&EPA
            United States
            Environmental Protection
            Agency
            Environmental Research
            Laboratory
            CorvallisOR 97330
EPA 6
            Research and Development
A Stream Systems
Evaluation—
An Emphasis on
Spawning
Habitat for
Salmonids

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                RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology.  Elimination  of traditional grouping was  consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:

      1.  Environmental  Health Effects Research
      2.  Environmental  Protection Technology
      3.  Ecological Research
      4.  Environmental  Monitoring
      5.  Socioeconomic Environmental Studies
      6.  Scientific and Technical Assessment Reports (STAR)
      7.  Interagency  Energy-Environment Research and Development
      8.  "Special" Reports
      9.  Miscellaneous Reports

This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on  the effects of pollution on humans, plant and animal spe-
cies, and materials. Problems are assessed  for their long- and short-term influ-
ences. Investigations include formation, transport, and pathway studies to deter-
mine the fate of pollutants and their effects. This work provides the technical basis
for setting standards to minimize undesirable changes in living organisms in the
aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                                EPA-600/3-79-109
                                                October 1979
          A STREAM SYSTEMS EVALUATION—


AN EMPHASIS ON SPAWNING HABITAT FOR SALMONIDS


                        by
              Mostafa A0 Shirazi
              Freshwater Division
    Corvallis Environmental Research Laboratory
            Corvallis, Oregon 97330
                       and
                 Wayne K. Seim
     Department of Fisheries and Wildlife
            Oregon State University
            Corvallis, Oregon 97331
  Corvallis Environmental Research Laboratory
       Office of Research and Development
      U.S. Environmental Protection Agency
            Corvallis, Oregon 97330

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                               DISCLAIMER
     This report has been reviewed by the Corvallis Environmental
Research Laboratory, U.S. Environmental Protection Agency, and approved
for publication.  Mention of trade names or commercial products does
not constitute endorsement or recommendation for use.
                                   11

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                                FOREWORD


     Effective regulatory and enforcement actions by the Environmental

Protection Agency would be virtually impossible without sound scientific
data on pollutants and their impact on environmental stability and

human health,,  Responsibility for building this data base has been

assigned to EPA's Office of Research and Development and its 15 major

field installations, one of which is the Corvallis Environmental

Research Laboratory (CERL).


     The primary mission of the Corvallis Laboratory is research on

the effects of environmental pollutants on terrestrial, freshwater,

and marine ecosystems; the behavior, effects and control of pollutants

in lakes and streams;  and the development of predictive models on the

movement of pollutants in the biosphere.


     This report is the product of a special conference at Gleneden,

Oregon, June 4-6, 1979, to discuss and rewrite a white paper originally

prepared by Shirazi and Seim on development of a united approach for

evaluation of spawning habitat.  Invited participants are listed below.

This report was shaped as the outcome of intensive work sessions directed

towards crystalizing a consensus.  The senior authors are, of course,
indebted to these scientists for their contributions, but they derive

greatest satisfaction from the support their work has received.
Peter Bisson
Weyerhauser Company
505 North Pearl St.
Centralia, WA  98531

Robert L. Beschta
Department of Forst Science
Oregon State University
Corvallis, OR  97331

Kenneth Bovee
Cooperative Instream Flow
   Service Group
U.S. Fish f, Wildlife Service
Drake Creekside Building
2625 Redwing Road
Fort Collins, CO   80521
Mason Bryant
Forest Sciences Laboratory
Pacific Northwest Forest and
   Range Experiment Station
P.O. Box 909
Juneau, AK   99801

C.J, Cederholm
Fisheries Research Institute
University of Washington
c/o Department of Natural Resources
RR. 1, Box 1375
Forks, WA   98331
                                    iii

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Tom C. Chamberlin
Ministry of Environment
Resource Analysis Branch
Victoria, BC
Canada V8V 1X4

Donald Corley
Boise National Forest
1075 Park Blvd.
Boise, ID   83704

Jack Gakstatter
Freshwater Division
Environmental Protection Agency
Corvallis, OR   97330

James D. Hall
Dept. of Fisheries and Wildlife
Oregon State University
Corvallis, OR   97331

Peter Klingeman
Water Resources Research Institute
Oregon State University
Corvallis, OR   97331

K. Koski
National Marine Fisheries Service
Auke Bay Laboratory
P.Oo Box 155
Auke Bay, AK   99821
Richard Lantz
Oregon Department of Fish and Wildlife
Regional Office
Rt, 5, Box 325
Corvallis, OR   97330

Fred Lotspeich
Freshwater Division
Environmental Protection Agency
Corvallis, OR   97330

Thomas E. Maloney
Freshwater Division
Environmental Protection Agency
Corvallis, OR   97330

Milton E. Parsons
Siuslaw National Forest
545 SW 2nd Street
Corvallis, OR   97330

William Platts
U.So Dept. of Agriculture--
  Intermountain Forest and Range
  Experiment Station
316 E. Myrtle St.
Boise, ID   83706

Robert Rulifson
U.S0 EPA, Region X
1200 6th Avenue
Seattle, WA   98101
                                    Thomas A. Murphy
                                    Director, CERL
                                   iv

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                               CONTENTS

INTRODUCTION 	   1
A UNIFYING SUBSTRATE STATISTIC 	   2
VISUAL ESTIMATION OF SUBSTRATE COMPOSITION AND NUMBER OF SAMPLES ..   6
THE ADEQUACY OF SAMPLE WEIGHT 	  10
METHODS OF OBTAINING GRAVEL SAMPLES 	  16
ANALYSIS OF GRAVEL—WET SIEVING	  21
CALCULATION OF SUBSTRATE STATISTICS 	  24
   LEAST SQUARES GRAPHICAL METHOD 	  24
   QUANTILE GRAPHICAL METHOD 	  26
   METHOD OF MOMENTS 	  26
   CHOICE OF METHODS 	  26
ESTIMATING LOCALIZED AND STREAMWIDE IMPACTS  	  28
   EVALUATION OF STREAM SYSTEMS 	  29
CONCLUSION AND RECOMMENDATION 	  32
REFERENCES 	  34

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                                 ABSTRACT

     As  a  result  of  silvicultural activities  in  the  Pacific Northwest,
various  levels of sediments and  debris enter  the streams,  often degrading
spawning substrate of salmonid fishes.  Simple but reliable procedures
are needed to monitor spawning gravels to assess the  level of these
impacts.  This paper presents a  preliminary rationale for  conducting
a monitoring program with the objective of assessing  the level of
sedimentation impact both locally in a given  stream spawning site as
well as more generally for the entire stream  that might be impacted
by watershed management activities.
                                   vi

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                              INTRODUCTION

     Nonpoint source pollution (NFS) is recognized as a serious problem
in the United States and throughout the world.  Water quality management
programs conducted under state and federal legislation have identified
nonpoint sources of pollution as a significant obstacle to attaining the
1983 goal of water quality adequate for fish, wildlife and recreation.
Stream sedimentation is one of the greatest NFS pollution problems,
primarily because widespread activities such as agriculture, logging,
livestock grazing and road construction are major sources of increased
sediment loading.  For example, logging and road construction in the
Pacific Northwest introduces various levels of sediments and debris
into streams and rivers.  This can result in the degradation of riffle
habitats critical for salmonid fish reproduction and for the production
of invertebrate food organisms necessary for the rearing of juvenile
fish.  In mountain streams spawning takes place in riffles where the
water velocity is usually 45 to 75 cm/sec (1.5-2.5 ft/sec) and the water
depth is 15 to 90 cm (6 to 36 inches).  Salmonid reproduction and the
production of invertebrate food organisms respond adversely to excessive
sedimentation in these areas.  A study of spawning habitats could,
therefore, provide a relatively simple, sensitive and meaningful indicator
of watershed management impacts.

