The Fishes of the Eel River Drainagej A Review and Annotated

The Fishes of the Eel River Drainage j
A Review and Annotated Bibliography
by
Larry R. Brown
University of California
Department of Wildlife and Fisheries Biology
Davis, California 95616
2
FOREWARD
This document is meant as a review of the existing published and
unpublished literature on the fishes of the Eel River and some of the physical
characteristics of the drainage which affect them.
In the process of
preparing this document, I have become aware that much of the work on this
system is in unpublished form and is often difficult to find.
Sinc e I wish
this document to be as complete and current as possible, I plan to continually
update this paper through the duration of our project (1986- 1990).
3
INTRODUCTION
The purpose o f this paper is to review what is known about the fishe s of
the Eel River drainage.
First, I present a short gene ral introduc tion to the
fishes followed by more detailed sections on each species.
Second, I discuss
some of the physical characteristics of the drainage and how they relate to
the fishes.
Finally, I present an overview of the history of fisheries
problems and management in the basin.
Although I will not discuss it here,
interesting work has also been done and continues on the aquatic insects of
the area (Teague 1982, Power 1986).
GENERAL
The Eel River is the third largest drainage in California, with a mean
annual discharge of 5.4 million acre feet.
It drains much of Mendocino County
and parts of Humboldt and Lake Counties and has a drainage area of
approximately 3,700 square miles (Lee and Baker 1975).
The Eel River supports
a rich anadromous fish fauna which includes steelhead (Salmo gairdneri),
chinook salmon (Oncorhynchus tshawy1;scha), coho salmon (0. kisutch), coastal
cutthroat trout (Salmo clarki clarki), American shad (Alosa sapidissima), and
Pacific lamprey (Lampetra tridentatus).
One race of steelhead (sUlllller
steelhead) is considered to be threatened.
The largest population of this
race is located in the Middle Fork of the Eel River, within the Mendocino
National Forest and is being protected under a management plan (Jones and
Ekman 1980).
The river system also has a limited fauna of native resident species
including Sacramento sucker (Catostomus occidentalis), prickly sculpin (Cottus
asper) , coastrange sculpin
(Gasterosteus aculeatus) .
(~aleuticus),
and threespine stickleback
California roach (Lavinia symmetricus) and
4
Sacramento squawfish (ptychocheilus grandis) have been introduced to the
system in the recent past.
California roach were introduced sometime in the
early 1970s (Lee and Baker 1975, Burns et al. 1972) and have become one of the
most abundant fishes in the warmer sections of the drainage (VTN 1982, Jones
1980, Jones and Ekman 1980, Brown 1980, Brown 1976c).
Squawfish were
illegally introduced into Pillsbury Reservoir, located on the upper reaches of
the mainstem Eel River, in 1979 or 1980 and are now spreading rapidly
throughout the system (Brown et al. 1987).
Small populations of other
introduced species such as green sunfish (Lepomis cyanellus) and brown
bullhead (Ictalurus nebulosus) are also present in the system.
FISHES OF THE EEL RIVER
Chinook Salmon (Oncorhynchus tshawytscha)
The most recent estimate of the size of the Eel River chinook salmon
population places the annual run at 103,000 fish (U.S. Heritage Conservation
and Recreation Service 1980).
The Eel River ranks third in the state in
chinook salmon production.
the basis of California Department of Fish and
On
Game (CDFG) file information, Mills (1983b) estimated that chinook salmon were
able to ascend 374.4 miles of 102 tributary streams in the Eel River drainage.
The earlier estimates of Anderson (1972) placed the run of chinook salmon at
69,000 fish with 802 miles of available spawning habitat.
The large
discrepancy in available habitat presumably occurs because Anderson (1972)
includes both tributary streams and the mainstem Eel River.
The more recent
population estimate is considered more accurate (Forrest Reynolds, CDFG,
personal communication).
The vast majority of fish produced
1n
the Eel River are fall run fish.
A
few spring run chinook salmon have been observed in Middle Fork Eel River but
5
the numbers are so small they are described as on the brink of extinction
(Jones and Ekman 1980).
The following information applies to fall run chinook
salmon.
Adult chinook salmon appear to enter the lower river as early as August
and peak runs occur in October and early November.
Fish hold in pools below
Fernbridge and begin to move upstream with the arrival of the first large
storm and the associated peak in flow.
Salmon reach the upper tributaries in
October or November wi th peak runs near Dos Rios in November or December and
continuing into January (Burns et al. 1972, Anderson 1972).
Adult chinook salmon utilize the mainstem Eel River, the Van Duzen River,
the North, South and Middle Forks, and large and small tributaries for
spawning (Leos and Mills 1983a, vrN 1982, Burns et al. 1972).
Spawning
chinook have been noted in North Fork Eel River from the mouth to four miles
upstream (Horton et al. 1968).
The Middle Fork Eel is utilized from the mouth
to Asa Bean Crossing, with spawning also occurring in several tributaries
including Black Butte Creek (Smith and Elwell 1959).
that
many
It has also been found
smaller tributaries which are dry or intermittent later in the
season are utilized by salmon in years when flows are high enough to provide
access (Leos and Mills 1983a, Brown 1980, Brown 1976a, Burns et al. 1972,
Shapovalov 1937).
In some years, low flows can restrict access to some of the
smaller tributaries (Brown 1977).
Salmon appear to move as far upstream as
possible under the prevailing flow conditions (vrN 1982).
As a consequence,
artificially produced low flows below Cape Horn Dam have restricted access to
the areas above Tomki Creek (Lee and Baker 1975).
Anderson (1972) estimated
that there were about 15.3 miles of available habitat above Van Arsdale
Reservoir, but more recent studies state that there is a limited amount of
6
sui table spawning habitat in this section (VTN 1982).
Eel River chinook salmon apparently are able to pass over shallower
riffles than salmon from other areas, often using minimum depths of 18 cm (.6
ft) rather than the 24 cm (.8 ft) depth suggested by Thompson (1972, cited in
VTN 1982).
flows.
Migration
was
stimulated more by peak flows rather than steady
Even at low flows (62-95 cfs) considerable upstream passage occurred
at night if sufficient passage depths were available (VTN 1982).
VTN (1982), after consulting persons familiar with areas similar to the
Eel River system, modified the IFG (U.S. Fish and Wildlife Instream Flow
Group) chinook salmon spawning depth curve for use in the Eel River.
original curve has an optimum suitability at about 18 cm (0.6
ft)
The
to 34 cm
(1.1 ft) and then declines sharply to a low suitability from 46 to 152 cm (1.5
to 5.0 ft).
The curve used by VTN increases rapidly from zero suitability at
18 cm (0.5 ft) to optimum levels between about 27 em (0.9 ft) and 52 em (1.7
ft), declines rapidly to a low suitability at about 107 cm (3.5 ft), and then
declines gradually to zero suitability at 183 em (6.0 ft).
On
the basis of
this curve, VTN suggested an optimum flow release of 175 to 200 cfs for
chinook salmon spawning below Cape Horn Dam.
Instream flow studies conducted
by VTN (1982) on the mains tern Eel River above Cape Horn Dam indicate a peak in
available habitat at 170 cfs, but little suitable substrate
was
available.
Calculations have been made of available spawning gravels at different flows
for the mains tern Eel River and South Fork Eel River and several of its
tributaries (Puckett and Hinton 1974).
Young salmon appear to move downstream soon after emergence (Leos and
Mills 1983b).
Downstream migration at Dos Rios begins in late February or
March, reaches a peak in April or May, and is usually completed by late July
7
\7N 1982, Burns et al. 1972).
The si ze of migrating salmon ranged from 25 to
02 mm (FL) with the modal fork l e ngth in April being 38 mm.
The modal f ork
length inc reased to about 76 mm by the end of July (Burns e t al. 1972).
Leos
and Mi lls (1983b) captured fry ranging in size from 33 to 69 mm FL during a 16
~h
to 6 April 1983 trapping period.
River was in late May.
3h~1l
~
1959).
Peak migration on Middle Fork Eel
Migration ended in the middle of June (Smith and
Puckett (1976) reported capturing downstream migrants from late
t o early November .
Studies by VTN (1982) and Beak Consultants (1986)
showed peak outmigration in the area around Tomki Creek to occur in April or
May with outmigrants present from March to early June.
Emigration appears to be primarily related to temperature although in
natural situations changes in temperature are related to changes in flow and
other physical factors as well.
VTN (1982) showed that outmigration began at
temperatures of 17- 20 C, slowed at 20 C, and halted at 24 C.
Outmigration of
chinook salmon from the area between Scott and Cape Horn Dams also follows
this pattern, but due to differences in flow regime these temperatures occur
later in the season.
By manipulating the temperature of water releases from
Cape Horn Dam it was demonstrated that temperature rather than flow or other
physical parameters is the primary factor influencing emigration.
Coho Salmon (Oncorhynchus kisutch)
The annual run of coho (silver) salmon consists of approximately 42,000
fi sh (U.S. Heritage Conservation and Recreation Service 1980), the second
larg e st production in the state.
Using CDFG file information, Mills (1983b)
estimated that coho salmon could ascend 246.3 miles of stream in 69 tributary
streams in the Eel River system.
Anderson's (1972) earlier estimates placed
8
~
run size at 30,000 fish and 894 miles of available habi tat .
As stated for
chinook salmon, the more rece nt estimates are considered more accura te
<'orrest Reynolds, CDFG, personal communication) .
Coho salmon are generally confined to the South Fork Eel River, the lower
~tem
Eel River and the Van Duzen River and their tributaries.
The
s:pe>iIli.ng run begins in mid-October, peaks in November, and tapers off into
flecember.
Brown (1980) observed coho salmon in the tributaries to the lower
.ainstem Eel River and in Outlet Creek, a tributary to the upper mainstem Ee l
River .
Shapovalov (1937) reported that coho salmon spawned in the headwaters
of Outlet Creek in December and January.
Emergence occurs in February or March and the young school and feed in
shallow water.
Around July or August when water temperatures increase and
flows decrease, the fish move to deep pools.
in the stream.
These fish spend a year or more
Two of the main causes of summertime mortality are high
temperatures and loss of habitat due to decreased flow.
Biomass of coho
salmon was estimated at 0.1 g/m2 at two stations on Outlet Creek tributaries
and 0.4 g/m2 at twelve stations on lower mainstem Eel River tributaries (Brown
1980 ) •
Outmigrating coho salmon were captured by Leos and Mills (1983b) during a
16 March to 6 April 1983 trapping period.
mm FL (126 fish).
These yearling fish averaged 73-116
Puckett (1976) reported that juvenile fish were trapped in
t ributaries to the South Fork Eel River from mid-March to early August.
Murphy (1952), utilizing counts of coho salmon collected at Benbow Dam
from 1938 to 1950, calculated survival rates for the final year of ocean life.
Survival rates ranged from 15.8 to 56.9 percent with a mean of 35.6 percent.
The best estimate of grilsing rates (percentage of males of a cohort returning
9
=ilse)
ranged from 6.9 to 33.8 percent with a mean of 18 percent.
Using
elation analysis, Murphy (1952) found significant relationships for a
~~~
correlation of total egg deposition and the size of the population
__ ,~~~ one ocean season and for a multiple corre lation of size of the
~~2U~',on
after one ocean season versus spawning season runoff and total egg
.iE!pcEd':lion ,
:2uD steelhead (Salmo gairdneri gairdneri)
Steelhead are the most widely distributed fish in the Eel River system
(3E=ucs
et al. 1972).
Anderson (1972) estimated the yearly run at 115,000 fish
1,269 miles of available habitat.
~3Ces
A more recent and accurate estimate
the run at 84,000 fish (U.S. Heritage Conservation and Recreation
See 1980) .
Mills (1983b) estimated that 747.7 miles of stream in 248
1"'a')' streams were availabl e to fall run steelhead.
......
~.a:
IIC'R
Spawning adults or
of juveniles have been reported from the headwaters of Outlet
(::hapovalov 1937), North Fork Eel River (Horton et a1. 1968), Middle
Grainage from the mouth to at least Haynes Delight on the North Fork of
'!Ex1f PUrl< (Smith and Elwell 1959), mainstem Eel River to Scott Dam (Anderson
and in South Fork Eel River and its tributaries.
Steelhead enter the Eel River in varying numbers throughout the year.
are winter (fall) steelhead and enter from November through April.
spn;n in February, March and April (Burns et a1. 1972).
~
These
Lee and Baker
report that movements into the estuary start in late summer and
~s=re~
migration as early as August.
The early August to October run is
3O~DSed
mainly of 'half- pounders' or grilse.
Half- pounders are steelhead
- aave s pent two years in freshwater and only a single season in the ocean
10
1925) .
Larger fish migrate from October onward, with the spring run
ting in April and May.
~ters
~ dJrougb
'!!::::r:::e =-
Shapovalov (1937) reported steelhead spawning in
of Outlet Creek from January through June, but especially 1n
June.
Steelhead were reported to appear at Asa Bean Falls on
rlt Eel River during December and January with spawning occurring
o"ri;;g February and March (Smith and Elwell 1959).
~pe~
Steelhead arrive in the
wrinstem Eel from November through May with the majority reaching Cape
in the months of February, Ma=h and April.
~==:.,.
through May (Anderson 1972). VTN (1982) recorded peak numbers at Van
~~~e ~
~
_
in April, January, and February during their studies in the
1979- 80, 1980-81, 1981-82, respectively.
~nds
~~
Spawning occurs from
They also reported that 1 or
of high flow were required to bring the fish into the upper Eel
drainage •
.;Juveniles spend 1-4 years in freshwater, though most migrate when 1 or 2
'P-!=S
old
• _
ebwe
E
(Burns et al. 1972).
-~
During their residence in freshwater,
has a profound impact on the distribution of this species in the
system.
Kubicek (1977) divides the river into three sections.
At
elevations conditions are suitable for salmonids because of cool inflows.
elevation streams are also suitable because they occur in the fog zone
_"",,_2
_ter temperatures are kept low by reduced insolation .
The middle
of the area are generally too warm for salmonids during the summer,
juvenile steelhead do occur there in low numbers.
4EEE~ed
_=r-
Brown (1976c)
that in July juvenile steelhead were present in pools, near cool
upwellings, and in the riffles at both upper and lower mainstem Eel
iii.::__.:- stations .
~~~sites ,
In August and September, no fish were seen in pools at upper
while the distribution at downstream stations remained unchanged.
11
Brown (1980) conducted censuses of the fishes at upper and lower mainstem Eel
River sites and found that juvenile steelhead composed 10.8% of the fishes at
lower rive r sites but only 0.2% of the population at upper river sites.
The
catch on the upper river was dominated by young-of-year while the lower rive r
population was composed of several size classes.
Brown (1980) also found that
biomass was generally higher in tributary streams.
Biomass averaged 0.8 g/m2
at 24 main river stations and 2.2 g/m2 at 167 tributary stations.
Juvenile
habitat in the Middle Fork Eel River is generally restricted to the area above
Eel River Ranger Station and the upper reaches of tributary streams (Smith and
Elwell 1959).
