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ANNUAL PROGRESS REPORT
PROJECT TITLE: Steelhead Production Factors
PROJECT NUMBER: F-120-R-10
PROJECT PERIOD: 1 October 1993 to 30 September 1994
Prepared by: R.B. Lindsay
R.K. Schroeder
K.R. Kenaston
Oregon Department of Fish and Wildlife
2501 S.W. First Street
P.O. Box 59
Portland, Oregon 97207
This project was funded in part by the Sport Fish and Wildlife Restoration
Program administered by the U.S. Fish and Wildlife Service.
CONTENTS
INTRODUCTION
JOB 1.3--WILD BROODSTOCK DEVELOPMENT
Objective
Summary of Accomplishments
Discussion
JOB 2.2--REDUCTION OF STRAYING IN HATCHERY STEELHEAD
Objective
Summary of Accomplishments
Discussion
Origin of Strays
Acclimation
Return From 1991 Releases
Return From 1992 Releases
Recycled Adults
Residual Juveniles
Salmon-Steelhead Catch Card
Catch and Release of Hatchery Steelhead
JOB 4.1--STERILIZATION OF HATCHERY STEELHEAD
Objective
Summary of Accomplishments
Discussion
Return From 1990 Releases
Return From 1991 Releases
Return From 1992 Releases
Maturation
Fertility
ACKNOWLEDGMENTS
REFERENCES
APPENDIX A. Life History Data from Adult Winter
Steelhead in the Siuslaw River, 1994
APPENDIX B. Creel Survey Methods and Estimated Sport
Catch, Siuslaw River, 1993-94 Run
APPENDIX C. Adult Steelhead Returns-- Unadjusted Data
APPENDIX D. Temperature and Dissolved Oxygen in the
Portable Raceway on Whittaker Creek During the Time
Steelhead were being Acclimated, 1994
INTRODUCTION
The persistence of hatchery programs and of productive natural
populations of anadromous fish may depend, in part, on the ability of fish
managers to conserve genetic resources. The only way to conserve genetic
resources of steelhead, given present technologies, is by maintaining wild
stocks (Hershberger 1980). Man influences the genetic diversity of wild fish
by changing habitats, by harvesting fish, and by stocking hatchery fish.
The goal of the steelhead research project is to provide managers with
recommendations that will help them decrease the risk of detrimental effects
of hatchery programs on the genetic characteristics of wild steelhead.
Lindsay et al.(1988) identified four objectives to reach this goal, but
dropped one objective and added another in 1991 (Lindsay et al. 1991). The
objectives are:
1. Make recommendations for collecting wild broodstock and for rearing their
progeny so that indigenous broodstock can be used in hatchery programs in
compliance with the Wild Fish Management Policy (ODFW 1992).
2. Develop strategies to reduce the number of hatchery strays spawning with
wild fish.
3. Recommend changes in site-specific hatchery practices to reduce selection
and inbreeding in hatchery operations. (Deleted from study in 1991.)
4. Evaluate the feasibility of reproductively isolating hatchery fish from
wild fish.
5. Develop methods management biologists can use to estimate the percentage
of hatchery steelhead spawning in streams managed for wild steelhead.
(Added to study in 1991.)
The following sections describe work conducted from October 1, 1993
through September 30, 1994. Job numbers reference objectives and tasks in our
study proposal. For example, Job 2.2 is task 2 under objective 2.
JOB 1.3--WILD BROODSTOCK DEVELOPMENT
Objective
Develop solutions to problems of holding wild adults, incubating eggs
pending disease clearance, and rearing juveniles that will return at an
acceptable rate. Much of this objective has been completed and is presented
in Lindsay et al. (1990, 1991, 1992 and 1993) and in Schroeder (in prep.).
Summary of Accomplishments
We released smolts from wild Siuslaw parents collected in 1992-93 into
Lake Creek in April 1994 along with a control group of Alsea stock. We also
collected 17 wild and 5 hatchery (Siuslaw stock) winter steelhead in 1993-94
for the Salmon and Trout Enhancement Program (STEP) so they could continue
broodstock development in the Siuslaw River basin.
We found no difference between Siuslaw and Alsea stocks in relative
return of 3-salt adults released as smolts into the Siuslaw River in 1991.
However, the Siuslaw stock had a much lower stray rate back to Alsea River
than the Alsea stock, suggesting a genetic component in homing behavior. In
spite of later migration timing, the 1993-94 sport catch of Siuslaw 3-salts
was similar to that of Alsea 3-salts in the Siuslaw River.