     For several decades, fishery biologists have known the general
properties of spawning gravels used by salmonids.  However, the lack
of a relatively simple, reliable and standardized method of character-
izing the gravels has hindered quantitative descriptions of changes
caused by sedimentation.  This paper describes a comprehensive procedure
to assess and monitor the effects of watershed management activity on
stream spawning habitat, applicable both to individual spawning sites
and to an entire stream system.  This monitoring program is designed to
minimize costs and work effort.  It is anticipated that this procedure
will provide the groundwork for a serious effort in compiling the com-
prehensive data base required to evaluate effects of land use on streams
over large geographical areas in the United States.
                                   1

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                      A UNIFYING  SUBSTRATE  STATISTIC

      Fisheries  researchers  generally  agree that  excess  fine  sediments
 in the  spawning gravel  of salmonids are  a  cause  for  embryo and  larval
 mortality  (Iwamoto  et^ a^. 1978).  Several  measures of substrate fines
 have  been  advocated,  namely,  fractions less  than .83 mm,  3,3 mm,  or
 6.5 mm.  Even if there  is no  consensus on  a  unified  definition  of fines,
 the causal factor of  mortality is generally  believed to be the  filling
 of spaces  within the  gravel.  This causes  substantial reduction in the
 replacement of  metabolite-laden water with oxygen-laden water during
 the incubation  of embryos and alevins and  the  trapping  of alevins during
 emergence  from  the  gravel.

      Since natural  spawning substrates contain a wide range  of  particle
 sizes including silt,  sand, gravel and cobble, permeability  to  flow
 and thus embryo survival depends not  only  on fine materials  in  the sand
 range,  but also on  the  presence of gravel  and  cobble.   Permeability is
 a strong function of  pore size distribution, which in turn is affected
 by the  size composition of the particles and by  their shapes and  packing
 arrangement.  Shape angularity of the particles  directly  influences the
packing arrangement.  There exists no convenient measure  of natural
packing of substrate  in a stream bottom.   Lotspiech  (1978) presented
convincing arguments  that combined measures  of central  tendency (i.e.,
 the mean)  and the sorting coefficient (i.e., the standard deviation)
 should provide  an indirect but adequate measure  of potential change in
permeability.

     In an extensive  analysis of the relationship between permeability
and gravel composition, and in an attempt  to arrive at a  logical  alter-
native measure  of spawning gravel, Platts  et_ al_.  (1979) demonstrated
that information on the entire textural composition of the gravel  is
necessary.  They proposed the geometric mean particle diameter  (d  ) as
an appropriate  statistic because
      (1) d  is  a conventional statistical measure used in sedimentary
          o
petrology and engineering to represent sediment  composition.
                                    2

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     (2) d  is a convenient standard measure that enables comparison of
          &
sediment sample results between two studies.
     (3) d  may be calculated from d<,. and d.,, two parameters
that may also be used to calculate the standard deviation.
     (4) d  relates to the permeability and porosity of channel
          &
sediments and to embryo survival, at least as well as "percent fines."
     (5) d  is a more complete description of total sediment composi-
          &
tion than "percent fines" and sediment composition evaluations in many
cases involve less sampling error using d .
                                         6
     (6) d  relates to porosity and permeability, and thus it is
          o
potentially a suitable unifying measure of channel substrate condition
as it impacts embryo survival.
     In a comprehensive review paper of embryonic survival, Shirazi
(unpublished) showed an empirical relationship of survival during
different embryo to alevin emergence stages with geometric mean diameter
of the spawning substrate (Figure 1).  Percent embryo  survival is plotted
against the geometric mean diameter of the substrate within the redd.
The positive trend relating these two variables is unmistakable.  To
account for minor egg size differences among  species,  d   was  divided by
                                                       &
a value for egg diameter  (d ) for that species in order to produce a more
                           6
strongly correlated relationship with survival  (Figure 2).  The utility
and the adequacy of a generalized scalar  (d ) are indicated in the
                                           &
figures by the strong correlation it exhibits with embryo survival from
diverse sources of data.
     There may be justification for  further  research  to  obtain  a more
complete description of the substrate  than d .  Vigorous research  will
                                             o
hopefully continue, but for it to be successful and to provide  the data
base, the full substrate composition must accompany all  survival test
results.  Having this  information, d , percent fines, or other  convenient
                                     &
measures may be readily estimated and  correlated  with embryo survival
studies.

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100


 90


 80


 70


 60


 50


 40


 30

 20


 10

  0
                n
A
               Species
           O Coho
           • Coho
           O Coho
           O Coho
           O Cutthroat
           D Sockeye
           A Steelhead
           A Steelhead
       Source
Koski, 1966
Phillips, etal., 1975
Tagart,  1976
Cederholm, Unpublished
Cederholm et al., 1974
Cooper,  1975
Phillips, et al., 1975
Cederholm, etal., 1974
     Place
Drift Creek, OR
Laboratory
Clearwater Creek,WA
Laboratory
Stequaleho Creek, WA
Laboratory
Laboratory
Stequaleho Creek, WA
                             I
                  I
   0
    10         15          20         25          30
  GEOMETRIC  MEAN  DIAMETER,  dg (mm)
                                        35
   Figure 1.  Relationship between percent embryo survival and substrate composition expressed in geometric
            mean diameter.

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Ui
   100

    90

    80

    70

<  60

|  50

^  40

    30

    20


    10

     0
0
                                                  n
                     1.0
2.0
                  Species
             O Coho
             • Coho
                Coho
                Coho
             O Cutthroat
             D Sockeye
             A Steelhead
             A Steelhead
                                                                    Source
                                           Place
                                              9
                                              €
               Koski, 1966            Drift Creek, OR     ~
               Phillips, et al., 1975     Laboratory
               Tagart, 1976           Clearwater Creek, WA
               Cederholm, Unpublished Laboratory         —
               Cederholm et al., 1974  Stequaleho Creek, WA
               Cooper, 1975           Laboratory
               Phillips, et al., 1975     Laboratory        ~~
               Cederholm, et al., 1974  Stequaleho Creek, WA
3.0
                                                      4.0
                                                  dg/de
5.0
6.0
7.0
             Figure 2.  Relationship between percent embryo survival and substrate composition in multiples of
                      egg diameter.

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     VISUAL ESTIMATION OF SUBSTRATE COMPOSITION AND NUMBER OF  SAMPLES

      To accomplish the objective  of monitoring and assessing  stream
 gravel  composition,  the following facts  must  be considered:
      (a)   Substrate  composition varies both horizontally and  vertically
 at a given time  and  location.
      (b)   Substrate  composition changes  through time  because  of  bed  form
 movement  (e.g.,  bar  progression)  and the  entrainment  and deposition  of
 fine material.
      (c)   Within a given  stream reach, bed forms and  channel  patterns
 tend to repeat as  similar geomorphic conditions  are encountered  (e.g.,
 a sequence  of pool-riffle complexes)0

     Because of  the  natural variability  of stream  gravel  composition
 in time and space, a rapid stratification of  the gravel  environment
 would be desirable to  reduce the  overall  sampling  effort.  It must be
 remembered  that  site assessment (gravel  composition)  must  be  coupled
 with area determination to establish net  gravel  quality  and quantity
 within a stream  reach  or  system.  The experiment described here
 addresses gravel composition differences  at typical spawning  sites
 within an area,  each site on the  order of ten  to several  hundred
 square meters.   This experiment tested the ability to estimate visually
 relative differences in the composition of two neighboring gravel patches.
 No attempt was made  to delineate  the boundaries of these  patches even
 though the composition at times appears to change  continually between
 these patches.   A variety of spawning substrates was  sampled, including
 streams in the Siuslaw National Forest in Oregon,  a segment of the Rogue
 River in Oregon  and a  small salmon stream in southeast Alaska.  The
 sampling team initially had no experience in matching visual composition
with the results of sieve analysis.