The mainstem Eel River from Outlet Creek to Cape Horn Dam is
considered poor juvenile habitat because of high temperatures (Anderson 1972);
however, subsequent studies have shown that in some years water temperatures
are low enough for salmonids to survive in this area (VI'N 1982).
Fite (1973)
observed that as temperatures increased to 29 C at his South Fork Eel River
study site, juvenile steelhead sought out cool water springs at the bottoms of
pools or were found feeding in riffles.
Feeding of juvenile steelhead was studied by Fite (1973) and Ashley
(1974) as part of their studies of roach and sucker, respectively.
steelhead were found to be consuming primarily insects in the drift.
abundant taxon in the diet
was
ephemeropteran nymphs.
The most
Both authors observed
spatial segregation of feeding between trout and other species .
both roach and sucker consumed primarily algae.
Juvenile
Additionally,
In both studies, competition
between trout and the other species studied was concluded to be minimal.
Juveniles migrate downstream at all times of the year but most migrate in
the spring and early summer.
In gene ral, the older fish migrate first and a re
followed by progressively younger, and smaller, fish.
At Dos Rios, for
12
e xample, 1+ and older fish moved downstream in February, Marc h and April.
Fish less than 1 year old moved downstream from April to September, with the
peak movement occurring in April and May (Burns et al. 1972).
move ment of juveniles as well (Lee and Baker 1975).
The re is a fall
Smith and Elwell (1959)
t rapped outmigrants in the Middle Fork Eel River and captured fish throughout
the May 18 to September 26 sampling period.
Maximum numbers were captured in
late June-early July with few fish captured subsequently until just after the
first storm of the season.
Anderson (1972) reported that peak outmigration in
the upper Eel River occurs from March through May with a secondary peak
OClCurring after the first major runoff in the fall.
Puckett (1976) reported
that juvenile steelhead migrated throughout the year with catches of young- ofyear being highest in April through June.
A detailed study of outmigration
from the area above Van Arsdale Dam in the upper Eel River showed that 1+ and
older fish migrated first.
Outmigration began in late January and continued
into June or July (VTN 1982). Fish aged 0+ began outmigrating in late March to
mid- April with a peak in June or July.
Comparisons with outmigration from
Tomki Creek, which followed the pattern described by Anderson (1972),
indicated that lower water temperatures due to bottom release from Pillsbury
Reservoir were delaying outmigration from the area between Van Arsdale and
Scott Dams.
This conclusion was reinforced by the results of a subsequent
study which linked outmigration with water temperatures of 17 to 19 C (Peak
Associates 1986).
Summer Steelhead (Salmo gairdneri gairdneri)
Summer steelhead are the most intensively managed fish in the Eel River
drainage.
It is the only fish covered by a specific management plan (Jones
13
and Ekman 1980).
The Middle Fork Eel River population of summer steelhead is
the southernmost population of this race known and represents 50- 80% of the
Cali fornia population (Puckett 1975b).
Based on yearly counts of adults, the
population was at a low of 198 in 1966 following the devastating flood of
1964, increased to a high of 1,522 in 1974 and then fluctuated from a low of
377 in 1978 to a high of 1,601 in 1982 (Easthouse 1985, Jones 1980).
A small
population of fish also persists in the Van Duzen River (Puckett 1975b).
In
1967 , 82 fish were observed migrating into the Van Duzen River of which about
half were observed in upstream pools in August.
Between 1979 and 1986, the
population has fluctuated between 8 and 58 fish (CDFG files).
Mills (1983b),
based on CDFG file information , estimated that there was only 43.1 miles of
habitat avaiable to spawning summer steelhead with the majority (all but 2.5
miles) occurring in the Middle Fork Eel River drainage.
A population may have
existed in the North Fork Eel River (Jim Gilman, CDFG retired, personal
COIlIllunication, cited in CDFG 1978) but none have been reported in recent times
(Horton et al. 1968).
Summer steelhead ascend the Middle Fork Eel River from April through June
each year.
These fish hold in deep pools through the summer, fall and winter
and then spawn in the upper Middle Fork Eel River and its tributaries in the
spring. (Jones 1980, Jones and Ekman 1980, Brown 1976d, Puckett 1975b).
Puckett (1975b) reported that summer steelhead smolt at 1 to 3 years of age
with 4% smolting at 1 year of age, 79% at 2 years, and 17% at 3 years.
He
found the upstream migration to be composed of 1% 2-year-olds, 46% 3-yearolds, 44% 4-year-olds, and 9% 5-year-olds.
Only 9% of the fish were repeat
spawners .
Predation by rl.ver otter and poaching by man have been reported,
but the
14
~tes t
dangers to the population seem to be flooding, low flows, and
sedimentation (Jones and Ekman 1980, Jones 1980, Puckett 1975b).
The smallest
pnp.la tion of steelhead has observed after a large flood in 1964, which filled
.uGh of the holding habitat (Jones 1980, Jones and Ekman 1980).
~
stabilized the population increased to its present level.
As the
Poor logging
;rectices, road building and grazing, which can increase sedimentation, are a
~eat
2Le
to both pool morphology and the quality of spawning gravels.
important to both passage of adults and water temperatures.
1985)
Low flows
Easthouse
observed that the range of adult slUlllller steelhead was displaced
dohnstream during a low flow year due to insufficient water for passage over
barriers which are passable in normal years.
In normal years, water
Teaperatures range from 17 to 24 C (Jones 1980).
~t
~
higher temperatures during his study.
Easthouse (1985) observed
High water temperatures may be
particular problem for the Van Duzen River population.
Water temperatures
ranged from 18 to 26 C in July 1967.
~
J uvenile summer steelhead are most abundant in the upper portion of the
~e
~
Fork Eel River drainage, especially in the North Fork of Middle Fork
its tributaries.
Juvenile fall run fish also occur here and can not be
separated from juvenile slUlllller steelhead.
population estimates.
Brown (1976d) conducted juvenile
At 2 stations on the North Fork of Middle Fork Eel
-ver , they found standing crops of .61 and .95 g/m'.
The samples were
CCDpOSed of 30% young- of- year and 70% older fish, and 6% young-of- year and 94%
alder fish, respectively.
d
Brown (1976b) sampled more stations on North Fork
Middle Fork Eel River and on 3 tributaries and found standing crops ranging
from 0 .2 to 6.1 g/m'.
Predators on juveniles include mergansers, kingfishers,
river o tter and probably man (Easthouse 1985, Lorenz and Macedo 1983).
15
iiia:.i:.,..- trout (Salmo gairdneri)
Sot much is known about the populations of resident rainbow trout in the
Many reports briefly mention their presence above barriers to
'~~neneg~e_
,.-,ee
-,-=c-.-'%
.:
d migration (eg. Jones and Ekman 1980, Jones 1980, Anderson 1972,
t
and Elwell 1959).
Fisk and Pelgen (1955) mention that the fishery in
starry Reservoir is partially supported by a natural population of trout
that spawning adult steelhead have been planted in the reservoir to
3aQJile_nt
~S2r¥oir
the native population.
Evans (1956) conducted a study on the
whic h demonstrated that 65% of the fish caught by fisherman were
Brown e t al. (1987) conducted three pass depletion estimates on Rice Fork
River and Bear Creek, a tributary stream.
pnprn1ation was 0.33 fish/m' or 1.58 g/m'.
=:::iBated population
~ng
In Rice Fork Eel River, the
0.09 fish/m2 or 0.11 g/m2.
The differences in
crop were attributed to differences in the temperature and primary
~oductivi ty
~~r
was
In Bear Creek, the estimated
of the streams.
Squawfish were present in the Rice Fork Eel
but were absent from Bear Creek.
:Qestal c utthroat trout (Salmo clarki clarki)
Murphy and DeWitt (1951) mention the presence of cutthroats in the lower
River, primarily in the Salt River.
~to
sucker (Catostomus occidentalis)
The Sacramento sucker from the Eel River and other nearby drainages was
~gjna ll y
19(7) .
described as a new species
(Catostomus humboldtianus) by Snyder
It was soon relegated to being, at best, a subspecies of the
16
Sacramento sucker (Moyle 1976), and recently Ronald Fritsche (Humboldt State
University, personal communication) has concluded that they are not distinct
enough
to merit subspecies status.
drainage .
Sucker are distributed throughout the
They have been observed in both the upper and lower sections of the
uainstem Eel River, including the estuary (VTN 1982, Brown 1980, Brown 1976c ,
Anderson 1972).
They have also been reported from the North Fork Eel Rive r
( Brown et al. 1987, Kubicek 1977, Horton et al. 1968), the Middle Fork Eel
River up to Osborne Station where the Devil' s Den Roughs acts as a barrier
( Brown et al. 1987, Jones 1980, Jones and Ekman 1980, Smith and Elwell 1959),
the South Fork Eel River (Brown et al. 1987, Kubicek 1977), and the Van Duzen
River (Brown et al. 1987, Kubicek 1977).
Despite their wide distribution in
the larger portions of the mainstem Eel River they are present in only some of
the accessible tributaries (VTN 1982, Brown 1980).
Brown (1980) r eported that
24. 4% of the fish observed during snorke l surveys at his lower mainstem Eel
River sites and only 2% of the fish seen during counts in the upper river were
sucker .
Sucker never exceeded 5% of the catch during summer surveys by VTN
( 1982) in the upper mainstem Eel River.
Studies by Brown (1976c) and Ashley (1974) showed that habitat use by
sucker changes with size.
Both observed that young- of- year sucker were found
primarily along the edges of pools and deep riffles or in shallow riffles.
the fish matured they moved into deeper waters until, as adults, they moved
about the pools in schools ranging from several to several hundred fish.
Ashley (1974) observed that these schools broke up at night as the adults
dispersed to feed in shallow water.
Ashley (1974) also studied the summer feeding habits of sucker.
All
sizes of sucker consumed, in order of importance, algae, invertebrates, and
As
17
debris.
Diatoms were the most important alga in the diet of 0+ suckers, while
juvenile and adult suckers consumed primarily Cladophora.
Chironomids were
the most important invertebrate in the diet of all but adult sucker, which
consumed primarily ephemeropteran nymphs.
Post-larval suckers were observed
feeding at all depths in the water column but soon became bottom oriented.
He
concluded that the possibility of competition between sucker and steelhead was
limited because of different diets and vertical separation of feeding areas.
It is not known when sucker spawn but Ashley (1974) collected ripe
females on April 28, 1972 and on June 9, 1972 captured females that were spent
or resorbing gonadal products.
This indicates that spawning probably occurs
in May.
Sacramento squawfish (Ptychocheilus grandis)
Squawfish were illegally introduced into Pillsbury Reservoir, in 1979 or
1980, and are presently spreading throughout the rest of the drainage.
Squawfish were captured during outmigrant trapping at the Potter Valley
Powerhouse and at the fish screens in 1980 and 1981 (VTN 1982).
captured in the summer fish surveys until 1982.
They were not
By 1986, squawfish
populations had increased to the point that they were the most abundant
species at many upstream mainstem Eel River sampling stations (PG and E,
unpub.).
drainage.
Squawfish are now distributed throughout a large part of the
Brown et al. (1987) observed juvenile squawfish in South Fork Eel
Ri ver below Benbow Dam, near the town of Redway.
Brown et al. (1987) did not
observe squawfish in the Middle Fork Eel River between Williams Creek and
Black Butte Creek on 25 July 1986.
By 6 September 1986, juvenile squawfish
were common in the area around Black Butte Creek and were present above Black
18
Butte Creek.
Adult and juvenile squawfish were conunon in the l ower Middle
Fork Eel River, during both sampling periods.
Squawfish were not observed in
the North Fork Eel River at the Mina Road crossing and were not present in the
Van Duzen River, near Grizzly Creek, in 1985 (Brown et al. 1987); howeve r,
these systems will probably be invaded in the near future.
Squawfish do not seem to invade many small tributary streams for some
reason.
VI'N (1982) noted squawfish in the mainstem Eel River during their
sunmer population surveys in 1982, but captured very few in the tributary
streams.
In 1986, even though squawfish had become very abundant in the
mainstem Eel River, they were still absent from most of the tributary streams
(PG and E, unpub.).
The one stream they had invaded was Garcia Creek.
Brown
et al . (1987) found a high density of squawfish in Rice Fork Eel River (1.17
fish/m2 or 3.85 g/m2
),
but squawfish were absent from Bear Creek, a tributary,
which contained primarily rainbow trout.
Adult squawfish are apparently restricted to large pools.
to occupy both large and small pools.
Juveniles seem
Invasion of upstream areas results from
the upstream movements of juveniles rather than adults (Brown et al. 1987).
The diet of squawfish in mainstem Eel River, Middle Fork Eel River, Rice Fork
Eel River and Pillsbury Reservoir was studied by Brown et al. (1987).
Squawfish measuring less than 100 mm SL consumed primarily insects.
Larger
fish consumed a variety of organisms including fish, frogs, and lamprey
annnocoetes.
Cal ifornia roach (Lavinia symmetricus)
Like squawfish, roach is an introduced species in the Eel River system.
Roach was not included in early surveys of the drainage by Snyder (1907) and
19
Shapovalov (1939).
Both Lee and Baker (1975) and Anderson (1972) described
r oach as a recent introduction.
Horton et al. (1968) did not observe roach in
t heir survey of the North Fork Ee l River.
introduction occurred around 1970.
These data s uggest that the
Roach also occur above Pillsbury Reservoir
(Brown et al. 1987) suggesting that the invasion may have originated there,
perhaps as a bait bucket introduction.
Whenever they were introduced, roach
have now spread throughout the Eel River system and in many areas are the most
abundant fish, during low flows.
Puckett (1977) observed roach in the Eel River estuary.
Brown (1980,
1976c) observed roach from Van Arsdale Reservoir to the estuary and in all
tributaries inspected.
all sample sites.
roach/m2
•
All size classes (0+,1+, and older) were present at
In 1976, 4 stations on the upper river had densities of 3.3
In his 1980 study, Brown found that roach composed 97.6% of the
f ish population, by number, in upper river pools but only 6.6% in the lower
river.
Average biomass at upper mainstem Eel River stations was 3.2 g/m2 and
4 .9 g/m2 in the tributaries, mile values of only 0.2 g/m2 were obtained from
the lower river and lower river tributary stations.
roach to be abundant in the upper mainstem Eel River.
roach were the most abundant fish in 1980 and 1981.
this area is seasonal.
VTN (1982) also found
During the sunnner,
The dominance of roach in
Steelhead were often more abundant in the spring and
early stBllDer but as the water warmed, roach increased in number and steelhead
decr eased (VTN 1982).
Roach have also been reported from the South Fork Eel
River (Brown et al. 1987, Kubicek 1977), North Fork Eel River (Brown et al.
1987 , Kubicek 1977) and the Van Duzen River (Brown et al. 1987, Kubicek 1977).
Fi te (1973) studied the diet of roach and steelhead in South Fork Eel
River.
He described the feeding zone of roach as being intermediate to those
20
obse rved for trout and suc ker .
