Release Strategies to Improve Post-Release Performance of
Hatchery Summer Steelhead in Northeast Oregon.
Lance Clarke, Michael Flesher, Shelby Warren , and Richard Carmichael
By
STUDY DESIGN1. Acclimation vs. Direct-Release: One group released after a
16-57 day acclimation, the other group direct-released on same day. 14 paired groups.
• Spring Creek, (1987-1990)• Deer Creek, (1991-1996)• Little Sheep Creek, (1993-1996)
2. Volitional vs. Forced Release following Acclimation: Both groups acclimated for at least 27 days,1 group provided a 14-21 day volitional release the other group forced from acclimation pond. 6 paired groups.
• Spring Creek, (1996-1999)• Deer Creek, (1998-1996)
LOWER GRANITE DAM
SnakeRiver
Washington
Oregon
Gra
nde
RondeRiver
Wallowa River
Imnaha
River
Littl
e Sh
eep Cr
.
N
SpringC
r.
Deer C
r.
020 20 40
Kilometers
SNAKE RIVER BASIN STUDY AREA
Col umbiaR.
COMMON METHODS1. Rearing in hatchery raceways to yearling stage, water temperature
range = 10 -14 C. Fish trucked 3.5 to 4.5 h to acclimation sites.
2. Release groups of 25,000 to 50,000. Fish were freeze-branded or PIT-tagged to measure outmigration travel time and survival to
dam. All fish received coded-wire-tags; tag recoveries used to estimate smolt-to-adult survival and straying.
3. Acclimation ponds are rectangular and concrete, supplied with stream water.
Response Metrics 1. Outmigration Travel Time
2. Outmigration Survival
3. Smolt-to-Adult-Survival
4. Stray Rate Index
PIT Tagging and Coded-Wire-Tagging at Irrigon Hatchery
Big Canyon Acclimation Pond
Adult Returns to Wallowa Hatchery
ACCLIMATION VERSUS DIRECT-RELEASE RESULTS
0
20
40
60
80
100
120
140
AcclimatedDirect
1991 1992 1994 1995 1996
Deer Creek
19960
20
40
60
80
100
120
1993 1994 1995
Little Sheep Creek
TRAV
EL D
AYS
SIMILAR TRAVEL TIME TO LOWER GRANITE DAM
N = 163-509
(Paired t-test, P = 0.649)
RELEASE YEAR
% S
URVI
VAL
0
20
40
60
80
100
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996
Spring Deer Little Sheep
ACCreek DR
SIMILAR OUTMIGRATION SURVIVAL TO DAM
P = 0.874
Vertical lines = 95% CI
% S
MOL
T-TO-
ADUL
T SU
RVIV
AL
0
0.5
1
1.5
2
2.5
RELEASE YEAR1987 88 89 90 91 92 93 94 95 1996
Spring Deer Little Sheep
ACCreek DR
ACCLIMATED GROUPS HAD HIGHER SURVIVAL TO ADULTHOOD (P = 0.013)
N = 8,260
93
RELEASE YEAR
% S
TRAY
RAT
E
0
5
10
15
20
25
30
1987 88 89 90 91 92 94 95 1996
35Creek
ACCLIMATED GROUPS HAD LOWER STRAY RATES (P < 0.001)
Spring Deer Little Sheep
AC DR
N = 861
020 20 40
Kilometers
Mouth (RK 0)
Pelton Trap (RK 161)
Sherars Falls (RK 69)
Warm Springs NationalFish Hatchery (RK 154)
Springs
Warm
River Deschutes
River
COLUMBIA RIVERDeschutes River Basin
54% Direct-Release
59% Direct-Release above Sherars Falls
56% of recoveries after 1 February were Direct-Release
% SURVIVAL TO LOWER GRANITE DAM
% S
MOL
T-TO-
ADUL
T SU
RVIV
AL
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 10 20 30 40 50 60 70 80 90
r 2 = 0.1122P = 0.1096N = 24
DOES OUTMIGRATION SURVIVAL MATTER?
