 1973, Reiser also provide shade. Some anad- and Wesche 1977) collected romous fish--chinook salmon and gravel samples from active redds steelhead, for example--enter and graded them through a series freshwater streams months before of sieves. The substrate compo- they spawn, and cover is essen- sition selected in artificial tial for fish waiting to spawn. spawning channels reflects the Many spawning areas are rela- judgment of those who determined tively open segments on streams the particle sizes best suited where fish are vulnerable to for selected species. In the disturbance and predation during Robertson Creek spawning channels, gravel ranging from 2 to 10 cm redd (nest) construction and spawning. Nearness of cover to was used for pink, coho, and spring chinook salmon (Lucas spawning areas may be a factor in the actual selection of 1959). In the Jones Creek spawning sites by some species. spawning channel, gravel ranged Johnson et al. (1966) and from 0.6 to 3.8 cm (MacKinnon et al. 1961). The Tehama-Colusa 1/ Table 3-Recommended temperatures for spawning and incubation of salmonid fishes-

Species Spawni ng temperature Incubation temperature-2/

Fall chinook Spring chinook Summer chinook Chum Coho Pink Sockeye KOkanee Steel head Rainbow Cutthroat Brown

J' -11 From Be1 1 (see text footnote 1). -21 The higher and lower values are threshold temperatures at which mortality will increase if exceeded. Eggs will survive and devel op normal ly at 1ower temperatures than indicated, provided initial development of the embryo has progressed to a stage that is tolerant of colder water. -31 From Hunter (1973). vfl

Table 4-Water depth, velocity, and substrate size criteria for anadromous and other salmonid spawning areas

Species of fish Source Depth Velocity Substrate size

Meters Cm/s Centimeters

Fall chinook Thompson (1972) Spring chinook Thompson (1972) Summer chinook ~eiserg/ Chum Smith (1973) Coho Thompson 11972) Pink salmon Collin s4 soc key&/ Kokanee smi th-(1973) Steel head Smith (1973) Rainbow trout Smith (1973) Cutthroat Hunter (1973) Brown trout Thompson (1972)

-1/ From Be1 1 (see text footnote 1). J -2/ Unpublished data of D. W. Reiser, Idaho Coop. Fish Res. Unit, J Moscow. 1978. 31 Estimated from other criteria. -47- See text footnote 3. -51 No specific criteria established. -61 From Hunter (1973). 1/ spawning channels contain gravel defined: Thompson (1972) used a that ranges from 1.9 to 15.2 cm 90-to 95-percent confidence (Pollock 1969). Bell (see limit; Hunter (1973) used the footnote 1) states that, in middle 80-90 percent of the general, the spawning bed in measurements; Smith (1973) used artificial channels should be a two-sided tolerance limit composed of 80 percent 1.3-to within which there was 95- 3 -8-cm gravel with the balance percent confidence that 80 up to 10.2 cm. Acceptable percent of the measurements ranges of substrate size for would occur with a normal dis- various salmonids are summarized tribution; others have simply in table 4. listed ranges of depth and velocity. Water depth and velocity criteria for salmonids REDD AREA as defined by different investi- Area of gravel substrate gators are found in tables 4 and required for a spawning pair varies with the species (table 5). Burner (1951) proposed that a conservative estimate of the Riffle number of salmon a stream could accommodate could be obtained by dividing the area suitable for spawning by four times the average redd area. Redd area can be computed by measuring the total length of the redd (upper edge of pit to lower edge of tailspill) and the average of several equidistant widths. Riffle WATER DEPTH AND VELOCITY Preferred water depths and velocities for various spawning salmonids have been determined by measuring water depth and velocity ove5,active redds (Sams and Pearson,- Thompson 1972, Smith 1973, Hooper 1973, Hunter 1973, Reiser and Wesche 1977). These measurements were usually - Riffle taken at the upstream edge of the redd because that point most closely approximates conditions before redd construction and reflects the depths and velo- Figure 3-Longitudinal sections of spawning areas (from cities selected by the fish. Reiser and Wesche 1977): A. Convexity of the substrate Preferred depth and velocity at pool-riffle interchange induces downwelling of water into the gravel. Area likely to be used for spawning is criteria have been variously marked with an X. B. Redd construction results in negligible currents in the pit (facilitating egg deposition) and increased currents over and through (downwelling) -2/ Unpublished report, "A study the tailspill. C. Egg-covering activity results in the to develop methods for determining formation of a second pit which may also be used for spawning, as well as covering the eggs in the first pit. spawning flows for anadromous sal- Increased permeability and the convexity of the tailspill monids," by R. E. Sams and L. S. substrate induces downwelling of water into the gravel, Pearson. Oreg . Fish Comm., Portland, creating a current past eggs, bringing oxygen to them 1963. and removing metabolic wastes. Table 5-Average area of salmonid redds and area recommended per spawning pair in channels2

Average area Area recommended Species Source of redd per spawning pair ------Sauare meters-----

Spring chinook Burner (1951 ) 3.3 Fall chinook Burner (1951 ) 5.1 Summer chinook Burner (1951 ) 5.1 Coho Burner (1951 ) 2.8 Chum Burner (1951) 2.3 Sockeye Burner (1951 ) 1.8 Pink Hourston and .6 MacKinnon (1957) Pink Wells and .6-.9 McNei 1 (1970) Steel head Orcutt et al. (1968) 5.4 Steel head Hunter (1973) 4.4 Rainbow Hunter (1973) .2 Cutthroat Hunter (1973) .09-. 9 Brown Rei ser and .5 Wesche (1977)

-1/ Modified from Clay (1961). /

Many salmonids prefer to STREAMFLOW spawn at the pool-riffle interchange (Hazzard 1932, Hobbs Streamflow regulates the 1937, Smith 1941, Stuart 1953, amount of spawning area avail- Briggs 1953). Tautz and Groot able. D. H. Fry in Hooper (1975) reported that chum salmon (1973) summarizes the effect of chose to spawn in an acceler- discharge on the amount of ating flow, such as that found spawning area in a stream. at a pool-riffle interchange. By placing crystals of potassium As flows increase, more and permanganate on the gravel more gravel is covered and surface, Stuart (1953) demon- becomes suitable for strated the presence of a down- spawning. As flows con- welling current at these inter- tinue to increase, velocities change areas and suggested that in some places become too the current may assist the fish high for spawning, thus in maintajning its position with canceling out the benefit a minimum of effort. The gravel of increases in usable in these areas was easy to spawning area near the excavate and relatively free of edges of the stream. silt and debris. The nature Eventually, as flows in- of currents before, during, and crease, the losses begin to after spawning is shown in outweigh the gains, and the figure 3. actual spawning capacity of the stream starts to decrease. Table 6-Water depth, velocity, and size of substrate measured in spawning areas of salmonids

Species Source Depth Velocity Substrate How and where developed Remarks

Meters --Cm/s Centimeters Chinook salmon Hamilton and >O. 24 31 - - Oregon-Coquille River Remington (1962) Fall chinook warned/ .12-1.22 15-107 California-American, and Consumnes

westgat&/ Rivers

Kier (1964) 2.24 31-92 California-Feather, Eel, and Mad

Rantz (1964) River Systems

Horton and ~ogers~ 2.21 37-107 California-Van Ouzen River - Chambers et a1 .q .30-.46 30-69 Washington-Columbia River and Vat 0.4 ft above bed tributaries Sams and ~ears.06' 2-18 .27-94 Oregon - 4 streams in Willamette 107 redds sampled; V at River Basin 0.63 depth or 0.2 ft and 0.8 depth from surface

Thompson (197216' 2.24 30-91 90-958 confidence interval ; Oregon, 440 redds sampled; wide range of streams streams represented a wide variation of

hydraulic characteristics

Smith (1973) 2.24 30-76 Tolerance interval; Oregon, 7 streams 50 redds sampled; V at with varying hydraulic conditions 0.4 ft above bed - Spring chinook Chambers et a1.I' .46-. 53 53-69 Washington-Columbia River and V at 0.4 ft above bed tributaries

Sams and pearso&' L. 18 .08- .85 Range; Oregon, 3 streams in 270 redds sampled; V at Willamette River Basin 0.6 ft depth or 0.2 ft and 0.8 ft depth from surface.

Thompson (1972)~ 2.24 30-91 90-95% confidence interval ; Oregon, 158 redds sampled ; wide range of streams streams representative of a wide variation of

hydraulic characteristics

Smith (1973) Tolerance interval; Oregon, 7 streams 142 redds sampled; V at with varying hydraulic conditions 0.4 ft above bed

~eised' >.I5 14-69 Range; Idaho, 5 small streams 58 redds sampled; V at 0.6 ft depth from surface

Sumner chinook Reiser 1' 8' .30- .85 25-109 Range; Idaho, Salmon River 50 redds sampled; V at 0.6 ft depth from surface

Chum salmon Thompson (1 972) 2.18 46-97 90-952 confidence interval ; Oregon, 177 redds sampled; on a wide range of streams streams represented a wide variation of

hydraulic characteristics

Smith (1973)~' 2.18 46-101 Tolerance interval ; Oregon, 5 214 redds sampled; V at streams with varying hydraulic 0.4 ft above bed.

conditions

~ol1ings 91 .15-.53 21-101 -- Vmeasured 0.4 ft above bed

Coho salmon Chambers et a1 .g .30-. 38 37-55 Washington, Columbia River and Redds measured 0.4 ft above tributaries bed

Sams and Pearson (1963)5/,. 15 14-93 Range; Oregon, 4 streams 123 redds sampled; V at 0.6 ft depth or 0.2 ft and

0.8 ft depth from surface Table 6-Water depth, velocity, and size of substrate measured in spawning areas of salmonids -(Continued)

Species Source Depth Velocity Substrate How and where developed Remarks

Meters Cm/s Centimeters

Coho salmon Thompson (19~2)~' 20.18 30-91 -- 90-958 confidence interval; 251 redds sampled;

Oregon, 10-12 streams with varying streams represent

hydraulic conditions wide variation of hydraulic characteristics

Smith (1973) Tolerance interval; Oregon, 7 128 redds sampled; V

streams with varying hydraulic measured 0.4 ft above bed

conditions - Pink salmon ~ol1ings 61 91 V measured 0.4 ft above bed - Sockeye salmon Chambers et a1.4' Washington V at 0.4 ft above bed - Clay (1961 ) V at 0.4 ft above bed

Kokanee Thompson (1972) 90-95% confidence interval; Oregon, 106 redds sampled;

wide range of streams streams represent wide variation of hydraulic

characteristics

Smith (1973161 Tolerance interval; Oregon, 3 106 redds sampled; Vat

streams with varying hydraulic 0.4 ft above bed

conditions

Middle 80% of range; Washington, 177 redds sampled; V at

flow 2-30 ft3/s 0.4 ft or 0.25-0.30 above bed

Steelhead trout 95% confidence interval ; Oregon 51 redds sampled

Winter steel head Smith (1973)c' Tolerance interval; Oregon, 11 115 redds sampled; V at streams with varying hydraulic 0.4 ft above bed

conditions

~ngma@/ Range; Washington 62 redds sampled

Hunter (1973) Middle 90% of range; Washington, 19 114 redds sampled; Vat

streams with varying hydraulic 0.4 ft or 0.25-0.30 ft above conditions _ bed Hunter (1973) Range; Washington 19 redds sampled; V at

0.4 ft or 0.25-0.30 ft above

bed

Range; Washington, on streams 30 redds sampled; V at

of 180 ft3/s 0.4 ft or 0.25-0.30 ft above bed

Range; Washington, Satsop River 4 redrls sampled; V at 0.4 ft or 0.25-0.30 ft above

bed

Sumner steel head Smith (1973) 2.24 43-97 - - Tolerance interval ; Oregon, 90 redds sampled; V Deschutes River 83 redds sampled D; V at 0.4 ft above bed

Orcutt et al. (1968) .21-21.52 24-55 1.27-10.16 Range; Idaho, 6 streams in Clearwater 54 redds sampled; V

and Salmon River watersheds measured at the surface Table 6-Water depth, velocity, and size of substrate measured in spawning areas of salmonids -(Continued)

. .-

Species Source Depth Velocity Substrate How and where developed Remarks

-Meters --Cm/s Centimeters Sumner steelhead ~eise& 0.12-.41 38-100 -- Range; Idaho, 3 streams 46 redds sampled; V measured at 0.6 ft depth

from surface

Rainbow trout Smith (1973)g > .18 48-91 0.64-5.18 Tolerance interval ; Oregon, 51 redds sampled; V at

Deschutes River 0.4 ft above bed

Hooper (1973) .21-.33 43-82 .64-7.62 Range; California, Feather River 10 redds sampled; V at 0.21 above bed

Bovee (1974) - - Estimated from 1iterature

Waters (1976) - - California, Pit River

Hartman (1969) - - British Columbia, Kootenay Lake

Cutthroat trout Hooper (1973) .16-.64 Range; California

Cedarholm - - Range; Washington 3 redds sampled (in Hunter 1973)

(resident) Hunter (1973) .64-5.08 Range; Washington, streams 23 redds sampled; V at 0.5-2.0 ft3/s 0.4 ft or 0.25-0.30 ft from bed

(sea-run) Hunter (1973) .64-10.16 Range; Washington, streams 16 redds sampled; V at

5.0-15.0 ft3/s 0.4 ft or 0.25-0.30 ft from bed

Brown trout Smith (1973) .64-7.62 Tolerance interval; Oregon, 5 115 redds sampled; V at

(Hunter 1973) streams with varying hydraulic 0.4 ft from bed

conditions

Brown trout Thompson (1972)g 2.24 21-64 - - 90-95% confidence interval ; Oregon, 115 redds sampled on a wide range of streams Hooper (1973) -- 30-91 .64-7.62 Range; California Bovee (1974) 2.15 40-52 - - Estimated from literature Reiser and Wesche (1977) 2.09 14-46 .64-7.62 Middle 80% of range; Wyoming, 121 redds sampled; V at

5 small streams 0.6 ft depth from surface

L1unpublished report, "The relationship between flow and available salmon spawning gravel on the American River below Nimbus Dam," by

K. Warner. Calif. Dep. Fish and Game Admin., Sacramento, 1953.

l/~npublished report. "The relationship between flow and usable salmon spawning gravel, Consumnes River, 1956," by J. Westgate. Calif. Dep.