Discussion
About 33,000 smolts--progeny of wild Siuslaw River steelhead--were
released into Lake Creek in spring 1994 along with a control group of 36,000
smolts, progeny of Alsea Hatchery steelhead (Table 1). Relative survival,
straying, and contribution to fisheries of the two groups will be compared
when the adults return in 1995-1996. This is the last release of Siuslaw
stock steelhead as part of our study. ODFW managers and volunteers are
continuing to develop a wild broodstock program for steelhead in the Siuslaw
River.
Adult steelhead from Siuslaw and Alsea stock smolts released into
the Siuslaw River in 1991 returned as 3-salts in 1993-1994 (Table 2).
Adults from these two stocks were sampled with traps on tributaries in the
Siuslaw basin (Figure 1, Table 3) and with a statistical creel survey
(APPENDIX B). Fish that strayed into the Alsea River were sampled with a
creel survey and with a trap at Alsea Hatchery on the North Fork Alsea
River. Adults were called strays if they were captured in a basin other
than the one in which they were released as smolts. Chi square analyses
of 2 x 2 contingency tables were used to test for statistical differences
in 3-salt returns of Siuslaw and Alsea release groups. Sampling effort
varied between 1992-93 (2-salts) and 1993-94 (3-salts), so we could not
compare age composition by brood for the two stocks. Analyses of
differences in 2-salt returns for the two groups were presented by Lindsay
et al. (1993).
The migration timing of 3-salt Siuslaw stock was later than that of
Alsea stock based on catch in the sport fishery and in tributary traps in the
Siuslaw River. Sport anglers caught 60% of the Siuslaw stock in March, the
last month of the fishery. None of the Alsea stock were caught in March. In
addition, 81% of the Siuslaw stock but none of the Alsea stock were caught in
tributary traps after April 1. These results are consistent with 2-salt
returns in 1992-93 when 69% of the Siuslaw fish but only 10% of the Alsea fish
were caught in traps after April 1. The late migration timing of Siuslaw
stock was related to the time their parents were captured for broodstock.
Eighty seven percent of the eggs collected from this brood came from females
captured after April 1, 1990.
In spite of later migration timing, the sport catch of Siuslaw 3-salts
was similar to that of Alsea 3-salts in the Siuslaw River (Table 2). This
contrasts with the 1992-93 two-salt catch where significantly (P < 0.01) fewer
Siuslaw stock hatchery fish were caught by sport anglers than Alsea stock
(Lindsay et al. 1993).
Straying back to Alsea River was reduced by using Siuslaw stock for
hatchery releases into the Siuslaw River. Significantly (P < 0.01) fewer 3-
salt Siuslaw stock released as smolts into the Siuslaw River strayed back to
the Alsea River than did Alsea stock released into the Siuslaw (Table 2). The
results are consistent with 2-salts returns in 1992-93 (Table 2); however,
Alsea Hatchery trap was closed March 25 in that year and some late migrating
Siuslaw stock could have been missed. Historically, Alsea hatchery adults
released as smolts into the Siuslaw River have strayed back to the hatchery at
a high rate rather than returning to the Siuslaw (Kenaston 1986). Results
from this first of three brood year releases suggest a genetic component in
homing behavior.
We used combined trap and sport catch data in the Siuslaw and Alsea
rivers to estimate relative survival between 3-salt Siuslaw and Alsea stocks.
We found no significant difference (P = 0.56) in return rate between 3-salt
Siuslaw and Alsea stocks. However, a higher proportion of Alsea stock strayed
to the Alsea River. Lindsay et al. (1993) found no statistically significant
difference in an index of return rate between the same brood of Siuslaw and
Alsea 2-salts. Because of the late egg take, Siuslaw smolts released in 1991
were smaller than Alsea smolts (see Table 1, page 3) and, consequently,
survival might be expected to be lower for Siuslaw than for Alsea smolts.
JOB 2.2--REDUCTION OF STRAYING IN HATCHERY STEELHEAD
Objective
Identify management or hatchery practices that contribute to straying of
hatchery steelhead and recommend changes in these practices to reduce rates of
straying.
Summary of Accomplishments
Three broods of hatchery steelhead were differentially fin clipped at
hatcheries throughout the state and released as smolts in the spring of 1990,
1991, and 1992 to determine the extent and origin of stray adult returns
(Lindsay et al. 1992). Two-salt hatchery strays from the three release years
averaged 6% of the sport catch in 11 coastal streams in 1991-92, 12% of the
catch in six coastal streams in 1992-93, and 12% of the catch in eight coastal
streams in 1993-94. In all three run years the Alsea River contained the
highest percentage of stray hatchery fish, with most originating from
outsystem smolt releases from Alsea Hatchery.