     At each location, the areal  extent of the spawning  gravels was
visually stratified into three groupings  (based on apparent composition
of the surface gravels):  A for coarse, C for fine, and  B for intermediate.
Channel form was indirectly included by associating the relative coarseness
of gravels with  flow velocities; coarse gravels are typically found  under
                                    6

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relatively faster waters.  A single 12" core sample was collected within
each area and field-sieved.

     Subsequent analysis of the field data indicated that when mean
particle diameter in bed material differed by about 10% for any two
samples at a site, the visual procedure was capable of correctly
identifying the coarser material 87% of the time (Table 1).  When
differences were about 20%, the visual estimation of relatively
coarser material was correct 93% of the time.  To get an idea of the
differences in the compositions of A, B, and C, the reader should refer
to the analysis of a typical site sample collected in Indian Creek
(Figure 3a)„

     These results indicate that visual estimation procedures may be
useful for characterizing the relative composition of the underlying
bed material at a particular site.  Canadian experience (Chamberlin,
pers. comm.) suggests that trained observers can estimate percentage
of fine (< 2mm), gravel  (2-64 mm) and larger material to ± 10% in test
gravels.  Such a capability would allow a relatively rapid assessment of
quality and quantity of potential spawning gravels along a particular
stream reach.  However, detailed gravel measurements would be necessary
at specific sites for evaluating composition changes along the stream
or through time.  It may be useful to speculate on how accurately observers
can visually assess gravel characteristics in comparison to the variability
in the area determinations which are necessary for overall reach or
system assessment.  If precise area measurements are difficult (as
in mobile bed rivers) then rapid visual estimates of bed composition
referenced to a few quantitative samples may provide useful monitoring
information.

     As a consequence of visual stratification of gravels, sample
sizes may be adjusted to reflect the degree of variability within the
sites of interest.  The presence of broad zones of homogenous material
suggest fewer sample points than would a mosaic of widely different
bed material compositions.

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Table 1.  GEOMETRIC MEAN DIAMETER d   (mm) OF SUBSTRATE CATEGORIES
                                   O
          (A, B, AND C) SHOWING SCORES FOR 10% AND 20% DIFFERENCE
          IN RELATIVE COARSENESS ESTIMATION,


1
2
3
4
5
6A
6B
7
8A
8B
9A
9B
10
11
12
13A
13B
14B
14C
14D
15
16A
16B
17
18
19
Coarse
A
46.4
22.5
31.0
24.7
23.1
27o6
23.9
20.2
24.4
12.5
31o4
26.5
25.8
35.1
83.1
39.0
41.9
59.0
21.8
58.7
22.2
6.5
8.7
28.3
16.0
33.8
Possible Score
Rating
Success %
Intermediate
B
14.5
16.7
27.5
22.1
14.4
13.9
23.3
23.7
16.9
11.8
13.2
22.4
19.0
38.9
62.9
39,7
2005
30,9
1806
58.8
22.6

6.4
23.1
10.3
22.5
76

Fine
C
14.2
18.9
22.6
9.6
13.3
8.5
16.9
14.9
14.4
6.2
6.8
26.4
26.1
18.8
25.1
15.2
17.4
17.3
48.4
65.3
19.5
807
7.9
19.4
4.3
32.7


Score
10%
3
2
3
3
3
3
3
2
3
3
3
2
2
3
3
3
3
3
1
1
3
1
2
3
3
2
66
87

20%
3
3
3
3
3
3
3
3
3
3
3
3
2
3
3
3
3
3
1
3
3
1
2
3
3
2
71
93

«
  A full score of 3 was assigned if A was coarser than B and C, and B
  coarser than C.                   8

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     To determine the number of samples to be taken in an area consisting
of tens of hundreds of sites, one must combine the visual information
on variability of the composition in the site with the desire to attain
a certain level of resolution.  This procedure allows enough flexibility
to assess either as small an area as that occupied by a redd or an entire
riffle of several hundred square meters.  In both instances taking only
three samples may be adequate, with obvious implications on the accuracy
attained in each case.  To assess reaches of an entire stream system
stretching several kilometers, the level of resolution need not be too
demanding.  For example, the authors surveyed a two-kilometer reach of
Canal Creek in nearly four hours.  They combined results of this visual
survey with two site estimates of gravel composition (Items 8A and 8B in
Table 1) to obtain the results shown in Table 2.
Table 2.  STREAM REACH EVALUATION OF SPAWNING GRAVEL COMPOSITION IN
          IN CANAL CREEK, JUNE 29, 1975.

Relative
coarseness
Cl
C
B
A
Al
Total:
Approx. mean
diameter (mm)
6
9
12
18
26

Approx. gravel
area in m
24
672
1191
768
137
2792
Percent of
total
1
24
43
27
5
100
 Total stream length surveyed:  2130 m
 Total stream reach covered as a result of beaverdam: 400 m
 Approximate stream width:  2,5 m
 Approximate spawning area:  50% of the reach
     It appears that this level of effort may be entirely adequate  in
many cases and should provide a general assessment of quality of
substrate with attached areal extent for the stream reach.

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                     THE ADEQUACY OF A SAMPLE WEIGHT

      The question of sample weight  must  be addressed in terms of its
 adequacy to assess a spawning site  for the effects of sediments on success
 of  reproduction and development  of  salmonid fishes.   It is evident that
 there is considerable variability in data relating survival  to geometric
 mean.   For  example,  at 50%  survival  (Figure 1),   the mean geometric diameter
 is  10 mm, but,  due to the scatter in the data,  a range of diameters from
 7.5 mm to 12.5  mm could also  lead to the same result.   The level  of
 variation is more pronounced  in  the  midrange of d .   The true source
                                                  o
 of variation can only partially  be  related to the procedural  difficulties
 in assessing the gravel  composition.   Natural variability within  bed
 material at spawning  sites  and within egg packets has  been documented
 by Koski  (1966),  Tagart  (1976),  Platts (1974, 1979),  and Corely and
 Burmeister  (1978).  Two-fold  variation in the geometric mean  even within
 a single redd is  not  unusual.  That  alone can cause  the scatter under
 natural  conditions.   Difficulties in accurately estimating the number
 of eggs deposited and enumerating emergent fry  further contribute to
 possible sources  of errors.   Consequently,  the  margin  of error attributed
 to d   is probably rather small.
    o
     The problem of adequate  sample  weight  may  now be  evaluated as
 follows.  If a  gravel  patch has  a true mean geometric  diameter equal to
 d  , how large  a sample  weight should we analyze to  estimate  d   with
 gt                                                            gt
 reasonable accuracy,  say to within  ±10%?  An experiment was  conducted
 in Oak Creek using a  frame  sampler 30x30x30 cm.   Gravel was extracted
 and placed randomly in five different containers marked 1 through 5.
The contents of  each  container were  dried,  sieved and  analyzed.   Results
were compiled for sample 1, samples  1  and 2, samples  1,  2 and 3,  etc.,
 each time increasing  the sample  weight,  with the idea  of attaining a
 limit as the weight increased.   Unfortunately, we did  not take a  sample
 too small to be  totally  inadequate.    Nevertheless, in  this experiment,
d  fluctuated mildly  and tended  to approach a limit, hopefully approxi-
 o
mating the true  value of d  , as  the  sample weight became very large.
More specifically, these values  were  14.4,  14.9,  14.7,  15.3,  and  15.1 mm.
                                     10

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     100

      90

      80
   cr  70
   UJ
   ?  60
   u_
   H  50
  a:
  u
  Q_
      20

      10

       0
o   A
A   B
D   C
dg(mm)

  25
   14
   9
                                 I                 10
                          PARTICLE DIAMETER, d  (mm)
                                                   100
Figure 3a.  Particle size distribution for spawning gravels in Indian Creek, Siuslaw National Forest,
         Oregon.