Fish and Game, Inland Fish. Admin. Rep. 58-2, Sacramento, 1958.

/unpublished report, "The optimum stream flow requirements for king salmon spawning in the Van Duzen River, Humboldt County, California," by

J. L. Horton and D. W. Rogers. Calif. Dep. Fish and Game, Water Proj. Branch Admin. Rep. 69-2, Sacramento, 1969.

'unpublished report, "Research relating to study of spawning grounds in natural areas," by J. S. Chambers, G. H. Allen, and R. T. Pressey. Wash. Dep. Fish., Olympia, 1955.

5/~eetext footnote 2.

g~ecormnendedspawning criteria.

L1unpublished data of D. W. Reiser, Idaho Coop. Fish. Res. Unit, Moscow, 1977

/see footnote 2, table 4.

y~eetext footnote 3.

X1unpublished progress report, steelhead redd study, by R. G. Engman. Wash. State Dep. Game, Olympia, 1970.

u~ersonalcomnunication, J. W. Hunter, Wash. Dep. Game, Olympia, 1976. If spawning area is plotted Section 2 against streamflow, the Section 4 curve will usually show a rise to a relatively wide plateau followed by a gradual decline. Using the criteria described, methods have been developed for recommending stream discharges for spawning. Figures 4 and 5, taken from Collings (1972), ~dg!?of exemplify the process of depth water/ and velocity contouring to Edge of dank full Section 2 water -surface area 0 determine the area suitable for / \ Section 4 / spawning at a given discharge. Another method (Thompson 1972) VELOCITY CONTOURS uses cross channel transects on IN FEET spawning bars and consists of PER SECOND quantifying the width af the stream at different flows that of flow / meet depth and velocity criteria 0 .' /WSc- ( fig. 6 ) . When measurements _--- have been taken over a wide _-_____----- range of flows, a graph is _ ------plotted of flow versus suitable spawning areas (Collings 1972, and fig. 7) or usable width Figure 4-Example of water depth and velocity contouring for one river discharge in a study reach of the North (Thompson 1972, and fig. 8 ) . The Nemah River (from Collings 1972). optimum spawning flow is defined as the discharge at which the largest spawning area or usable width occurs. Detailed descrip- tions of spawning flow method- Section 2 Section 4 ologies are described by Sams / and Pearson (see footnote 2), on (1972), Collings (1972, TRf'),Waters (19761, and Stalnaker and Arnette (1976).

b '~d~eof bank full water-surface area

DISCHARGE: 94.6 ft2 AREA OF PREFERRED DEPTH: 1045 ft2, BETWEEN 1.0 and 1.5 ft AREA OF PREFERRED VELOCITY: 1706 ft2, BETWEEN 1.0 and 2.25ftls AREA PREFERRED FOR SPAWNING: 726 ft2

Figure 5-Determining area of study reach that is preferred for spawning by fall chinook salmon at one -3' Unpublished report. "~ener- river discharge, North Nemah River (from Collings 1972). alization of spawning and rearing discharges for several Pacific salmon species in western Washington," by M. R. Collings. U.S. Geol. Surv., open file report. 1974. 1 25 FEET ~4

SPAWNING BAR CROSS SECTION

Spawninq flow criteria Minimum depth = 0.6ft Velocity = less than 3.0 but greater .7 1.9 than 1.0 ftls Flow = width x mean depth x mean velocitv Flow = 25ft x 0.75ft x 1.93ft/s = 36 h3/s Stream width usable for spawning Usable width = 't'eam width usable 10 stations Figure 6-Transect method of determining --- 25ftx 6 10 stream width usable for spawning (from = 15.0ft Thompson 1972).

all Chinook

loo0 4 Greatest spawnable------1-

FLOW (CUBIC FEET PER SECOND)

Figure 8-Method (usable width technique) for determining 10 0 spawning flow (from Thompson 1972). 0 10 20 50 100 200 DISCHARGE (CUBIC FEET PER SECOND)

Figure 7-Method (usable area technique) for selecting preferred spawning discharge, North Nemah River (from Collings 1972). gravels has been demonstrated by Stuart (1953), Sheridan (1962), Vaux (1962). Vaux (1962) stated that the initial source of oxygen in intragravel water is the atmosphere and listed the following three steps for transport of oxygen to the intragravel environment: Dissolution of oxygen through air-water interface into stream water.

Transport of oxygenated water to the stream bottom. Interchange of oxygenated water from the stream into the porous gravel interior.

Factors that control the INCUBATION water interchange between stream and gravel bed are: Although incubation is stream surface profile, gravel inextricably tied to spawning, permeability, gravel bed depth, the habitat requirements of and irregularity of the stream- embryos during incubation are bed surface (Vaux 1962, 1968). different from those of adults Sheridan (1962) noted in salmon while spawning and warrant a spawning areas in southeast separate discussion. When an Alaska, that ground water con- adult fish selects a spawning tained very little oxygen and site, the incubation environment that the oxygen content of is also being selected. Suc- intragravel water decreased with cessful incubation and emergence gravel depth; thus the major of fry, however, is dependent on source of oxygen in intragravel both extragravel and intragravel water is the stream itself, chemical, physical, and hydraulic Wells and McNeil (1970) attrib- parameters--dissolved oxygen uted high intragravel oxygen in (DO), water temperature, bio- pink salmon spawning beds to chemical oxygen demand (BOD) of high permeability of the sub- material carried in water and in strate and stream gradient, substrate, substrate size (percentage fines), channel Intragravel water temper- gradient, channel configuration, atures are similarly influenced by temperatures of the stream. water depth (head), surface water discharge and velocity, Ringler (1970) and Ringler and permeability, porosity, and Hal 1 ( 1975 ) observed that temper- apparent velocity in gravel. atures of intragravel water lagged 2-6 h behind those of surface waters in attaining diurnal maximum--a function of SURFACE STREAM. the interchange rate of surface INTRAGRAVEL RELATION and intragravel water. Interchange of water in a Apparent velocity (velocity stream with that in streambed of water moving through gravel ) is a function of the hydraulic head and the permeability of the gravel (Coble 1961). Thus, as Surface flow 3.5 ft3/s depth of surface water increases, a corresponding increase in apparent velocity can be expected. Wickett (1954) found a direct relation between gage height readings in a stream and subsurface flow ( fig. 9) . Reduction in permeability from fine sediment deposition will reduce both the interchange of surface and intragravel water and the apparent velocity of the intragravel water (Gangmark and Bakkala 1960, Wickett 1962, ) I I I I I I Cooper 1965 . .2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 GAGE READING MAIN STREAM (FEET) DISSOLVED OXYGEN Figure 9-Relation between subsurface water flow 30 cm (12 in) in a controlled-flow side channel and main stream Critical concentrations of gage readings. The subsurface flow varied with changes dissolved oxyqen have been in discharge of the main stream adjacent to the controlled-flow side channel (from Wickett 1954, courtesy experimentali; determined for of the Journal of the Fisheries Research Board of salmonid embryos at different Canada).

Table 7-Critical levels of dissolved oxygen for salmonid embryos at various stages of development

Temperature Stage of critical value of Source Species devel opment Days units-1 1 dissolved oxygen

Wickett (1954) Chum salmon Pre-eyed Pre-eyed Pre-eyed Faintly eyed A1 derdice Chum salmon - - et a1 . (1958) - -

Lindroth (1942) At1 antic Doomed salmon Nearly hatching Hatching Hayes et al. Atlantic Eyed 25 - - (1951 ) salmon Hatching 50 - -

-11 A temperature unit equals 1OF above freezing (32°F) for a period of 24 h. -21 From Wickett (1954). developmental stages (Lindroth 1942, Hayes et al. 1951, Wickett

1954, Alderdice et al. 1958). Water Velocity Critical oxygen levels defined by Alderdice et al. (1958) are those that barely satisfy respiratory demands (table 7). Doudoroff and Warren (1965) believe the critical levels in table 7 are unreliable, because they found that embryos exposed to dissolved oxygen levels below saturation throughout development were smaller and that hatching was delayed or occurred prematurely. From laboratory tests with coho, chum, and chinook, and steelhead eggs by

Alderdice et a1 . ( 1958 ) , Silver 14 ! I I I I I I I,, al. (1963), and Shumway 2 3 4 5 6 7 8 9101112 et et DISSOLVED OXYGEN CONCENTRATION al. (1964), the following sum- (MILLIGRAMS PER LITER) mary of oxygen concentration and egg development has been pre- Figure 10-Relation between mean lengths of steelhead pared: trout sac fry when hatched and dissolved oxygen concentrations at which the embryos were incubated at different water velocities and at 95°C(from Silver et al. Sac fry from embryos in- 1963). cubated in low and inter- mediate oxygen concentrations were smaller and weaker than sac fry reared at higher concentrations, and thus they may not Water velocity survive as well as larger 1350 cm/h A 580cm/h fry (Silver et a1 . 1963, and 92cm/h figs. 10 and 11).

Reduced oxygen concentrations lead to smaller newly hatched fry and a lengthened incubation period (Shumway et al. 1964, and figs. 12 and 13).

a Low oxygen concentrations in the early stages of development may delay hatching, increase the 18 incidence of anomalies, or 4 5 6 7 8 9101112 DISSOLVED OXYGEN CONCENTRATION both. Low oxygen concen- (MILLIGRAMS PER LITER) tration during the latter stages of development may Figure 11-Relation between mean lengths of chinook stimulate premature hatch- salmon sac fry at hatching and dissolved oxygen ing (Alderdice et al. concentrations at which the embryos were incubated at different water velocities and at 11 "C(from Silver et al. 1958). 1963). by Phillips and Campbell (1961) for coho salmon and steelhead (fig. 15). Based on their field experiments, Phil lips and Campbell concluded that intragravel oxygen concentration must average 8 mg/l for high survival of coho salmon and steelhead embryos. Brannon (1965) com- pared newly hatched sockeye salmon fry developed at three different oxygen levels, and found length and other ana- tomical differences in the three groups (table 8); however, those raised in low oxygen concen- "IPl DISSOLVED OXYGEN CONCENTRATION (MILLIGRAMS PER LITER) trations eventually attained nearly the same weight by the Figure 12-Three-dimensional diagram of effect of oxygen fry stage as did those incubated concentration and water velocity on the mean dry weights of newly hatched coho salmon fry. The two broken lines (curves) delimit the reduced oxygen concentrations at different water velocities, and also the reduced velocities at different oxygen concentrations that resulted in reductions of the dry weights of fry to less than 80 percent (upper broken line) and less than 67 percent (lower broken line) of the mean weight of fry that hatched at the highest oxygen concentration and water velocity tested (from Shumway et al. 1964).

J O2345678910 DISSOLVED OXYGEN CONCENTRATION (MILLIGRAMS PER LITER)

Figure 14-Relation between dissolved oxygen concentration and embryo survival (from Coble 1961).

' *o&&, DISSOLVED OXYGEN CONCENTRATION (MILLIGRAMS PER LITER)

Figure 13-Three-dimensional diagram of "hatching delay" (median hatching time, in days, minus 44) of coho salmon fry in relation to both oxygen concentration and water velocity (from Shumway et al. 1964).

In field studies, Coble

(1961) found a positive correl- MEAN DISSOLVED OXYGEN CONCENTRATION ation between steelhead embryo (MILLIGRAMS PER LITER) survival and intragravel dis- Figure 15-Relation of mean dissolved oxygen to survival solved oxygen content ( fig . 14) . of coho embryos, Needle Branch, December 20,1960, to A similar relation was reported February 28, 1961 (from Phillips and Campbell 1961). Table 8-Characteristics of alevins at hatching after being incubated in three oxygen concentrations (from Brannon 1965)

O2 concentra t ion (mg/ 1)

Description 3.0 6,O 11.9

Temperature units to 50% hatching 1200 1200 1200

Length in mi 11imeters 16.3 18.6 19.7

Yolk sac shape Spherical Longitudinal Longitudinal

Pigmentation Lightly on On head and On head and head starting on back back Visibility of the Not visible Distinguish- Readily visible dorsal and anal fin rays able

Caudal fin devel opment Forming Forming We1 1 advanced

in water fully saturated with In many streams containing oxygen. Although dissolved incubating salmonid eggs, water oxygen concentrations required temperatures are colder than for successful incubation depend 4.5OC during the winter; eggs on both species and develop- develop normally and success- mental stage, concentrations at fully, however, because spawning or near saturation with tem- and initial embryo development porary reductions no lower than occur when temperatures are 5.0 mg/l are recommended for warmer. anadromous salmonids. Zxtremely cold water and air temperature can cause TEMPERATURE mortality among incubating eggs and fry by the formation of There are upper and lower frazil or anchor ice that reduces temperature limits (thresholds) water interchange. Anchor ice for successful incubation of normally forms in shallow water salmonid eggs (table 3). Combs typical of spawning areas and and Burrows (1957) and Combs may completely blanket the (1965) noted that pink and surface of the substrate and chinook salmon eggs could toler- thereby prevent water inter- ate long periods of low temper- change between stream and gravel. ature, provided the initial In addition, ice dams may form temperature was above 6.0°C and that can impede flow or even embryogenesis had proceeded to a dewater spawning areas, Sub- particular developmental stage. sequent melting of the dam may Combs and Burrows (1957) because floodlike conditions lieved salmon eggs deposited in resulting in the displacement water colder than 4.5OC would and scouring of redds, In an not produce as viable a fish as egg planting experiment, Reiser eggs spawned into warmer water. and Wesche (1977) found eggs in Vibert boxes completely frozen low and, when they are high, even though buried 15 cm in the oxygen levels are usually high. substrate and covered with more Others have found egg survival than 13 cm of water. Anchor ice related to apparent velocity-- had formed at least twice during for example, Pyper (in Cooper the incubation period. Neave 1965) in sockeye eggs (fig. 16), (1953) and McNeil (1966) also Coble (1961) in steelhead (fig. noted the problems of freezing 17), Gangmark and Bakkala (1960) on egg survival. in chinook, Wickett (1962) in pink salmon, and Phillips and BIOCHEMICAL OXYGEN DEMAND Campbell (1961) in coho and steelhead. In the last study, The oxygen demand of organic high egg survivals were asso- matter in the stream may reduce ciated with apparent velocities the oxygen concentration, partic- of more than 20 cm/h. Wickett ularly in the intragravel envi- (1962) found low survival in ronment. The impact of organic areas where apparent velocities matter in a stream depends on were 0.5-1.5 cm/h and high the chemical, physical, and survivals where velocities were hydraulic characteristics (for more than 7 cm/h. Silver et al. example, dissolved oxygen con- (1963) and Shumway et al. (1964) tent, temperature, and reaer- related apparent velocity to ation capability) of the stream. size of fry at a hatchery. Excessive recruitment of organic Silver et al. found that size of material to a stream may result steelhead and chinook fry de- in reduced oxygen concentrations pended on apparent velocities, and detrimental impacts on eggs. even at velocities as high as 740-1350 cm/h. Shumway et al. APPARENT VELOCITY found that reduced velocities (3-10 cm/h) resulted in de- The single most important creased size of fry at all hydraulic component in the oxygen levels tested (2.5-11.5 intragravel environment used for mg/l) egg incubation is apparent velocity, defined as the rate of seepage and expressed as the volume of liquid flowing per unit time through a unit area normal to the direction of flow (Terhune 1958, Coble 1961, Vaux 1968). Apparent velocity is important in bringing dissolved oxygen to the eggs and removing metabolic waste products.