A third brood of about 30,000 Alsea Hatchery winter steelhead was
acclimated in a portable raceway in Whittaker Creek (Siuslaw River) to
determine if acclimating smolts will reduce straying and increase homing to a
tributary release site. The fish were released after 30 days in the raceway
along with two control groups.
Acclimating Alsea stock smolts for 33 days at the Konnie site on Lake
Creek before releasing them into Lake Creek in 1991 increased the brood’s
smolt to adult survival. However, acclimation did not reduce straying of
adults back to Alsea River.
Acclimating smolts for 30 days in Whittaker Creek in 1992 did not
increase the homing accuracy of 2-salt adults returning in 1993-94 compared to
a control group released directly into Whittaker Creek. Both groups showed a
high degree of homing to Whittaker Creek once they entered the Siuslaw River.
Acclimation did not increase survival from smolt to adult or reduce straying
of adults compared to the control released directly into Whittaker Creek.
Discussion
Origin of Strays
The Oregon Department of Fish and Wildlife differentially marked three
broods of hatchery steelhead to document the extent of adult straying and to
determine the origin of strays. Finclipped smolts were released in 1990,
1991, and 1992. Adult strays from these releases in the 1991-92 and in the
1992-93 run years were reported in Lindsay et al. (1992) and Lindsay et al
(1993), respectively. To evaluate straying, we conducted creel surveys on two
coastal streams and obtained creel data from district managers on six other
coastal streams in 1993-94. We also used trap catches in five coastal basins.
On the average, stray hatchery steelhead composed 12% of the catch in
the eight streams where creel surveys were conducted in 1993-94 (Table 4).
The highest number was in the Alsea River where 30% of the adults caught were
hatchery strays. Eighty-eight percent of the hatchery fish that strayed into
the Alsea River in 1993-94 were reared at Alsea Hatchery and released into
other river systems as smolts ("outsystem" releases). Adults returning from
outsystem releases of smolts into the Siuslaw River alone accounted for 73% of
the strays into the Alsea River (Table 5).
Strays composed a large percentage of the hatchery fish caught in traps
in tributaries within the Alsea basin, but a much lower percentage in
tributaries in basins outside the Alsea (Table 6). As with the sport catch,
most strays in Alsea tributaries originated from outsystem releases of smolts
from Alsea Hatchery.
Acclimation
To evaluate if acclimating hatchery fish before release reduces
straying, we acclimated a fourth brood of Alsea Hatchery winter steelhead in
the Siuslaw basin in 1994. We acclimated the first brood on the Konnie
Memorial property on Lake Creek in 1991. The location was changed in 1992 to
Whittaker Creek so that, in addition to straying, we could evaluate the use of
acclimation to attract hatchery returns to a collection site so they could be
separated from wild fish as part of Objective 4. We can trap returning
hatchery fish in Whittaker Creek but not in Lake Creek because of its large
size. We constructed a trap in September 1992 in Whittaker Creek to capture
returning adults (Figure 2).
The fourth brood of about 30,000 Alsea hatchery steelhead was acclimated
for 33 days in March 1994 in a portable raceway (Figure 3) on Whittaker Creek
(RM 46.5) about 200 yards upstream from its confluence with the Siuslaw River.
Two diesel trash pumps pumped 460 gpm of water from Whittaker Creek into the
raceway. Loading in the pond at time of transfer was 7.7 lbs/gpm (1.5 lbs/cu
ft). The fish were hand fed every 1.5 hrs each day from 0800 to 1800 hours, 7
days a week. Water temperature and dissolved oxygen were monitored daily
(APPENDIX D). Loading in the pond at time of release on March 29 was 10.6
lbs/gpm (2.0 lbs/cu ft).
Two control groups were released 1 day after the acclimated group. One
control group of about 30,000 smolts was released directly into Whittaker
Creek (“Whittaker Creek direct release”) The other group of 46,000 smolts was
released into the mainstem Siuslaw River (“mainstem control release”) at four
different locations to simulate past hatchery releases into the Siuslaw (Table
7). A fourth group, reared from eyed eggs to smolts in an earthen pond on
Letz Creek (RM 105) in the Siuslaw basin by STEP volunteers, were released
into Whittaker Creek on March 28. The Letz Creek group will enable us to
compare straying to Alsea River of Alsea stock reared to smolt wholly within
the Siuslaw to that of groups reared to smolts in Alsea Hatchery and released
into the Siuslaw.
