life history of western washington winter steelhead, a 30 year perspective hal michael washington...
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Life History of Western Washington Winter
Steelhead, a 30 Year Perspective
Hal MichaelWashington Department of Fish and Wildlife
STEELHEAD ARE NOT SALMON
• Salmon “overwhelm” the environment.• Salmon populations generally return
and spawn over relatively short periods of time.
• Salmon populations zero in on “one” solution to the ecosystem they live in.
Winter steelhead life history and population dynamics are what
they are because they are necessary for the long term survival of the population. Survival of a population is dependant on retaining all
aspects of a population, not just the most convenient.
BIOLOGICAL CHARACTERISTICS OF A
HEALTHY POPULATION OF WILD WINTER STEELHEAD IN WESTERN WASHINGTON
RETURN TO FRESHWATERSteelhead Entry to Snow Creek
0.000
0.200
0.400
0.600
0.800
1.000
1.200
OCT NOV DEC JAN FEB MARCH APRIL MAY
Month
Perc
ent of R
un
RETURN TO FRESHWATER
• Timing different for different ages
SPAWNING LOCATION
• Prefer upper portions of tributaries• Mainstems not the preferred habitat for
rearing, particularly lower mainstems
proportion of Green River SH escapment in tributaries
0
0.1
0.2
0.3
0.4
0.5
0.6
0.719
78
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Pro
po
rtio
n e
scap
emen
t in
tri
bs
SPAWN TIMING
• As with return timing, is lengthy. Generally February-May.
• May be lots of wild spawning before March 15
Redd accumulation
0.000
0.200
0.400
0.600
0.800
1.000
1.200
JAN 1-15 JAN 16-31
FEB 1-15
FEB 16-29
MAR 1-15
MAR 16-31
APRIL 1-15
APRIL16-30
MAY
Date
Cum
ula
tive
Per
centa
ge
SURVIVAL TO EMERGENCE
• Varies within season.• May vary between seasons.
SH Survival to Emergence
0
500
1000
1500
2000
2500
0 20 40 60 80 100 120
Julian date of Spawning
Num
ber o
f Em
erge
nts Snow wild 80-81
Salmon Hatchery 80-81
Snow wild 76-77
Snow wild 77-78
SMOLT AGES
• Puyallup 2004-1:2:3, only 16 fish– 44:50:6 with age 1 fish averaging the
longest
• Snow/Salmon 1978-2001– 10.3:82.4:7.3
Effect of nutrient addition on Keogh steelhead smolt ages
0%20%40%
60%80%
100%age 4
age 3
age 2
age 1
Freshwater Age Composition of Adult Steelhead in Green River, WA
0%
20%
40%
60%
80%
100%
Spring in Which Adults Sampled
Per
centa
ges Age-4
Age-3
age-2
Age-1
STRAY RATES
• Because they don ‘t die after spawning it is difficult to evaluate.
• BC experience• Snow Creek first returns• Snow Creek repeat spawners.
REPEAT SPAWNERS
• Apparently critical to long-term survival of run.
• Waddell Creek NEVER (5 complete broods) had first returning spawners replace parent brood.
• Keogh River has seen similar problem.
RESIDENT/ANADROMOUS
• Resident “rainbow” an important part of population
• Recognized as part of population in Waddell Creek.
• Anadromy/residency optional depending on fish age, size, watershed conditions
HABITAT CHARACTERISTICS SUPPORTING A HEALTHY
POPULATION OF WILD WINTER STEELHEAD IN
WESTERN WASHINGTON
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
EF-1* EF-2* EF3
Location
De
ns
ity
wiig
hte
d p
erc
en
t in
cre
as
e in
len
gth
SH-0
SH-1
COHO
SALMON CREEK INCREASE IN LENGTHMANY CHUM SPAWN IN LOWER REACHES
SNOW CREEK INCREASE IN LENGTHFEW CHUM SPAWN IN CREEK
0.0
10.0
20.0
30.0
40.0
50.0
60.0
EF-1* EF-2 EF-3 EF-4 EF-5
Location
De
ns
ity
we
igh
ted
me
an
inc
rea
se
in le
ng
thSH-0
SH-1
COHO
SOOS CREEK STEELHEAD REMOVE LOW FLOW YEARS
SH esc-3 yr shift
0
100
200
300
400
500
600
700
0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100
Flow adjusted coho spawner biomass density
Ste
elh
ea
d s
pa
wn
ers
Steelhead Parr per metre in Treatment and Control Habitats
0
20
40
60
80
100
Controls Structures Nutrients Structures& Nutrients
nu
mb
er p
er m
etre
Greatest effect came from combined treatment of structures and nutrient enrichment. It is essentially additive.
WINTER HABITAT AVAILABILITY AND QUALITY DETERMINE SMOLT OUTPUT
Steelhead
0.0
50.0
100.0
150.0
200.0
250.0
300.0
350.0
400.0
EF-1 Snow
EF-2 Snow
EF-3 Snow
EF-4 Snow
EF-5 Snow
STREAM FLOWS/HYDROGRAPH
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.160
0.180
RAIN
SNOW
DAMS
FISHERY MANAGEMENT CHARACTERISTICS
SUPPORTING A HEALTHY POPULATION OF WILD WINTER STEELHEAD IN
WESTERN WASHINGTON
BASIC HARVEST MANAGEMENT CONSIDERATIONS
• Harvest needs to come proportionally from all segments of the run.
• Early returning segments need to be restored.
• Repeat spawners need to be restored.
CATCH AND RELEASE
• Very successful with resident trout.• Offers a conceptually satisfying fishery;
high opportunity and low mortality.• Mortality measured at around 5%.
CATCH AND RELEASE CONCERNS
• Successful C&R applied to post-spawning stocks.
• Some evidence in sturgeon that C&R too close to spawning leads to resorption of eggs.
• For SH, how does C&R “too close” to spawning affect spawning location, fry production, and survival to repeat spawn?
CHARACTERISTICS OF A HEALTHY WINTER STEELHEAD POPULATION I
Return from ocean at least November to MaySpawn at least January-MayRepeat spawners make up a significant portion of escapementSpawn primarily in upper reaches of tributariesSmolt ages primarily 1 and 2 in south to 3 and 4 in northFreshwater habitat complexStreamflows controlled by natural forces and patterns
CHARACTERISTICS OF A HEALTHY WINTER STEELHEAD POPULATION II
Resident and anadromous spawners present
Large escapements of salmon in areas where steelhead spawn and rear. Spawner biomass of 1-2 kg per square metre
ONLY WHEN THE LAST TREE HAS DIED AND THE LAST
RIVER HAS BEEN POISONED AND THE LAST FISH HAS BEEN CAUGHT WILL WE
REALIZE THAT WE CAN NOT EAT MONEY