High oxygen levels do not, in themselves, guarantee high egg survival. In two redds with similar dissolved oxygen concentrations but different apparent velocities, embryonic development may be better in the redd with the higher rate of water APPARENT VELOCITY exchange (Coble 1961). Coble (CENTIMETERS PER SECOND) states that, in general, when apparent velocities are low, Figure 16-Relation between rate of flow of water through a gravel bed and the survival of eyed sockeye eggs in the oxygen concentrations will he gravel (from Cooper 1965). PERMEABILITY OF STREAMBED GRAVELS (CENTIMETERS PER MINUTE)

0 1 2 5 10 20 50 100 Figure 18-Observed relation reported by Wickett (1958) MEAN APPARENT VELOCITY (CENIIMETERS PER HOUR) between permeability of spawning beds and survival of pink and chum salmon to the migrant fry stage (from McNeil and Ahnell 1964). Figure 17-Relation between apparent velocity and embryo survival (from Coble 1961).

Biornn (1969) Chinook salmon -

SUBSTRATE MATERIALS Steelhead ---- Spawning bed materials a1 so influence the development and emergence of fry. ~ermeability of the substrate (the ability of a material to transmit fluids) sets the range of subsurface water velocities (Wickett 1962). Low permeabilities result in lower apparent velocities and reduced oxygen delivery to and 20- metabolite removal from the eggs. Wickett (1958) found that 10- survival of pink and chum salmoc eggs was related to 0 10 20 30 40 50 60 permeability (fig. 18). McNeil PERCENTAGE FINE SEDIMENT and Ahnell (1964) concluded that Figure 19-Percentage emergence of fry from newly highly productive spawning fertilized eggs in gravel-sand mixtures. Fine sediment was streams had gravels with high granitic sand with particles less than 6.4 mm. permeability. Permeability was high (24,000 cm/h) when bottom materials had less than 5 percent where eggs had developed nor- (by volume) sands and silts that mally but the hatched fry were passed through a 0.833 mm sieve unable to emerge because of and was relatively low (less sediment. Phil lips et a1 . than 1 300 cm/h) when fine (1975) found an inverse relation sediments made up more than 15 between quantity of fine sedi- percent of the bottom material. ments and fry emergence. Bjornn (1969) and McCuddin (1977) Successful fry emergence is demonstrated that survival and hindered by excessive amounts of emergence of chinook salmon and sand and silt in the gravel. steelhead embryos were reduced Even though embryos may hatch when sediments less than 6.4 mm and develop, survival will be in diameter made up 20-25 per- poor if they cannot emerge. cent or more of the substrate Koski (1966) examined redds (figs. 19 and 20). Biornn (1969) Chinook salmon - STREAMFLOW Steelhead---- Streamflow requirements of incubating salmonid eggs are largely unknown partly because of the lack of information on interactions of surface flows and the intragravel environment. According to Stalnaker and Arnette (1976), most agencies that are concerned with fish n 30- habitat do not attempt to deal specifically with streamflows for incubation but only for spawning, on the assumption that flows suitable for spawning will be suitable for incubation. 0 ,,I,, 0 10 20 30 40 50 60 U.S. Fish and Wildlife Service PERCENTAGE FINE SEDIMENT personnel at times have re- Figure 20-Percentage emergence of swim-up fry placed in commended an increase in flow gravel-sand mixtures. Sediments were 1- to 3-mm for incubation over that present particles in the study by Phillips et al. (1975), less than 2 mm in the study by Hausle and Coble (1976), and less at spawning (Hale in Hooper than 6.4 mm in studies by Bjornn (1969) and McCuddin 1973). Oregon Department of (1977).

Table 9. General habitat guidelines for incubation of salmonid embryos

Parameter Recommended limit

Di ssol ved oxygen At or near saturation; lower threshold - 5.0 mg/l Water temperature 4"-14°C-1 1 Permeabi 1i ty More than 1 300 cmlh Sediment composition Less than 25% by volume of fines 26.4 mm Surface flow Sufficient to a1 low fry to emerge Surface velocity Velocities should be 1ess than those that scour the redds and displace spawning bed materi a1 s Apparent velocity More than 20 cmlh Biochemical oxygen Should not diminish or deplete the demand dissolved oxygen content below stated 1eve1 s

-11 Upper and lower values are threshold temperatures. Eggs will develop normal ly at lower temperatures provided initial development has progressed to where they become tolerant of cold. Fish and Wildlife personnel use planted chinook eggs to stream field observations to judge flows that increased 100 times recommended incubation flows during egg planting. Other that are often equivalent to investigators have also noted about two-thirds of the spawning the deleterious effects of flow. Thompson (1972), however, flooding on egg survival (Hobbs pointed out that the two-thirds 1937, Neave 1953, Gangmark and rule does not always hold, and Bakkala 1960, Sheridan and adequate flow depends largely on McNeil 1968). As noted by the particular stream. Research Chapman (1962), abnormally high is currently underway in Idaho flow at the wrong time causes and Alaska to quantify the increased mortality. Moderately instream flow needs for suc- high flows are beneficial in cessful incubation and hatching assuring adequate interchange of of salmonid eggs. intragravel and surface waters and improving the oxygen supply Forest practices, such as to embryos. roadbuilding and clearcut logging, may increase the water Because species-specific yield from a watershed and incubation criteria have not sometimes contribute to the been developed, generalization flooding in a stream (Rothacher is needed to define suitable 1971). Rapid fluctuations in incubation for anadromous sal- streamflow can decrease egg monids. General guidelines for survival by disturbing redds and salmonid incubation based on the, thereby crushing and dislodging preceding information are eggs. Gangmark and Broad (1956) presented in table 9. attributed complete mortality of FISH FOOD PRODUCTION AREAS Density of juvenile anadromous salmonids may be regu- lated by the abundance of food (perhaps expressed as competition for space) in some streams (Chapman 1966). Food for these salmonids comes primarily from the surrounding land and from the substrate within the stream; the relative importance of terrestrial and aquatic insects varies with stream size, loca- tion, riparian vegetation, and time of year,

VELOCITY According to Scott (1958) and Allen (1959), velocity is the most important parameter in determining the distribution of aquatic invertebrates in streams. JUVENILE REARING Most aquatic invertebrates live in a vertical boundary layer on the stream substrate where Habitat requirements of velocities are near zero. Water juvenile anadromous fish in velocities just above the bound- streams vary with species, size, ary layer, however, are typical and time of year. The rearing of r$Ffle areas (Pearson et period extends from fry emer- a,Needham and Usinger 1956, gence to seaward migration and Delisle and Eliason 1961, Arthur can range from a few days for 1963, Ruggles 1966, Kimble and chum and pink salmon to 3 or 4 Wesche 1975, and table 10). years for steelhead trout. For fish that spend an extended time in fresh water, the quantity and DEPTH quality of the habitat sets the The influence of water limits on the number of fish depth on aquatic insect pro- that can be produced. Important duction is poorly understood, habitat components for juvenile but Needham and Usinger (1956) salmon and trout are fish food and Kennedy (1967) found the production areas, water quality largest numbers of organisms in and quantity, cover, and space. shallow areas typical of riffles. The interaction of some of these In a study by Kimble and Wesche habitat components with bio- (1975), mayflies (Ephemerop- logical features of the envi- tera), stoneflies (Plecoptera), ronment have been studied and caddisflies (Trichoptera) (Giger 1973, Hooper 1973), but were found in depths less than specific criteria for rearing habitat have not been completely defined for anadromous salmonids -41 Unpublished report, "Factors in streams, We will discuss affecting the natural rearing of features of stream habitat and juvenile coho salmon during the summer relate them to salmonid pro- low flow season," by L. S. Yearson, K. duction where warranted by the R. Conover, and R. E. Sams. Fish. data available. Comm. Oreg., Portland, 1970. Table 10-Water velocity criteria for aquatic invertebrates

Source Vel ocity range Meters per second Kennedy (1967), Pearson et a1 .- Surber (1951 ) Delisle and Eliason (1961) Hooper (1973) Giger (1973) Needham and Usinger (1956) Kimble and Wesche (1975) Thompson (1972)

-1/ See text footnote 4.

0.3 m. Hooper (1973) reported (1947) reported that, in general, that areas of highest inverte- the diversity of available cover brate productivity usual ly occur for bottom fauna decreases as in streams at depths between the size of inert substrate 0.15 and 0.9 m if substrates and particles decreases. Rubble velocities are suitable. seems to be the most productive substrate. Large rubble substrate provides insects with a SUBSTRATE firm surface to cling to and Stream substrate compo- also provides protection from sition is another factor that the current. regulates the production of invertebrates; highest pro- The importance of insects duction is from gravel and produced in riffles as food for rubble-size materials (Needham fish is documented by Waters 1934, Linduska 1942, Smith and (1969), and Pearson et al. (see Moyle 1944, Sprules 1947, footnote 4) reported higher coho Ruttner 1953, Cummins 1966, production per unit area in Thorup 1966, Kennedy 1967, pools with large riffles up- Corning 1969, Hynes 1970). stream than in pools with small Substrate size is a function of riffles upstream. water velocity, with larger materials (rubble and boulder) Velocity, depth, and sub- associated with fast currents strate criteria for optimum fish and smaller materials (silt and food production are: sand) with slow-moving water. Velocity 0.46-1.07 m/s Pennak and Van Gerpen Depth 0.46-0.91 m (1947) noted a decrease in Substrate Composed largely of number -of benthic invertebrates coarse gravel in the progression rubble- (3.2-7.6 cm) and bedrock-gravel-sand. A similar rubble (7.6-30.4 cm) decrease was noted by Kimble and Wesche (1975) in the series rubble-coarse gravel-sand and RIPARIAN VEGETATION fine gravel-silt. Sprules Terrestrial insects are also important food items for salmonids. They may enter Kennedy 1967, Allen 1969). streams by falling or being Plant material that falls into blown off riparian vegetation the stream from riparian vege- and by being washed in from tation may be an important shoreline areas by wave action source of food to aquatic in- or rapid flow fluctuations vertebrates. Sekulich and (Mundie 1969, Fisher and LaVoy Bjornn (1977) found that ter- 1972). Once in the stream, restrial insects were second these organisms are entrained by only to chironomids (midges) in the current, become a part of importance as food for juvenile the drift, and are fed upon by anadromous salmonids in the fish Surber 1936, Kelley et streams they studied. Groups of a1. ,?' Delisle and Eliason 1961, insects and other arthropods that may become a part of terrestrial drift include: Diptera (flies), Orthoptera (grass- hoppers and crickets), Coleop- tera (beetles), Hymenoptera (bees, wasps, and ants), Lepi- doptera (butterflies and moths), Homoptera (leaf hoppers), and Araneida (spiders).