Adult steelhead from acclimated and control groups of Alsea smolts
released into the Siuslaw River in 1992 and 1991 (Table 7) returned as 2-salts
and 3-salts, respectively, in 1993-94. Adults from these groups were sampled
with a statistical creel survey (APPENDIX B) and with traps on 10 tributaries
in the Siuslaw basin (see Figure 1, page 5, and Table 3, page 6). Fish in the
Alsea River were sampled with a non-statistical creel survey and with the trap
at Alsea Hatchery on the North Fork Alsea River. Chi square analyses of 2 x 2
contingency tables were used to test for statistical differences in return
between acclimated and control groups.
Return From 1991 Releases: Acclimating Alsea hatchery smolts for 33
days at the Konnie site on Lake Creek before release increased smolt to adult
survival but did not reduce straying of adults back to the Alsea River (Table
8). We found 25% more (significant @ P = 0.03) acclimated than control fish
(2-salt and 3-salt adults combined) in Siuslaw and Alsea fisheries and in
tributaries. Based on the Alsea fishery and on trap catch at Alsea Hatchery,
we found no difference (P = 0.58) in the proportion of acclimated fish and of
control fish that strayed into the Alsea River.
Return From 1992 Releases: Acclimated and control (i.e. direct) groups
of smolts released into Whittaker Creek in 1992 homed back to Whittaker Creek
as 2-salt adults in 1993-94 with a high degree of accuracy. Of the returning
adults caught in tributary traps, 98% of the acclimated group and 96% of the
direct group returned to Whittaker Creek (Table 9). Only 23% of the mainstem
control group were caught in the Whittaker Creek trap (Table 9).
Based on 2-salt returns, acclimating Alsea hatchery smolts at Whittaker
Creek for 30 days did not increase smolt to adult survival or reduce straying
of adults back to Alsea River compared to the Whittaker Creek direct release.
Although we found no statistical difference in return of 2-salt adults between
the acclimated group and the direct group, about 12% more acclimated than
direct fish were sampled in fisheries and in traps in the Siuslaw and Alsea
rivers (adjusted for differences in release numbers)(Table 10).
The proportion of the total Siuslaw-Alsea sport and trap catch of each
of the three release groups observed in the Alsea River was not significantly
different (P = 0.41) among groups, indicating acclimation did not reduce
straying to the Alsea River. Stray rates into the Alsea River were 19%, 20%,
and 22% for the Whittaker Creek acclimated, the Whittaker Creek direct, and
the mainstem control groups, respectively. Straying of adults back to the
Alsea River from smolts reared at Alsea Hatchery but released into the Siuslaw
River has been a management problem for many years (Kenaston 1986).
Fewer of the mainstem control group were captured in the Siuslaw River
in traps and in the Alsea River in the fishery and at Alsea Hatchery than the
two Whittaker Creek groups. However, sport catch of the three groups in the
Siuslaw River was similar (P = 0.91) (Table 10). Data from traps in the
Siuslaw were not a good index of survival of the mainstem group because these
fish entered all trapped tributaries in the Siuslaw (Table 9), and likely
entered tributaries not trapped as well. Fishery data in the Siuslaw may be
biased because the mainstem group did not have a specific tributary to return
to as did the other two groups. The mainstem group may have stayed in the
main river longer and been more vulnerable to the fishery than the acclimated
and Whittaker direct groups. Because the stray rate among the three release
groups appeared similar, the number of fish observed in the Alsea River was
probably the best index of survival of the groups. The number of adults from
the mainstem release observed in the Alsea River was significantly less (P <
0.05) than the number from the two Whittaker Creek releases indicating
survival of the mainstem release was less.
Distribution of sport catch through time and within different areas of
the river was generally similar except that more of the Whittaker direct group
were caught by sport anglers in January and in the Upper Siuslaw than the
other two groups (Tables 11 and 12). We have no explanation for this
difference. The mainstem group is the standard for comparison because it
mimics the pattern of past releases of hatchery fish into the Siuslaw River.
Sport catch of steelhead in the Siuslaw River in 1993-94 is shown in APPENDIX
B.
Recycled Adults: The purpose of attracting adult hatchery steelhead to
a tributary is to ultimately remove those adults from the population of wild
spawners. However, the purpose of most steelhead hatchery programs is to
provide sport harvest for anglers. We recycled adult steelhead through the
fishery to determine if these fish increased sport catch while homing to a
collection site for a second time.
Hatchery steelhead captured at the Whittaker Creek trap were tagged and
hauled in a tank in a pickup truck to the head of tidewater in the Siuslaw
River. Recycled fish were sampled in tributary traps and in the sport fishery
in the Siuslaw River.
Only 56% of the recycled acclimated fish and 51% of the recycled direct
fish could be accounted for in traps and in the sport fishery. The percentage
of recycled fish that we could account for, as indicated by trap catch at
Whittaker Creek, differed little through time (Table 13). Of the recycles
caught in traps, 92% of the acclimated fish and 94% of the direct fish were
recaptured in Whittaker Creek indicating homing accuracy was high the second
time through the river.