Whe n in a riffle, roach spent most of their
time just above the bottom in a stationary location eating periphyton and
occassionally seizing drift.
During the spring and e arly st.nruner, feeding
occurred in the early morning.
Samples taken in mid- July indicated that
feeding occurred throughout the day.
The diet of roach was dominated by algae
which constituted 73 percent of the diet by weight.
was composed of insects.
The remainder of the diet
On a monthly basis the percentage of insects was
greater during the summer when insect abundance was highest.
feeding overlap with trout
The general
for insects was 40 percent with a 41 percent
overlap in the species consumed.
The two most important insects in the diet
o f roach and trout did not overlap.
Considering the small amount of insects
in the diet of roach on the basis of volume, Fite (1973) considered
competition between the two species to be unimportant.
Fite (1973) observed medium- sized roach in the shallow riffles and pool
headwaters.
Large roach and very small roach were observed in large pools.
The large roach inhabited deep open water or areas around large rocks and
boulders.
Roach fry were observed in the shallows of both pools and riffles.
Brown (1976c) found roach to be most abundant on the periphery of pools, at
the head of pools, and in slow riffles.
Fi te (1973) observed larger roach
chasing smaller roach in the early spring.
The larger roach were members of
large schools observed around rock outcrops, suggesting that this aggression
was associated with spawning.
Threespine stickleback (Gasterosteus aculeatus)
Stickleback have been reported in the mainstem Eel River from Cape Horn
Dam downstream to the estuary (VTN 1982, Brown 1980, Brown 1976c, Anderson
21
1972), downstream from Devil's Den Roughs in the Middle Fork Eel River (Jones
1980, Jones and Ekman 1980, Smith and Elwell 1959), and in the North Fork Eel
River (Horton et a l. 1968).
Stickleback comprised 57% of the fish seen in
pools during snorkel surveys by Brown (1980) in the lower mainstem Eel River.
Pacific lamprey (Lampetra tridentatus)
Lamprey have been noted in the North Fork Eel River (Horton et al. 1968),
throughout the Middle Fork Eel drainage (Jones 1980, Jones and Ekman 1980,
Smith and Elwell 1959), and in the mainstem Eel River from Van Arsdale Dam to
Outlet Creek (VTN 1982, Anderson 1972).
Ammocoetes were trapped from above
Van Arsdale Dam in 1980, 81, and 82 (VTN 1982).
Brown et al. (1987) captured
lamprey ammocoetes from South Fork Eel River and the Van Duzen River.
Lamprey
are probably well distributed in the system, but the burrowing habit of the
larvae make them difficult to capture.
Lamprey were observed spawning in the main channel of
River on 15 May, 1959 (Smith and Elwell 1959).
June.
Fork Eel
Spawning had ended by mid-
Smith and Elwell captured annnocoetes in outmigrant nets from May to
mid- July.
June.
~1iddle
VTN (1982) captured ammocoetes moving downstream from April through
Brown et al. (1987) found a lamprey ammocoete in the gut of a squawfish
from the Rice Fork Eel River, which is located above Pillsbury Reservoir.
This indicates the presence of a landlocked population of lamprey, probably
Pacific brook lamprey (Lampetra pacifica).
American shad (Alosa sapidissima)
Shad have been reported in the mainstem Eel River as far upstream as Dos
Rios (Puckett 1976) and the proposed English Ridge Dam site (Burns et
al.
22
1972).
Brown et al. (1987) observed adults in the mainstem Eel River near
Fort Seward, Alderpoint and McCann.
in September 1986.
Burns et al.
enter the Eel River annually.
with a peak in May and June.
24 C.
Juveniles were observed near Fort Seward
(1972) estimate that 5,000 to 10,000 shad
They enter the river from April through July
Water temperatures at this time range from 10 to
Young shad begin moving downstream in July or August with a peak
usually in October.
Puckett (1976) reported downstream movements of young
shad from late July to early November.
Prickly sculpin (Cottus asper)
Brown (1980) observed prickly sculpin in the lower Eel River and
tributaries.
They composed 0.1% of the fish seen in lower river pools.
Average biomass at one main river station was 0.1 g/m2 and 0.6 g/m2 at 18
tributary stations.
Sculpin, presumably prickly sculpin, have also been
reported from the Middle Fork- North Fork Eel River area (CDFG 1978).
Prickly
sculpin are also present in the estuary (Puckett 1977, Murphy and DeWitt
1951).
Brown et al. (1987) found prickly sculpin in the Van Duzen Rive r, near
Grizzly Creek.
Coastrange sculpin (Cottus aleuticus)
Coastrange sculpin were reported from the estuary by Puckett (1977).
Brown et al . (1987) observed coastrange sculpin in the Van Duzen River, near
Grizzly Creek.
Green sturgeon (Acipenser medirostrus)
Burns et al. (1972) report that there was once an important fishery for
23
green sturgeon, with fish found at least as far upstream as Garberville .
are now seen.
Few
Young sturgeon, ranging in length from 63 to 178 mm FL, were
captured during their downstream migration in June, July and August.
Sturgeon
were noted in the lower river and estuary by Murphy and DeWitt (1955) but were
not observed by Puckett (1977).
Downstream migrants were trapped from the end
o f May to September (Puckett 1976).
Green sunfish (Lepomis cyanellus)
Green sunfish were introduced to the Eel River drainage sometime before
1939 , since they are mentioned as present in the drainage by Shapovalo v
( 1939 ).
They are found in the mainstem Eel River from Pillsbury Reservoir to
Fortuna (VTN 1982, Brown 1980, Brown 1976c, Anderson 1972, Fisk and Pelgen
1955 , Murphy and DeWitt 1951, Shapovalov 1939), in the South Fork Eel to
Benbow Dam (Shapovalov 1939) and in the Middle Fork Eel up to a mile below
Williams Creek (Smith and Elwell 1959).
Brown (1980) captured green sunfish in the riffles of the upper Eel River
and in Tomki Creek.
Green sunfish composed 0.2% of the fish seen during
snorkel surveys of pools.
Green sunfish do not appear to be very abundant in
the drainage.
Brown bullhead (Ictalurus nebulosus)
Shapovalov (1939) also reported brown bullheads in the drainage and
indicates they are distributed in the same areas as green sunfish.
Brown
( 1976c) reported bullheads in the upper and lower mainstem Eel Rive r but in
1980 they were only caught in the upper river stations (Brown 1980).
and DeWitt (1951) also reported bullheads in the lower river.
Murphy
VTN (1982)
24
report catching bullheads during only 1 of 3 years of their summer surveys.
Brown et al. (1987) reported bullheads from Outlet Creek and the mainstem Eel
River below Outlet Creek.
Smith and Elwell (1959) reported that bullheads
were only present in the extreme lower reaches of the Middle Fork Eel River.
Other introduced species in Pillsbury Reservoir
A number of other species of fish have been introduced into Pillsbury
Reservoir.
These species have not yet established reproducing populations
downstream.
Largemouth bass (Micropterus salmoides) was introduced to Pillsbury
Reservoir in 1986 as a squawfish control measure.
These fish reproduced in
the spring of the year and the young appear to be doing well (Phil Baker,
CDFG, personal communication).
Golden shiner (Notemigonus chrygoleucas) has been captured in outmigrant
traps at the fish screen at Cape Horn Dam implying it is present in Pillsbury
Reservoir (VTN 1982).
It has been reported as far downstream as Outlet Creek
(Anderson 1972).
Bluegill (Lepomis macrochirus)
was
also captured frem below Pillsbury
Reservoir by VTN (1982) and Brown et al. (1987) implying a population in
Pillsbury Reservoir.
Shapovalov (1939) noted reports of bluegill by other
persons, but never verified them himself.
Threadfin shad (Dorosoma petenense) was captured by VTN (1982) in 1982
implying a population in Pillsbury Reservoir.
This species has never before
been reported frem the drainage and probably represents a new introduction.
Anderson (1972) reported that eastern brook trout (Salvelinus fontinalis)
and kokanee (OnchorhYDchus nerka) were stocked in previous years but that
25
populations of these species had never become established .
other fishes from the estuary
A wide variety of freshwater, estuarine and marine species have been
reported from the lower mainstem Eel River and the estuary of the Eel River.
A number of these have already discussed on an individual basis.
The
remaining species are mentioned briefly below.
Three instances of striped bass (Morone saxatilis) were reported by
Sbapovalov (1939), but this species has not been observed during any
subsequent studies.
Pacific sardine (Sardinops caerulea) was described as abundant by Murphy
and DeWitt (1951) but was not observed by Puckett (1977).
Starry flounder (Platichthys stellatus) has been noted by Puckett (1977),
Brown (1976c), and Murphy and DeWitt (1951).
The following species were noted by Murphy and DeWitt (1951) and Puckett
( 1977): Pacific herring (Clupea harengus) , topsmelt (Atherinops affinis),
shiner perch (Qymatogaster agwgata), staghorn sculpin (Cottus armatus), and
bay pipefish (Syngnathus griseolineatus or Sygnathus leptorhynchus).
In addition, Murphy and DeWitt (1951) reported tomcod (Nicrogadus
proximus) and pile perch (Damalichtys vaca).
Puckett captured northern
anchovy (Engraulis mordax), surf smelt (HYj)Omesus pretiosus), long fin smelt
( Spirinchus thaleichthys), redtail surfperch (Amphisticus rhodoterus), walleye
surfperch (HY]Jerprosopon argenteum), saddleback gunnel (Pholis ornata),
Pacific sandlance (Ammodytes hexapterus), cabezon (Scorpaenichthys
III8I'IIlOratus), english sole (Parophrys vetulis), and sand sole (Psettichthys
ooelanostictus) .
26
PHYSICAL FACTORS AFFECfING THE FISHES
Flow
The Eel River is relatively undeveloped and still has the natural
enormous annual fluctuations in flow that characterize large coastal streams
in California.
The Eel River experiences floods on the average of every six
years (Jones and Elonan 1980).
The shortest period between floods was 1 year
and the longest period was 23 years, for the period 1900- 1974.
severe flood in this period was in late December 1964.
Scotia on December 23, 1964 was 752,000 cfs.
The most
The discharge at
In the Middle Fork Eel River
drainage this flood resulted in pool filling, changes in channel morphology
and loss of riparian vegetation (Jones 1980, Jones and Elonan 1980).
Similar
effects occurred throughout the drainage (Wendy Jones, CDFG, personal
communication).
Much of the present channel morphology still reflects the
effects of the 1964 flood.
As mentioned in the species descriptions, flow patterns are important in
stimulating upstream migration by salmon, and steelhead (VTN 1982, Burns et
al. 1972).
Flow also determines the amount of spawning gravels available (VTN
1982, Puckett and Hinton 1974), the distance spawning fish can penetrate into
the headwaters of spawning streams (VTN 1982, Brown 1977), and the amount of
rearing habitat available (VTN 1982).
The annual cycle of flood and drought probably accounts for the scarcity
o f exotic introduced fishes such as green sunfish (Lepomis cyanellus) and
brown bullhead (Ictalurus nebulosus).
annual floods in numbers.
Presumably they cannot survive the
However, introductions of native California fishes
such as roach and squawfish have been very successful partly because these
species are adapted to this flow regime.
26
PHYSICAL FACl'ORS AFFECTING THE FISHES
Flow
The Eel River is relatively undeveloped and still has the natural
enormous annual fluctuations in flow that characterize large coastal streams
in California .
The Eel River experiences floods on the average of every six
years (Jones and Ekman 1980).
The shortest period between floods was 1 year
and the longest period was 23 years, for the period 1900- 1974.
severe flood in this period was in late December 1964.
Scotia on December 23, 1964 was 752,000 cfs.
The most
The discharge at
In the Middle Fork Eel River
drainage this flood resulted in pool filling, changes in channel morphology
and loss of riparian vegetation (Jones 1980, Jones and Ekman 1980).
Similar
effects occurred throughout the drainage (Wendy Jones, CDFG, personal
communication).
Much of the present channel morphology still reflects the
effects of the 1964 flood.
As mentioned in the species descriptions, flow patterns are important in
stimulating upstream migration by salmon, and steelhead (VTN 1982, Burns et
al. 1972).
Flow also determines the amount of spawning gravels available (VTN
1982, Puckett and Hinton 1974), the distance spawning fish can penetrate into
the headwaters of spawning streams (VTN 1982, Brown 1977), and the amount of
rearing habitat available (VTN 1982).
The annual cycle of flood and drought probably accounts for the scarcity
of exotic introduced fishes such as green sunfish (Lepomis cyanellus) and
brown bullhead (Ictalurus nebulosus).
annual floods in numbers.
Presumably they cannot survive the
However, introductions of native California fishes
such as roach and squawfish have been very successful partly because these
species are adapted to this flow regime.
27
Temperature
Kubicek (1977) provides a basin wide study of summer water temperatures
in the Eel River drainage.
He measured water temperatures with a handheld
thennometer at 179 stations throughout the Eel River Basin, and also collected
data from 30 thermographs.
Based on these data, observations of the fishes
present at each station, and a literature review of the temperature
requirements of salmonids, he divides the mainstems of the Eel River into
three types of habitat.
Stream sections reaching a maximum of 28.0 C or greater for at least 100
continuous minutes were considered lethal for salmonids.
Lethal sections were
l ocated in the middle reaches of the mainstems of the Eel Rive r where there
W'lS
little tributary inflow or shading.
Stream sections reaching a maximum
temperature of less than 26.5 C were classified as satisfactory.
These
sections were generally located in the headwaters where cool tributaries and
good canopy were common or in the lower areas of the drainage, within the fogbelt where morning fog reduced insolation of the stream.
Marginal sections
had maximum temperatures between 26 .5 and 28.0 C, and occurred as transition
zones between lethal and satisfactory areas.
Subsequent studies of salmonid distribution in the Eel River drainage
have generally conformed with Kubicek's c lassificati on.
For example, VTN
(1982 ) classified the sections of mainstem Eel River from Cape Horn Dam to
Tomki Creek and from Tomki Creek to Outlet Creek as marginal and lethal in
1980 and 1981.
In those years, few steelhead were observed in those stream
sections during the summer.
In 1982, these areas were classified as
satisfactory and marginal and steelhead were common throughout the summer.
They also noted that as steelhead became rare during the summer, roach became
28
more corrunon.
Smith and Elwell (1959) noted temperature r elated c hanges in the fishes
present in the Middle Fork Eel River.
As temperatures increased during the
surruner, sucker began to predominate in the catch and steelhead became less
common in the area below Williams Creek.
The area above Williams Creek was
described as a transition zone where suckers and trout occurred together.
Observations by Brown et al. (1987) suggest that a similar pattern may be
established between squawfish and rainbow trout.
Even in the lethal zones, Kubicek (1977) sometimes observed salmonids in
t he deeper pools, throughout the drainage.
These pools had become stratified
or were being influenced by seepage of cooler water from below the substrate.
The steelhead were inhabiting the cooler bottom water.
vrN (1982) also noted
stratified pools but did not observe the cool bottom water being utilized by
fish.