-5/ Unpublished report, "A method to determine the volume of flow required by trout below dams: a proposal for investigation," by D. W. Kelley, A. J. Cordone, and G. Delisle. Calif. Dep. Fish and Game, Sacramento, 1960. increased from 10.OO to 15.7OC, and then weight decreased with a further increase in temperature to 18.4OC (Burrows in Bell, see footnote 1). Baldwin (1956) noted a similar relation for brook trout, with increases in percentage weight gain with increased temperature from 9.1 to 13.1°C and a subsequent decrease in percentage weight gain with temperatures exceeding 17.1°C. At 17.1°C,brook trout feeding decreased and, when temperature reached 2 1.2 OC, the fish only ate 0.85 percent of their body weight per day. By comparison, a 100-mm-long salmonid that weighs 10 g would need to eat about 1.8 percent of its body weight each day to maintain itself and 2.5 percent WATER QUALITY to grow rapidly in 15OC water. Temperature Salmonids prefer a rather narrow range of temperature in Salmonids are cold water which to live (table 11), and fish with definite temperature temperature may help regulate requirements during rearing. density. In laboratory stream Water temperature influences channels, Hahn ( 1977 ) found growth rate, swimming ability, twice as many steelhead fry availability of dissolved remained in channels with daily oxygen, ability to capture and fluctuating (8O-19OC) or con- use food, and ability to with- stant 13.5 OC water temperatures stand disease outbreaks. Brett than in a channel with constant (1952) lists the upper lethal 18.5OC water. Fry density in a temperature for chinook, pink, channel with constant 8.5 OC sockeye, chum, and coho salmon water was double that in chan- as 25.1°C. The upper lethal nels with constant 13.5OC or temperature for rainbow trout fluctuating temperatures. Water lies between 24' and 29.5OC temperatures in a particular depending on oxygen concen- stream vary seasonal ly, tem- tration, fish size, and accli- poral ly, and spatially ( for mation temperature (McAfee example, between forested and 1966). Slightly lower temper- nonforested areas). Seasonal atures can be tolerated but are and temporal changes are largely stressful. out of human control; certain land-use practices (for example, Bell (see footnote 1) channelization or removal of stated that, in general, all shade trees), however, can cold water fish cease growth at change the temperature in sec- temperatures above 20.3OC be- tions of streams. If riparian cause of increased metabolic vegetation is removed, exposing activity. Fa1 1 chinook finger- the stream to direct sunlight, lings had increasing percentage water temperatures usually weight gains as temperature was increase in summer (Greene 1950, Table I1 -Preferred, optimum, and upper lethal temperatures of various salmonids (from Bell 1973 unless otherwise noted) r I Preferred temperature Optimum Upper lethal Species range temperature temperature I I I ------"C------

Chinook 7.3-14.6 q12.2 25.2 Coho 11.8-14.6 3'20.0 25.8 Chum 11.2-14.6 y13.5 25.8 Pink 5.6-14.6 10.1 25.8 Sockeye 11.2-14.6 y15.0 24.6 Steel head '7.3-14.6 10.1 24.1 Cutthroat 9.5-12.9 -- 23.0 Brown 3.9-21.3 -- 24.1

1/ From Bell (see text footnote 1). /- From an unpubl ished report, "Fish health and Management: concept and methods of aquaculture," by G. W. Klontz, Univ. Idaho, Moscow, 1976. 31 From Brett et al. (1958). /- From Garside and Tai t (1958).

Chapman 1962, Gray and Edington rate, food consumption rate, and 1969, Meehan 1970, Narver 1972, the efficiency of food utili- Moring and Lantz 1974, Moring zation of juvenile coho salmon 1975 ) . Colder winter temper- all declined when oxygen was 4 atures may result from loss of or 5 mg/l (Herrmann et al. 1962, canopy and adversely affect egg and figs. 21, 22, and 23). incubation (Greene 1950, Chapman 1962). Juvenile chinook salmon avoided water with oxygen DISSOLVED OXYGEN concentrations near 1.5-4.5 mg/l in the summer, but reacted The concentration of dis- less to low levels in the fall solved oxygen in streams is when temperatures were lower important to salmonids during (Whitmore et al.1960). rearing. At temperatures above 15OC, concentrations of dis- In a review paper, Davis solved oxygen regulate the rate (1975) examined information on of active metabolism of juvenile incipient oxygen response thresh- sockeye salmon (see footnote 1). olds for salmonids (table 12), Fry (1957) proposed that where and developed oxygen criteria the oxygen content became un- with three concentrations suitable, the active metabolic (table 13). At the highest rate decreased. Rainbow trout concentration, fish had ample swimming speeds were reduced 30 oxygen and could function with- and 43 percent when oxygen was out impairment. At the middle reduced to 50 percent of satu- concentration, the average ration at temperatures of member of a species begins to 21'-23OC and 8'-10°C, respec- exhibit symptoms of oxygen tively (Jones 1971). Growth 1 80- 2 Y t; + 60- (3

$ 40- 1956 tests f O1 1955 tests .O Surviving fish 0 Or 1956 Tests AA Only or mostly 06 1955 Tests 4 20- dying fish Surviving fish AA Only or mostly Y3 - dying fish 2 0- f U

YI a -20- OXYGEN CONCENTRATION (MILLIGRAMS PER LITER) &A

-40- I I 1 r I 1 I 23456789 Figure 23-Food conversion ratios for frequently fed age- 0 OXYGEN CONCENTRATION class coho salmon, or their weight gains in grams per (MILLIGRAMS PER LITER) gram of food (beach hoppers) consumed, in relation to dissolved oxygen concentration. A food conversion ratio of zero (not a ratio having a negative value) has been Figure 21 -Weight gains (or losses) in 19 to 28 days among assigned to each group of fish that lost weight. The curve frequently fed age-class 0 coho salmon, expressed as has been fitted only to the 1956 data (from Herrmann percentages of the initial weight of the fish, in relation to et al. 1962). dissolved oxygen concentration. The curve has been fitted to only the results of tests performed in 1956. All of the 1956 positive weight-gain values are results of 21-day tests (from Herrmann et al. 1962). saturation, except in small streams with large amounts of debris from logging or other sources (Hall and Lantz 1969) or in larger, slow-moving streams receiving large amounts of municipal or industrial waste.

Or 1956 tests SUSPENDED AND (Y 1955 tests .O Surviving fish AA Only or mostly DEPOSITED SEDIMENT dying fish l Suspended and deposited fine sediment can adversely affect salmonid rearing habitat if present in excessive amounts. High levels of suspended solids may abrade and clog fish gills, OXYGEN CONCENTRATION reduce feeding, and cause fish (MILLIGRAMS PER LITER) to avoid some areas (Trautman Figure 22-Grams of food (beach hoppers) consumed by 1933, Pautzke 1938, Smith 1939, frequently fed ageclass 0 salmon per day per gram of Kemp 1949, Wallen 1951, Cooper initial weight of the fish, in relation to dissolved oxygen concentration. The curve has been fitted to only the 1956, Bachman 1958, Cordone and 1956 data (from Herrmann et al. 1962). Kelley 1961). According to Bell ( see footnote I), streams with distress; at the lowest concen- silt loads averaging less than tration, a large portion of the 25 mg/l can be expected to fish population may be affected. support good freshwater fisheries. State turbidity standards Dissolved oxygen concen- for Colorado, Wyoming, Montana, trations are normally near and Oregon are set at no more Table 12-Incipient oxygen response thresholds for various salmonids (modified from Davis 1975)"

Oissolved oxygen Species Source Size Temperature Concentration Saturation Response

Percent

Arctic char Holeton (1973) 15.8 Signs of asphixia and loss of equilibrium

Brown trout Irving et al. (1941) 50 Blood not fully saturated with O2 below this level Brook trout Irving et al. (1941) 50 ,I

Graham (1949) 63.2 Onset of 02-dependent metabolism

50.7 Reduced cruising speed

,I 0, 98.8 Onset of 02-dependent metabolism

I 7 5 Reduced activity all temperatures

Beamish (1964) Standard oxygen uptake reduced below this level

Rainbow trout Irving et al. (1941) Below this level, blood is not fully saturated with oxygen

Randall and 120-250 g 8.5-15 5.18-7.34 Circulatory changes occur, including a slowing

Smith (1967) of the heart Downing (1954) 13.3 + 1.4 17 + .5 9.74 Any reduction in oxygen led to more rapid death cm in cyanide

Jones (1971) 20 mo. old 8-10 5.94-5.67 43 percent reduction in maximum swimming speed

,I I 20 mo. old 21-23 4.50-4.34 30 percent reduction in maximum swimming speed

Itazawa (1970) 235-510 g 2.3-13 8.73-6.74 Blood not fully saturated with O2 below this level

Kutty (1968) -- 15 5.08 Altered respiratory quotient, little capacity for anaerobic metabolism below this level

Randall and - - 15 5.18-6.47 Changes in oxygen transfer factor and Smith (1967) effectiveness of O2 exchange occur

Rainbow trout Hughes and Saunders 400-600 g 13.5 5.35 Breathing amplitude and buccal pressure elevated

(1970) Cameron (1971 ) 300 g 10, 15, 20 4.71-5.75 Blood not fully saturated with O2 below this level

Lloyd (1961) 1-11 g 17.5 5.78 Toxicity of zinc, lead, copper, phenols increased markedly below this level

Sockeye salmon Brett (1964) 50g 20-24 9.17-8.53 Available oxygen level appears to limit active metabolism and maximum swimming speed

Davis (1973) 1579g 13 6.74 63.6 Blood not fully saturated with O2 below this level

Randall and 1.5-1.7 kg 15 5.07 50 Elevated blood and buccal pressure, breathing

Smith (1967) rate increased Coho salmon Whitmore et al. (1960) 6.3-11 cm -- 4.5 -- Erratic avoidance behavior Hicks and 5.1-14.8 m 12 + 1 9.0 83.1 Acute mortality in kraft pulpmill effluent increased DeWitt (1971) below this level

Davisetal.(1963) Juvenile 10-20 11.33-9.17 100 Reduction of O2 below saturation produced some lowering of maximum sustained swimning speed

Oahlberg et al. (1968) " 20 9.17 100 I ,I Herrmann (1958) I 8.0-4.0 87.2-43.6 Growth rate proportional to oxygen level with best growth at 8.0 mg/l, lowest at 4.0 mg/l Chinook salmon Whitmore et al. (1960) 6.3-11 cm summer temp. 4.5 Marked avoidance of this level in sumner " 6-3-11 cm fall temp. 4.5 Little avoidance of this level in fall

Davis et al. (1963) Juvenile 10-20 11.33-9.17 100 Reduction of O2 below saturation lowered maximal sustained swimning speed

Atlantic salmon Kutty and 87-135 g 15 4.5 44-33 Salmon stop swimning at a speed of 55 cm/s at O2 levels Saunders (1973) below this; faster swimming requires more oxygen

1'courtesy of the Journal of the Fisheries Research Board of Canada. Table 13-Response of freshwater salmonid populations to three concentrations of dissolved oxygen (modified from Davis 1975, courtesy of the Journal of the Fisheries Research Board of Canada) Saturation at given temperatures ( "C) Oxygen 0 5 10 15 20 25 Response Mg/l ------Percent------Function without impairment 7.75 76 76 76 76 85 93

Initial distress symptoms 6.00 57 57 57 59 65 72

Most fish affected by lack 4.25 38 38 38 42 46 51 of oxygen

than 10 JTU, 10 NTU, 5 JTU and 5 Sumner and ~rnith,g/ Tebo 1955, NTU over background levels, 1957, 1974, Tarzwe1194957, respectively. g/ Ziebell 1957, Casey,- Bartsch 1960, Cordone and Pennoyer,s/ Cordone and Kelley (1961) Chapman 1962, Bjornn et al. suggest that indirect rather 1977). than direct effects of too much fine sediment damage fish populations. Indirect damage to the fish population by destruc- tion of the food supply, lowered egg or alevin survival, or changes in rearing habitat -8/ Unpublished mimeographed probably occurs long before the report, "A biological study of the adult fish would be directly effects of mining debris dams and harmed (Ellis 1936, Corfitzen,-7/ , hydraulic mining on fish life in the. Yuba and American Rivers in California," by F. H. Sumner and 0. R. Smith. Submitted to the U. S. District, Eng. Office, Sacramento, California, from Stanford Univ., 1939.

- Unpublished mimeographed report, "The effects of placer mining (dredging) on a trout stream," by 0. E. -- Casey. Annu. Prog . Rep. , Proj . - JTU = Jackson turbidity units. F-34-R-1. Water Quality Investigations, NTU = Nephelome tric turbidity Federal Aid in Fish Restoration, Idaho units. Dep. Fish and Game, Boise, 1959.

-7/ Unpublished mimeographed -lo/ Unpublished mimeographed report, "A study of the effect of silt report, " Notes on silt pollution in on absorbing light which promotes the the Truckee River drainage," by A. J. growth of algae and moss in canals," by Cordone and S. Pennoyer. Calif. Dep. W. D. Corfitzen. U.S. Dep. Int., Bur. Fish and Game; Inland Fish Admin. Reclam., 1939. Rep. , Sacramento, 1960. Deposited sediment may reduce available summer rearing Control (without sediment) ( fig. 24) and winter holding Test (with sediment) (fig. 25) habitat for fish (Stuehrenberg 1975, Klamt 1976, Bjornn et al, 1977)- Bjornn et al. (1977) added fine sediment (less than 6-4 mm in diameter) to natural stream channels and found juvenile salmon abundance decreased in almost direct proportion to the amount of pool volume lost to fine sediment ( fig . 2 6 ) . Because sediment budgets are difficult to determine for each stream, Bjornn et ale recommended using the percentage of fine sediment in

selected riffle areas as an TESTY01 1 3 4 6 5 7 8 index of the "sediment health" SPECIES -AGE SH1 SH1 sH1 SHo SHo SHo CKO CKO O~U~IN~-WILD~HATCHERY-~ WILD of streams. They reasoned that IUDEDDEDNESS 113 2/3 F F 112 F 1/2 F if the riffles contained negligible amounts of fine sedi- Figure 25-Densities of fish remaining in the Hayden Creek ment, then the pools and inter- artificial stream channels after 5 days during the summer tests, 1974 and 1975: SH, = age 1 steelhead; CKo age 0 stitial spaces between the chinook; 1/3 = key boulders in pools 1/3 imbedded with boulders of the stream substrate sediment; F = key boulders in pools fully imbedded (from would also have negligible Bjornn et al. 1977). amounts of sediment.

Control I without sediment \ n Test with sediment) M

TEST NO 10 12 11 16 13 13 13 14 15

SPECIES-ACE CKO CKO SHo SHo CKO SHo CKOSHO CTO CT1,?