The fate of the missing recycles is unknown. If recycled fish were
straying at a high rate throughout the Siuslaw basin, we would have expected
to catch more fish in traps outside of Whittaker Creek. Mortality from
handling fish does not explain the high number of missing fish. Only 14 fish
were listed in poor condition at the release site. No recycled fish died
during transport. In addition, we have trucked and held adult fish for
several weeks in the past with little mortality. However, the number of fish
hauled was generally less than was often the case with the reycled fish.
Evenson and Cramer (1984) could account for only about 50% of spring chinook
salmon recycled through the Rogue River in the fishery or back to the hatchery
where they were initially collected. Few of these fish strayed into
tributaries. They attributed the missing fish to mortality. Some recycled
steelhead in the Siuslaw will be tagged with radio transmitters in winter
1994-95 to determine the fate of the missing fish.
Sport anglers caught and kept 12% of the recycled acclimated fish and 7%
of the recycled direct fish. The percentages increased to 18% and 11%,
respectively, if released fish were included.
Another way of looking at contribution of recycles is the increase in
catch of hatchery fish. From this perspective, recycling increased the number
of hatchery fish caught and kept by 35% and 17%, respectively for acclimated
and direct groups. If fish caught and released were included, the catch of
hatchery fish increased 46% and 23%, respectively. On average, anglers
released 12% of first-run hatchery fish caught but 30% of recycled fish
caught. Recycled fish were most likely in poorer condition than first-run
fish. We have no explanation for the difference in sport catch of recycled
fish between the acclimated and direct groups.
Residual Juveniles: The release of smolts into tributaries to increase
the homing of adults would impact resident populations if the smolts did not
migrate (residuals). We sampled Whittaker Creek in 1994 with electrofishers
from the release site upstream to look for residuals. We found hatchery fish
as far upstream as 3 miles from the release site nearly 2 months after release
(Figure 4). We did not sample beyond 3 miles. In general, the proportion of
residuals tended to decrease upstream (Figure 4). A comparison of the length
frequency distribution of residuals with that of the original smolt release
showed that the residuals were the smaller fish at release (Figure 5). We
found no difference in the number of residuals between acclimated and control
groups (excludes the Letz Creek group). We also sampled the mainstem Siuslaw
below the release site in 1994 with a boat electrofisher and found few
hatchery fish, which was consistent with results in earlier years.
Salmon-Steelhead Catch Card
The salmon-steelhead catch card was changed in 1991 so that anglers
could record fish that were caught and released. ODFW hopes the number of
released fish can be estimated from this voluntary record. In 1992
regulations on several streams, including the Siuslaw River, were changed to
require the release of fish that were not finclipped. During creel surveys of
11 streams (1991-92 through 1993-94 run years), we asked anglers how many fish
were caught and released and, of these, how many were recorded on their catch
cards.
The percentage of released fish that were recorded averaged 30% in 11
coastal streams but was variable among streams and among years (Table 14).
The percentage of released fish recorded by anglers increased in 1993-94 in
the four streams where creel surveys were conducted for all three run years
(Table 14). This indicates an increase in anglers’ awareness of the voluntary
part of the catch card or in anglers’ willingness to record released fish.
Because of the variablity in recording, the number of released fish cannot yet
be accurately estimated from the catch card without a survey of anglers each
year by stream to determine the percentage of released fish that are being
recorded.
Catch and Release of Hatchery Steelhead
Anglers released an average of 20% of the hatchery steelhead they caught
in streams where wild fish had to be released (Table 15). This percentage was
similar to the 1993-94 fisheries in the Chetco River (23% of the hatchery fish
were released) where anglers could keep wild steelhead. Based on interviews
with anglers, 40-90% of the hatchery fish were released because they were
spawned out or in poor condition (Table 16). Other reasons given for
releasing hatchery fish were that some anglers released most of the fish they
caught and that some steelhead were considered too small to keep.
JOB 4.1--STERILIZATION OF HATCHERY STEELHEAD
Objective
Determine if hatchery steelhead can be sterilized to reproductively
isolate them from wild fish without reducing return rates.
Summary of Accomplishments
Adults from sterile and control groups released into the South Santiam
in 1990, 1991, and 1992 returned as 4-salts, 3-salts, and 2-salts,
respectively, in 1994. Return rate of sterile groups was much lower than that
of control groups. Most adults returning from sterile groups were not
sterile.
