U.S. Dept Commerce/NOAA/NMFS/NWFSC/Publications
NOAA F/NWC-187 - Status and Future of Spring Chinook Salmon in the Columbia River Basin—Conservation and Enhancement
SESSION III: Hatchery Management Strategies and Supplementation
Session Chair: C. Mahnken, National Marine Fisheries Service, Manchester, Washington
EVALUATION OF OUTMIGRATION PERFORMANCE AND SMOLT-TO-ADULT
The spring chinook salmon (Oncorhynchus tshawytscha)
hatchery program in the Grande Ronde Basin is inadequate to provide
adult returns capable of meeting broodstock, supplementation, and
harvest objectives (Carmichael at al. 1986). There we not enough
facilities in northeastern Oregon to expand yearling smolt production.
Water sources suitable for siting new facilities are very limited
because of severe winter conditions and summer flows and temperatures.
To meet the long-term adult escapement goals, production of spring
chinook smolts may be needed from well-water facilities such as Irrigon
Hatchery. Well-water facilities generally have temperature regimes
suitable for production of subyearling spring chinook smolts. There are
obvious economic and hatchery production benefits associated with
releases of subyearling smolts. For these reasons we began an evaluation
of production and release of subyearling smolts. We chose Irrigon
Hatchery as the incubation and rearing site because it theoretically has
suitable water temperatures to produce a 23-g smolt for release in May
of the first rearing year.
Our specific objectives were 1) to assess and compare
outmigration performance of subyearling and yearling smolts and 2) to
determine smolt-to-adult survival and benefits to hatcheries for
subyearling smolts. Rapid River stock eggs were obtained from Idaho in
1986, 1987, and 1988. Eggs used for subyearling production were
transported to Irrigon Hatchery for incubation and rearing. Eggs were
incubated at a constant temperature of 11.20C. Replicate groups of
approximately 40,000 were marked Ad+CWT and replicates of 20,000 were
cold branded. In all 3 years, fish were transported to Lookingglass
Hatchery the first week of May and were held for approximately 2 weeks
before release. Mean length, mean weight, and visual index of smolting
were determined just prior to release. Yearling smolts were produced at
Lookingglass Hatchery under the standard production program and were
marked and branded as described for the subyearling smolts.
Branded fish were recovered and enumerated at Lower
Granite Dam as part of the Smolt Monitoring Program. Migration success
was determined as the percentage of branded fish released that were
estimated to have passed Lower Granite Dam. Migration success, duration,
and rate were determined for both subyearling and yearling smolts.
Yearling smolts were released only in 1988 and 1989 so no comparisons
for 1987 releases could be made. In both 1988 and 1989, he yearling
smolts were released 43 days earlier than the subyearling smolts. We
used comparisons between yearling and subyearling smolts only as ma
index of success because of the differences in release time and size.
We were unable to achieve the target release size of 23 g
in 1987, 1988, or 1989. This was attributed to reduced growth in April
that resulted from handling for marking and branding purposes (Fig. 1).
Subyearling smolts were released in mid-May each year with a mean fork
length range of 102-107 min and a mew. weight range of 12.5-15.0 g (Table 1). Yearling smolts were released earlier at a larger size in both 1988 and 1989 (Table 1).
Migration success of yearling smolts was slightly better in 1988;
however, in 1989, the migration success of subyearling smolts was over
two times better than the yearling molts. We did observe differences in
migration rate and duration between yearling and subyearling smolts. The
length of time from release to migration completion was substantially
longer for subyearling smolts and the migration rate of subyearling
molts was slower (Fig. 2).
SURVIVAL OF SURYEARLING SPRING CHINOOK SALMON SMOLTS
Richard W. Carmichael and Rhine T. Messmer
Oregon Department of Fish and Wildlife
Badgley Hall, Eastern Oregon State College
La Grande, Oregon 97504
Table l. Release information for Rapid
River stock subyearling and yearling spring chinook molts released from
Lookingglass Hatchery. Standard deviation is presented in parentheses.
Age at release, brood years
Mean fork length (mm)
Mean weight (g)
1 April 1988
3 April 1989
20 May 1987
13 May 1988
15 May 1989
We observed significant shifts in the length frequency
and mew, length of subyearling smolts from the time of release to time
of recapture at Lower Granite Dam. (Fig. 3). This
length shift was in part a result of growth; the length of many migrants
recovered at Lower Granite Dam was greater than the length of the
largest fish at release. Zaugg et al. (1986) reported significant
mean-length shifts for 0-age spring chinook that were released from
Little White Salmon Hatchery and recaptured in the Columbia River;
however, the magnitude of change was much less than that which we
The outmigration, performance of subyearling molts indicates good potential for success of this rearing-release strategy (Fig. 4).
However, the true measure of success is survival to adulthood.
Preliminary information regarding smolt-to-adult survival is not
encouraging. One-ocean (age 2) and two-ocean. (age 3) adults from
1986-brood releases should have returned in 1988 and 1989, respectively.