ORIGIN W W H H W H W H H W

0 I I I 1 Figure 24-Densities of fish remaining in artificial stream 0 2 5 50 75 100 channels after 5 days during winter tests, 1975: W = wild; PERCENTAGE POOL AREA H = hatchery; 1/2 = boulders in pools 1/2 imbedded with sediment; F = fully imbedded; CK, = age 0 chinook salmon, SH, = age 0 steelhead trout; CT, = age 0 Figure 26-Fish numbers in upper test pool versus cutthroat trout, CT,.2 = age 1 cutthroat trout (from Bjornn percentage pool area deeper than 0.30 m, during the et al. 1977). sediment additions into Knapp Creek, 1973 and 1974. Arrows denote observations not used in fitting the regression line. P = prior to addition of sediment; 1 = after first addition; 2 = after second addition; 3 = after third addition (from Bjornn et al. 1977). COVER that seek refuge within rock and Cover is perhaps more rubble substrate in Idaho streams important to anadromous sal- (Chapman 1966, Chapman and monids during rearing than at Bjornn 1969, Everest 1969, any other time, for this is when Morrill and Bjornn 1972). they are most susceptible to predation from other fish and The relative importance of terrestrial animal s . Cover cover is illustrated by experi- needs of mixed popula-kions of ments in which salmonid abun- salmonids are not easily deter- dance declined when cover was mined (Giger 1973). Shelter reduced (Boussu 1954, Peters and needs may vary diurnally (Kalle- Alvord 1964, Elser 1968) and in berg 1958, Edmundson et a1 . experiments where salmonid 1968, Allen 1969, Chapman and abundance increased when cover Bjornn 19691, seasonally (Hartman was added to a stream (Tarzwell 1963, 1965, Chapman 1966, Chap- 1937, 1938, Shetter et al. 1946, man and Bjornn, 1969), by Warner and Porter 1960, Saunders species (Hartman 1965, Ruggles and Smith 1962, Chapman and 1966, Allen 1969, Chapman and Bjornn 1969, Hunt 1969,1976, Bjornn 1969, Lewis 1969, Pearson Hahn 1977, Hanson 1977). et al. (see footnote 4 ) , Wesche 1973, Hanson 1977), and by fish STREAMFLOW size (Butler and Hawthorne 1968, Allen 1969, Chapman and Bjornn Recommended streamf lows for 1969, Everest 1969, Wesche 1973, rearing habit at have usually Hansori 1977). been based on the individual components (such as food, cover) Overhead cover--riparian of habitat rather than numbers vegetation, turbulent water, or biomass of fish. Thompson (1972) listed guidelines for logs, or undercut banks--is used by most salmonids (Newman 1956, developing streamflow recom- Wickham 1367, Butler and Haw- mendations in rearing habitat: thorne 1968, Baldes and Vincent e adequate depth over riffles 1969, Bjornn 1969, Chapman and riffle/pool ratio near Bjornn 1969, Lewis 1969, Lister 50:50 and Genoe 1970, Wesche 1973). approximately 60 percent of Beside providing shelter from riffle area covered by flow predators, overhead cover pro- riffle velocities of 0.31- duces areas of shade near stream 0.46 m/s margins. These areas are the e pool velocities of 0.09- preferred habitat of many juve- 0.24 m/s nile salmonids (Hartman 1965, stream cover available as Chapman 1966, Allen 1969, shelter for fish. Everest 1969, Mundie 1969, Everest and Chapman 1972). Such guidelines are obviously based on the food production, Submerged cover--large cover, and microhabitat needs of rocks in the substrate, aquatic fish, rather than the relation vegetation, logs, and so on--is between streamf low and fish also used by rearing salmonids. production. Hoar et al. (1957) and Hartman (1965) observed that newly emerged salmonids tend to hide under stones. Similar behavior is typical of overwintering juvenile steelhead and chinook Streamf low has been related to cover (Kraft 1968, 1972, Wesche 1973, 1974, and figs. 27, 28, and 29); streamflow and pool area to standing crop of Hog Pork Creek Douglas Creek #7 fish (Kraft 1968, 1972, Nlckel- X Douglas Creek #1 son and Reisenbichler 1977, and fig. 30) ; standing crop to cover (Wesche 1974, Nickelson and Reisenbichler 1977, and figs. 31 and 32) ; and standing crop to a habitat quality index (Nickelson 1976, and fig. 33). Such studies suggest a definite relation between stream carrying capacity for fish and discharge.

PERCENTAGE AVERAGE DAILY FLOW

Figure 29-Comparison of percentage of habitat reduction with percentage decrease in average daily flow and hypothetical percentage decrease in fish population (data from Wesche 1974, from White 1976).

00:

PERCENTAGE BASE FLOW

Figure 27-Comparison of percentage reductions of fish numbers and cover in three runs in Blacktail Creek, Montana (data from Kraft 1968, from White 1976).

t ? i lO0l Douglor Creek #I: Hog Pork Creek j

1 4b SO 60 70 80 POOL VOLUME (CUBIC METERS)

Figure 30-Relation between pool volume and juvenile coho standing crop (from Nickelson and Hafele 1978).

MEAN COVER RATING Figure 28-Changes observed in the mean trout-cover rating as flow was reduced at the Douglas Creek No. 1,7, and Hog Park Creek study areas (from Wesche 1974). HABITAT QUALITY INDEX COVER X AREA Figure 33-Relation between a habitat quality index and Figure 31-Relation between mean trout cover ratings and coho salmon biomass in six Elk Creek study sections at standing crop estimates of trout at eleven study areas flows of 3.00, 2.25, and 1.50 ft3/s(from Nickelson 1976). (from Wesche 1974).

Douglas Creek #6 SPACE 7 Space requirements of juvenile salmonids in streams vary with species, age, and time Hog Park Creek / of the year and are probably related to abundance of food Douglas Creek #1 / (Chapman 1966). The inter- 40 Deer Creek #2 actions and relation between cover, food abundance, and microhabitat preferences of the

20 various species of salmonids are not well understood; until they are, spatial needs of the fish

10 will be less than adequately defined. Deer Creek #1 From measurements of fish densities in streams, we have Log Y = 0.0204 + 5.338 X some idea of spatial requirements of juvenile salmonids. Pearson et al. (see footnote 4) Nickelson and Reisenbichler 0 0.1 0.2 0.3 0.4 0.5 (1977), and Nickelson and Hafele MEAN COVER RATING (1978, and fig. 30) found that coho standing crop was directly Figure 32-Relation between cover times area and cutthroat trout standing crop in two Oregon coastal streams (from related to pool volume. Bjornn Nickelson and Reisenbichler 1977). et al. (1977) found a similar relation for chinook salmon in small streams (fig. 26). Pear- son et al. found a close relation between total stream area and coho numbers--perhaps an example of the idea that more space equals more food equals more fish. Food and space are thought to be the most important factors influencing fish density in streams (Larkin 1956, Chapman 1966). Studies in California by Burns ( 1971) revealed signi- Cicant correlations between living space and salmonid.biomass; decreased living space resulted

in increased fish mortality. Residents Migrants Not surprisingly, the highest A Chum and pink salmon A v Coho salmon v mortality was associated with 0 Atlantic salmon the summer low flow period. The 8 Brown trout o Rainbow trout studies of Kraft (1968, 1972 Brook trout and fig. 27) and Wesche (1974, 0 Observed territory and fig. 29) lend support to the concept that reductions in discharge decrease living space and thus decrease numbers and biomass of salmonids.

Changes in streamf low Figure 34-Average area per fish (on a logarithmic scale) influence velocities and area of against age (from Allen 1969). riffles more than area of pools. Giger (1993) suggested that if set spatial demands are the primary regulators of fish density in pools, then increasing the flow in streams may not lead to increased abundance. He accepts the logic of Chapman's (1965) idea that spatial requirements of fish control their density below ceilings set by the scpply of food. Chapman (1966) suggested that salmonids have a minimum spatial requirement that has been fixed over time by the minimum food supply.

Space needed by fish increases with age and size. Brook trout 0 Observed territory Allen (1969) assembled data on densities of salmonids in streams and found positive LENGTH (CENTIMETERS) correlations between area per fish and age or length (figs, 34 Figure 35-Average area per fish against length on and 35). Additional data on logarithmic scales (from Allen 1969). densities of salmon and trout with age, size, and locality are presented in table 14 and figure 36. Allen concluded from the data he examined that densities of 10-cm salmonid9 averaged2 about 0.17 fish/m (1.7 g/m ). Table 14-Densities of salmon and trout in streams

Age/ Areal Fish/ Stream size or Species size fish area Weight/area flow rate Comnents Reference

Yr/cm M~ M~

Pink salmon egg-alevin 0.001 1000 B.C. Hunter (1959)

Washington Bliss and Heiser (1967)

A1 as ka Hoffman (1965)

B.C. Hunter (1959)

Alaska Merrell (1962)

0+/ 2 .33 3.0 B.C. Mckett (1958)

Chum salmon egg-alevin .001 1000 B.C. Hunter (1959)

Washington Bliss and Heiser (1967)

B.C. Hunter (1959)

Coho salmon B.C. Wickett (1958)

alevin Oregon Chapman (1965)

Oregon Chapman (1965)

B.C. Hunter (1959)

B.C. Wickett (1951)

2.9 .37 - - Avg. flows: range, 41.6-183 ft3 Oregon Hall and Lantz (1969) (1.92-4.28) (.26-.52) Chinook salmon .74 1.35 12.9 Median 4-5 m Idaho, est. of Bjornn (1978)

1.69 .59 5.4 6-10 m summer rearing

capacity

(.59-3.301) (1.70-.30) (6.4-.86) Flows range 0.107-1.3 m3/s 4 streams in Sekulich and Bjornn (1977)

Idaho

Idaho Bjornn et al. (1977)

Chinook salmon 4 streams in Idaho Bjornn et al. (1974)

Steelhead trout .93 1.08 6.1 Medium, width about 4-5 m Idaho, est. of Bjornn (1978)

1.43 .70 3.2 " summer rearing

1.92 .52 3.0 Medium, width about 6-10 m capacity

16.67 .06 4.3 Medium, 4-5 m

5.88 .17 13.0 Medium, 6-10 m

4 streams in Idaho Bjornn et al. (1974)

6.67 .15 " - - )I ,,

3.88 .258 " " Small " Hanson (1977)

,I 4,

I, I,

4.35 .23 -- Medi urn 14.49 .069 - -

II I!

26.14 .038 -- Large Idaho average Graham (1977) (m/fish) (fish/m) (Lochsa River) densities for

three sections; low

densities result

from low spawning

escapements Table 14-Densities of salmon and trout in streams -(Continued)

Age/ Area/ Fish/ Stream size or Species size fish area Weight/area flow rate Comnents Reference

Yr/cm -M~ Steelhead salmon I+ 109.89 Large (Lochsa River) (cont. from previous page) Graham 1977 (m/f ish) 60.06 Large (Selway River) " I, ,I (m/fish) 23.47 (m/fish) 17.84 Small tributaries Idaho, trib. of Lochsa R. "

" Idaho, trib. of Selway R. " a I, ,I I, I, , I4

Small Idaho, densities are those " )I present in the fall after stocking in early spring Large (Lochsa River) Idaho, avg. density for "

" 3 sections

Small (trib. streams)

8, L, $8

Flow - 0.27--.56 cms Densities are those present " during July-August in the fall after stocking in early spring Flow - 0.59-0.95 cms I, ,I 8, ,I Atlantic salmon Small streams Scotland, densities are Mills (1969) those present in the fall " $I " after stocking in early " I, " spring

I, II 1, I, II

Small streams Scotland, densities are Mills (1969) I, those present in the fall I It after stocking in early I ,I ,I spring

0, I, Il 40

$1 I I,

I, I, ,I

Brown t root Mean width 0.9 m England, small, headwater LeCren (1969) 2.2 m streams I, ,I 3.0 m I I, II I 3.7 m , I, ,, ,I I 2.5 m I, I, ,I 6.6 m I, I, 0, I1 .9 m ,I I, ,I 2.2 m I, 1, I, 3.0 m I 8, (I $1 # 3.7 m ,I I, I, 2.5 m I, I, I, I, I, 6.6 m I, I, I* 00

Small, widths range 0.6- Densities are averages of Mil 1s (1969) 1.5 m, avg. 1.0 m 4 stream sections I,

I, 0 0, ,I 9, I,

,I Scot1 and I#

)I lo England LeCren (1965)

I a, England Horton 1961

I( It California Needham, et al. (1945)

,I ,I New Zealand Allen (1951)

On , England Horton (1961 )

)I I New Zealand Allen (1951)

a, In New Zealand Allen (1951) Densities of age-0 trout and salmon at the end of their first summer (70-120 mm iq length) average about 5 m of stream per fish (mode about 2 a Steelhead - rainbow m ). After 2 years of re3ring, r Brown trout densities averaged 2-16 m /qish, o Coho Chinook and for larger fish, 15-27 m / x Atlantic salmon fish (fig. 36). The spread in densities portrayed in figure 36 results partly from differences in natural or artificial stocking rates, size of stream, and habitat quality.

Juvenile salmonids usually occupy sites in streams referred to as "focal points" from which they venture out to perform other functions (Wickham 1967 ) . AAA Characteristics of these focal .. points in water velocities, water depths, substrate, and cover represent the microhabitat preferences of the fish (table Figure 36-Densities of age 0, I, II, and older salmon and trout in streams usuaily after 1, 2, 3, or more summers of 15) to remain oriented into the growth, respectively (see table 14 for sources of data).