Discussion
We released groups of sterilized summer steelhead into the South Santiam
River in 1990, 1991, and 1992 (Table 17). Methods used to sterilize fish were
described by Lindsay et al. (1989). Fish were reared to smolts at South
Santiam Hatchery and released at Pleasant Valley Bridge (RM 33) in April. In
all three years, the mean length of sterilized groups at release was smaller
than that of corresponding control groups (Table 17).
Sterilized summer steelhead released in 1990, 1991, and 1992 returned as
4-salts, 3-salts and 2- salts, respectively, in 1994 (Table 18). Adult
returns were evaluated with trap catches at South Santiam Hatchery at the base
of Foster Dam, the uppermost limit of summer steelhead migration. A 40
hr/week creel survey of sport anglers in the South Santiam River was conducted
in summers 1992 and 1993 but few experimental fish were observed (Lindsay et
al. 1993 and Lindsay et al. 1992). The creel was dropped in 1994.
Return From the 1990 Release
Total return from the 1990 release averaged 0.76% from sterilized groups
compared to 3.05% from control groups (Table 18). Age at return was extended
in the sterilized group. Although few 4-salt adults returned from either the
treated or control groups, 3-salt adults composed 61% of the brood year return
of the sterile group compared to 27% of the control group.
Return From the 1991 Release
Return of 3-salt and 2-salt adults from the 1991 release of sterilized
fish averaged 0.47% for sterile groups compared to 1.61% for control groups
(Table 18). As with the 1990 release, age at return was extended for the
sterilized group. Three-salt adults composed 63% of the return of the sterile
group and 36% of the return of the control group.
Return From the 1992 Release
Two-salt adults from the 1992 release returned in 1994. Return from
smolt to adult for sterilized groups averaged 0.25%, much lower than the 1.6%
return from control fish (Table 18). Results are consistent with the return
of 2-salts from 1990 and 1991 releases.
Maturation
Adults from sterilized groups that returned to South Santiam Hatchery in
1993 were held until spawning in early 1994 and examined for sexual
development. Most of the treated fish that returned to the South Santiam
River were males. Of the 39 treated fish held at the hatchery only 2 were
females. One fish appeared truly sterile and its sex could not be determined.
Externally, the treated males appeared similar to control males in
development of secondary sexual characteristics. Although milt was hand
extruded from only nine of the treated males during the normal period of
spawning at the hatchery, all treated males appeared to be sexually mature
when examined internally. Gonads from sterilized males were misshapen (Figure
8) and sperm ducts on those that could not be hand stripped appeared
underdeveloped. Gonads of 2-salt sterilized males weighed the same
(P = 0.63, n = 32) as gonads of 2-salt control males. However, gonads of 3-
salt sterilized males weighed significantly less (P = 0.04, n = 34) than those
of same-age control males (Table 19). Mean fork length of 2-salt and of 3-
salt treated males was not significantly different (P = 0.34, n = 32 and P =
0.34, n = 34, respectively) from that of same-age controls (Table 19).
Of the two treated females, one contained eggs that did not ripen by the
end of spawning at the hatchery in mid-February. The other female was spawned
with control males to estimate fertility.
Fertility
Nine males from sterilized groups that could be hand spawned were
crossed with 27 control females (each male crossed with three different
females) to determine if the males were fertile. Nine control males were also
crossed with the same control females. The only treated female that ripened
was crossed with three control males. A control female was crossed with the
same control males. About 300-500 eggs were used in each cross. Survival was
assessed at the eyed-egg stage. A paired t-test on pooled survivals for each
of the nine treatment and control males was used to test for statistical
differences in survival.
Egg survival between treated and control males crossed with control
females was nearly identical, averaging 84% and 88%, respectively (P = 0.56,
n = 9). Survival of eggs from the treated female was 72% compared to 92% from
the control female. Results show that gonads from treated fish were viable
and that the fish were not sterile. However, deformities in male reproductive
ducts or organs evidenced by our inability to hand extrude milt may prevent
most of the sterilized males from spawning naturally. Treated fish would
likely exhibit spawning behaviors because mature gonads were present in fish
that returned.