Them were no hatchery recoveries of any marked adults from subyearling
smolt releases in either year. Lindsay at al. (1989) observed good
outmigration success and poor smolt-to-adult survival for subyearling
smolts released in the Deschutes River. We are unsure of what the adult
age composition will be for subyearling smolt returns; however, if
adults produced from 0-age smolts return at the normal total age, the
majority of adults produced from the first releases in 1987 will return
Carmichael, R. W., R. Boyce, and J. Johnson. 1986. Grande Ronde River
spring chinook production report (US v. Oregon), 36 p. Oregon
Department of Fish and Wildlife, P.O. Box 59, Portland, OR 97207.
Lindsay, R. B., B. C. Jonasson, R. K Schroeder, and B. C. Cates.
1989. Spring chinook salmon in the Deschutes River, Oregon. Oregon
Department of Fish and Wildlife, Information Report 89-4:1.92.
(Available from Oregon Department of Fish and Wildlife, P.O. Box 59,
Portland, OR 97207.)
Zaugg, W. S., J. E. Bodle, J. E. Manning and E. Wold. 1986. Smolt
transformation and seaward migration in 0-age progeny of adult spring
chinook salmon (Oncorhynchus tshawytscha) matured early with photoperiod control. Can. J. Fish. Aquat. Sci. 43:885-888.
QUESTIONS AND ANSWERS
- What were the weights after recapture at Lower Granite Dam, given the shift in the mean length?
- The mean was 20 g.
- Given that them is spill at
the dams in mid-April, it is likely that yon missed this for the May
release; what is the success of subyearlings in passing the dam?
- There are some data for
passage through the lower dams, but few at McNary Dam. Most subyearlings
are probably barged from Lower Granite Dam. With the PIT tags it can be
seen that some wild fish migrate late. The Grande Ronde wild fish are
like the subyearlings, migrating in mid-May to late June.
- The wild fish from the Tucannon River us the same as the subyearling May release.
- Did you record PIT tags at Lower Granite Dam? Did you get length/frequency data?
- Fish were tagged from trap
boxes in the Grande Ronde and at Lookingglass Hatchery. These PIT-tagged
fish were passively monitored at Lower Granite Dam, so there were no
length data. But from two sources they are reported as 90-110 mm and 102
- Regarding the 0-age fish from Little White Salmon River—do the adults return as falls or springs?
- It is typical that they return as springs.
- They also have a traditionally low harvest rate.
- What about fishing pressures?
- The ocean catch is very little; also the in-river catch is small.
- Since there is concern about genetic maintenance, are particular characters selected?
- We are not doing major
selection for this group. If selection pressures are different from
those in yearlings, we do not know what the effects would be. We do not
believe that there would be genetic differences between the two.
- What about looking at subyearling and yearling smolt indices in Idaho?
- This had been planned for
the past year, but we could not get eggs from Idaho. We only had visual
observations on smolting. Similar percentages appeared to be "smolty"
between yearlings and subyearlings, which has also been noted in
unsuccessful subyearlings and yearlings.
- What has been done regarding size and age relationships?
- We have looked at gill Na+-K+ ATPase in yearlings and subyearlings. In subyearlings, although there are
not extensive indications of smoltification, there are some
indications, and that is the essential factor. Smoltification develops
more at release.
- Regarding freeze-brand data, did differences in the quality of brands affect these data?
- This is possible, but we did
have retention of marked groups and quality control, particularly in
the yearling and subyearlings, since they were branded at different
- We don't know yet how to supplement with yearlings, let alone subyearlings.
- Then is a lot of growth
after release. Have you looked at outmigration timing between the time
of release and time of recapture, particularly in regard to ecological
competition with wild fish? This looks like it might happen also with
the Leavenworth fish.
- No, we don't know the
effects of this; it would be difficult to assess. One could look at food
and spatial overlaps—it could be important.
- Are you convinced that there is growth, or might only the bigger fish get to Lower Granite Dam?
- We believe that it is mostly growth, since we see larger fish than at release; it is not just migration success.
- We see no differences
between mark quality and recovery. 0-age fish have most of their rearing
in the mainstem. Regarding the summer and fail fish, there are not many
of each at the same time. I would expect some competition with the
resident non-salmonid fishes.
- Why did you use Carson stock instead of a mid-Columbia stock?
- That was the only hatchery stock available.
Figure 1. Monthly growth and temperature profile for spring chinook
subyearling smolts reared at Irrigon Hatchery, 1986-88 broods.
Figure 2. Comparison of migration timing and duration past Lower
Granite Dam of yearling and subyearling spring chinook smolts released
from Lookingglass Hatchery in 1988 and 1989.
img src="messfig3.jpg" width="500" height="1023" alt="Figure 3" />
Figure 3. Length frequency distribution (fork length) at release from
Lookingglass Hatchery and at time of recapture at Lower Granite Dam for
spring chinook subyearling smolts of the 1986, 1987, and 1988 broods.
Figure 4. Comparison of passage indices (% of release) at Lower
Granite Dam between yearling and subyearling spring chinook smolts
released from Lookingglass Hatchery in 1988 and 1989.
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