Table 15-Depth, velocity, and substrate microhabitat preferences of salmonids in streams

Species Reference Age Depth Velocity Substrate

-M -M/ s -Cm Steel head Everest and Chapman (1972) <0.15 10.15 Rubble

,I 11 .60-. 75 .15-.30 Rubble

Hanson (1977) .51 mean .10 mean 10-30

1, I, .58 " .15 " 10-30 .60 " .15 " 10-30

Stuehrenberg (1975) <.30 .14 (range .03-.26)

I, I, >.I5 .16 (range .05-.37)

Thompson (1972) .18-.67 .6-. 49

Chinook Everest and Chapman (1972) .15-.30 <.I5 Silt

Stuehrenberg (1975) <.61 .09 (range .O-.21)

I, 11 <.61 .17 (range .05-.38)

Thompson (1972) ' .30-1.22 .06-.24

Coho Pearson et a1 .y -- .09-.21

Thompson (1972) .30-1.22 .05- .24

Nickelson and 7.30 <. 30

Reisenbichler (1977)

Cutthroat Thompson (1972) .40-1.22 .6- .49 --

Hanson (1977) .51 mean .10 mean 5-20

#I I4 .56 " .14 " 5-30

.57 " .20 " 5-30

.54 " .14 " 30

See text footnote 4. 39 current (Baldes 1968). Habitat between lo0 and 15OC during the selected by fish is influenced summer, dissolved oxygen usually by their ability and the avail- at saturation, suspended sedi- ability of food (Kalleberg 1958, ment less than 25 mg/l, and Mason and Chapman 1965, Chapman riffles with less than 20 per- 1966, Chapman and Bjornn 1969, cent fine sediment (less than Everest and Chapman 1972). 6.4 mm in diameter). The optimum combination of stream areas In summary, good rearing used by aquatic invertebrates habitat for anadromous salmonids and all ages of fish cannot be consists of a mixture of pools described until the interre- and riffles, adequate cover, lations between the components water temperatures that average are better understood. Arthur, J. F. 1963. The relationship of water velocities to aquatic insect populations on the Kern River, Kern Co. , Calif. Report for Independent Study 290, Dep. Biol. Fresno State Coll., Calif. Jan. 1963.

Bachman, R. W. 1958. The ecology of four north Idaho trout streams with reference to the influence of forest road construction. M.S. thesis, Univ. Idaho, Moscow. 97 p.

Baldes, R. J. 1968. Micro- habitat velocity occupied by trout. M.S. thesis, Colo. State Univ., Fort Collins. 33 p.

LITERATURE CITED Baldes, R. J., and R. E. Vincent. 1969. Physical parameters of microhabitats occupied Alderdice, D. F., W. P. Wickett, by brown trout in an and J. R. Brett. 1958. experimental flume. Trans. Some effects of temporary Am. Fish. Soc. 98(2):230- exposure to low dissolved 238. oxygen levels on Pacific salmon eggs. J. Fish. Res. Baldwin, N. S. 1956. Food Board Can. 15(2):229-250. consumption and growth of brook trout at different Allen, K. R. 1951. The Horo- temperatures. Trans. Am. kiwi Stream: A study of a Fish. Soc. 86 :323-328. trout population. N.Z. Mar. Dep. Fish. Bull. No. Bartsch, A. F. 1960. Settleable 10, Wellington. 231 p. solids, turbidity, and light penetration as fac- Allen, K. R. 1959. The dis- tors affecting water tribution of stream bottom quality. Biological Prob- faunas. Proc. N.Z. Ecol. lems in Water Pollution, SOC. 6:5-8. Trans. 1959 Seminar. U.S. Dep. Health, Educ. and Allen, K. R. 1969. Limitations Welfare, Tech. Rep. W60-3, on production in salmonid R. A. Taft Sanit. Eng. populations in streams, Cent. Cincinnati, Ohio. p. 3-18. In T. G. North- cote (ed.)>ymposium on Baxter, G. 1961. River utili- Salmon and Trout in Streams. zation and the preservation H. R. MacMillan Lectures in of migratory fish life. Fisheries, Univ. B. C. , Proc. Inst. Civ. Eng. Vancouver. 18 :225-244. Beamish, F. W. H. 1964. Res- Boussu, M. F. 1954. Relation- piration of fishes with ship between trout popu- special emphasis on stand- lations and cover on a ard oxygen consumption. small stream. J. Wildl. 11. Influence of weight Manage. 18:227-239. and temperature on respiration of several species. Bovee, K. D. 1974. The deter- Can. J. Zool. 42:177-188. mination, assessment and design of "instream value" Bjornn, T. C. 1969. Embryo studies for the northern survival and emergence Great Plains region. Rep. studies, Job. No. 5, Federal for the Northern Great Aid in Fish and Wildlife Plains Resour. Program. Restoration. Job Com- Denver, Colo. 205 p. pletion Rep., Proj. F-49-R- 7. Idaho Fish and Game Brannon, E. L. 1965. The Dep., Boise. 11 p. influence of physical factors on the development Bjornn, T. C. 1978. Survival, and weight of sockeye production, and yield of salmon embryos and alevins. trout and chinook salmon in Int. Pac. Salmon Fish. the Lernhi River, Idaho. Comm. Prog . Rep. No. 12. Bull. No. 27, Coll. of 26 p. For., Wildl. and Range Sci., Univ. Idaho, Moscow. Brett, J. R. 1952. Temperature 57 p. tolerance in young Pacific salmon, genus Oncorhynchus Bjornn, T. C. , M. A. Brusven, Myron Molnau, F. J. Watts, sp. J. Fish. Res. Board R. L. Wallace, D. R. Neil- Can. 9:265-323. son, M. F. Sandien, and L. C. Stuehrenberg. 1974. Brett, J. R. 1964. The res- Sediment in streams and its piratory metabolism and effects on aquatic life. swimming performance of Tech. Completion Rep. young sockeye salmon. J. Water Resour. Res. Int. Fish. Res. Board Can. Proj . B-025-IDA. Univ. 21:1183-1226. Idaho, Moscow. 27 p. Briggs, J. C. 1953. The be- Bjornn, T. C., M. A. Brusven, M. havior and reproduction of P. Molnau, J. H. Milligan, salmonid fishes in a small R. A. Klamt, E. Chacho, and coastal stream. Calif. C. Schaye. 1977. Trans- Dep. Fish and Game. Fish. port of granitic sediment Bull. 94. 62 p. in streams and its effects on insects and fish. For. Burner, C. J. 1951. Charac- Wildlife and Range Exp. teristics of spawning nests Stn., Completion Rep. of Columbia River salmon. Water Resour. Res. Inst. U.S. Fish and Wildl. Serv. Proj . B-0 3 6-IDA. Univ. Fish. Bull. 61(52):97-110. Idaho, Moscow. 43 p. Burns, J. W. 1971. The carry- Bliss, B., and D. Heiser. 1967. ing capacity for juvenile 1966 chum salmon hydraulic salmonids in some northern sampling. Wash. Dep. Fish California streams. Calif. Res. Div. Prog. Rep., Fish and Game 57(1):24-57. Olympia. p. 8-16. Butler, R. L., and V. M. Haw- Collings, M. R. 1972. A method- thorne. 1968, The reac- ology for determining tions of dominant trout to instream flow requirements changes in overhead arti- for fish. Proceedings, ficial cover. Trans. Am. Instream Flow Methodology Fish. Soc. 97(1):37-41. Workshop. Wash. State Water Program, Olympia. Cameron, J. N. 1971. Oxygen p. 72-86. dissociation characteristics of the blood of Combs, B. D. 1965. Effect of rainbow trout, Salmo temperature on the develop- gairdneri. Comp. Biochem. ment of salmon eggs. Prog. Physiol . 38 :699-704. Fish-Cult. 27 (3):134-137.

Chapman, D. W. 1962. Effects Combs, B, D., and R. E. Burrows, of logging upon fish 1957. Threshold temper- resources of the west atures for the normal coast. J. For. 60(8): development of chinook 533-537. salmon eggs, Prog. Fish- Cult. 19(1):3-6. Chapman, D. W. 1965. Net production of juvenile coho Cooper, A. C, 1956. A study of salmon in three Oregon the Horsefly River and the streams. Trans. Am. Fish. effect of placer mining SOC. 94(1):40-52. operations on, sockeye spawning grounds. Int. Chapman, D. W. 1966. Food and Pac. Salmon Fish. Comm. space as regulators of Publ. 3. 58 p. salmonid populations in streams. Am. Nat. 100: Cooper, A. C. 1965. The effect 345-357. of transported stream sediments on the survival Chapman, D. W., and T. C. Bjornn. of sockeye and pink salmon 1969. Distribution of eggs and alevins. Int. salmonids in streams, with Pac, Salmon Fish. Comm. special reference to food Bull. 18. 71 p. and feeding. p, 153-176. -In T. G. Northcote (ed,), Cope, 0. B. 1957. The choice Symposium on Salmon and of spawning sites by Trout in Streams. H. R. cutthroat trout, Proc. MacMillan Lectures in Utah Acad. Sci., Arts, and Fisheries, Univ. B.C., Lett. 34 :73-79. Vancouver. Cordone, A. J., and D. W. Kelley. Clay, C. H. 1961. Design of 1961. The influence of f ishways and other fish inorganic sediment on the facilities. Can. Dep. aquatic life of streams. Fish., Ottawa. 301 p. Calif. Fish and Game 47(2):189-228. Coble, D. W. 1961. Influence of water exchange and Corning, R. V, 1969. Water dissolved oxygen in redds fluctuation, a detrimental on survival of steelhead influence on trout streams. trout embryos. Trans. Am, Proc. 23rd Ann. Conf. Fish. Soc. 90(4):469-474. Southeast. Assoc. Game and Fish Comm., p. 431-454. Cummins, K. W. 1966. A review Doudoroff, P., and C. E. Warren. of stream ecology with 1965. Environmental special emphasis on organism- requirements of fishes and substrate relationships, wildlife--dissolved oxygen p. 2-51. In K. W. Cummins, requirements of fishes. C. A. TY~O~Jr., and R. T. Spec. Rep. No. 141. Oreg. Hartman (eds.), Organism- Agric. Exp. Stn., Corvallis. Substrate Relationships in Streams, Spec. Publ. No. 4, Downing, K. M. 1954. The Pymatuning Lab. of Ecology, influence of dissolved Univ. Pittsburgh, Pa. oxygen concentration on the toxicity of potassium cyanide to rainbow trout. ~ahlberg,M. L., D. L. Shumway, J. Exp. Biol. 31:161-164. and P. Doudoroff. 1968. Influence of dissolved Edmundson, E., F. H. Everest, oxygen and carbon dioxide and D. W. Chapman. 1968. on swimming performance of Permanence of station in largemouth bass and coho juvenile chinook salmon and salmon. J. Fish. Res. steelhead trout. J. Fish. Board Can. 25(1):49-70. Res. Board Can., 25(7): 1453-1464. Davis, G. E., J. Foster, C. E. Warren, and P. Doudoroff. Eiserman, F., G. Dern, and J. 1963. The influence of Doyle. 1975. Coldwater oxygen concentration on the stream handbook for Wyoming. swimming performance of USDA Soil Cons. Serv. juvenile Pacific salmon at various temperatures. Trans. Am. Fish. Soc. Ellis, M. M. 1936. ~rosion 92 (2):Ill-124. silt as a factor in aquatic environments. Ecology Davis, J. C. 1973. Sublethal 17(1):29-42. effects of bleached kraft pulpmill effluent on res- Elser, A. A. 1968. Fishpopu- piration- and circulation in lations of a trout stream sockeye salmon (Oncorhynchus in relation to major nerka). J. Fish. Res. habitat zones and channel Board Can. 30(3):369-377. alterations. Trans. Am. Fish. Soc. 97(4):389-397. Davis, J. C. 1975. Minimal dissolved oxygen require- Everest, F. H. 1969. Habitat ments of aquatic life with selection and spatial emphasis on Canadian interaction of juvenile species: a review. J. chinook salmon and steelhead Fish. Res. Board Can. trout in two Idaho streams. 32(12):2295-2332. Ph. D. thesis, Univ. Idaho, Moscow. 77 p. Delisle, G. E., and B. E. Eliason. .196 1. Stream flows required Everest, F. H., and D. W. Chap- to maintain trout popu- man. 1972. Habitat lations in the Middle Fork selection and spatial Feather River Canyon. interaction by juvenile Water Proj. Branch Rep. No. chinook salmon and steelhead 2, Appendix, Calif. Dep. trout in two Idaho streams. Fish and Game, Sacramento. J. Fish. Res. Board Can. 19 p. 29(1) :91-100. Fisher, S. G., and A. LaVoy. River drainages. M. S . 1972. Difference in lit- thesis, Univ. Idaho, toral fauna due to f luc- Moscow. 91 p. tuating water levels below a hydroelectric dam. J. Gray, J. R. A,, and J. M. Eding- Fish. Res. Board Can. ton. 1969. Effect of 29(10):1472-1476. woodland clearance on stream temperature. J. Fry, F. E. J. 1957. The Fish. Res. Board Can. aquatic respiration of 26(2):399-403. fish, p. 1-64. In M. E. Brown (ed.), ~heThysiology Greene, G. E. 1950. Land use of Fishes. Vol. 1, Aca- and trout streams. J. Soil demic Press, Inc., New and Water Conserv. 5:125-126. York. Hahn, P. J. K. 1977. Effects Gangmark, H. A., and R. G. of fluctuating and constant Bakkala. 1960. A com- temperatures on behavior of parative study of stable steelhead trout (Salmo and unstable spawning areas qairdneri). PLD. thesis, for incubating king salmon Univ. Idaho, Moscow. at Mill Creek. Calif. Fish and Game. 46:151-164. Hall, J. D., and R. L. Lantz. Gangmark, H. A,, and R. D. 1969. Effects of logging Broad. 1956. Further on the habitat of coho observations on stream salmon and cutthroat trout survival of king salmon in coastal streams. spawn. Calif. Fish and 355-375. In T. G. Game. 42:37-49. rthcote (edr Symposium Salmon and Trout in Garside, E. T., and J. S. Tait. Streams. H. R. MacMillan 1958. Preferred temper- Lectures in Fisheries. ature of rainbow trout Univ. B.C., Vancouver. (Salmo qairdneri Richardson) and its unusual relation- Hamilton, J. A. R., and J. D. ship to acclimation temper- Remington. 1962. Salmon ature. Can. J. Zool. and trout of the South Fork 36:563-567. Coquille River in relation to the Eden Ridge hydro- Giger, R. D. 1973. Streamflow electric project. Pac. requirements for salmonids . Power and Light Co., Port- Oreg . Wild1 . Comm. Job. land, Oreg. 83 p. Final Rep. , Proj . AFS 62-1, Portland. 117 p. Hanson, D. L. 1977. Habitat selection and spatial Graham, J. M. 1949. Some interaction in allopatric effects of temperature and and sympatric populations oxygen pressure on the of cutthroat and steelhead metabolism and activity of trout. Ph.D. thesis, Univ. the speckled trout, Idaho, Moscow. 66 p. ~alveiinusfontinalis. Can. J. Res. 27:270-288. Hartman, G. F. 1963. Observa- tions on behavior of juvenile brown trout in a Graham, P. J. 1977. Juvenile stream aquarium during steelhead trout densities winter and spring. J. in the Lochsa and Selway Fish. Res. Board Can. 20(3):769-787. Hartman, G. F. 1965. The role Hicks, D. B., and J, W. DeWitt. of behavior in the ecology- - 1971. Effects of dissolved and interaction of under- oxygen on kraft pulp mill yearling coho salmon effluent toxicity. Water (Oncorhynchus kisutch) and Resour. Res. 5 :693-701. steelhead trout (Salmo gairdneri). J. Fish. Res. Hoar, W. S., H. A. Keenleyside, Board Can. 22(4):1035-1081. and R, G. Goodall. 1957. Reaction of juvenile Hartman, G. F. 1969. Repro- Pacific salmon to light. ductive biology of the J. Fish. Res. Board Can. Gerrard stock of rainbow 14:815-830. trout. p. 53-67. -In T. G, Northcote (ed.), Sym- Hobbs, D. F. 1937. Natural posium on Salmon and Trout reproduction of Quinnat in Streams. H. R. Mac- salmon, brown and rainbow Millan Lectures in ~isheries, trout in certain New Univ. B.C., Vancouver. Zealand waters, N. Z. Mar. Dep. Fish. Bull. No. 6.