ACKNOWLEDGMENTS
We acknowledge the following individuals, associations, corporations,
and agencies for their cooperation and help in conducting this study. Much of
our work occurs on private lands in the Siuslaw River basin. We thank Phil
Davidson (Davidson Industries), Scott Keep (Seneca Sawmill Co.), Willie
Bronson and Tom Holt (Willamette Industries), John Perry (International Paper
Co.), Bob Keefer (Lane County Parks), Dale Claassen (Swanson-Superior Forest
Products), David Thompson, Dan Grimm, Charlie Richardson, Steve Bernette
(Siuslaw Salvage and Sales), Elma Rust, and Chris Parker for access to their
property for spawning surveys and to install traps. We especially thank the
McAllister family in Mapleton for letting us use their private river access as
a release site for steelhead we recycle through the sport fishery. Victor
Shawe and his crew at South Santiam Hatchery provided much of the help for the
sterilization experiment. We also acknowledge the help of ODFW personnel in
the Tillamook District, Lincoln District, and South Coast District for
collecting creel and adult trap data. ODFW biologists Will Beidler and George
Westfall in the Siuslaw District are gratefully acknowledged for their help
and support of our project, most of which occurs in their district. Gary
Hoppe and crew with the Eugene District BLM have been very cooperative in our
use of the Whittaker Creek campground as an acclimation and trapping site. We
thank the Eugene Chapter of the Northwest Steelheaders for their help in
setting up our portable acclimation raceway on Whittaker Creek. We also
acknowledge and thank Lisa Burton and Lynn Hood of the Mapleton Ranger
District of the U.S. Forest Service and Rick Rodgers of the Veneta office of
the Oregon State Department of Forestry for their cooperation with trapping
steelhead on their lands. Finally, we thank seasonal biologists, David Low,
Gary Dale, Kodi Taggart, Stephanie Comfort, and Jeff Kamps who did most of the
field work in 1993-94.
REFERENCES
Evenson M.D. and Cramer S.P. 1984 An evaluation of recycling hatchery spring
chinook salmon through the sport fishery in the upper Rogue River.
Oregon Department of Fish and Wildlife, Information Reports (Fish) 84-
10, Portland.
Hershberger, W.K. 1980. Genetic impact of hatchery and other types of
management on anadromous salmonids. Affidavit filed on 21 January 1980
in the case of United States v. State of Washington in the U.S. District
Court, Western District of Washington, Tacoma.
Kenaston, K.R. 1986. Coastal steelhead production factors. Oregon
Department of Fish and Wildlife, Fish Research Project F-120-R, Annual
Progress Report, Portland.
Lindsay R.B., K.R. Kenaston, and R.K. Schroeder. 1988. Steelhead production
factors. Oregon Department of Fish and Wildlife, Fish Research Project
F-120-R, Annual Progress Report, Portland.
Lindsay R.B., K.R. Kenaston, and R.K. Schroeder. 1989. Steelhead production
factors. Oregon Department of Fish and Wildlife, Fish Research Project
F-120-R, Annual Progress Report, Portland.
Lindsay R.B., K.R. Kenaston, and R.K. Schroeder. 1991. Steelhead production
factors. Oregon Department of Fish and Wildlife, Fish Research Project
F-120-R, Annual Progress Report, Portland.
Lindsay R.B., R.K. Schroeder, and K.R. Kenaston. 1992. Steelhead production
factors. Oregon Department of Fish and Wildlife, Fish Research Project
F-120-R, Annual Progress Report, Portland.
Lindsay R.B., K.R. Kenaston, and R.K. Schroeder. 1993. Steelhead production
factors. Oregon Department of Fish and Wildlife, Fish Research Project
F-120-R, Annual Progress Report, Portland.
ODFW (Oregon Department of Fish and Wildlife). 1992. Wild Fish Management
Policy. Oregon Department of Fish and Wildlife Administrative Rule No.
635-07-525 through 635-07-529, Portland.
Schroeder, R.K. A review of capture techniques for adult anadromous
salmonids. Oregon Department of Fish and Wildlife, Information Reports
(Fish) (In Prepartion), Portland.
APPENDIX A
Life History Data from Adult Winter Steelhead
in the Siuslaw River, 1994
Appendix Table A-1. Summary of life history types and average lengths of
adult steelhead captured in tributaries of the Siuslaw River, 1994.
Appendix Table A-2. Percentage females and percentage by saltwater age of
hatchery and of wild steelhead captured in tributaries of the Siuslaw River,
1994.
Appendix Table A-3. Freshwater smolt ages of wild steelhead captured as
adults in tributaries of the Siuslaw River, 1994.
Appendix Figure A-1. Migration timing of wild and of hatchery adult steelhead
based on trap catch in Whittaker Creek, 1993-94 run year.
APPENDIX B
Creel Survey Methods and Estimated Sport Catch,
Siuslaw River, 1993-94 Run
Creel Survey Methods
We surveyed about 39 miles of the Siuslaw River and Lake Creek,
constituting most of the productive fishery area in the basin. We began
surveys the first of December and sampled most days until the end of March
when the steelhead fishing season closed.
