Transcript Presentation - Pacific States Marine Fisheries Commission

Recruitment in Wild Smolt and Adult
Steelhead Trout: the 30-year Experience at
the Keogh River.
Bruce R. Ward
B.C. Ministry of Environment, U.B.C.
And
Don J.F. McCubbing
In-Stream Fisheries Research Inc., Vancouver, B.C.
Funding
Habitat Conservation Trust Fund
Study Location
Steelhead of the Keogh River
Trends in Adult Steelhead at the
Keogh River
Trends in Smolt Yield at Keogh
Steelhead survival and abundance trends
Oregon Coho & BC (Keogh) Steelhead
6
5
4
3
2
20
15
1991-95 (0.6%)
7
25
1978-90 (3.3%)
Oregon Marine Survival (%)
8
Oregon Coho
30
Keogh Steelhead
10
5
1
0
1960 1965 1970 1975 1980 1985 1990 1995
Ocean Entry Year (t-3)
0
Keogh R Marine Survival (%)
9
1960-77 (6.1%)
10
Conservation designation
Recruitment from the Ocean
smolt-to-adult survival trend
Smolt-to-Adult Survival
Climate Change

our management, policy and legal
systems, plus many of our built
environments may not resilient enough
to cope with real present day or
projected future changes in fish,
salmon, and habitats that result from
climate change and weather extremes.

http://fisheries.c-ciarn.ca/
Climate Change and Steelhead
•El Nino/La Nina
•Pacific Decadal Oscillation
•Global Climate Change
Back-Calculated Smolt Length and
Survival
45.0
40.0
35.0
% survival
30.0
25.0
20.0
15.0
10.0
5.0
0.0
14
16
18
20
BACK-CALCULATED SMOLT
LENGTH (cm)
22
24
26
Observed
Expected
30.00
25.00
20.00
15.00
10.00
5.00
SMOLT YEAR
1999
1997
1995
1993
1991
1989
1987
1985
1983
1981
1979
0.00
1977
SMOLT-TO-ADULT SURVIVAL
(%)
Observed and Expected Survival Rates
Wild Steelhead @ Keogh River
Tracking wild and LGB smolts in
Queen Charlotte Strait
Surgically-Implanted Steelhead
Smolt
(7 Months Post-Implantation)
4.5 mos
15 mos
Post 2004/2005 Survivals
Species
Survival to
River Mouth
(%)
Survival to QCS
Line (%)
FW survivors
to QCS Line
(%)
Wild Steelhead smolt
77
31
40
Hatchery Steelhead smolt
71
29
42
Steelhead Smolt Recruitment @ Keogh
12000
10000
8000
80's
Fert
6000
90s
4000
WRP
2000
0
500
1000
1500
2000
2500
12000
10000
Smolt Recruits
0
8000
80s
Fert
6000
90s
WRP
4000
rplcmt@ 4%
rplcmt@15%
2000
0
0
200
400
600
Spawners
800
1000
3000
1990’s regime affects freshwater
12000
Smolt Recruits
10000
8000
80s
Fert
6000
90s
WRP
4000
rplcmt@ 4%
rplcmt@15%
2000
0
0
200
400
600
Spawners
800
1000
Freshwater
capacity falls
6000 to less
than 3000
Climate changes in freshwater as well
Spring migration
(r2=0.65)
number per metre
Steelhead Parr per meter in
Treatment and Control Habitats
100
80
60
40
20
0
Controls
Structures
Nutrients
Structures
& Nutrients
Mean length of 2-year-old (broken line, circles) and 3-year-old
(solid line, squares) steelhead smolts. Open markers indicate
years affected by nutrient addition. Odd- and even-year
variation is attributed to Pink salmon abundance.
Percent composition of age 1 (grey bar), age 2 (black bar), age 3 (white bar), and
age 4 (hatch bar) steelhead smolts in the Keogh River in 1996 and 1997 (no
nutrient addition), and from 1998 to 2003 (nutrients added).
Smolts per spawner production
4.5
ln(smolts/spawner)
4.0
1980s
3.5
1990s
3.0
Fert
2.5
WRP
2.0
y = -0.0013x + 3.3284
1.5
1.0
y = -0.0032x + 2.616
0.5
0.0
0
500
1000
1500
Spawners
2000
2500
3000
Number of Smolts per Spawner
Steelhead smolt recruits
60
80s
Fert
90s
WRP
Predicted
50
40
30
Replacement at 4%
20
10
Replacement at 15%
0
0
1000
2000
Number of Spawners
3000
Number of Smolts per Spawner
Recruitment in Freshwater
70
80s
Fert
90s
WRP
Predicted
60
50
40
30
20
10
0
0
1000
2000
Number of Spawners
3000
The steelhead smolts per
spawner and number of
spawners in the Keogh
River during the 1980s
(diamonds) and the 1990s
(triangles), nutrient
experiments in the mid1980s (squares), and initial
results during WRP to 2003
(circles). Our modified
Beverton-Holt fit to these
data (solid points)
statistically distinguishes
the 1980s and nutrient
experiments from all other
treatments, while the 1990s
and initial watershed
restoration treatments
cannot be statistically
distinguished.
Summary







>30-yrs of study of freshwater and marine influences to
variation in steelhead recruitment implicate mainly climate
Trends in adult and smolt abundance suggest production regimes
cahnges in both
Trends in abundance and survival at Keogh are mirrored over a
broad geographic area of the southern distribution, and in other
species (e.g., coho) suggesting a common cause.
Mortality in the ocean duriung t he first few weeks appears high,
but requires further study
Productivity and capacity in freshwater is altered by nutrient
dynamics, including marine-derived nutrients from Pink salmon
and probably habitat destruction/restoration
A highly variable riverine environment controlled by
precipitation affects all steelhead life stages
Divine Intervention?
or rather - playing God!
Wild (98-02) and Wild/Living Gene Bank (2003)
Steelhead Counts - Keogh River
•Increased adults, but….will
this increase recruits?
350
1998
250
1999
2000
200
2001
2002
150
2003
140
100
80
60
40
Date
3/30
3/23
3/9
3/16
3/2
2/23
2/9
2/16
2/2
1/26
1/19
1/5
1/12
12/29
0
12/22
20
12/8
3/30
3/23
3/16
3/9
3/2
2/23
2/16
1998
1999
2000
2001
2002
2003
12/1
Date
2/9
2/2
1/26
1/19
1/12
1/5
12/29
12/22
12/15
0
12/8
50
Nos of Fish
120
12/15
100
12/1
Nos of Fish
300