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99.99


  99.9
  99.8
   99
   98

   95

   90
o:
LU
H-
z
LU
o
IT
LU
QL
   50
    10
    5


     I
    .5

    .1
   .05
   .01
         O A

            B

            C
           I  I I
                   Particle Characteristics  (mm)
                       '16
             '50
'84
                '95
1.34 4.30  25.5   151.2  484.6  .958

 .95 2.36   9.48 38.2   95.0  .804

 .67  1.76   7.67 33.4   87.6  .950
                                                                       o
                                                                o
                                                           o
                                                     o
                                               o
                                   CL
                             O
I  I  I  I I I I I
                             I  I  I
                          I    I  I  I  I I I I I
     .03  .05
                             .51             5     10
                                  SIEVE OPENING (mm)
                                                    50   100
                                                300
        Figure 3b.  Gravel composition in Indian Creek showing three textures,

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The results suggest that a sample size of 5 to 10 kg produced the
desired accuracy.  Other important observations are (a) the patch
was indeed fairly homogenous as evidenced from analysis of individual
samples, (b) the size fraction between 50 to 76 mm was on the order of
5 to 10% of the total sample weight, and (c) an equivalent sample size
can be obtained with 6" core FRI (McNeil) sampler.

     Because of these observations and the widespread use of FRI samplers,
one can generalize the experimental results as follows:   (a) core diameter
should be two to three times the size of largest particles sampled, and
(b) the weight fraction of the largest particles  (or the  content of the
coarsest sieve when appropriate) should be on the order of 5 to 10% of
the total weight.

     The adequacy of the sample weight obtained with a freezecore method
is discussed in the next sections.  In general, it is determined by the
radial extent of the frozen core relative to the  size of  the largest
particles attached and by the ability to extract  the core without losing
excessive amount of particles.

     For application to a coarser substrate, a large core diameter must
be used.  Gravel patches are seldom homogenous.  There are pockets of
fine and coarse particles appearing randomly with depth and areal
directions.  Therefore, the above rule must be applied in combination
with the visual estimation procedure discussed earlier.

     The following experiments will demonstrate the heterogenous nature
of gravel patches in the Poverty spawning area in the South Fork Salmon
River, Idaho, and will also give an idea of adequate sample weight.  The
Poverty area has been monitored for more than a decade using various
methods.  Corley's data for 1976 show that the mean diameter is 13.3 mm
(corrected for the effects of wet sieving) and the range  for mean
diameter is 7 mm to 23„7 mm.  We compared 1978 measurements taken by
Corley in the Poverty area with the largest gravel sample ever taken in
that area or elsewhere by Platts (Figure 4).  Platts1 sample size of
620 kg, which consisted of a typical redd, gives  d  ^23.3 mm.  Corley's
                                                  o
                                   13

-------
tr
UJ
  100

   90

   80

   70

E  60
LJ_

H-  50

o  40
or
£  30

   20

    10

     0
               Platt's  Freeze Core  620 kg (1978)
             — Cor ley's 12" Core 25 kg (1978)
o  Site  2-1
A  Site  2-2
a  Site  2-5
O  Site  3-2
•  Site  1-2
                       9mm <  dg < 25 mm
.04    .1
                            I                 10
                          SIEVE  OPENING  (mm)
                                                100
Figure 4. Comparison between compositions of an entire redd and 12 inch core samples near redd,

-------
data taken near that sample give a range 9 mm < d  < 24.5 mm.
                                                 o
Corley's samples were on the order of 25 to 45 kg taken with a 12" core.
Detailed vertical analyses of Platts1 sample demonstrate that the patch
was coarse throughout and, thus, perhaps an upper limit of gravel compo-
sition in Poverty area.  Unfortunately, Corley did not use a sieve
greater than 25 mm opening and thus his data were extrapolated to obtain
d  in Figure 2.
 o

     Now, according to Platts, particles were all smaller than 203 mm,
and less than 7% were greater than 127 mm.  Corley's sampler, therefore,
satisfies the size selection rule stated above even if it captures the
stated proportion of large particles.  On the other hand, the use of a  6"
core would be only marginally adequate, if not actually inadequate.
                                     15

-------
                   METHODS OF OBTAINING GRAVEL SAMPLES

      The  primary purpose  of developing these  procedures  is  to obtain  a
 representative  sample  of  the substrate to  a depth used by spawning  salmonids.
 Theoretically,  we wish to extract  an  undisturbed  core of gravel.  The two
 most  common methods  are frozen  core samples developed separately  by Ryan
 (1970) and Walkotton (1976)  and grab  (or manual)  sampling techniques  designed
 by McNeil and Ahnell (I960),

      In the freezecore method  a metallic  tube  about  one inch in  diameter
 is driven into  the gravel.   Liquid carbon  dioxide (C02)  is  throttled
 into  the tube through  a bank  of small  nozzles.  The expansion of  the
 gas rapidly freezes  interstitial water outside  the tube,  thereby  attach-
 ing a solid core  of  substrate materials to the  tube,  which  is then
 extracted for analysis.   The  dimensions of the  core and  the total
 size of the sample can be varied by a  combination of  (a)  depth of tube
penetration into  the gravel,  (b) length of time C02 is applied and
 (c) use of more than one  tube in a given area.  Freezing efficiency is
inversely related to gravel density.   Efficiency  declines rapidly beyond
about 4 minutes of application  of CO,,.

     The manual sampling method consists of inserting a  large diameter
tube  (4 to 12 inches)  into the  gravel  bed  to  a depth  of  4 to  12 inches
and extracting by hand  or scoop the gravel  and sand inside  the pipe.
An estimate of the suspended material  that  escapes the gravel  sample
is obtained by retaining,  for subsequent analysis, a  subsample of the
water column in the pipe,  once  the contained  water is thoroughly mixed.

     A photographic method analyzing surface  (or  armor) material visible
through clear water was developed by Ritter and Helley (1969).  Photo-
graphic prints of a stream bottom segment  are analyzed with specialized
scanning equipment.  These devices incorporate computation  facilities
that enable counting,  sizing, and even particle size distribution.  Once
the system is set up and calibrated,  photographic records of  hundreds
of particles can be analyzed in a matter of minutes.   This method is  good
                                    16

-------
for extremely large quantities of work but is restricted to the analysis
of the surface layer of gravel, hence the utility of this method is
limited.

     The main advantages of the freezecore method are (a) the ability
to sample in deep water or under ice on frozen streams,  (b) the routine
application of uniform procedures, i.e., duration of CCL application
and depth of core, and (c) the ability to analyze samples from different
depths within the substrate.  Disadvantages are (a) the  equipment weight
and field transport problems, (b} the cost of CCL recharge, (c) the
difficulty of sampling in gravel coarser than 32 to 64 mm in diameter
 with a single probe, and (d) inability to sample from dry gravel patches,
and (e) disturbance during probe insertion and loss of particles during
probe removal.

     Advantages of manual sampling are (a) simplicity of equipment and
procedure, (b) flexibility in modifying sample diameter  with respect to
gravel characteristics, and  (c) possibility of combining with benthic
invertebrate sampling.,  Disadvantages are (a) bias associated with different
operators who might extract the gravel selectively, including the suspended
fines segment, (b) difficulty in sampling in deep water, and (c) diffi-
culty of inserting the core into a coarse gravel bed»

     The disadvantages of freezecore and manual sampling may be reduced
to acceptable levels.  For example, Lotspiech and Reid  (1979) used
steel tubes instead of copper to reduce problems of tube bending during
insertion and extraction of the frozen core.  They also  used aluminum
C02 tanks to minimize carrying weight while increasing refrigerant
capacity.  To minimize operator bias with manual sampling all substrate
components must be removed to a pre-determined depth,,  A scoop should
be used when possible.

     This discussion relates primarily to the mechanical advantages  and
disadvantages of various sampling methods.  Some sampling  bias can be
reduced by taking a very large sample,,  Obviously  all  attempts to
minimize bias should be made before increasing sample  size.   Increasing
                                     17

-------
 sample size should not be used to disguise problems inherent in the
 sampler itself.