VOLITIONAL RELEASE FORCED VERSUS
0
20
40
60
80
0
20
40
60
80
VolitionalForced Spring
Creek
Deer Creek
1997 1998 1999
19991998
TRAV
EL D
AYS
SIMILAR TRAVEL TIME TO LOWER GRANITE DAMN = 46-189
N = 40-61
P = 0.316
% S
URVI
VAL
0
20
40
60
80
100
Deer Spring
VOLCreek FR
1997 1998 1999
RELEASE YEAR
OUTMIGRATION SURVIVAL WAS SIGNIFICANTLY HIGHER FOR VOLITIONAL RELEASE (P = 0.035)
Vertical lines = 95% CI
0
0.2
0.4
0.6
0.8
1.0
SURVIVAL TO ADULTHOOD WAS NOT DIFFERENT (P = 0.658)
1996 1997 1998 1999
RELEASE YEAR
% S
MOL
T TO
ADU
LT S
URVI
VAL
N = 1,896
Deer Spring
VOLCreek FR
30
0
5
10
15
20
25
1996 1997 1998 1999
RELEASE YEAR
% S
TRAY
RAT
E Deer Spring
VOLCreek FR
VOLITIONAL RELEASE DID NOT REDUCE STRAYING (P = 0.852)
N = 194
Use of Volitional Release to Remove Residuals
Big Canyon Facility Little Sheep Facility
Release Year % Male
Numberremoved
Stream Density(no./100
m2) % MaleNumber removed
Stream Density(No./100
m2)2003 76 2,014 7.0 2004 65 0 9.22005 -- -- 5.6 92 8,470 13.82006 72 4,968 6.8 73 9,187 14.72007 67 0 21.3 81 9,701 10.62008 73 2,361 6.0 59 0 14.32009 84 2,457 5.6 78 4,733 8.22010 68 0 10.9 65 0 27.72011 70 0 3.5 65 0 16.8
2.0
0.0
0.5
1.0
1.5
MEAN
% S
MOL
T-TO-
ADUL
T S
URVI
VAL
..Survival to Adulthood, Four Month vs.
Two Month AcclimationTwo-factor ANOVA; P <0.005
Four Month Two Month
2000 2001 2002 2003 2004 2005RELEASE YEAR
(Spring Chinook, Umatilla Hatchery Program)
CONCLUSIONS1. Acclimation increased survival to adulthood and
decreased straying. Acclimation appears to ameliorate affects of stress.
2. Volitional release did not increase survival to adulthood or decrease straying. Survival results consistent with similar studies.
3. Juvenile outmigration survival did not correlate well with survival to adulthood.
Judge the success of release groups based on adult returns.
Survival results not consistent with other steelhead acclimation studies.
Management action: all releases are now acclimated.
Management action: retain some volitional releases to remove residuals.
Adjust Acclimation Protocols to the Hatchery Program
1. Acclimation locations, length, timing, feeding protocols, etc., can affect success of release groups. Hatchery specific investigations are needed. Unpublished data from the Wallowa program suggests that
straying is 30-40% higher for fish acclimated at Wallowa Hatchery than those at Big Canyon.
2. For supplementation programs, small temporary acclimation ponds spread throughout the watershed may promote a better distribution of returning adult spawners.
3. Acclimation is an ideal time to develop behavioral traits (i.e. prey or predator recognition training) that may improve survival.
4. Volitional release used as a tool to remove residuals; however, difficult to judge the success of that strategy.
For More InformationClarke, L.R., M.W. Flesher, T.A. Whitesel, G.R. Vonderohe, and R.W. Carmichael. 2010. Post-release performance of acclimated and direct-released hatchery summer steelhead into Oregon tributaries of the Snake River. North American Journal of Fisheries Management 30:1098-1109.
Clarke, L.R., M.W. Flesher, S.M. Warren, and R.W. Carmichael. 2011. Survival and straying of hatchery steelhead following forced or volitional release. North American Journal of Fisheries Management 31:116-123.
Clarke, L.R., W.A. Cameron, and R.W. Carmichael. 2012 Performance of spring Chinook salmon reared in acclimation ponds for two and
four months before release. North American Journal of Aquaculture 74: 65-72
NOW, WHAT DID HE SAY?