Brown (1980) measured oxygen concentrations in several pools and noted
that shallow }X>ols that did not stratify had between 5.7 and 5.9 mg
0,
/1 while
several deeper pools that did stratify had oxygen concentrations of below 1 mg
0,
/1 near the bottom.
Cold pools are particularly important to the population
of summer steelhead in Middle Fork Eel River (Jones 1980, Jones and Ekman
1980).
The cold pools in the Middle Fork Eel River appear to be the result of
stratification, while cold pools in other areas of the Eel River drainage can
be the result of stratification or inflows of cooler water (Vicki Ozaki,
National Parks Service, personal communication).
FISHERIES AND FISHERIES MANAGEMENT
Anderson (1972) stated that the Ee l River ranked second in California in
the production of both coho salmon and steelhead and third in production of
c hinook salmon.
While the difficulty in sampling a large unregulated system
29
l ike the Eel River makes the calculation of such estimates diffic ult, it is
c lear that the Eel River produce s an important number of these species for
both the c ommercial and sport catch.
The commercial catch consists primarily
of c hinook salmon, but the sport catc h consists of a wide variety of species
(Mills 1983a, Puckett 1975a, Murphy and DeWitt 1951).
The major part of the
sport catch consists of juvenile steelhead, though adult anadromous fishes of
all species are also sought and captured.
Unfortunately, production of
anadromous fish in the Eel River has been declining in historical times.
The
construction of Scott and Cape Horn Dams has been implicated as at least
partially responsible for this decline (Anderson 1972, Burns et al. 1972) but
o ther factors such as overfishing, poor logging and grazing practices, and
other human activities which increase erosion, flooding and sedimentation are
probably more important.
The importance of and need to protect the fishes of the Eel River has
been recognized since the 1930s when Shapovalov conducted a number of studies
in the area (Shapovalov 1937, 1939, 1940a, 1940b, 1945) and suggested the
formation of special management areas for the Eel River (Shapovalov 1938,
1941, Shapovalov and Vestal 1938).
Shapovalov began a program of fish rescue
and habitat improvement work in the Eel River area in 1938 (Shapovalov 1938),
which continued through the early 1960s.
Habitat improvement projects of
various sorts have continued to the present.
Much of the work subsequent to
Shapovalov's has been primarily concerned with assessing the possible impacts
of new water projects and studying the affects of existing projects (ego
Ander s on 1972, Burns et al. 1972), though the inclusion of the Eel River in
the Wild and Scenic Rivers system has renewed interest in assessing the
importance of Eel River salmon production and enhancing that production
30
Reynolds 1983, Reynolds and Mills 1982}.
Sonunarstrom (1984) provides an
excellent summary of the responsibilities and goals of the various federal,
s tate, local and private organizations and individuals involved in fisheries
management work in Mendocino County, which includes portions of the mainstem
Eel River, South Fork Eel River and Middle Fork Eel River.
Reynolds and Mills
(1982) outline the responsibilities of the various agencies with regard to the
Wild and Scenic Rivers Act.
The most recent perceived threat to the salmonid production of the Eel
River is the introduction of Sacramento squawfish into the system.
The
Sacramento squawfish, like the roach is well adapted to fluctuating streams
and is expected to do well in the system.
As
of the Sl1IllIler of 1986, squawfish
have been found in the mainstem Eel River down to Fernbridge (D. McCleod,
CDFG, personal communication), in the South Fork Eel River near Garberville,
and in the Middle Fork Eel at the Eel River Ranger Station (Brown et al.
1987).
Brown and Moyle (1981) reviewed the literature on squawfish and
concluded that in natural systems they rarely affect salmonid populations but
they can consume large numbers of young salmon below dams and in other
artificial situations.
In the Eel River, their preferred prey (SCulpins and
crayfish; Brett, Takagi and Moyle, U.C. Davis, unpub.) are uncommon so their
predation on salmon and steelhead could become a problem.
They are already
c onsidered to be a nuisance by fisherman who fish Pillsbury Reservoir and the
river above it (W.L. Jones, personal communication).
SUMMARY
The fishes of the Eel River drainage, especially the anadromous
s almonids, have been the subject of a number of studies; however, these
s tudies have generally been concerned with assessing the actual or possible
31
e ffects of existing or suggested water development projects, in a specific
a rea.
The fishes, their interactions and their habitat requirements have
never been studied on a system wide basis.
Stream flow and water temperature
have been shown to have a strong effect on the distribution and abundance of
the fishes.
Sacramento squawfish are rapidly spreading through the system.
Whether or not squawfish will negatively effect the production of anadromous
salmonids is unknown at this time.
LITERATURE CITED
Anderson, K.R. 1972. Report to the California State Water Resources Board by
the Department of Fish and Game regarding water applications 18785 and
18786, Eel River, Lake and Mendocino Counties. Calif. Dept of Fish and
Game. Envir. Ser. 65p
Ashley, P. 1974. The summer feeding ecology of the Humboldt sucker, Catostomus
humboldtianus and juvenile steelhead Salmo gairdneri gairdneri in the
upper Eel River system. Master's thesis, Humboldt State University,
Arcata. 76 p.
Beak Consultants Incorporated. 1986. Article 41 studies to determine the
effects of water temperature on downstream migration of anadromous
salmonids in the upper Eel River below Lake Pillsbury. Beak Consultants
Inc., Portland. 56 p., plus appendices.
Brown, C. 1976a. Observations of king salmon spawning in Outlet Creek, Eel
River, 1975-1976. Calif Dept. of Fish and Game. Contract Ser. Sec. Info.
Rept. 76-1.
_ _ , C. 1976b. Estimates of standing stocks of juvenile steelhead in the
North Fork of the Middle Fork Eel River, 1976. Calif. Dept. of Fish and
Game, Reg. 1, Cont. Servo Sect. Info. Rept. No. 76- 5. 7p.
_ _ , C. 1976c. A study of the distribution of fishes in the Eel River, 1975.
Calif. Dept. of Fish and Game, Reg. 1, Cont. Servo Sect. Info. Rept. No.
76- 3. 9p.
_ _ , C. 1976d. Counts of adult spring-run steelhead and estimates of
standing stocks of juvenile steelhead in the upper Middle Fork Eel River,
1975. Calif. Dept. of Fish and Game, Reg. 1, Cont. Servo Sect. Info.
Rept. No. 76- 1. 6p.
_ _ , C. 1980. Standing crops and distribution of fishes in selected reaches
of the Eel River system. Calif. Dept. of Fish and Game. Anadromous Fish.
Br. Admin. Rept. No. 80.
32
C.J., Jr. 1977. An estimate of king salmon (Onchorhynchus tschawytscha)
spawning in Tomki Creek, tributary to Eel River, in 1975-76. Calif. Dept.
of Fi sh and Game. Envir. Ser. Br. Admin. Rept. No. 77-2a. IIp.
~,
L. R .• P.B. Moyle, and B. Herbold. 1987. Eel River survey: first year
stuiies. Rept. to Calif. Dept. Fish and Game.
~~.
___ • L.R. and P.B. Moyle. 1981. The impact of squawfish on salmonid
pop.Jlations: a review. North American Journal Of Fisheries Management
1: 104-111.
J . W., J.M. Hayes, L.K. Puckett, E.S. Smith, T.B. Stone, and W.F. Van
Woert. 1972. Fish and wildlife aspects of alternative Eel River
developnent plans. Calif. Dept. of Fish and Game Memorandum Report, 128p .
~~S.
• 1978 . The fish and wildlife resources of the Big Butte- Shinbone planning
unit (U.S. Forest Service and Burea of Land Management) and
reo:> ""endations for their protection. Calif. Dept. of Fish and Game,
Region I and Region III. 20p. plus appendices.
??sTnc-~,
K.B. 1985. A biological survey of summer steelhead Middle Fork Eel
Etiver, 1985. Calif. Dept. of Fish and Game, unpublished report.
~~S.
".A. 1957. The 1956 fisheries studies at Lake Pillsbury, Lake County,
California. Calif. Dept. of Fish and Game. Inland Fish. Admin. Rept . No.
57- 30 . 12pp.
L.O. and O.E. Pelgen. 1955. A limnological survey of Lake Pillsbury,
~.
~
County, California. Calif. Dept. of Fish and Game. Inland Fish. Br.
Rept. No. 55-23. 17pp.
~.
7"_=
.R. 1973 . Feeding overlap between roach and juvenile steelhead in the
River. Master's thesis, California State Universi ty, Humboldt.
:;;:;e].
5i::r.:on. J., D. Rodgers and L. Puckett. 1968. Stream survey North Fork Eel
""WeI" .
Calif Dept of Fish and Game. Water Projects Branch.
~ces.
.E. 1980 . Summer steelhead (Salmo gairdneri) in the Middle Fork Eel
Over and their relationship to environmental changes, 1966 through 1978.
=ali.f. Dept of Fish and Game. Anad. Fish. Br. Admin. Rept. No. 80-2 . 25p.
_ __ •
.~. and E. Ekman. 1980. Summer steelhead management plan- Middle Fork
- tbe Eel River. Rept. to CDFG and USFS. 48 p.
P.F. 1977. Summer water temperature conditions in the Eel River
w~ th reference to trout and salmon. Master's thesis, Humboldt
~~ University, Arcata. 200p.
~~~k.
~ue9.
~
_ .? and P.H . Baker. 1975. Eel- Russian Rivers streamflow augmentation
stDd~: reconnaissance fisheries evaluation. Calif. Dept. of Fish and
• unpublished report. 59p.
33
Leos, R. and T.J. Mills. 1983a. Salmon spawning stock surveys in the Eel River
Basin, 1982-83. Appendix E. In, F.L. Reynolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries. Calif .
Dept. of Fish and Game. The Resources Agency.
; R. and T.J. Mills. 1983b. Eel River juvenile trapping program 1983.
Appendix F. In, F .L. Reynolds, 1983 status report of California wild and
scenic rivers salmon and steelhead fisheries. Calif. Dept. of Fish and
Game. The Resources Agency. 57 p., plus appendices.
Lorenz, J.M. and R.A. Macedo. 1983 . Report of the 1982 Middle Fork Eel River
patrol. Calif. Dept. of Fish and Game, unpublished report. 31 p., plus
appendices.
Mills, T.J. 1983a. Sport fisheries of the lower Eel River September 1 through
October 15, 1982. Appendix B. In, F.L. Reynolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries. Calif .
Dept. of Fish and Game. The Resources Agency. 57 p., plus appendices.
_____ ' T.J. 1983b. Utilization of Eel River tributary streams by anadromous
salmonids. Appendix H. In, F.L. Reynolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries. Calif.
Dept. of Fish and Game. The Resources Agency. 57 p., plus appendices.
Moyle, P.B. 1976. Inland Fishes of California. University of California Press,
Berkeley, California.
Murphy, G.I. 1952. Analysis of silver salmon counts at Benbow Dam, South
Fork- Eel River, California. Calif. Fish and Game 38: 105-112.
____~' G.I. and J.W. DeWitt, Jr. 1951. Notes on the fishes and fishery of the
lower Eel River, Humboldt County, California. Calif. Dept. of Fish and
Game. Bureau of Fish Conserv. Admin. Rept. No. 51- 9. 30 p.
Power, M.E. 1986. The role of primary consumers in structuring communities of
Northern California streams. NSF Grant Proposal. 45p .
Puckett, L.K. 1975a. Sport fisheries of the Eel River, 1972-1973. Calif. Dept.
of Fish and Game. Memo. Rept. 29pp.
____-:-:-' L.K. 1975b. The status of spring-run steelhead (Salmo gairdneri) of
the Eel River system. Calif. Dept. of Fish and Game Memo. Rept. 22p.
____~~, L.K. 1976. Observations on the downstream migrations of anadromous
fishes within the Eel River system. Calif. Dept. of Fish and Game. Memo.
Rept. 35pp.
----~7'
L.K. 1977. The Eel River estuary - observations on morphometry,
fishes, water quality and invertebrates . Calif . Dept. of Fish and Game
Memo. Rept.
34
____~-' L.K . and R.N. Hinton. 1974. Some measurements of the relationship
between streamflow and king salmon spawning gravel in the main Ee l and
South Fork Ee l Rivers . Calif. Dept . o f Fis h and Game . Envir. Ser . Br.
Admin . Rept. No.74-1.17p.
F. L. 1983. 1983 status report of Californi a wild and scenic river
salmon and steelhead fisheries. Calif. Dept. of Fish and Game. The
Resources Agency. 57 p., plus appendices.
~lds ,
____ , F. L. and T.J. Mills. 1982. 1982 status report of California wild and
scenic rivers salmon and steelhead fisheries. Calif . Dept. of Fish and
Game . The Resources Agency. 159p.
Sbapovalov , L. 1937. Report on an investigation of debris and pollution in the
streams in and about Little Lake Valley, near Willits , Mendocino County,
California. Typewritten rept. to Calif. Div. Fish and Game, Bur. Fish
Cons., Dec. 10, 1938. 16p.
____~--~.' L. 1938. A suggested program of fish rescue and improvement work
for the Eel River drainage basin, California. Calif. Dept of Fish and
Game . Bureau of Fish Conserv. Admin. Rept. No. 38-18.
______~--' L. 1939. Recommendat ions for management of the fishe ries of the
Eel River drainage basin, California. Calif. Dept of Fish and Game . Bur.
of Fish Conserv. Admin. Rept. 39- 2. 19 p.
____~~--, L. 1940a. Preliminary report on the effect of the use of wate r at
Lake Pillsbury and at Van Arsdale Reservoir on the salmon and trout of
the Eel River system. Calif. Dept. of Fish and Game. Bur. Fish Conserv.
40-1.
L. 1940b. Some calculations regarding the natural s pawning of king
salmon in the South Fork of the Eel River above Benbow Dam, season of
1938-1939. Calif. Dept . of Fish and Game. Bur. Fish Conserv. Admin. Rept.
40-2.
____~--~ ' L. 1941. Prospectus for an Eel River fish management area. Calif .
Dept . of Fish and Game. Bur. Fish Conserv. Admin. Rept. 41- 15.
______~~ ' L. 1945. Observations on controlled flows in the Ee l River , Lake
and Mendocino Counties, California, September 25-26, 1945. Calif. Dept.
of Fish and Game . Bur. Fish Conserv. Admin. Rept . 45- 26.
______~~' L. and E.H. Vestal . 1938. Preliminary out line of s uggested stream
and lake improvement in the Eel River wate rshed. Calif. Dept. of Fis h and
Game. Bureau of Fish Conserv. Admin . Rept . No . 38-11.
sad th, E.J., Jr. and R.F. Elwell. 1959. Supplementary basic fisherie s data ,
Middle Fork of Eel River investiga tion. Calif. Dept. of Fish and Game.
Contract Ser., unpublished report. unpaged.
34
____~-' L.K. and R.N. Hinton. 1974. Some measurements of the relationship
beb,een streamflow and king salmon spawning gravel in the main Eel and
South Fork Eel Rivers. Calif. Dept. of Fish and Game. Envir. Ser. Br.