      The following case studies are presented to enable comparison of results
 from freezecore  with FRI samplers:
      1)   Berry Creek near Corvallis, Oregon has a very coarse substrate.
 Five samples were taken in the following manner.  After a spot was chosen
 in  the stream, a 12" diameter sampler was placed on the spot and a single
 freezecore  sample was extracted from within the 12" core sample, then
 the remaining material was extracted.  The data were analyzed separately
 for the  freezecore sample and in combination with the remaining parts of
 the 12"  core sample.   Theoretically, the freezecore represented a subsample
 of  the 12"  core  sample.   The  experiment should demonstrate a direct
 comparison  of the two methods (Table 3).

 Table  3.  COMPARISON OF  RESULTS FROM FREEZING FRI (McNEIL)  SAMPLES.

Sample #
1
2
3
4
5
Mean
d mm
g
Freezecore
9.7
42
42
33.9
37
32.9

12" core
32.7
43.5
43.0
27.0
66
42.4

     On the average, samples taken by the two methods are within  25% of
one another; individually they may differ by a factor greater than 3.
The 12" core samples averaged 25 kg each, the freezecore samples  were
about 5 kg.

     2)  In a second experiment with a coarse substrate in the Rogue
River, 12" diameter core samples and tri-tube freeze samples  (Lotspeich
                                   18

-------
and Reid 1979) were obtained side by side.  Eleven such samples were
collected and analyzed,,  The average weights of the tri-tube samples and
12" cores were 13.3 and 25.4 kg with a standard deviation of 6.9 and
3.2 kg, respectively (Table 4).
Table 4.  COMPARISON OF TRI-TUBE FREEZECORE AND 12" MANUAL CORE SAMPLES
          TAKEN FROM ROGUE RIVER, OREGON,

Sample ID
Bridge Hole
Hatchery Site
Sand Hole
Big Butte
Mean

B
C
A
B
C
A
B
C
A
C

d mm
g
Tri-core
30,4
24.0
42.1
18.0
69.6
34.2
22.6
46.0
15.6
19_.3_
32.1

12" core
30.9
17.3
21.8
18.6
48.4
58.7
58.8
65.3
22.9
19. 5
35.0

     On the average  samples differed  only about  10%.   The tri-tube presents
a significant  improvement over  single tube freezecore, even though the
Rogue River presented  a  severe  test of the system.  Note that  the
difference in  the  results of  the  methods  is not  always in the  same
direction.  Calculations presented by Lotspeich  and Reid (1979)  differ
slightly  from  those  given here  due to different  estimation procedures.
The  same  10% difference  appears using their method  as well.

     3)   Platts  (1979) obtained 15  single freezecore  samples in South
Fork Salmon River, Poverty  area during 1977.  There were considerable
variations in  the  sample weights  as well  as the  geometric means.  The
average sample weight  was 5.1 kg  with a standard deviation of 3.7 kg.
The  average of the 15  geometric mean  diameters was 34.6 mm with a 20.6 mm
                                     19

-------
deviation  from this mean.  We attribute this  difficulty to  the  incon-
sistency of  sampling with  a  freezecore in  a relatively  coarse substrate.
Because of this scatter, the size fractions from  all  samples were  combined
to obtain  an average geometric mean equal  to  20.4 mm.   This is  within  the
range of results  (7 < d  < 23 „ 7 mm and average  =  13.3 mm) obtained  by
                       o
Corley using 12"  core samples in 1976.  Platts1 freezecore  samples  were
obtained in  egg pockets and  this may explain  the difference between the
two means.   The aggregates of Platts1 single  freezecore samples in  egg
pockets during  1977 agree well with the entire  redd sample  taken in 1978.

     4)  There  have been many attempts to  directly compare  freezecore
samples with 6" core samples.  Among these are  the unpublished  work of
Cederholm and yet to be published work of  Koski.  Both  works were restricted
to relatively fine artificial gravel mixes.   Both indicate  single freeze-
cores produced  satisfactory  results under  these conditions.

     Ringler (1970) in his Master's thesis compared freezecore  samples
with 6" core samples both obtained from redds in Drift  Creek.   He found
that the freezecore nearly always underestimated the fines  smaller  than
083 mm and 3,3 mm.

     We will conclude, based on the analysis  of the foregoing case  studies,
that: (a)  by combining the analysis of many freezecore  samples  taken from
a spawning site, a reasonable estimate of  the mean composition  of that
site is obtainable, (b) single freezecore  samples, particularly if  taken
in a coarse substrate with a single tube may  not be a good representation
of a. gravel patch, and (c) it is expected  that a good representation
of the patch over the range of grain size up  to 100 mm  substrate is
obtained by a tri-core method.
                                   20

-------
                    ANALYSIS OF GRAVEL—WET SIEVING

     Access to spawning areas with motorized vehicles is not always
possible and transporting large gravel samples from the stream bank
to the vehicle often presents a problem.  Therefore, serious consideration
should be given to on-site analysis by wet sieving the gravel„

     Equipment required for wet sieving includes a set of sieves, a
bucket with an overflow nozzle and a graduated cylinder.  In general,
it is desirable that the sieve sizes should represent a geometric
progression (e.g. 128, 64, 32, 16, 8, 0... 0.064 nun).  However, the
specific sizes chosen will depend upon the actual stream being sampled
and the need to maintain consistency of sizes with past sampling or
other comparative work.   If, for the selected sieve series, a large
proportion of the material collects on one sieve, an additional,
coarser sieve may be added to facilitate the sieving process.

     The content of the 4-mm and coarser sieves can be wet  sieved  and
analyzed volumetrically in the field using the bucket and graduated
cylinder.  Particles retained on all sieves on will also contain some
interstitial and surface water,,  The amount will vary with  particle  size
and become quite significant at sizes below 4 mm.  To avoid introducing
excessive errors in the volumetric determination, the sieved  samples should
be allowed to drain before the volumetric measurements are  made  (draining
with sieves inclined and the material periodically turned over will
expedite this process).  The contents of the fine sieves, i.e. size  ranges
less than 4 mm, may be either processed in the field or taken to the
laboratory for dry weight analysis.  This also applies to particles  passing
the smallest sieve used.  The error  introduced by wet sieving, because  of
the water present, can be corrected  by using data in Table  50

     If dry sieving is used for particles smaller than 4 mm,  the  two sets
of data must be combined.  Combining the volumetric  and  gravimetric
analysis requires knowledge of average  gravel density.   For this  purpose,
the dry contents of the  2 mm  sieve should be used  for  rock  density
                                    21

-------
Table 5.  WATER GAINED  IN A WET SIEVING PROCESS AND CORRECTION FACTOR
          FOR VOLUMETRIC DATA.*

Sieve
inches
3

2

1

1/2

1/4

1/8

1/16

1/32

1/64

1/128

1/512

size
nun
76,2
64
50,8
32
25,4
16
12.7
8
6.35
4
3.18
2.0
1.59
1.0
,79
.5
.40
.25
,20
.125
,10
.063
Gram
Gram
P=2.2
.02
.02
.02
.02
.03
.03
.04
.05
.05
.07
.08
.10
oil
.13
.15
.19
.21
.27
.30
038
o43
.54
water
dry
P=2.
.01
.02
.02
.02
.02
.03
.03
.04
.05
,06
.07
.09
.10
.12
.14
.18
.20
025
.28
.35
.39
.49
gained
gravel
6 p=2.9
.01
.01
.02
.02
.02
.03
.03
.04
.05
,06
.07
.08
,09
.12
.13
.17
.19
.23
.26
.33
.37
.47
Correction
to wet
P=2.2
.97
.96
.96
.95
.94
.93
.92
.91
.89
.87
.86
.83
.81
.77
.75
.70
.68
.63
.60
.54
.52
.46
factor
sieved
P=2.6
.96
.96
.96
.95
.94
.93
.92
.90
.88
.86
.85
.81
.80
.76
.73
.69
.66
.61
.58
.52
.50
.44
applied
gravel
P=2.9
.96
.96
.95
,94
.94
o92
.91
.89
.88
.85
.84
.81
.79
.75
.72
.67
.65
.59
.57
.51
.48
.42