Hausle, D. A,, and D. W. Coble. Hoffman, T. C, 1965. South- 1976. Influence of sand in eastern Alaska pink salmon redds on survival and forecast studies. Pre- emergence of brook trout. emergent fry program. Trans. Am. Fish. Soc, Alaska Fish and Game Inf. 105 (1):57-63. Leafl. 47, Juneau. 29 p.

Hayes, F, R., I. R. Wilmot, and Holeton, G. F. 1973. Res- D. A. Livingstone. 1951, -piration of Arctic char The oxygen consumption of (Salvelinus alpinus) from the salmon egg in relation a high Arctic lake. J. to development and activity, ~ish,Res. Board Can. J. Exp, Zool. 116:377-395. 30(6):717-723.

Hazzard, A. S. 1932. Some Hooper, D. R. 1973. Evaluation phases of the life history of the effects of flows on of the eastern brook trout, trout stream ecology. Dep. (Salvelinus fontinalis). Eng . Res., Pac. Gas and Trans. Am. Fish. Soc. Elec, Co., Emeryville, Calif, 97 p.

Herrmann, R. B. 1958. Growth Horton, P. A. 1961, The bio- of juvenile coho salmon at nomics of brown trout in a various concentrations of Dartmoor stream. J. Anim. dissolved oxygen. M.S. Ecol. 30:311-338. thesis, Oreg . State Univ., Corvallis. Hourston, W. R., and D. Mac- Kinnon. 1957. Use of an Herrmann, R, B., C. E, Warren, artificial spawning channel and P. Doudoroff. 1962. by salmon, Trans. Am. Fish Influence of oxygen con- SOC. 86:220-230. centrations on the growth of juvenile coho salmon. Hughes, G. M., and R. L. Saunders Trans. Am. Fish. Soc. 1970. Responses of the 91( 2) :153-167. respiratory pump to hypoxia in the rainbow trout (Salmo gairdneri). J. Exp. B-53 :529-545. Hunt, R. L. 1969. Effects of Johnson, R. L., P. E. Giguere, habitat alteration on and E. P. Pister. 1966. A production, standing crops progress report on the and yield of brook trout in Pleasant Valley spawning Lawrence Creek, Wis., channel. Admin. Rep, No. p. 281-312. In T. G. 66-4. Resour. Agency Northcote ( ed7, Symposium Calif., Calif. Dep. Fish on Salmon and Trout in and Game, Sacramento. Streams. H. R. MacMillan Lectures in Fisheries. Jones, D. R, 1971. The effect Univ. B.C., Vancouver. of hypoxia and anemia on the swimming performance of Hunt, R. L. 1976, A long-term rainbow trout (Salmo evaluation of trout habitat gairdneri) . J. Exp. Biol . development and its relation 55 :541-551. to improving managernent- related research. Trans. Jones, J. W. 1959. The salmon. Am. Fish. Soc. 105(3): Collins, London. 192 p. 361-365. Kalleberg, H. 1958. Obser- Hunter, J. G. 1959. Survival vations in a stream tank of and production of pink and territoriality and com- chum salmon in a coastal petition in juvenile salmon stream. J. Fish. Res. and trout (Salmo-- salar L. Board Can. 16(6):835-886. and S. trutta L.). Inst. ~res&ater Re%. Drottning- Hunter, J. W. 1973. A dis- holm 39:55-98, ocB" cussion of game fish in the State of Washington as Kemp, H. A. 1949. Soil pol- related to water require- lution in the Potomac River ments. Rep. by Fish Basin. Am. Water Works Manage. Div. Wash. State Assoc. J. 41(9):792-796, Dep. Game to Wash. State Dep. Ecol ., Olympia. Kennedy, H. D. 1967. Seasonal 66 PP- abundance of aquatic invertebrates and their Hynes, H. B. N. 1970. The utilization by hatchery ecology of running water. reared rainbow trout. U.S. Univ. Toronto Press. Bur. Sport Fish. and Wildl. 555 p. Tech. Pap. 12, 41 p.

Irving, L., E. C. Black, and V. Kier, W. M. 1964. The stream Stafford. 1941. The flow requirements of salmon influence of temperature in the lower Feather River, upon the combination of Butte County, California. oxygen with the blood of Calif. Dep. Fish and Game, trout. Biol. Bull. 80: Water Proj. Branch, Sacra- 1-17, mento. 17 p.

Itazawa, Y. 1970. Charac- Kimble, L. A., and T. A. Wesche. teristics of respiration of 1975. Relationship between fish considered from the selected physical para- arterio-venous difference meters and benthic com- of oxygen content. Bull. munity structure in a small Jap. Soc. Sci. Fish. mountain stream. Univ. 36 :571-577. Wyo,, Laramie. Water Resour. Res. Inst. Series 55. 64 p. Klamt, R. R. 1976. The effects LeCren, Em D. 1969. Estimates of coarse grantic sediment of fish populations and on the distribution and production in small streams abundance of salmonids in in England. p. 269-280. the central Idaho Batho- -In T. G. Northcote (ed.), lith. M.S. thesis, Univ. Symposium on Salmon and Idaho, Moscow. 85 p. Trout in Streams. H. R. MacMilIan Lectures in Koski, K V. 1966. The survival Fisheries., Univ. B.C., of coho salmon (Oncorhynchus Vancouver. kisutch) from egg deposition to emergence in Lewis, S. L. 1969. Physical three Oregon coastal streams. factors influencing fish M. S. thesis, Oreg. State populations in pools of a Univ., Corvallis. 84 p. trout stream. Trans. Am. Fish. Soc. 98(1):14-19. Kraft, M. E. 1968. The effects of controlled dewatering on Lindroth, A. 194 2. Sauerstof- a trout stream, M.S. fverbrauch der Fische. I. thesis, Mont. State Univ. , Verschiendene Entwicklungs- Bozeman. 31 p. und Altersstadien vom Lachs und Hecht. 2. vertl . Physiol . Kraft, M. E. 1972. Effects of 29:583-594. controlled flow reduction on a trout stream. J. Linduska, J. P. 1942. Bottom Fish. Res. Board Can. types as a factor in- 29(10):1405-1411. fluencing the local distribution of mayfly nymphs. Kutty, M. N. 1968. Respiratory Can. Entomol. 74:26-30. quotients in goldfish and rainbow trout. J. Fish. Lister, D. B., and H. S. Genoe. Res. Board Can. 25 (8) :1689- 1970. Stream habitat 1728. utilization by cohabiting underyearlings of chinook Kutty, M, N., and R. L. Saunders. (Oncorhynchus tshawytscha) 1973. Swimming performance and coho (0,kisutch) of young Atlantic salmon salmon in the Big Qualicum (Salmo-- salar) as affected River, British Columbia. by reduced ambient oxygen J. Fish. Res. Board Can. concentration. J. Fish. 27(7):1215-1224. Res. Board Can. 30(2): 223-227. Lloyd, R. 1961. Effect of dissolved oxygen concen- Larkin, P. A. 1956. Inter- trations on the toxicity of specific competition and several poisons to rainbow population control in trout (Salmo qairdneri freshwater fish. J. Fish. Richardson). J. Exp. Biol. Res. Board Can. 13(3): :27-342. Lucas, K. C. 1959. The Robert- LeCren, E. D. 1965. Some son Creek spawning channel. factors regulating the size Can. Fish. Cult. 25:4-23. of populations of freshwater fish. Mitt. Verein. McAfee, W. R. 1966. Rainbow theor. angew. Limn01 . trout. p. 192-215. In A. 13:88-105. *Calhoun (ed.), inland‘- Fisheries Management. Mills, D. H. 1969. Survival of Calif. Dep. Fish and Game, juvenile Atlantic salmon Resour. Agency, Sacramento. and brown trout in some Scottish streams. p. 217- McCuddin, M. E. 1977. ,Survival 228. -In T. G. Northcote of salmon and trout embryos (ed.), Symposium on Salmon and fry in gravel-sand and Trout in Streams. H. R. mixtures. M.S. thesis, MacMillan Lectures in Univ. Idaho, Moscow. 30 p. Fisheries. Univ. B.C., Vancouver. MacKinnon, D., L. Edgeworth, and R. E. McLaren. 1961. An Moring, J. R. 1975. The Alsea assessment of Jones Creek watershed study: effects spawning channel 1954- of logging on the aquatic 1961. Can. Fish. Cult. resources of three headwater 3:3-14. streams of the Alsea River, Oregon. Part I11 - Dis- McNeil, W. J. 1966. Effect of cussion and recommendations. the spawning bed envi- Oreg. Dep. Fish and Wildl. ronment on reproduction of Fish. Res. Rep. No. 9, pink and chum salmon. U.S. Portland. 24 p. Fish and Wildl. Serv. Fish. Bull. 65 :495-523. Moring, J. R., and R. L. Lantz. 1974. Immediate effects of McNeil, W., J. and W. H. Ahnell. logging on the freshwater 1964. Success of pink environment of salmonids. salmon spawning relative to Oreg. Wildl. Comm., Res. size of spawning bed Div., Proj, AFS-58, Final materials. U.S. Fish and Rep., Portland. 101 p. Wildl. Serv. Spec. Sci. Rep. Fish-No. 469. 15 p. Morrill, C. F. and T. C. Bjornn. Mason, J. C., and D. W. Chapman. 1972. Migration response 1965. Significance of of juvenile chinook salmon early emergence, environ- to substrates and temper- mental rearing capacity and atures. Idaho Water Resour. behaviorial ecology of Res. Inst. Tech. Comple- juvenile coho salmon in tion Rep. Proj. A-038-IDA, stream channels. J. Fish. Moscow. 27 p. Res. Board Can. 22(1): 173-190. Mundie, J. H. 1969. Ecological implications of the diet of Meehan, W. R. 1970. Some juvenile coho in streams. effects of shade cover on p. 135-152. In T. G. stream temperatures in Northcote (edx, Symposium southeast Alaska. USDA on Salmon and Trout in For. Serv. Res. Note Streams. H. R. MacMillan PNW-113, 4 p., Pac. North- Lectures in Fisheries, west For. and Range Exp. Univ. B.C., Vancouver. Stn., Portland, Oreg. Narver, D. W. 1972. A survey Merrell, T. R., Jr. 1962. of some possible effects of Freshwater survival of pink logging on two eastern salmon at Sashin Creek, Vancouver Island streams. Alaska. p. 59-72. -In N, Fish. Res. Board Can. J. Wilimovsky (ed.), Sym- Tech. Rep. 323, 55 p, posium on Pink Salmon. Inst. Fish., Univ. B.C., Vancouver. Neave, F. 1953. Principles Orcutt, D. R., B. R. Pulliam, affecting the size of pink and A, Arp. 1968. Char- and chum salmon populations acteristics of steelhead in British Columbia. J. trout redds in Idaho Fish. Res. Board Can. streams. Trans. Am, Fish 9(9):450-490. Soc. 97(1):42-45.