Admin. Rept. No. 74- 1. 17p.
Reynolds, F.L. 1983. 1983 status report of California wild and scenic river
salmon and steelhead fisheries. Calif. Dept. of Fish and Game. The
Resources Agency. 57 p., plus appendices.
____ , F.L. and T.J. Mills. 1982. 1982 status report of California wild and
scenic rivers salmon and steelhead fisheries. Calif. Dept. of Fish and
Game. The Resources Agency. 159p.
Sbapovalov, L. 1937. Report on an investigation of debris and pollution in the
streams in and about Little Lake Valley, near Willits, Mendocino County,
California. Typewritten rept. to Calif. Div. Fish and Game, Bur. Fish
Cons., Dec. 10, 1938. 16p.
____~~-, L. 1938. A suggested program of fish rescue and improvement work
for the Eel River drainage basin, California. Calif. Dept of Fish and
Game. Bureau of Fish Conserv. Admin. Rept. No. 38-18 .
______~--, L. 1939. Recommendations for management of the fisheries of the
Eel River drainage basin, California. Calif. Dept of Fish and Game. Bur.
of Fish Conserv. Admin. Rept. 39-2. 19 p.
______~--' L. 1940a. Preliminary report on the effect of the use of water at
Lake Pillsbury and at Van Arsdale Reservoir on the salmon and trout of
the Eel River system. Calif. Dept. of Fish and Game. Bur. Fish Conserv.
40-1.
L. 1940b. Some calculations regarding the natural spawning of king
salmon in the South Fork of the Eel River above Benbow Dam, season of
1938- 1939. Calif. Dept. of Fish and Game. Bur. Fish Conserv. Admin. Rept.
40-2.
____~----' L. 1941. Prospectus for an Eel River fish management area. Calif.
Dept. of Fish and Game. Bur. Fish Conserv. Admin. Rept. 41- 15.
______~~, L. 1945. Observations on controlled flows in the Eel River, Lake
and Mendocino Counties, California, September 25-26, 1945. Calif. Dept.
of Fish and Game. Bur. Fish Conserv. Admin. Rept. 45 - 26.
, L. and E.H. Vestal. 1938. Preliminary outline of suggested stream
and lake improvement in the Eel River watershed. Calif. Dept. of Fish and
Game. Bureau of Fish Conserv. Admin. Rept. No. 38-11.
Smith, E.J., Jr. and R.F. Elwell. 1959. Supplementary basic fisheries data,
Middle Fork of Eel River investigation. Calif. Dept. of Fish and Game.
Contract Ser., unpublished report. unpaged.
35
Sccma rstrom, S. 1984. Mendocino County salmon and steelhead management plan.
Mendocino County Fish and Game Advisory Committee. 103p.
Snyder , J.O. 1907. The fishes of the coastal streams of Oregon and Northern
California. Bulletin of the Bureau of Fisheries 27:153 - 189.
______ , J.O. 1925. The half-pounder of the Eel River, a steelhead trout.
Calif. Fish and Game 11:49- 55 .
ea.,."Ue , S.A. 1982. Stream microhabitat selectivity, resource partitioning, and
niche shifts in grazing caddisfly larvae. Master's thesis, University of
California, Davis. 62 p.
VTN , Inc. 1982. Potter Valley project (FERC No. 77) Fisheries study final
report. VTN Oregon Inc., Wilsonville, Oregon. 320 p. plus appendices.
BIBLICCRAPHY
The purpose of this annotated bibliography is to aid persons interested
in the fishes and fisheries of the Eel River system.
The notes are meant to
convey the general purpose of each of the cited articles and in most cases do
not contain much detailed information.
In most cases, the notes consist of
the author's abstract or a summarization of the summary or conclusion portion
of the article.
In a few cases the notes are removed from the annotated
bibliography of Brown (1976).
Anderson, K.R. 1972. Report to the California State Water Resources Board by
the Department of Fish and Game regarding water applications 18785 and
18786, Eel River, Lake and Mendocino Counties. Calif. Dept of Fish and
Game. Envir. Ser. 65p.
This report documents the response of the California Department of
Fish and Game's response to the request of PGE for relicensing of the
Potter Valley Project.
The report provides a general description of the
fishes and fisheries of the area and describes, in detail, the pe=ieved
problems created by the project.
A number of interim changes in the
operation of the project are suggested and a request made for cooperative
studies for the long term solution of fish and wildlife problems.
Ashley, P. 1974. The summer feeding ecology of the Humboldt sucker, Catostomus
humoldtianus and juvenile steelhead Salmo gairdneri gairdneri in the
upper Eel River system. Master's thesis, Humboldt State University,
A=ata. 76 p.
This thesis concerns the feeding habits of the Humboldt sucker and
steelhead trout and possible competition between the two species.
The
summer diets of age 0, juvenile and adult sucker were composed of algae,
invertebrates and debris.
diet of age
° sucker,
Diatoms were the most important algae in the
whereas, Cladophora was the most important alga in
37
the diets of juvenile and adult sucker.
Chironomid larvae were the most
important invertebrate food items of age 0 and juvenile sucker.
Ephemeropteran nymphs were the most important invertebrate in the adult
diet.
Juvenile steelhead rarely ingested algae or debris and their diet
cons isted almost entirely of invertebrates.
up the bulk of the diet .
Epheme ropteran nymphs made
The pote ntial food competition between sucker
and trout was low due to vertical separation of their feeding areas, the
selectivity of trout for ephemeropteran nymphs, and the feeding
flexibility of all age classes of sucker.
Beak Consultants Incorporated. 1986. Article 41 studies to determine the
effects of water temperature on downstream migration of anadromous
salmonids in the upper Eel River below Lake Pillsbury. Beak Consultants
Inc., Portland. 56 p., plus appendices.
Juvenile chinook salmon and steelhead trout emigrations from the Eel
River below Scott Dam were monitored in spring 1985 to determine
relationships between timing of emigration movements and changes in water
temperature and flow.
Timing of emigration for both chinook and
steelhead juveniles varied between the unregulated Tomki Creek and the
project regulated Eel River above Cape Horn Dam.
Differences in
temperature regimes rather than flow and moon phase appeared to have the
greatest effect on emigration.
VTN Oregon's 1980- 1982 study.
Results of this study were compared to
Differences in emigration among years
appeared highly related to differences in project operation, temperature,
and flow.
38
Brown, C. 1976a. An annotated bibliography of Eel River fish and wildlife
reports which were prepared by the contract services section. Calif.
Dept. of Fish and Game. Contract Servo Sect. Info. Rept. 76-6. 18p.
This report was prepared by the Contract Services Section with the
purpose of citing and annotating all reports prepared by the Contract
Services Section on the fish and wildlife of the Eel River System through
1976.
_____ , C. 1976b. Observations of king salmon spawning in Outlet Creek, Eel
River, 1975- 1976. Calif Dept. of Fish and Game. Contract Ser. Sec. Info.
Rept. 76- 1.
Outlet Creek and some of its tributaries were surveyed for salmon
carcasses in December 1975 and January 1976 to obtain information on king
salmon spawning distribution in the area.
A total of 160 king salmon
were examined of which 46 were females, 54 were males and 60 were
unidentifiable.
Males less than 61 cm fork length (grilse) comprised 41%
of the male salmon measured and 24% of all salmon measured.
Most of the salmon (70%) observed were in Outlet Creek from Long
Valley Creek to a swampy area known as "The Outlet".
About 27% were
found from Bloody Run Creek to Long Valley Creek, and 3% were found in
Outlet Creek below Bloody Run Creek.
Long Valley, Bloody Run, Broaddus
and Baechtel Canyon Creeks had no fish.
Creek.
One fish was found in Willits
Sherwood Creek was not surveyed.
____ , C. 1976c. Estimates of standing stocks of juvenile steelhead in the
North Fork of the Middle Fork Eel River, 1976. Calif. Dept. of Fish and
Game, Reg. 1, Cont. Servo Sect. Info. Rept. No. 76 - 5. 7p.
Populations of juvenile steelhead-rainbow trout were sampled by
electrofishing in the North Fork of Middle Fork Eel River and three of
its tributaries (Rock Creek, Willow Creek, and Morrison Creek) in
39
September 1976.
Salmonid biomass varied from 0.8 to 2.8 g/m' stream
surface area in four stations in Rock Creek, 0.2 to 6.1 g/m' in seven
stations in Morrison Creek, and 0.6 to 2.5 g/m' in nine stations in North
Fork of Middle Fork Eel.
Biomass
was
0.5 g/m' in one station in Willow
Creek (Notes from Brown 1976a).
______ , C. 1976d. A study of the distribution of fishes in the Eel River, 1975.
Calif. Dept. of Fish and Game, Reg. 1, Cont. Servo Sect. Info. Rept. No.
76- 3. 9p.
The distribution of the fishes was monitored in the summer of 1975
by electrofishing in five stations below Eel Rock and ten stations above
Dos Rios in the Eel River.
Steelhead were found almost exclusivel y in
riffles in the upper river, but they occurred in pools and riffles in the
lower river.
Other species encountered included California roach,
Sacramento sucker, green sunfish, brown bullhead, starry flounder, threespine stickleback, and prickly sculpin (Notes from Brown 1976a).
______ , C. 1976e. Counts of adult spring-run steelhead and estimates of
standing stocks of juvenile steelhead in the upper Middle Fork Eel River,
1975. Calif. Dept. of Fish and Game, Reg. 1, Cont. Servo Sect. Info.
Rept. No. 76-1. 6p.
Adult spring-run steelhead were counted by diving in pools in the
Middle Fork Eel, and juvenile steelhead- rainbow trout biomass
was
estimated by electrofishing in the North Fork of Middle Fork Eel River.
One hundred and forty-two steelhead were counted in the Middle Fork Eel
and its tributaries above Hoxie Crossing.
Biomass was 1.0 and 0.6 g/m'
in two stations on the North Fork of Middle Fork Eel (Notes from Brown
1976a) .
40
_____ , C. 1980. Standing crops and distribution of fishes in selected reaches
of the Eel River system. Calif. Dept. of Fish and Game. Anad. Fish. Br.
Admin. Rept . No. 80.
Fish were sampled by electro fishing and observed by diving in the
Eel River system as part of a program designed to gather information to
be used to plan mitigation for potential water projects.
The most Common fishes caught and observed were steelhead and roach.
Steelhead biomass averaged 0.8 g/m2 (0.7 lb/acre) in 24 main river
stations and 2.2 g/m2 (2.0 lb/acre) in 167 tributary stations.
Roach
biomass averaged 2.7 g/m2 (2.4 lb/acre) in both 12 main river stations
and in 17 tributary stations.
Most juvenile steelhead in reaches of the Eel River examined in this
study spend the first year of their lives in tributaries and migrate to
the lower river and estuary for the rest of their freshwater lives.
Few
stay in the upper river through their second summer, but pr oportionately
more stay in the North Fork of Middle Fork Eel through two summers.
Brown, C.J., Jr. 1977. An estimate of king salmon (Onchorhynchus tschawytscha)
spawning in Tomki Creek, tributary to Eel River, in 1975- 76. Calif. Dept.
of Fish and Game. Envir. Ser. Br. Admin. Rept. No. 77-2a. IIp.
The objective of this study was to estimate the number of king
salmon spawning in Tomki Creek and to determine their size, sex, and
distribution.
Numbers of fish were estimated by mark and recapture, and
data were analyzed using the method of Schaefer.
An estimated 401 salmon spawned from December 1975 through January
1976.
There were 1.1 females for every male.
The male salmon averaged
759 mm and ranged from 330 to 965 nun, and the females averaged 759 mm and
ranged from 533 to 975 mm fork length.
Ninety- seven percent of the run
spawned in main Tomki Creek and 3 percent spawned in three major
41
t ributaries.
Low water restricted the distribution of the fish (Notes
from Brown 1976a).
_____ , C.J., Jr., and R. Haley. 1974 . A preliminary analysis of the potential
for enhancing salmon and steelhead fisheries in the Eel River basin.
Calif. Dept. of Fish and Game, Memo. Rept. 41p. plus 49 p. appendix.
This report presents a review of the literature on salmon and
steelhead mitigation and enhancement projects of California and other
West Coast states .
The purpose is to measure progress in the field of
fisheries enhancement and to form a base for evaluating the potential of
the various enhancement techniques.
The report contains an evaluation of
watershed management, rearing ponds, fish rescue, stream improvement,
fishing access, nongame fish control and water development, and the
potential of each for enhancing Eel River salmon and steelhead fisheries
(Notes from Brown 1976a).
Brown , L.R., P.B. Moyle, and B. Herbold.
studies .
1987. Eel River survey: first year
Rept. to Calif. Dept. Fish and Game.
This report documents the results of studies of the distribution
and abundance of the fishes of the Eel River drainage, the microhabitat
use of those fishes and their diets .
Particular emphasis is place on the
biology of the Sacramento squawfish which is presently invading the
s ystem.
Colonization of streams by squawfish, appears to be the result
of the upstream movements of juveniles.
with deep pools.
Adults are restricted to areas
Squawfish will probably colonize all of the aTe8S now
inhabited by California roach.
42
Burns, J.W., J.M. Hayes, L. K. Puckett, E.S. Smith, T.B. Stone, and W.F. Van
Woert. 1972. Fish and wildlife aspects of alternative Eel River
development plans. Calif. Dept. of Fish and Game Memorandum Re port, 128p.
The primary purpose of this report is to identify the potential
effects of twelve alternative Eel River water projects on fish and
wildlife in the Eel River Basin and along twelve water conveyance routes.
The report concludes that any of the twelve alternative means of
developing and conveying water from the Eel River would have an overall
detrimental impact on fish and wildlife (Notes from Brown 1976a).
CDFG. 1966. Fish and wildlife problems and study requirements in relation to
North Coast water development. Calif. Dept. of Fish and Game. Water
Proj. Br. Rep. No.5. 229p.
This report reviews the proposed water projects (as of 1966) for the
whole North Coast Area, including the Eel River drainage.
The report
identifies areas of concern in relation to maintaining fish and wildlife
values after construction of the proposed projects and formulates a
number of study needs for each drainage area •
. 1978. The fish and wildlife resources of the Big Butte-Shinbone planning
unit (U. S. Forest Service and Burea of Land Management) and
recommendations for their protection. Calif. Dept. of Fish and Game,
Region I and Region III. 2Op. plus appendices.
The purpose of this report is to provide fish and wildlife
information for use in the preparation of management plans for this
management unit.
The summer steelhead population of the Middle Fork Eel
is described as the most valuable fishery resource .
Winter-run steelhead
are described as the second most valuable resource.
Land uses
contributing to erosion such as road building, logging and livestock
grazing are identified as the primary concerns in management of the
fisheries.
43
Day, J.S. 1963. An evaluation of the effects of highway construction on
Longvale Creek, Mendocino County. Calif. Dept. of Fish and Game. Water
Proj. Admin. Rept. No. 63-4. 14p.
This report documents the results of an investigation of the effects
of highway construction on Longvale Creek, Mendocino County, during the
summer of 1961.