*  The values in this table have been obtained from detailed analysis of
   substrate ranging from 0.63 mm to large gravel based on unpublished
   work of Thompkins, Shirazi, and Klingeman.  Example:  The volumetric
   displacement of a 2-mm sieve is 300 cm3.  From prior analysis, the
   estimate of the gravel density is known to be 2.69 g/cm3.  The dry
   weight of the gravel according to the table is 300 x .81 = 243 g.
                                    22

-------
determination by simply dividing the dry weight of the material in grams
by its displaced volume of water in cubic centimeters.  This requires
bringing a sample of such material to the laboratory for analysis.
Unpublished data from Klingeman show that the choice of 2 mm for density
determination is reasonable, although there is a slight change of density
with particle sizes used.  The error is on the order of one percent of  the
mean for a range of 14 sieve sizes.  Correspondence of the density of 2 mm
and larger particles should be confirmed where likelihood of difference
is apparent.
                                    23

-------
                   CALCULATION  OF SUBSTRATE  STATISTICS

      Examples  of three  procedures for  calculting the geometric  mean
diameter and the geometric variance  of two  samples  of gravel  are  given
in  this section  for  the purpose  of demonstrating the relative effort
needed and  the relative accuracy obtainable with each procedure.   The
gravel samples A,  B, and  C were  obtained  from  Indian Creek.   They are
plotted on  semi-logarithmic  scales in  Figure 3a.

LEAST SQUARES  GRAPHICAL METHOD

     The graph of  sample  A is shown  replotted  in Figure  3b on a log-
probability paper.  The straight  line  passing  through the data  is the
                                                       2
least squares  fit  with  a  coefficient of determination r  equal  to
0.958 which can  be interpreted as  the  test  of  lognormality.   The
         2
average r  for 100 samples was 93 which is  very  good indication
that spawning  gravel is lognormally  distributed.  The data for  sample
B are not shown  on the  plot  to avoid crowding.   The  coefficient of
determination  for  the least  squares  linear  fit to that set of data is
0.804.

     The details of this procedure are listed  in Table 6.  Columns one
and two are the  original data listed in terms  of weight percentiles.
Column three (designated X)  is the log transform of  column one.   Column
four (designated Y) is  the inverse probability transform of column two.
The latter can be obtained from tabulated standardized normal distribution
function available in textbooks of statistics.  They also can be  calculated
with  small programmable calculators.  Next, Y is regressed over  X.  The
linear equation now can be used to obtain all  statistics as listed.  Note
that the percent fines, for  example, less than 3.3 mm can be  calculated
from the equation, thereby relating that point statistically  to the entire
distribution.   The procedure reduces the variability, otherwise unavoidable,
if the data were used directly.  This method yields  the following:
     d=25.5mm                  a   =5.93
      gA                             gA
     d   = 9.48 mm                  a   = 4.02
      %                             gB
                                   24

-------
Table 6.  ILLUSTRATIVE EXAMPLE OF LEAST SQUARE/GRAPHICAL PROCEDURE  FOR
          SAMPLE A IN INDIAN CREEK, OREGON.

Sieve opening
d mm
(D
127
102
64
32
16
8
4
2
1
.5
.25
.125
.063

Percent finer
F(d)
(2)
100
82.6
80.6
44.0
26.6
16.8
10.3
7.53
5.60
3.01
.67
.17
0
X = 1.407 + .777 Y
logio d
X
(3)

2.009
1.806
1.505
1.204
.909
.602
.301
0
-.301
-.602
-.902

r2 = .958
Y
(4)

.938
.863
-.151
-.625
-.962
-1.265
-1.458
-1.590
-1.880
-2.473
-2.929


                          d5  =  1.34  mm
                          d,,. = 4.30 mm
                           16
                          d-- = 25.50 mm
                          dg4 = 151.21 mm
                          d  = 484.33 mm
                          d  =  d..,. = 25.5 m
                           g     50
                          v   —  j    — »j. y+j
                          8   d50

                    %  Fines  
-------
 QUANTILE GRAPHICAL METHOD
      A common,  simple  graphical  procedure  consists  of estimating directly
 from  the  data  the  diameters  at the  84th  percentile  (i.e.  d0.)  and at
                                                           84
 the 16th  percentile  (i.e. d.. ,) of the distribution.   The  geometric mean
 and the geometric  variance is then:
                      v
                      ag = / d84/d!6
     For the two samples given above, we  have
        d   = 104 x 7.4 = 27.7          a   =  104/7.4 = 3.8
         SA                               SA
        d   = 50 x 3.8 = 13.8           a   =  50/3.8 = 3.6
                                         8B
METHODS OF MOMENTS
     The details of this method are described  in Table  7.   It consists
of taking the n   root of the product of n numbers as required by
definition of the geometric mean.  The procedure for calculating the
geometric variance is also given.  For the two samples
     d   = 25.5 mm                 a      4.0
      *A                            §A
     d   = 14.7 mm                 a    = 4.1
      gB                            SB
CHOICE OF METHODS
     Considering both the adequacy of the theoretical basis as well as
the simplicity in procedure, the quantile graphical method should be
favored over the others.  The least squares method is more precise in
calculating the geometric variance than the second method, however, it
is difficult to assess the theoretical adequacy of the third method
from this aspect„  At times it might be necessary to obtain a systematic
estimation of the geometric variance so that the entire distribution,
including back-calculation of percent fine becomes possible.  In that
case the first procedure is recommended.  For monitoring and assessment
objectives the quantile graphical method of calculation is quite adequate
(if d  is needed) and is the suggested procedure.
     6
                                   26

-------
    Table 7.  CALCULATION OF GEOMETRIC MEANS AND GEOMETRIC VARIANCE  BY THE  METHOD  OF  MOMENTS.
N3

••J

Sieve
Range
(D
d
mm
127
102-127
64-102
32-64
16-32
8.0-16
4.0-8.0
2.0-4.0
1.0-2.0
.5-1.0
.25-. 5
.125-. 25
.063-. 125





Size
Midpoint
(2)
dm
mm

114.5
83.0
48.0
24.0
12.0
6.0
3.0
1.50
.750
.375
.188
.094


d


Sample A
(3)
f


.1737
.0201
.3660
.1744
.0983
.0650
.0272
.0194
.0258
.0235
.0050
.0017
1.000

= ec =
5
=
(4)
P
% finer
100.0
82.63
80.63
44.02
26.59
16.76
10.26
7.53
5.60
3.01
0.67
0.17
-

3.239
e

25.508 mm
(5)
f(ln dm)


.823
.089
1.417
.554
.244
.116
.030
.008
-.007
-.023
-.008
-.004
£5=3.239,




(6) ?
f(ln dmr


3.904
.392
5.485
1.761
.607
.209
.033
.003
.002
.023
.014
.010
£5^12.442

d = er
gB £

(7)
f



.0540
.3010
.2260
.1490
.1070
.0480
.0360
.0349
.0335
.0083
.0023
1.000
2.689
= e

= 14.720
Sample
(8)
P
% finer

100.0
94.60
64.50
41.90
27.0
16.30
11.50
7.90
4.41
1.06
.23
-




mm
B
(9)
f(ln dm)



.239
1.165
.718
.370
.192
.053
.015
-.010
-.033
-.014
-.005
£9=2.689,





(10)
f(ln dm)2



1.054
4.511
2.283
.920
.344
.058
.006
.003
.032
.023
.013
£lO=9. 246




                           =  exp
= exp
                              1.951   .  „.-
                           =  e      = 4.042
   2.016    . --,
= e      = 4.136

-------
               ESTIMATING LOCALIZED AND STREAMWIDE  IMPACTS

     The ultimate goals of substrate monitoring  are  to  relate watershed
processes and land use to substrate conditions and  to assess the possible
impact of accelerated erosion on spawning habitat,  both locally in  one
or more riffles as well as more extensively  for  an  entire stream system.
The parameters used as measures of this impact can  be classified in the
categories:  (a) changes in the area of spawning gravel, i.e. the change
in the available habitat, and (b) changes in the composition of the
gravel, i.e. the quality of the habitat.  For the latter measure the
geometric mean diameter d  is assumed to be  a sufficient indicator.
                         &

     The extent of actual and potential spawning areas  for the species
of interest can be obtained through visual inspection and areal measure-
ment in the stream reach.  The quality of these  spawning areas can  then
be determined by using the sampling procedures previously outlined
in this document.