Generally, two creel clerks surveyed the fishery 5 days and one surveyed
the fishery 2 days each week. We divided the river into three areas: the
lower Siuslaw from tidewater (RM 22) to the mouth of Lake Creek (RM 29), the
upper Siuslaw from the mouth of Lake Creek (RM 29) to Whittaker Creek (RM
46.5), and Lake Creek from its mouth (RM 0) to Greenleaf Creek (RM 14.5).
During angler interviews, creel clerks recorded: the date, the area of river,
the number of anglers in the party, the number of vehicles the party brought
with them, the number of hours the party fished, the number of fish caught by
the party, and whether the angler fished from the bank or from a boat. Creel
clerks also collected a scale sample, recorded finclip, and measured fork
length of any fish kept by anglers.
Cars were counted at least one of three times each day a creel survey
was conducted. On days when both creel clerks were on the river, cars were
counted at two times during the day. Cars asssociated with bank anglers and
cars towing boat trailers or shuttle cars associated with boat anglers were
counted in each area. Data were averaged over the month for each time to
develop an average number of cars for each time within each strata. In
addition to month, each strata was defined by a river area, day type (weekday
or weekend day), and angler type (bank or boat angler). Strata in December
1993 were defined only by day type and angler type because river area was not
recorded.
Average daily car hours were estimated for each strata as the area under
the curve formed by the average monthly car counts at the start of fishing, at
9AM, at noon, at 3PM and at the end of fishing. Angler effort was assumed to
be zero at 1 hour before and 1 hour after sunrise, the legal start and end of
fishing. The average daily car count within a strata was expanded by the
number of days in the strata to estimate total car hours per strata.
We calculated the number of anglers per car from angler interview data
and multiplied that by the number of car hours for that strata to estimate
total angler hours for each strata. We divided that effort estimate by the
number of angler hours we sampled in angler interview to calculate an
expansion factor for the catch data collected in interviews. In the few cases
where sampled angler hours were greater than the estimated total angler hours
for the month (8 of 52 strata), we used an expansion factor of 1.0. Expanded
catch of different finmark groups were summed to estimate the total catch of
each group within the strata.
Estimated Sport Catch
Appendix Table B-1. Angler hours for winter steelhead in the Siuslaw River,
1994.
Appendix Table B-2. Catch and hours per fish for sport anglers in the Siuslaw
River, 1994. Includes wild and hatchery fish caught and released. Angling
regulations required the release of wild steelhead.
Appendix Table B-3. Sport catch of hatchery and of wild steelhead by month in
the Siuslaw River, 1994. Angling regulations required the release of wild
steelhead.
Appendix Table B-4. Combined sport catch of hatchery and wild steelhead by
month and by river section in the Siuslaw River, 1994. Angling regulations
required the release of wild steelhead.
Appendix Table B-5. Sport catch of hatchery and of wild steelhead by river
section in the Siuslaw River, January through March, 1994. December was
excluded because catch was not separated by river section. Angling
regulations required the release of wild steelhead.
Appendix Table B-6. Sport catch by boat and by bank anglers of hatchery and
of wild steelhead combined in the Siuslaw River, 1994. December was excluded
because catch was not separated by river section. Angling regulations
required the release of wild steelhead.
Appendix Table B-7. Number of hours per fish caught by boat and by bank
anglers for hatchery and wild steelhead combined in the Siuslaw River, January
throught March, 1994. December was excluded because catch was not separated
by river section. Angling regulations required the release of wild steelhead.
APPENDIX C
Adult Steelhead Returns--Unadjusted Data
Appendix Table C-1. Adults recovered in 1992-93 (2-salts) and 1993-94 (3-
salts) from Siuslaw and Alsea stocks of winter steelhead smolts released into
the mainstem Siuslaw River in 1991. Numbers not adjusted for differences in
numbers of smolts released.
Appendix Table C-2. Adults recovered in 1992-93 (2-salt) and 1993-94 (3-salt)
from acclimated and control groups of winter steelhead smolts released into
the Siuslaw River in 1991. Numbers not adjusted for differences in numbers of
smolts released.
Appendix Table C-3. Two-salt adults captured in traps in 1993-94 from four
groups of winter steelhead smolts released into the Siuslaw River in 1992.
Numbers were not adjusted for differences in the number of smolts released or
for trap efficiencies. Includes only fish caught in upstream traps.
Appendix Table C-4. Two-salt adults recovered in 1992-94 from groups of
winter steelhead smolts released into the Siuslaw River in 1992. Numbers were
not adjusted for differences in numbers of smolts released.
APPENDIX D
Temperature and Dissolved Oxygena in the Portable
Raceway on Whittaker Creek During the Time Steelhead
were being Acclimated, 1994