The results indicated that removal of streamside cover
increased water temperatures, increased erosion of non-riprapped stream
banks and produced undesireable stream bottom conditions in many areas.
The ability of the stream to support fish life was markedly reduced.
From observations of a nearby stream affected by a highway project, it
was concluded that riprap along both stream banks, where channel changes
occur, provides effective erosion control and improved conditions for
regrowth of stream cover.
Dixie, E.M. 1983. Beach selnlng efforts to capture salmon on the lower Eel
River, 1982. Appendix B. In, F.L. Reynolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries.
This report documents the results of a study to test the feasibility
of capturing chinook salmon, Oncorhynchus tshawytscha, and coho salmon,
~
kisutch, with beach seines for the purpose of marking them for mark
and recapture studies.
Delays in obtaining equipnent prevented a
thorough evaluation of the method.
Seven chinook salmon and 1 coho
salmon were caught in 47 seine hauls.
A total of 9 species of fish were
captured including chinook salmon, coho salmon, steelhead, Sacramento
3ucker, staghorn sculpin, starry flounder, redtail surfperch, American
shad and bay pipefish.
Easthouse, K.B. 1985. A biological survey of summer steelhead Middle Fork Eel
River, 1985. Calif. Dept. of Fish and Game, unpublished report.
A biological survey of summer steelhead (Salmo gairdneri) was
44
conducted on the Middle Fork Eel River between June 1 and September 30,
1985.
Steelhead populations were censused and biological data on habitat
conditions collected.
A population of 1,490 (1,463 alive, 27 dead) adult
steelhead was counted.
Electroshocking data indicated a smaller juvenile
standing crop than in 1984.
Streamflow was lower and water temperatures
higher than in recent sUl1Ullers.
Thermographs revealed that water
temperatures peaked in late July while handheld thermometers demonstrated
the important contributions of cool water from tributaries to cooling the
mainstem.
Evans, W.A. 1957. The 1956 fisheries studies at Lake Pillsbury, Lake County,
California. Calif. Dept. of Fish and Game. Inland Fish . Admin. Rept. No.
57- 30. 12pp.
A partial creel check was conducted during the 1956 season at Lake
Pillsbury in order to determine the relative importance of wild fish and
hatchery-reared fish in maintaining the trout fishery.
that wild trout made up 65 percent of the catch.
Results showed
They ranged throughout
the season from a high of 95 percent during the fall to a low of 35
percent during the late spring.
Fisk , L.O. and O.E. Pelgen. 1955. A limnological survey of Lake Pillsbury,
Lake County, California. Calif. Dept. of Fish and Game. Inland Fish. Br.
Admin. Rept. No. 55- 23. 17pp.
Lake Pillsbury was selected for study to determine the
characteristics of a fluctuating North Coast reservoir.
Such information
was wanted for the management of other such reservoirs which were
anticipated at that time.
September 1975.
The study was conducted from April to
The study gathered information on temperature, dissolved
oxygen concentrations, plankton and bottom invertebrates.
During the
die epin_ion was above 21 C (70 F), and
<!:ss~'""~
-.!Ie
of
"'':;:::!l2!'' =s belooo -1 parts per million wi thin several f eet below
in
J "ne.
h.R. 1973 . Feeding overlap between roach and juvenile steelhead in the
Fe] River . Master's thesis, California State University, Humboldt.
The extent of feeding overlap between roach (Hesperoleucas
s~tricus)
and juvenile steelhead (Salmo gairdneri)
South Fork, Eel River March 1972 to October 1972.
was
studied in the
Feeding behavior and
feeding overlap were shown to be closely associated with habitat and
aquatic insect population changes.
feeding zones.
Roach and trout inhabit two different
However, some overlap of these zones did occur.
Occas i onal interspecific aggression by trout toward roach helped maintain
or increase this spatial segregation.
t ime and location
was
Increased segregation in feeding
observed during the more critical period of low
flow and high temperature.
Segregation may have been limited by the
simplicity of the habitat. The major food of the roach
algae, 73 percent by volume.
attached
Some feeding overlap for insects occurred.
The general feeding overlap for insects
ove rlap was 41 percent.
was
was
40 percent, and the species
However, the two most important insects did not
overlap in the diet of roach and steelhead.
The community composition
and biology of the individual species of insects played a significant
role in determining fish interaction.
Competition for food by roach and
j uvenile steelhead in the riffle study section of the South Fork, Eel
River was of a limited nature.
Theory concerning feeding overlap and
competition is discussed (Author's abstract).
46
German, W.H. 1969. Dos Rios Reservoir: Impact survey report. U.S. Dept. of
Agriculture. Forest Service. Impact Survey Rept. Stage II.
This report documents the anticipated effects of the proposed Dos
Rios Reservoir on the Mendocino National Forest.
The discussion of the
fisheries is limited to the observation that anadromous fish will be
stopped at the dam and possible mitigation measures for this loss.
The
mitigation suggested was the operation of a hatchery to provide fish for
release in the upper and lower rivers.
Hinton, R.N., C. Fisher and R.D. Mallette. 1965. Fish and wildlife, Appendix
C, Dept . of Water Resources Bull. No. 136, North Coast Area
Investigation. 364p.
This report describes the fish and wildlife resources of the North
Coastal area, estimates streamflows required to maintain and enhance
these resources, evaluates the effects of proposed water projects,
suggests measures for preservation of fish and wildlife resources, and
delineates problems requiring further study.
The studies indicated that the North Coastal area of California
contains a wealth of economically and aesthetically valuable fish and
wildlife resources .
The construction of water developnent projects would
present difficult and formidable problems in the preservation of these
resources, especially anadromous fishes.
For the earlier-staged
projects, fish and wildlife could probably be preserved with conventional
methods, such as hatcheries, artificial spawning channels, and wildlife
browse manipulation.
However, projects proposed for the lower Eel and
Klamath rivers would pose problems of far greater complexity.
Preservation of fish and wildlife with these projects would require
entirely new techniques, and may not be possible in some respects (Notes
47
from Brown 1976a).
______ , R.N., C.E . Lindquist. 1968. Fish and wildlife. In South Fork Eel River
study. Appendix C. Calif. Dep~. of Water Resources, Bull. 173.
Reconnaissance-level fish and
wildl~fe
studies were conducted within
the South Fork Eel River drainage as part of the North Coastal Area
Investigation of the Department of Water Resources.
The report was
prepared to provide preliminary information on the fish and wildlife
resources that would be affected by possible water projects in the South
Fork Eel River Basin.
The studies indicated that the Cahto, Sebow, and Frost projects
would be desireable for fish enhancement.
Additional study i s
recommended to predict post-project water temperatures, increase
knowledge of existing resources, and more accurately define maintenance
and enhancement requirements, with accompanying costs and benefits (Notes
from Brown 1976a).
Horton, J., D. Rodgers and L. Puckett. 1968. Stream survey North Fork Eel
River. Calif Dept of Fish and Game. Water Projects Branch.
This report documents the results of a stream survey of the North
Fork Eel River from the mouth to Salt Creek.
The fishes observed during
the survey included Pacific lamprey, king salmon, rainbow trout,
steelhead rainbow trout, Humboldt sucker and threespine stickleback.
In
1967, salmon were observed spawning in the river for a distance of 4
miles upstream from the mouth.
Steelhead and stickleback were observed
at both upper and lower stations.
stations.
Sucker were only observed at upstream
48
Jones, W.E. 1980. Summer steelhead (Salmo gairdneri) in the Middle Fork Eel
River and their relationship to environmental changes, 1966 through 1978.
Calif. Dept of Fish and Game. Anad. Fish. Br. Admin. Rept. No. 80-2. 25p.
Annual surveys were conducted from 1966 through 1978 in the Middle
Fork Eel River to assess changes in habitat and adult summer steelhead
numbers following the devastating December 1964 flood.
Steelhead counts increased from 198 in 1966 to 1,522 in 1974, then
declined steadily to 377 in 1978.
The summer holdover area, in the upper
reaches of the Middle Fork between Bar and Uhl Creeks, is 42 kin (26
miles) in length.
Adult fish depended on deep pools for sUlllller survival.
Streamflows and surface water temperatures ranged from 0- 0.55 m3 /s (0-20
cfs) and 17.2-23.7 C (63- 75 F), respectively during the surveys.
Reconnnendations for managing and protecting this unique steelhead
strain are included.
, W.E. and E. Ekman. 1980. Summer steelhead management plan-Middle Fork
of the Eel River. Rept. to CDFG and USFS. 48 p.
This report summarizes what is known about the summer steelhead
population of the Middle Fork Eel River and formulates a plan for their
management.
Yearly surveys begun in 1966 have shown the population of
adult fish to fluctuate between the 198 steelhead observed in 1966 to a
maximium of 1,522 observed in 1974.
Reasons cited for the fluctuations
include pool filling and loss of riparian vegetation due to a severe
flood, winter droughts and possible dependent relationships of adults as
well as juveniles to other environmental factors.
Commercial and
recreational activities in the Middle Fork Eel drainage include timber
harvest, cattle grazing, hunting and fishing.
These activies are s een as
conflicting with the preservation of the summer run because of the
49
siltation and pollution caused by timber harvest and grazing and poaching
by hunters and fishennen.
Of three management strategies considered, the
alternative calling for the maintenance of the population at the highest
level observed during the survey period (1,522 fish) was considered the
most economically and technically feasible and socially and politically
acceptable.
On
the basis of this alternative a number of management
practices were recommended.
Kimsey, J.B. 1953. Fish rescue and stream improvement work in the north coast
area in 1952. Calif. Dept. of Fish and Game. Inland Fish. Admin. Rept.
No. 53- 9. 29 p.
This report documents the results of fish rescue and habitat
improvement work in the North Coast area, including the Eel River
drainage, for the year 1952.
Kubicek, ?F. 1977. Summer water temperature conditions in the Eel River
system, with reference to trout and salmon. Master's thesis, Humboldt
State University, Arcata. 200 p.
It was the objective of this study to determine, from a water
temperature standpoint, the locations and amounts of suitable habitat
available to native anadromous and resident salmonids in the mainstems of
the Eel River system during the sUlllJler.
Water temperatures were measured
wi th hand thermometers at 179 stations during the summer of 1973.
Addi tionally, temperature data were collected from 30 thermographs.
The
main forks of the Eel River were divided into stream sections having
similar temperature conditions with respect to suitability of habitat for
native salmonids.
Stream sections reaching a maximum temperature of 28.0 C or greater
for at least 100 continuous minutes were classified as "lethal" .
Stream
50
sections reaching a maximum from 26.5 C up to, but not including, 28.0 C
for at least 100 continuous minutes were classified as "marginal".
Stream sections reaching a maximum of less than 26.5 C were classified as
"satisfactory".
Of the total of 444.0 miles of stream surveyed, 196.25 miles (44.2
percent of the total) were classified as lethal; 96.25 miles (21. 7
percent of the total) were classified as marginal; and 151.5 (34.1
percent of the total) were classified as satisfactory.
Observations of
the distribution and abundance of salmonids supported the temperature
classification system.
In addition to the above, this thesis also contains a literature
review and discussion of the effects of temperature on salmon ids and the
major factors influencing stream temperature.
Extensive notes on the
distribution and abundance of nonsalmonid fishes observed during the
study are also included.
Lee, D.P. and P.H. Baker. 1975. Eel-Russian Rivers streamflow augmentation
study: reconnaissance fisheries evaluation. Calif. Dept. of Fish and
Game. unpublished report. 59p.
This paper provides an overview of the fisheries problems caused by
the operation of the Potter Valley Project and explores the possible
effects of six alternatives for operation of the facility.
The perceived
problems include loss of spawning habitat, insufficient water for the
upstream migration of adults, loss of smolts to the turbines and
diversion, and the delay of downstream migration by cold water releases
from Scott Dam.
It was concluded that the greatest fishery benefits
would be provided by Alternative Four which includes abandonment of the
powerhouse, enlargement of Lake Mendocino, and enlargement of the Potter
51
Valley tunnel.
Alternative Five, which includes abandonment of the
powerhouse, and Alternative Three, which retains the powerhouse operation
but includes an enlarged Lake Mendocino, would provide (in that order)
the next two greatest opportunities to restore anadromous fisheries in
the upper Eel River.
A fish hatchery was suggested as mitigation for
lost spawning habitat.
Leos, R. 1983. The operation of salmon trapping stations in the Eel River
drainage, 1982. Appendix D. In, F.L. ReYnolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries. Calif.
Dept. of Fish and Game.
This report documents the results of efforts to capture chinook and
coho salmon with weirs for the purpose of mark and recapture studies.
Two weirs were located on the South Fork Eel River and one on the
mainstem Eel River.
November 1982.
tagged.
The weirs were operated from October through
A total of 171 chinook and 1 coho salmon was catured and
The mean length of chinook salmon was 73.3 em (28.9 in. FL) and
ranged from 40 em (15.7 in.) to 113 cm (44.5 in.).
_ _ , R. and T.J. Mills. 1983a. Salmon spawning stock surveys in the Eel River
Basin, 1982- 83. Appendix E. In, F.L. ReYnolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries. Calif.
Dept. of Fish and Game.
Salmon spawning stock surveys were conducted on Eel River tributary
streams from 26 November 1982 to 21 January 1983 to 1) develop salmon
carcass recovery methods necessary to annually establish total in-river
run estimates for Eel River salmon stocks with emphasis on chinook
salmon, Oncorhynchus tshaWYtscha, 2) es tima te spawner escapement in
selected tributary streams, 3) rank survey streams by relative importance
based on spawner use, and 4) recover as many carcasses as possible to
check for Eel River Study spaghetti tags applied to live salmon earlier
52
in the s eason.
Live salmon, carcasses or skeletons were found in 25 of 41 tributary
streams surveyed.
A total of 4 coho salmon carcasses, 496 chinook salmon
carcasses, and 150 chinook salmon skeletons were recovered.
Eight
tributaries accounted for 88.5% (439) of the total nUJJlber of chinook
salmon carcasses recovered with Willits Creek, Grizzly Creek, and Long
Valley Creek receiving heaviest use.
_ _ , R. and T.J. Mills. 1983b. Eel River juvenile trapping program 1983.
Appendix F. In, F.L. Reynolds, 1983 status report of California wild and
scenic rivers salmon and steelhead fisheries. Calif. Dept. of Fish and
Game.
Downstream migrant salmon fry were captured in the Eel River basin
from 16 March 1983 through 2 June 1983 to determine if sufficient nUJJlbers
of naturally produced chinook salmon, Oncorhynchus tshawytscha,
captured for large scale trapping and tagging programs.
could be
Trapping was
conducted on two tributaries to the South Fork Eel River, two tributaries
to mainstem Eel River, one tributary to the Van Duzen River, and on the
South Fork Eel below Benbow Dam.
A total of 17,915 chinook salmon fry, 126 coho salmon yearlings and
1,008 steelhead were trapped from 16 March to 6 April 1983.
ranged in length from 33 to 69 mm FL.
116 mm FL.