     To demonstrate how this information can be used to assess stream-
wide impacts examine Table 8 which  contains hypothetical data for
spawning gravel quality and quantity in areas on Dream  Creek prior  to a
landslide in 1966.  Throughout the 4 miles of this  creek the spawning
                      2
gravel, totaling 510 m , had a mean d  of 12.5 mm, equivalent to
                                     o
predicted average egg survival of 62%.  Table 8 also shows the same
type of information obtained by monitoring after the landslide.  Note
that, though the quality of the gravel was reduced  (d   =8.3 mm), the
                                                     §2         2
total available spawning area was increased from 510 m  to 540 m  and
the overall predicted average survival was reduced to 33%.  If the  number
of spawning fish and number of eggs deposited in Dream  Creek remained
approximately the same after the landslide, the 34% reduction in d
                                                                  o
corresponds to a 47% reduction in the number of emerging fry produced by
the system.
                                  28

-------
Table 8.  SPAWNING GRAVEL AREA AND QUALITY BEFORE AND AFTER LANDSLIDE
          OF 1966 IN DREAM CREEK.*

Mile Post
1
2
3
4
Total or
mean
Area
Before
100
300
50
60
510
2
m
After
60
300
100
80
540
d
g
Before
13
10
12
15
12.5
mm
After
6
8
9
10
8.3
% Survival
Before
66
45
58
79
62
After
19
31
38
45
33

   hypothetical data.

EVALUATION OF STREAM SYSTEMS

     The geology and morphology of watersheds strongly influence sub-
strate composition in the stream systems draining them.  For this
reason one would not expect all spawning gravels in streams unaffected
by cultural activities to be of the highest quality.  A hypothetical
example is provided by Figure 5, which demonstrates the areal extent of
gravels of different quality as determined by measurements of d .  All
                                                               &
of these stream systems are relatively undisturbed by man, yet the
total stream area suitable for salmonid spawning (that expected to yield
less than 50% egg survival) varies from approximately 8% in Cascadia
Creek to approximately 77% in Flynn Creek.

     Three important qualifications must be introduced in this inter-
pretation to complete the picture.  One is that the total area of
spawning gravel of a particular quality in one system could be many
times greater than the second system, even if percentages are alike.
Thus, an additional column supplementing this information must be
provided in the real situation to enable comparison of one  system  with
another.  The second qualification is that the adequacy of  the habitat
differs with the species using the habitat.  An important aspect  of
species differences relating to survival is size.   For this  reason,
                                    29

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  100
UJ
or
   80
o 60
u.
o
I-
Ld
0
cr
LU
CL
40
     Q
          Estimated Embryo Survival
         0-25%
                                                  A—& Flynn Creek

                                                  D—a South Fork Salmon River

                                                  o—o Cascadia Creek
      0
                8
12
16
20    24
28
32     36    40    44    48
                           MEAN GEOMETRIC  DIAMETER  (dg)
    Figure 5.  Hypothetical assessment of quality and quantity of spawning habitat in three stream-watershed

             sys terns.

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interpretation of quality is best made with respect to a transformed
scalar d /d , i.e. in terms of multiples of egg diameter d , such
as in Figure 2.  The third, and perhaps the most important qualification
is that any implied adequacy of quality of habitat must relate to a
baseline condition in the absence of accelerated erosion.  It is not
unusual to find a natural substrate of small mean diameter producing
low survival.  In this case, the baseline that can be used for comparison
is, as expected, rather low as well.  In some stream systems the salmonids,
successfully adapting to the existing local environment, may maintain
relatively high population levels in the presence of rather low embryo
survival rates which are the result of the long term existence of marginal
baseline substrate conditions.  Additional mortalities caused by
reducing baseline conditions is expected to be deleterious to the
population, however.
                                    31

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                      CONCLUSIONS AND  RECOMMENDATION

     The  study of salmonid spawning habitats  or  habitats  potentially
usable for spawning may provide a meaningful  indicator  of watershed
characteristics because stream substrate conditions  integrate many
aspects of climate, vegetation, soil  type,  land  form and  human  activities.
This paper provides a unifying methodology  for sampling stream  substrates
and applying that methodology to the  monitoring  of substrate quality
and quantity.  The mean geometric particle  diameter  (d  )  provides a
                                                      o
convenient and theoretically sound parameter  that expresses the entire
range of  the particle distribution and effectively relates particle
size to salmonid embryo survival.  Thus d   is preferred to percent
                                         o
fines because it is biologically meaningful,  sensitive  to changes in
distribution and, most important, provides  a  theoretical  basis  for
substrate analysis by considering the entire  spectrum of  size composition.
In this respect particle size distribution  is taken  as  tending  toward
log-normality.  Either manual core or freezecore samplers may be adequate
when used properly.  Sampling recommendations include the following:
     (1)   The range of coarseness of  spawning or potentially adequate
spawning  substrates can be identified visually as a  basis for selecting
sample locations.
     (2)   Either manual core or freeze core samples  provide adequate
samples when used properly.
     (3)   The diameter of FRI (McNeil) type samplers  should be  two to
three times the diameter of the largest particle sampled.  The  12-inch
(30 cm) is suitable for a broad range of typical substrate coarseness.
     (4)   Single freeze cores or manual cores less than 15 cm in diameter
may give  inadequate sample size in coarse substrates.
     (5)   For relatively fine substrates, 5-10 kg sample  size is adequate
but this value should be increased when increasing coarseness is encountered,
     (6)   Sample depth should be 25 cm.
     (7)   The number of samples taken depends on variability and extent
of area sampled.  For many smaller spawning streams  a single riffle area
may often be well represented by one sample from each of  three  categories
of coarseness.
                                   32

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     (8)  Sieve series should follow the series in mm from 64, 32,  16,
8, etc. down to .063.  Where finer particles comprise an important  fraction
they should be retained and determined by any of the several standard-
ized methods.
     (9)  Water retention on sieved portions should be reduced by
draining prior to volumetric analysis.
     (10) On-site wet sieving is recommended for size groups greater
than 4 mm followed by volume determination using the water displacement  technique.
     (11) Particle size should be expressed as d  and determined by
            -
d  = y d  d1 ,  or other suitable methods as described  in  the  text.
on the investigator's objectives.
      (12)  By combining visual estimation and  actual sampling the  quality
     and areal extent of the various categories  of  coarseness may  be  estimated
for a single riffle, a stream section, or an entire stream  system,  depending
(13) For example, assessment of habitat quality  and quantity  of
spawning gravels could be made on the basis of the  d  categories of
                                                     o
greater than 15.25, 15.25 to 10.75, 10.75 to 7.0 and 7.0  mm,  respectively,
rated in terms of embryo survival estimates of 80 or greater, 80-50,
50-25 and 25 percent or less.  Comparison between existing  and the expected
normal background sediment characteristics will  provide the basis  to
assess extent and quality of spawning habitats.