Needham, P. R. 1934, ~uanti- Pautzke, C. F. 1938. Studies tative studies of stream on the effect of coal bottom foods. Trans. Am. washings on steelhead and Fish. Soc. 64:238-247. cutthroat. Trans. Am. Fish. Soc. 67(1937):232-233, Needham, P. R., J. W. Moffett, Pennak, R. -We, and E. D. Van- and D. W. Slater, 1945. Gerpen. 1947. Bottom Fluctuations in wild brown fauna production and trout populations in Con- physical nature of the vict Creek, California. J. substrate in a northern Wildl. Manage. 9:9-25. Colorado trout stream. Ecology 28 :42-48. Needham, P. R., and R. Usinger. 1956. Variability in fhe Peters, J. C., and W, Alvord. macrofauna of a single 1964. Man-made channel riffle in Prosser Creek, alterations in thirteen Calif., as indicated by a Montana streams and rivers. Surber sampler. Hilgardia Trans. North Am. Wildl. 24 :383-409. Conf. 29:93-102. Newman, M. A. 1956. Social behavior and interspecific Phillips, R. W., and H. J. competition in two trout Campbell. 1961. The species. Physiol , 2001. embryonic survival of coho 29:64-81. salmon and steelhead trout as influenced by some Nickelson, T. 1976. Develop- environmental conditions in ment of methodologies for gravel beds. 14th Ann, evaluating instream flow Rep. Pac. Mar. Fish, Comm., needs for salmonid rearing. Portland, Oreg. p. 60-73. P. 588-596. In J. F. brsborn and C~H.Allman Phillips, R. W., R. L. Lantz, E. (weds. ) , Instream Flow W. Claire, and J. R. Needs. Vol. 11. Am. Fish. Moring. 1975. Some effects Soc. Spec. Publ. of gravel mixtures on emergence of coho salmon Nickelson, T. E,, and R, E. and steelhead trout fry. Hafele. 1978. Streamflow Trans. Am. ~ish.Soc. requirements of salmonids, 104(3):461-466. Prog. Rep. Oreg. Dep. Fish and Wildl. AFS-62. Con- Pollock, R. D. 1969. Tehama- tract 14-16-0001-77-538, Colusa canal to serve as Portland. 25 p. spawning channel. Prog. Fish-Cult. 31(3):123-130. Nickelson, T. E., and R. R. Reisenbichler. 1977. Randall, D. J., and J. C. Smith. Streamflow requirements of 1967. The regulations of salmonids . Prog . Rep. cardiac activity in fish in Oreg. Dep. Fish and Wildl. a hypoxic environment. AFS-62. Contract 14-16- Physiol. Zool. 40(2): 0001-4247, Portland, 24 p. 104-113. Rantz, S. E. 1964. Stream Saunders, J. W., and M. W. hydrology related to the Smith. 1962. Physical optimum discharge for king alteration of stream habitat salmon spawning in the to improve brook trout Northern California Coast production. Trans. Am. Ranges. U. S. Geol . Surv. Fish. Soc. 91(2):185-188. Water-Supply Pap. 1779-AA. 16 p. Scott, D. 1958. Ecological studies on the Trichoptera Reiser, D. W., and T. A. Wesche. of the River Dean, Cheshire 1977. Determination of Arch. Hydrobiol. 54~340-392. physical and hydraulic preferences of brown and Sekulich, P. T., and T. C. brook trout in the selec- Bjornn. 1977. The carry- tion of spawning locations. ing capacity of streams for Wyo. Water Res. Inst., rearing salmonids as Laramie. Ser. No. 64. affected by components of 100 p. the habitat. Completion Rep. for Suppl. 99, USDA Ringler, N. H. 1970. Effects For. Serv. 79 p. of logging on the spawning bed environment in two Sheridan, W. L. 1962. Water- Oregon coastal streams. flow through a salmon M.S. thesis, Oreg. State spawning riffle in south- Univ., Corvallis. 89 p. eastern Alaska. U.S. Fish and Wildl. Serv. Spec. Sci. Rep. - Fish No. 407. 22 p. Ringler, N. H., and 3. D. Hall. 1975. Effects of logging J. on water temperature and Sheridan, W. L. and W. McNeil. dissolved oxygen in spawn- 1968. Some effects of logging on two streams in ing beds. Trans. Am. Fish. Alaska. J. For. 66(2): SOC. 104(1):111-121. 128-133. Rothacher, J. 1971. Regimes of 0. streamflow and their Shetter, D. S., H. Clark, and modification by logging. A. S. Hazzard. 1946. The p. 40-54. In Forest Land effects of deflectors in a section of a Michigan trout Uses and stream Environ- ment, Oreg State Univ., stream. Trans. Am. Fish. . SOC. 76:248-278. Corval lis.

Ruggles, C. P. 1966. Depth and Shumway, D. L., C. E. Warren, velocity as a factor in and P. Duodoroff. 1964. stream rearing and pro- Influence of oxygen con- duction of juvenile coho centration and water move- ment on the growth of steelhead trout and coho salmo~. Can. Fish Cult. salmon embryos. Trans. Am. 38:37-53. Fish. Soc. 93(4):342-356.

Ruttner, F. 1953. Fundaments Silver, S. T., C. E. Warren, and of limnology (Transl. by D. P. Doudoroff. 1963. G. Frey andF. E. J. Fry). Dissolved oxygen require- Univ. Toronto Press. ments of developing steel- 295 p. head trout and chinook salmon embryos at different water velocities. Trans. Am. Fish. Soc. 92(4): 327-343. Smith, A. K. 1973. Development Stuart, T. A. 1962. The ieap- and application of spawning ing behavior of salmon and velocity and depth criteria trout at falls and ob- for Oregon salmonids. structions. Freshwater Trans. Am. Fish. Soc. Salmon. Fish. Res. Rep. 10(2):312-316. No. 28, 46 p.

Smith, L. L., Jr., and J. B. Stuehrenberg, L. C, 1975. The Moyle. 1944. A biological effects of granitic sand on survey and fishery manage- the distribution and abun- ment plan for the streams dance of salmonids in Idaho of the Lake Superior north streams. M. S. thesis, shore watershed. Minn. Univ. Idaho, Moscow. 49 p. Dep. Cons. Div. Game and Fish, Tech. Bull. 1, 228 p. Surber, E. W. 1936. Rainbow trout and bottom fauna Smith, 0. R. 1939. Placer production in one mile of mining silt and its re- stream. Trans. Am. Fish. lation to salmon and trout SOC. 66:193-302, on the Pacific coast. Trans. Am. Fish. Soc. Surber, E. W. 1951. Bottom 69:135-139. fauna and temperature conditions in relation to Smith, 0. R. 1941. Spawning trout management in St. habits of cutthroat and Mary ' s River, Augusta eastern brook trout. J. County, Virginia. Va. J. Wildl. Manage. 5(4):461-471. Sci. 2:190-202.

Sprules, W. M. 1947. An eco- Tarzwell, C. M. 1937. Experi- logical investigation of mental evidence on the stream insects in Algonquin value of trout stream Park, Ontario. Univ. improvement in ~ichigan. Toronto Studies, Biol. 56. Trans. Am. Fish. Soc. Publ. Ont. Fish. Res. Lab. 66:177-187. 69:l-81. Tarzwell, C. M. 1938. An Stalnaker, C. B., and J. L. evaluation of the methods Arnette. 1976, Method- and results of stream ologies for determining improvement in the South- instream flows for fish and west. Trans. North Am. other aquatic life, p. 89- Wildl. Conf. 3:339-364. 138. -In C. B. Stalnaker, and J. L. Arnette (eds.), Tarzwell, C. M. 1957. Water Methodologies for the quality criteria for Determination of Stream aquatic life. 2 Bio- Resource Flow Requirements: logical Problems in Water An Assessment. U.S. Fish ~ollution. U.S. Dep. and Wildl . Serv. , Of £ice of Health, Educ. and Welfare, Biol. Serv., Washington, R. A. Taft San. Eng. Cent., D.C Cincinnati, Ohio. p. 246- 272. Stuart, T. A. 1953. Spawning migration, reproduction and Tautz, A. F., and C. Groot. young stages of the Loch 1975. Spawning behavior of trout (& trutta). Fresh- chum salmon (0. keta) and water Salmon. Fish Res. rainbow trout (Lgairdneri). Home Dep., Scotland. Rep. J. Fish, Res. Board Can. No. 5. 39 p. 32(5):633-642. Tebo, L. B., Jr. 1955. Effects Vaux, W. A. 1962. Interchange of siltation resulting from of stream and intragravel improper logging on the water in a salmon spawning bottom fauna on a small riffle. U.S. Fish and trout stream in the south- Wildl. Serv. Spec. Sci. ern Appalachians. Prog. Rep. Fish. 405. 11 p. Fish-Cult. 17(2):64-70. Vaux, W. A. 1968. Intragravel flow and interchange of Tebo, L. B., Jr. 1957. Effects water in a streambed. U.S. of siltation on trout Fish and Wildl. Serv. Fish Soc. Am. For. streams. Bull. 66:479-489. Proc. 1956 ~eeting,p. 198- 202. Wallen, E. I. 1951. The direct effect of turbidity on Tebo, L. B., Jr. 1974. Review fishes. Okla. Agric. and of selected parameters of Mech. Col., Arts and Sci. trout stream quality. In Studies, Biol. Ser. No. 2, Symposium on Trout ~abiGt 48(2):27. Research and Management. .Appalachian Consortium Warner, K. 1963. Natural Press. Boone, N.C. spawning success of land- p. 20-32. locked salmon (Salmo salar). Trans. Am. Fish. Terhune, L. D. B. 1958. The SOC. 92(2):161-164. Mark VI .groundwater stand- pipe for measuring seepage Warner, K., and I. Porter. through salmon spawning 1960. Experimental im- gravel. J. Fish. Res. provement of a bulldozed Board Can. 15(5):1027-1063. trout stream in Northern Maine. Trans. Am. Fish. Thompson, K. 1972. Determining SOC. 89(1):59-63. stream flows for fish life. -In Proceedings, Instream Waters, B. F. 1976. A method- Flow Requirement Workshop, ology for evaluating the Pac. Northwest River Basin effects of different stream- Comm., Vancouver, Wash. flows on salmonid habitat. p. 31-50. p. 254-266. In J. F. Orsborn and C. H. Allman Thorup, J. 1966. Substrate (eds.), Instream Flow type and its value as a Needs. Vol . 11. Am. Fish. basis for the delimitation Soc. Spec. Publ. of bottom fauna communities in running waters. p. 59-74. F. In K. W. Cummings, C. A. Waters, T. 1969. Inverte- - brate drift--ecology and Tryon, Jr., and R. T. significance to stream Hartman (eds.), Organism- Substrate Relationships in fishes. p. 121-134. -In Streams. Spec. Publ. No. T. G. Northcote (ed.), 4., Pymatuning Lab. of Symposium on Salmon and Ecology, Univ. Pittsburg , Trout in Streams. H. R. Pa. MacMillan Lectures in Fisheries. Univ. B.C., Trautman, M. B. 1933. The Vancouver. general effects of pollution on Ohio fish life. Trans. Am. Fish Soc. 63:69-72. Watts, F. J. 1974. Design of Wickett, W. P. 1954. The culvert fishways. Idaho oxygen supply to salmon Water Resour. Res. Inst. eggs in spawning beds. J. Rep. Proj. A-027-IDA, Fish. Res. Board Can. Moscow. p. 62. 11(6):933-953.

Wells, R. A., and W. J. McNeil. Wickett, W. P.. 1958. 2eview of 1970. Effect of quality of certain environmental spawning bed on growth and factors affecting the development of pink salmon production of pink and chum embryos and alevins. U.S. salmon. J. Fish. Res. Fish and Wildl. Serv. Spec. Board Can. 15(5):1103-1126. Sci. Rep. Fish. No. 616. 6 P. Wickett, W. P. 1962. Environ- mental variability and Wesche, T. A. 1973. Parametric reproduction potentials of determination of minimum pink salmon in British stream flow for trout. Columbia, p. 73-86. -In N. Wyo. Water Resour. Ser. No. J. Wilimovsky (ed.), 37. Water Resour. Res. Symposium on Pink Salmon Inst. Univ. Wyo., Laramie. 1960. H. R. MacMillan 102 p. Lectures in Fisheries. Univ. B.C., Vancouver. Wesche, T. A. 1974. Relation- ship of discharge reduc- Wickham, G. M. 1967. Physical tions to available trout microhabitat of trout. habitat for recommending M.S. thesis, Colo. State suitable streamflows. Wyo. Univ., Fort Collins. 42 p. Water Resour. Res. Inst., Laramie. Ser. No. 53. Ziebell, C. D. 1957. Silt and 71 p. pollution. Wash. Pollut. Control Comm. Info. Ser. White, R. G. 1976. Predicted 57-1. 4 p. effects of water withdrawal on the fish populations of the Teton River, Idaho. Completion Rep. to U.S. Bur. Reclam., For. ~ildl. and Range Exp. Stn. Contrib. No. 63, Univ. Idaho, Moscow. 47 p.

Whitmore, C. M., C. E. Warren, and P. Doudoroff. 1960. Avoidance reactions of salmonids and centrachid fishes to low oxygen concentrations. Trans. Am. Fish. Soc. 89(1):17-26.

Wickett, W. P. 1951. The coho salmon populations of Nile Creek. Fish. Res. Board Can., Prog. Rep. (Pac.) No. 89 :88-89.

GPO 989-357 k

The mission of the PACIFIC NORTHWEST FOREST AND RANGE EXPERIMENT STATION is to provide the knowledge, technology, and alternatives for present and future protection, management, and use of forest, range, and related environments.

Within this overall mission, the Station conducts and stimulates research to facilitate and to accelerate progress toward the following goals:

1. Providing safe and efficient technology for inventory, protection, and use of resources.

2. Developing and evaluating alternative methods and levels of resource management.

3. Achieving optimum sustained resource productivity consistent with maintaining a high quality forest environment.

The area of research encompasses Oregon, Washington. Alaska, and, in some cases, California, Hawaii, the Western States, and the Nation. Results of the research are made available promptly. Project headquarters are at:

Anchorage, Alaska La Grande, Oregon Fairbanks, Alaska Portland, Oregon Juneau, Alaska Olympia, Washington Bend, Oregon Seattle, Washington Corvallis, Oregon Wenatchee, Washington

Mailing address: Pacific Northwest Forest and Range Experiment Station 809 N.E. 6th Ave. Portland, Oregon 97232 ------~ - - - . --- I

1, The FOREST SERVl iilture is dedicated to the principle of )f the N on's forest resources Dna uril for sustained vie fe, and recreation. l and private forest nal Grasslands, it greater service to 1 1 11 i I The U.S. Depart 111 Applicants for al t programs will equal consideration 1, lor. sex. reliclior

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