Chinook fry
Coho yearlings ranged from 73 to
Juvenile steelhead ranged from 25 to 171 mm FL.
Analysis of
the length frequencies of chinook fry suggested that peak emigration
followed shortly after peak emergence.
The minimUJJl length for coded wire
tagging is about 40 mm FL but fish should be larger for the best results.
A total of 53.8% of the chinook fry captured met this criteria but too
few were captured at anyone time for an economical tagging operation.
53
, R. and T.J. Mills. 1983c. Design and evaluation of 1014 mortality
dOHnstream migrant salmon traps for use in the Eel River Basin, 1982 and
1983. Appendix I. In, F.L. Reynolds, 1983 status r eport of California
wild and scenic rivers salmon and steelhead fisheries. Calif. Dept. of
Fish and Game .
This report evaluates three different downstream migrant traps.
The
design of each trap is described, including a new design which resulted
in mortalities of only 4.3% at water velocities of 1.0 to 3.0 ftjsee.
Lorenz, J.M. and R.A. Macedo. 1983. Report of the 1982 Middle Fork Eel River
patrol. Calif. Dept. of Fish and Game, unpublished report. 31 p., plus
appendices.
This report presents the findings of the 1982 Eel River Patrol.
The
goals of the patrol were to enforce the fishing closure on 47 km (29
miles) of the Middle Fork Eel River and to gather biological data on the
swruner steelhead population.
A total of 1,054 adult steelhead were observed within the closure.
Juvenile populations exhibited a large year-class of young-of-the-year,
but yearlings were nearly absent.
A study of the behavior of adult
steelhead in reaction to swimmers was attempted but the results were
inconclusive.
The report also contains observations on barriers to migration, mass
land movements, water temperatures and flows, pool depths, the magnitude
of riparian canopy, and recommendations for resource management and
future river patrols.
Mills, T.J. 1983a. Sport fisheries of the lower Eel River September 1 through
October 15, 1982. Appendix B. In, F.L. Reynolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries. Calif.
Dept. of Fish and Game.
A c reel census was conducted along the l ower 22.5 km (14 miles) of
the Eel River from its mouth to the Van Duzen River confluence from 1
54
September 1982 through 15 October 1982.
Data gathered during this 45 day
period were used to estimate angler use, total hours e":pended angling,
and numbers of steelhead, Salmo gairdneri, and chinook salmon,
Oncorhynchus tshawytscha, caught in the lower Eel River.
_____ , T.J. 1983b. River mile and stream length index for the Eel River Basin,
California. Appendix G. In, F .L. Reynolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries. Calif.
Dept. of Fish and Game.
This report provides a river mile index for the location of the
confluence of tributary streams within the major river reaches of the Eel
River drainage, and lists stream names and lengths of tributaries.
_____ , T.J. 1983c. Utilization of Eel River tributary streams by anadromous
salmonids. Appendix H. In, F.L. Reynolds, 1983 status report of
California wild and scenic rivers salmon and steelhead fisheries. Calif.
Dept. of Fish and Game.
This report is a summary of the distributional records available on
the use of tributary streams by anadromous salmonids.
File information
of the California Department of Fish and Game was searched for
information on the use of tributary streams.
Based on this information
chinook salmon are able to ascend 374.4 stream miles in 102 tributary
streams, coho salmon can ascend 246.3 stream miles in 69 tributary
streams, winter run steelhead can ascend 747.7 stream miles in 248
streams, and spring run steelhead can ascend only 43.1 stream miles in
nine tributary streams and in a portion of the mainstream Van Duzen
River.
G.!. 1952. Analysis of silver salmon counts at BenbOl; Dam, South
Fork- Eel River, California. Calif. Fish and Game 38: 105-112.
~y,
Silver salmon (Oncorhynchus kisutch) were counted at Benbow Dam,
55
Runboldt Colmty, California, from 1938 to 1950.
Calculated survival
rates of the population for the final year of ocean life ranged from 15.8
to 56 . 9 percent wi th a mean of 35.6 percent.
The best estimated grilsing
rates ranged from 6.9 to 33.8 percent with a mean of 18 perce nt.
Correlation analysis was used to study the effects, on the
population, of total egg deposition, runoff during the spawning season,
runoff during the late incubation and hatching season, and runoff during
the dry season.
Statistically significant correlations were found for
egg deposition and size of the population after one ocean season and for
a multiple correlation of spawning season runoff and egg deposition
versus the population at the end of one oceari season.
____~' G.I. and J.W. DeWitt, Jr. 1951. Notes on the fishes and fishery of the
lower Eel River, Humboldt County, California. Calif. Dept. of Fish and
Game. Bureau of Fish Conserv. Admin. Rept. No. 51-9. 30 p.
This report documents the results of a general survey, conducted in
1950 - 1951, of the fishes and fisheries of the Eel River from the mouth
of the Van Duzen River to the Pacific Ocean.
The report includes a brief
description of the physical and chemical characteristics of the area, but
most of the infonnation concerns the fisheries.
composed primarily of juvenile steelhead.
The summer catch was
During the fall, king salmon
and half- pounder steelhead were the primary catch.
The winter catch was
composed of king salmon, silver salmon and steelhead.
The report also
briefl y discusses the other fishe s found in river.
~____ '
G.I. and L. Shapovalov. 1951. A preliminary analysis of Northern
California salmon and steelhead runs. California Fish and Game
37 :497-507.
This paper uses correlation analysis to look for relationships
56
between the king salmon, si lver salmon, and steelhead populations of the
South Fork Eel, Mad, Shasta, and Klamath Rivers.
The low number of
significant correlations among the rW1S was interpreted to indicate that
most fluctuations in abundance may be due to factors operating in the
fresh water phase of the life cycle or to density-independent factors in
the ocean operating on a local basis.
In light of these conclusions, the
authors suggested that salmonid production could be increased by insuring
that enough adults reached the spawning beds to fully utilize them,
improving streams by enlarging the available areas of spawning and
nursery habitat, maintaining natural conditions in existing stream
systems, and insuring the survival of young fish.
PintleI', H.E. 1954. The results of fish rescue work in Region III for 1953.
Calif. Dept. of Fish and Game. Inland Fish. Br. Admin. Rept. No. 54-16.
19p.
This report presents the results of fish rescue and habitat
improvement work in the North Coast region, including the Eel River
drainage, for the year 1953.
Potter, R.G., B.J. August, G.H. Pape. 1966. Developing the North Coast: An
action plan, progress report. Calif. Dept. of Water Res. Bulletin No.
105- 1. 58p.
This report outlines the current knowledge (as of 1966) of local
water problems in the North Coast area and includes preliminary
evaluations of these problems and specific plans for solutions to them.
In the Eel River drainage, projects on the Van Duzen River (Baseline
Reservoir) and South Fork Eel (Spring Creek Reservoir on Tenmile Creek,
Panther Reservoir on the East Branch South Fork Eel, and Cahto Reservoir
on the upper South Fork Eel) are discussed.
Enhancement of downstream
57
fisheries and increased recreational opportunities are the primary
benefits mentioned for all of the projects.
Power, M.E. 1986. The role of primary consumers in structuring communities of
Northern California streams. NSF Grant Proposal. 45p.
This proposal describes ongoing research concerning the interactions
of fishes, algae grazing insects and algae in the Rice Fork Eel River
above and below the confluence of Bear Creek.
Puckett, L.K. 1975a. Sport fisheries of the Eel River, 1972-1973. Calif. Dept.
of Fish and Game. Memo. Rept. 29pp.
A creel and angler use survey was conducted from September 1972
through August 1973 on the Middle Fork Eel, South Fork Eel and main Eel
rivers.
Approximately 53,600 angler days (202,500 hours) of use were
expended during the year and about 27,100 fish were caught.
The catch
was made up of approximately 900 American shad (Alosa sapidissima), 600
silver salmon (Oncorhynchus kisutch), 2,400 fall run king salmon
(Oncorhynchus tshawytscha), 14,200 juvenile steelhead (Salmo gairdneri),
2,500 half-pounder steelhead (Salmo gairdneri), 400 spring-run steelhead
(Salmo gairdneri), 4,300 winter-run steelhead (Salmo gairdneri), and
1,800 redtail surfperch (Amphisticus rhodoterus).
No fish was observed
in an angler's catch at turbidities that exceeded 30 Jackson Turbidity
Units (Author's abstract).
L.K. 1975b. The status of spring-run steelhead (Salmo gairdneri) of
the Eel River system. Calif. Dept. of Fish and Game Nemo. Rept. 22p.
Spring-run steelhead in the Middle Fork Eel River may make up about
80% of the native spring-run steelhead in California.
Since 1966, the
spring-run steelhead population in the Niddle Fork Eel River has been
58
increasing.
In 1974, the run in the Middle Fork Eel River <;as at least
1,850 fish (1,522 reached the summer holding area and 328 were landed in
the sport catch).
An examination of scales of 58 Van Duzen River fish in 1968 and 82
Middle Fork Eel River Fish in 1973 and 1974 showed that most had spent 2
years in freshwater and 2 years in the ocean.
Few were repeat spawners.
About 5,000 angler hours were expended each year from mid- April to
mid- June in 1973 and 1974 fishing for spring- run steelhead in the Middle
Fork Eel River.
Anglers caught an estimated 394 fish in 1973 and 328 in
1974 (Author's abstract).
____~~, L.K. 1976. Observations on the downstream migrations of anadromous
fishes within the Eel River system. Calif. Dept. of Fish and Game. Memo.
Rept. 35pp.
The downstream migrations of anadromous fishes were studied
periodically from 1959 through 1970 on the main Eel, Middle Fork Eel,
South Fork Eel, and Van Duzen Rivers.
Juvenile king salmon (Oncorhynchus
tshawytscha) were trapped from late March to early November.
Juvenile
silver salmon (Oncorhynchus kisutch) were trapped in tributaries of the
South Fork Eel River where thet were observed from mid-March to early
August.
the year.
Juvenile steelhead (Salmo gairdneri) were trapped during most of
Catches of
through June.
steelhead-of~the-year
were highest from April
In the South Fork Eel River system older steelhead usually
migrated earlier than fish of the year; however, the older fish also
moved concurrently with the fish-of- the-year.
Most juvenile American
shad (Alosa sapidissima) in the main Eel River were trapped from late
July to early November.
Juvenile green sturgeon (Acipenser medirostris)
in the main Eel River were trapped from the end of May to September
59
('-'\uthor 's abstract).
L.K. 1977. The Eel River estuary - observations on morphometry,
fishes, water quality and invertebrates. Calif. Dept. of Fish and Game
~1emo . Rept.
Water development projects proposed by state and federal
organizations to export water to Southern California could have a
profound effect on the estuary of the Eel River.
This study was
initiated in August 1973 to gain insight into the morphology of the
estuary, the aquatic life inhabiting the estuary (with special emphasis
on anadromous salmonids), and the extent to which the estuary serves as a
nursery for salmonids.
Fish sampling continued, biweekly beginning in
October 1973, through September 1974.
DWR surveys from spring 1974 to
fall 1976 provided information on invertebrates and on the water quality
of the estuary.
1-'----' L., R. Blake and J. Horton. 1968. Summer run steelhead: are they here
to stay? Outdoor California 29: 3-4.
This article gives a brief account of the life-history of summer
steelhead and their distribution.
The possible effects on the Eel River
populations of proposed water projects are also discussed.
~_~_'
L.K. and R.N. Hinton. 1974. Some measurements of the relationship
between streamflow and king salmon spawning gravel in the main Eel and
South Fork Eel Rivers. Calif. Dept. of Fish and Game. Envir. Ser. Br.
Admin. Rept. No. 74-1. 17p.
Studies to estimate the amount of spawning area available for king
salmon were conducted on the mainstem Eel River in 1966 and 1967, and on
the South Fork Eel River and three of its tributaries in 1966.
The
purpose of the studies was to provide basic data on water requirements of
60
king salmon in the event water projects are built within the Eel River
system.
Study sections 0.8 km (0.5 mile) long were established at six sites
on the main Eel River and at one site on the South Fork Eel River .
Study
sections were also established on the East Branch of the South Fork Eel
0 . 4 km (0.25 mile) long, on Tenmile Creek, 0 . 4 km (0.25 mile) long, and
on Redwood Creek, 0.2 km (0 . 1 mile long).
Each of the study sections was
representative of several miles of stream.
Suitable spawning gravel was
measured and mapped at each study section.
Water velocities and water
depths were measured at streamflows that ranged from 2.3 to 47.3 m3 /sec
(80 - 1,670 cfs) in the main Eel River and from 0.4 to 12.7 m3 /sec (13 450 cfs) in the South Fork Eel and its tributaries.
The results of plotting depth and velocity data and observations of
the river during stream surveys showed that the following streamflows
would cover most of the potential spawning areas and provide average
velocities across riffles near the midpoint of the range of suitable
velocities (0.7 m/sec - 2 . 3 ft/sec): Main Eel River - Confluence of Tomki
Creek to Outlet Creek - 36.8 m3 /sec (1,300 cfs); Outlet Creek to Dos Rios
- 22.6 m3 /sec (800 cfs); Dos Rios to Alderpoint - 25.5 m3 /sec (900 cfs);
Alserpoint to midway between Alderpoint and McCann - 19.8 m3 /sec (700
cfs); the remainder of the main river to Holmes - 48.1 m3 /sec (1,700
cfs); lower South Fork Eel - 11 . 3 m3 /sec (400 cfs); Tenmile Creek 3 . 5
m' /sec
(125 cfs); and Redwood Creek - 1. 4 m3 /sec (50 cfs).
There was no
potential spawning area in the lower East Branc h South Fork Eel (Author's
abstract) .
61
Reynolds, F.L. 1983. 1983 status report of California wild and scenic river
salmon and steelhead fisheries. Calif. Dept. of Fish and Game. The
Resources Agency. 57 p., plus appendices.
This
repor~
is the second in a series of fisheries status reports
for the California Wild and Scenic Rivers, which includes the Eel River.
It includes a review of 1982- 1983 fishery management activities and an
update on the status of the system.
Reconnnendations for improved
management and enhancement of the fisheries are also included.
Appendices B through H consist of studies carried out on the Eel River in
1982- 1983 (Each of these studies are also listed in this bibliography
separately, by author).
Reynolds, F.L. and T.J. Mills. 1982. 1982 status report of California wild and
scenic river salmon and steelhead fisheries. Calif. Dept. of Fish and
Game. The Resources Agency. 159p.
This report provides a brief history of the Wild and Scenic Rivers
studies, describes the history and physical characteristics of each of
the included drainages (including the Eel River drainage), and reviews
the status and importance of the salmon and steelhead fisheries in each
watershed.
The roles of the various regulatory agencies in managing
these resources are discussed and a number of recommendations made for
the improved management of these fisheries.
Roelofs, T.D. 1983. Current status of California summer steelhead (Salmo
gairdneri) stocks and habitat, and recommendations for their management.
Report to USDA Forest Service Region 5. 77 p., plus appendices.
This report deals with the current status of summer steelhead in
California.