      In conclusion, it remains to be stated and  emphasized  that spawning
habitat analysis and assessment is  studied here  as  an  avenue  to better
understanding of the more general driving elements  that cause and  maintain
the spawning habitat.  These elements have their roots in the watershed
itselfo  Fish habitat and therefore fish populations and  the  assemblage
of other organisms dependent on the gravel environment respond to  these
driving forces, but may be adversely influenced  by  man's  activities on
them.  Programs to monitor stream gravel conditions can therefore  be
a significant aspect in linking the watershed  and the  stream environments.
                                    33

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                               REFERENCES

Cederholm, C.J. and L.C. Lestelle.  1974.  Observations on the effects
     of landslide siltation on salmon and trout resources of the Clear
     Water River, Jefferson County, Washington, 1972-1973, Final Report,
     Part I, FRI-UW-7404, April 1974.  Fisheries Research Inst., Univ.
     Washington, Seattle.  133 pp.
Cederholm, C.J., W.J. Scarlett, and E.G. Salo.  1977.  Salmon spawning
     gravel composition data summary from the Clearwater River and
     tributaries, Jefferson County, Washington, 1972-1976.  Fisheries
     Research Inst. Circ. 77-1, Univ. Washington, Seattle.  135 pp.
Cooper, A.C.  1969.  The effect of transported stream sediments on
     the survival of sockeye and pink salmon eggs and alevin.  Internat.
     Pace Salmon Fish. Comm. Bull. XVIII, New Westminster, B.C., Canada.
     71 pp.
Corley, D0R., and L.A. Burmeister.  1978.  Fishery habitat survey of
     the South Fork Salmon River, 1977.  Boise § Payette National Forests,
     U.S. For. Serv., 1075 Park Blvd., Boise, ID 83706.  90 pp.
Iwamoto, R.No, E«0. Salo, M.A. Madej, and R.L. McComas.  1978.  Sediment
     and water quality:  A review of the literature including a suggested
     approach for water quality criteria, EPA 910/9-78-048, USEPA
     Region X, 1200 Sixth Ave., Seattle, Wash., Feb. 1978.  150 pp.
Koski, K.V.  1966.  The survival of coho salmon from egg deposition to
     emergence in three Oregon coastal streams.  M.S. Thesis, Oregon
     State Univ., Corvallis.  84 pp.
Lotspeich, F.  1978.  Biological significance of fluvial processes in
     the lotic environment.  USEPA, Corvallis Environmental Research
     Laboratory Working Paper CERL-042.  Corvallis, Oregon.
Lotspeich, F., and B. Reid.   1979.  A  tri-tube freezecore procedure for
     sampling stream  gravels.  Submitted to  Prog. Fish-Cult.   12 pp.
McNeil, W.J., and W.R. Ahnell.   1960.  Measurement  of  gravel  composition
     of  salmon  stream beds, College of Fisheries Circ.  #120,   Univ.
     Washington,  Seattle.
Phillips,  R.Wo,  R.L.  Lantz, E.W.  Claire,  and J.R.  Moring.  1975.   Some
      effects of gravel  mixtures on emergence of coho salmon and steelhead
      trout fry.   Trans.  Am.  Fish. Soc. 104(3):461-466.
                                     35

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Platts, W.S.   1974.   Geomorphic and  aquatic  conditions influencing
     salmonids and stream classification—with application to ecosystem
     classification.   USDA,  For0 Serv.,  Surface Environ, and Mining
     Proj. R.  Billings, Montana.  200 pp.
Platts, W.S0, M.A. Shirazi,  and D.H. Lewis.   1979.  Sediment particle
     sizes used by salmon for spawning, and methods for evaluation.
     EPA-600/3-79-043.  April 1979.   USEPA,  Corvallis Environmental
     Research Laboratory, Corvallis, Oregon.  32 pp.
Ringler, N.H.  1970.  Effects of logging in the spawning bed environment
     in two Oregon coastal streams.  M.S, Thesis, Oregon State Univ.,
     CorvalliSo  96 pp.
Ritter, J.R,, and E.J. Helley,   1969.   Optical method for  determining
     particle size of coarse sediment.  Techniques  of Water Resources
     Investigation, U.S0  Geol.  Surv,  Book 5,
Ryan,  P.   1970.   Design and  operation of an in situ frozen core gravel
     sampler.  Dept.  Fisheries and  Forestry,  Pacific Station,  Canada.
Shirazi,  M»A.   1979.  A unified analysis of embryonic survival of
      salmonids.   Unpublished,
Shirazi,  M.A.,  D.H.  Lewis,  and W.K. Seim.   1979.   Monitoring spawning
      gravel in managed forested watersheds, a proposed procedure.
      EPA-600/3-79-014.   Feb. 1979.   USEPA, Corvallis Environmental
      Research Laboratory, Corvallis, Oregon.  13 pp.
 Tagart, J.V.  1976.  The survival from egg deposition  to  emergence of
      coho salmon in  the Clear Water River, Jefferson County, Washington.
      M.S. Thesis, Univ, Washington, Seattle,  101  pp.
 Thompkins,  C., M.A,  Shirazi,  and P,  Klingeman.   1979.  Correction to
       a wet-sieving  analysis of gravel. Unpublished.
 Walkotten,  W.J.   1976,   An  improved  technique for  freeze  sampling
       streambed  sediments.   USDA For.  Serv.  kes.  Note PNW-281,  Pacific
       Northwest  For.  and Range Exp. Stn., Portland.  11 pp.
                                       36

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                                     TECHNICAL REPORT DATA
                              (Please read Instructions on the reverse before completing)
    REPORT NO.
   _EPA-600/3-79-109
               3. RECIPIENT'S ACCESSION NO.
  '4. TITLE AND SUBTITLE
    A STREAM SYSTEMS EVALUATION--AN EMPHASIS ON SPAWNING
    HABITAT FOR  SALMONIDS
               5. REPORT DATE
               October  1979  issuing date
              16. PERFORMING ORGANIZATION CODE
  7. AUTHOR(S)
    Mostafa A. Shirazi and Wayne K. Seim
              8. PERFORMING ORGANIZATION REPORT NO.
  9. PERFORMING ORGANIZATION NAME AND ADDRESS
   Env.Res.Lab.-Corvallis and Dept. Fisheries  S Wildlife
   Off.of Res. S Develop.     Oregon State  University
   Envirn.  Prot. Agency       Corvallis, OR 97331
   Corvallis, OR 97330
                                                              10. PROGRAM ELEMENT NO.
               11. CONTRACT/GRANT NO.
  12. SPONSORING AGENCY NAME AND ADDRESS
      Environmental Research Laboratory--Corvallis
      Office of Research and Development
      Environmental Protection Agency
  -   Corvallis. OR   97330                     	
               13. TYPE OF REPORT AND PERIOD COVERED
                 inhouse
              14. SPONSORING AGENCY CODE
                 EPA/600/02
 15. SUPPLEMENTARY NOTES
     Contact:   Mostafa A.  Shirazi, Corvallis,
 OR  97330 503-757-4751  (FTS  420-4751)
 "^"ABSTRACT	'	
     As  a  result of silvicultural activities in the  Pacific Northwest, various
     levels  of sediments and  debris enter the streams,  often degrading spawning
     substrate of salmonid  fishes.   Simple but reliable procedures are needed
     to  monitor spawning gravels  to assess the level  of these impacts.  This
     paper presents a preliminary rationale for conducting a monitoring program
     with  the  objective of  assessing the level of sedimentation impact both
     locally in a given stream  spawning site as well  as more generally for the
     entire  stream that might be  impacted by watershed  management activities.
|17.
                                 KEY WORDS AND DOCUMENT ANALYSIS
                   DESCRIPTORS
                                               b.lDENTIFIERS/OPEN ENDED TERMS
                           c.  COSATI Field/Group
     substrate
     sediments
     salmon
     spawning habitat
     gravelbed stream
     monitoring
  spawning habitat
  assessment
08/F
08/H
06/F
  . DISTRIBUTION STATEMENT

  Release to public
19. SECURITY CLASS (This Report)
 unclassified	
                           21. NO. OF PAGES
44
                                               20. Seci 'RITY CLASS (This page)
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                                                                          22. PRICE
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                                               37

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