Their known distribution is described, along with
information on their life history and aspects of their behavior including
seasonal movements, habitat selection and fright responses.
The
62
populations inhabiting the Middle Fork Eel River and Van Duzen River are
discussed as are other California populations.
threats to all the populations are discussed.
Actual and potential
The author makes several
management recommendations aimed at protecting, and where possible,
enhancing the fish stocks and their habitat.
Rowell, J.H., Jr. 1962. The 1962 steelhead rescue report for region 3. Calif.
Dept. Fish and Game. Inland Fish. Admin. Rept . 16p.
This report presents the results of fish rescue and habitat
improvement work for the Nort Coast area, including the Eel River
drainage, for the year 1962.
Sanders, S . W. 1983. Annual Report Van Arsdale Fisheries Station 1982- 83 .
Calif. Dept. of Fish and Game. Anad. Fish. Br. Admin. Rept. No. 83- 8. 7p.
This report presents the fish counts at the Van Arsdale fish
facility for the year 1982- 1983.
Shapovalov, L. 1937. Report on an investigation of debris and pollution in the
streams in and about Little Lake Valley, near Willits, Mendocino County,
California. Typewritten rept. to Calif. Div. Fish and Game, Bur. Fish
Cons., Dec.10, 1938. 16p.
This report documents an investigation of debris and pollution which
was
felt to limit access of populations of king salmon, silver salmon and
steelhead to the streams above Willits.
headwaters of Outlet Creek .
streams
was
These streams comprise the
The author concluded that access to these
being restricted and suggested corrective measures.
____~~___ , L. 1938. A suggested program of fish rescue and improvement work
for the Eel River drainage basin, California. Calif. Dept of Fish and
Game. Bureau of Fish Conserv. Admin. Rept. No. 38- 18.
This report suggests a program of fish recue and habitat improvement
work for the Eel River drainage.
This program
was
eventually extended to
63
the entire North Coast region.
____-=~-= '
L. 1939. Recommendations for management of the fisheries of the
Eel River drainage basin, California. Calif. Dept of Fish and Game. Bur.
of Fish Conserv. Admin. Rept. 39-2. 19 p.
This report presents the results of a survey of the fishes of the
Eel River drainage, a summary of the fishery management problems in the
drainage and outlines a number of recommendations for the solution of
these problems.
The same information is presented in Shapovalov (1941a).
____~~~ , L. 1939b. Fish rescue work in the Eel River drainage in 1938.
Calif. Dept. of Fish and Game. Bur. Fish Conserv. Admin. Rept. 39-3.
This report presents the results of fish rescue and habitat
improvement work in the Eel River drainage for the year 1938.
=-77~-=--' L. 1940a. Fish rescue work in the North Coast district in 1939.
Calif. Dept. of Fish and Game. Bur. Fish Conserv. Admin. Rept. 40-3.
This report presents the results of fish rescue and habitat
improvement work in the North Coast region, including the Eel River
drainage for the year 1939.
____~~~ ' L. 1940b. Preliminary r eport on the effect of the use of water at
Lake Pillsbury and at Van Arsdale Reservoir on the salmon and trout of
the Eel River system. Calif. Dept. of Fish and Game. Bur. Fish Conserv.
40- 1.
This report documents that on 23 and 24 August 23, 1938 there was a
total input to Pillsbury Reservoir of 34.75 cfs.
1.7 cfs was released below Van Arsdale Reservoir.
Of this amount, only
The authors note that
this small release is not sufficient to maintain the fishe ries downstream
of Van Arsdale Reservoir.
64
_ _ _ ---:-_ ' L. 194Oc . Some calculations regarding the natural spa,ming of king
salmon in the South Fork of the Ee l River a bove Benbow Dam, season of
1938-1 939 . Calif. Dept. of Fis h and Game . Bur . Fis h Conserv. Admin . Rept.
40-2 .
Based on a mark-recapture experiment conducted on the South Fork Eel
Ri ve r duri ng the 1938- 1939 season, the author calculated that between 2
and 3 million juve nile king salmon were produced in the area above Benbow
Calc ulations based on the number of spawning females passing over
Dam .
Benbow Dam (2,571 of 6,001 total fish) gave a much higher number (about 7
mi ll i on young salmon).
A number of assumptions were made in both
cal c ulations, making it impossible to decide which number was more
accurate.
__-=__ ,
L. 1941a. Pros pectus for an Eel River fish management area. Calif.
Dept. of Fish and Game. Bur. Fish Conserv. Admin. Rept. 41- 15.
This report documents a proposal for the establishment of "fish
manageme nt areas" .
These areas would provide for the coordination of
s t udies and management practices in particular areas of the state.
The
report discusses the difficulties of implementing proper fishery
management practices and also identifies fishery problems specific to the
Eel River drainage.
These probl ems include: 1) Benbow Dam fishways, 2 )
fishway at Cape Horn Dam at Van Arsdale Reservoir, 3) blocking of
s pawning grounds by Scott Dam at Lake Pillsbury, 4) debris and pollution
in the streams in and about Little Lake Valley, near Willits, 5) flow in
Eel River below Van Arsdale Rese rvoir, t o confl ue nce wit h Middle Fork of
Ee l Rive r, 6) spea ring of salmon and steelhead in the lowe r Eel River, 7)
poaching for immature trout, especially pr ior to the opening of the
s ummer fi s hing season (April - May), 8) death of trout during hot spells,
especially in the South Fork of Eel River between Dyerville and
-~
-, '
65
Rattlesnru{e Creek and in the mainstem Eel River between Dyerville and
Bell Springs Station, 9) pollution from creameries near Ferndale.
Recommendations are made for the solution or improvement of each problem
and a comprehensive
n~agement
plan for the Eel River drainage is
presented.
____-=-=~' L. 1941b. Fish rescue work in the North Coast district in 1940.
Calif. Dept. of Fish and Game. Bur. of Fish Conserv. Admin. Rept. 41-12.
This report presents the results of fish rescue and habitat
improvement work in the North Coast region, including the Eel River
drainage for the year 1939.
____-=-=~' L. 1942. Fish rescue work in the North Coast district in 1941.
Calif. Dept. of Fish and Game. Bur. Fish Conserv. Admin. Rept. 42-12.
This report presents the results of fish rescue and habitat
improvement work in the North Coast region, including the Eel River
drainage for the year 1941.
-
, L. 1944. Fish rescue work and stream improvement work in the North
Coast area in 1942. Calif. Dept. of Fish and Game. Bur. Fish Conserv.
Admin. Rept. 44- 27.
--:::--
This report presents the results of fish rescue and habitat
improvement work in the North Coast region, including the Eel River
drainage for the year 1942.
____-=__~'
L. 1945a. Fish rescue and stream improvement work in the North
Coast area in 1944. Calif. Dept. of Fish and Game. Bur. Fish Conserv.
Admin. Rept. 45-7.
This report presents the results of fish rescue and habitat
improveme nt work in the North Coast region, including the Eel River
drainage for the year 1944.
66
____~~~' L. 1945b. Fish rescue and stream improvement work in the North
Coast area in 1943. Calif. Dept. of Fish and Game. Bur. Fish Conserv.
Admin. Rept. 45-4.
This report presents the results of fish rescue and habitat
improvement work in the North Coast region, including the Eel River
drainage for the year 1943.
______~--, L. 1945c. Observations on controlled flows in the Eel River, Lake
and Mendocino Counties, California, September 25-26, 1945. Calif. Dept.
of Fish and Game. Bur. Fish Conserv. Admin. Rept. 45-26.
On
September 25 and 26, 1945, PGE varied the normal amount of water
released from Scott Dam to determine the minimum and maximum flows that
could be maintained in the Eel River between Lake Pillsbury and Van
Arsdale Reservoir without serious detrimental effects on fish life and
fishing.
The flows investigated were 40, 75, 300 and the normal 208 cfs.
Observations indicated only a very slight loss of trout due to
stranding of fish at 75 cfs, but a moderate loss occurred at 40 cfs.
The
author recommended that , whatever flow is maintained, it should be
maintained at a constant rate rather than continually fluctuating.
The
author also recommends the installation of a fishway or elevator to allow
anadromous salmonids to utilize the spawning areas above Scott Dam.
____-=__~'
L. 1949. Fish rescue and stream improvement work in the North
Coast area in 1945. Calif. Dept. of Fish and Game. Bur. Fish Conserv.
Admin. Rept. 49.
This report presents the results of fish rescue and habitat
improvement work in the North Coast region, including the Eel River
drainage for the year 1945.
67
______~~' L. and E.H. Vestal. 1938. Preliminary outline of suggested stream
and lake improvement in the Eel River watershed. Calif. Dept. of Fish and
Game. Bureau of Fish Conserv. Arunin. Rept. No. 38-11.
11,is report identifies the presence of dams, which block or
partially block access of the spawning runs to some of the best spa\;ning
gravels in the drainage, and poor logging practices, which result in log
jams, increased siltation, pool filling, and reduced flows, as major
reasons for the observed decline in salmonid production.
The authors
suggest a program of barrier removal and fish rescue work to help correct
these problems.
The proposed fish rescue work consists of maintaining
the connections of tributaries to the main river during low flows and
rescueing fish in isolated pools and returning them to the river.
Sommarstrom, S. 1984. Mendocino County salmon and steelhead management plan.
Mendocino County Fish and Game Advisory Committee. 103p.
The stated purpose of this report is to improve coordination among
the various groups involved in fisheries management work in the county.
In doing so, the report provides a review of the responsibilities and
goals of the various federal, state, local and private groups and
individuals involved in fisheries management work in the county.
Habitat
protection was selected as the first priority for county management
efforts to "achieve and maintain optimum natural production of salmon and
steelhead in each Mendocino County watershed."
Smith, B.J. 1976. Eel-Russian Rivers streamflow augmentation studies. Dept. of
Water Resources Bull. No. 105-5.
The fisheries information in this report is limited to excerpted
portions of Lee and Baker's 1975 report.
68
Smith , E.J., Jr . and R . F. Elwel l . 1959 . Supp l eme n tary bas i c fi s he r ies data,
Middle Fo rk of Eel River investigati on. Calif. Dept. of Fish and Game .
Contract Ser ., unpublished r e port . unpaged.
The purpose of this r epor t was to make a vailable for use a l arge
amount of basic fishe rie s data obtained during studie s o f the poss ible
effects of proposed water d e velopment projects on the fis herie s of the
Middle Fork Eel River.
The fishes present included king s almon, spring
and winte r run steelhead, Pacific lamprey, rainbow trout, green sunfish,
Humboldt sucker, and threespine stickleback.
The report contains the
results of temperature studies, fish population studies, adult fish
migration, spawning distribution, location of rearing areas for young
fish, location of barriers and spawning gravel surveys.
Snyder, J.O. 1907. The fishes of the coastal streams of Oregon and Northe rn
California. Bulletin of the Bureau of Fisheries 27:153-189.
This article documents the fish fauna of the smaller coastal
drainages of Oregon and northern California.
Study sites in the Eel
River Drainage incllrle the South Fork Eel River, at and near Garberville,
and the Van Duzen River.
The species taken include Pacific lamprey,
Humboldt sucker, threespine stickleback and prickly sculpin.
species were not incllrled.
Salmonid
This article also contains the original
species descript i on o f the Humboldt sucker, which is now considered to be
Sacramento sucker (Ronald Fritsche , Humboldt State University, personal
communication ) .
_ __ , J.O. 1925. The half pcuyler of the Eel River, a steelhe ad trou t .
Calif. Fis h and Game 11:49-55.
This report dOCUileDts the life history o f the Eel River half- pounder
and establishe s that it is a st.eelhead t r out.
An examinat i on of scales
69
revealed that the half- pounders are steelhead that have spent two years
in the stream and one s eason in the ocean .
• eegue, S.A. 1982. Stream microhabitat selectivity, r esource partitioning, and
niche shifts in grazing caddisfly larvae.
california, Davis. 62 p.
~ticrosite
~hste r's
thesis, University of
selectivity, resource partitioning, and nic he shifts in
five species of grazing caddisfly larvae (Glossosoma califica, G.
penitum , Dicosmoecus gilvipes, Neophylax rickeri, and
~
splendens) were
quantified by underwater measurement of microhabitat availability and
utilization in three northern California streams (Elder and Fox Creeks
and South Fork Eel River).
The microhabitat parameters water depth,
water velocity, rock size, rock roughness, and slope were measured.
Comparisons of habitat available to habitat used revealed significant
selection for at least two microhabitat parameters by each population,
with water depth and velocity being the most important.
Comparisons' of·
habitat used between species showed significant partitioning of at least
two microhabitat parameters at each site, with depth being partitioned at
all sites.
Comparisons of habitat used between sites quantified a major
niche shift by D. gilvipes in its preference for riffles versus pools.
Non-parametric discriminant analysis revealed significant microhabitat
partitioning on a multivariate level at two sites and correctly
classified 70% and 88% of these larvae to species depending on their
microhabitat parameter values.
Size-selective predation by dippers and
steelhead is proposed as a hypothesis to explain the observed resource
partiti oning and niche shift.
70
U.S. Dept. of the Interior. Fish and Wildlife Service. Office of the Regional
Director. Region 1. 1950. Branscomb Reservoir South Fork Eel River:
Preliminary evaluation ['e port on fish and wildlife resources . 20p.
This report recognizes that the project was not economical for
hydroelectric generation or large enough to provide significant flood
control.
The reasons given for the project are that it might improve the
fish and wildlife value of the area and provide additional opportunities
for recreation.
By providing steady summer flows of cool water, the
project would improve downstream nursery areas for steelhead and coho
salmon.
Also, fall flows could be manipulated to improve adult access to
downstream spawning areas and improve conditions for sport fishing.
U.S. Heritage Conservation and Recreation Service. 1980. Final environmental
impact statement. Proposed designation of five California rivers in the
national wild and scenic rivers system. Vol. 1. 322p.
This study documents the possible envirorunental impacts of including
five California rivers in the national wild and scenic rivers system.
The rivers considered are the Klamath, Trinity, Eel, Smith and lower
American Rivers.
Basic fisheries information on each system is included.
VTN, Inc. 1982. Potter Valley project (FERC No. 77) Fisheries study final
report. VTN Oregon Inc., Wilsonville, Oregon. 320 p. plus appendices.
This report contains the results of a number of studies that were
undertaken to determine an operating schedule for PG and E's Potter
Valley Project that was acceptable to all interested parties.
The
objectives of these studies were to: 1) determine the minimum streamflow
releases necessary to provide adequate passage of upstream migrant adult
chinook salmon and steelhead trout; 2) determine the timing and number of
upstream migrant adult chinook salmon and steelhead trout; 3) quantify
71
the amount of spal'fiing and rearing habitat available to chinook salmon
and steelhead trout; 4) determine the timing and number of downstream
migrant juvenile salmonids; 5) evaluate the feasibility of channeling the
Hearst Riffle to provide a channel of adequate depth and velocity for
passage of upstream migrants; 6) determine whether and, to what extent,
mitigation measures should be undertake n; 7) determine the fishing
conditions for each flow being tested.