escapement goals? we don’t need no stinking ‘scapement goals! hal michael washington department...
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ESCAPEMENT GOALS? WE DON’T NEED NO STINKING
‘SCAPEMENT GOALS!
Hal Michael Washington Department of Fish and Wildlife
AN ESCAPEMENT GOAL
Spawners
Catch
Adults
The Burning Question
• What information do we have available to use to set an escapement goal for steelhead if current models give results that are constrained by the fishery previously imposed on the stock?
This report is available free from WA DNR
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.
Effect of nutrient addition on Keogh steelhead smolt ages
0%20%40%
60%80%
100%age 4
age 3
age 2
age 1
KEOGH RIVER
• Approximately 259,000 sq m surface area• Loaded with equivalent of 64,260 kg
carcasses, in addition to 50,000 pinks every other year
• Approx biomass loading of 0.63 kg/ sq m• Soos Cr, a Green R. trib, has 249,000 sq m
(96% of Keogh)• Skagit R has 21,129,900 sq m (81.6 times
larger than Keogh)
SOOS CREEK I
• Small stream, tributary to Green River with a hatchery and rack near mouth
• For 1981-2002, Chinook and coho passed upstream have averaged 0.14 kg per square metre; maximum in 2000 of 0.63
SOOS CREEK STEELHEAD IISH esc-3 yr shift
0
100
200
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400
500
600
700
0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100Flow adjusted coho spawner biomass density
Ste
elh
ead
sp
awn
ers
SH esc-3 yr shift
SOOS CREEK STEELHEAD IIIREMOVE 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 0.100Flow adjusted coho spawner biomass density
Ste
elh
ead
sp
awn
ers
SH esc-3 yr shift
SKAGIT RIVER
• Surface area of streams accessible to coho is 81.6 times as large as Keogh River.
• If Keogh averages 50,000 pink, a simple expansion gives 4,080,000 pinks for the Skagit
• Current goal for Skagit pink is 330,000
• Snow CreekSalmon Creek Coho Salmon
Mean FL Survival Mean FL Survival
to return to return• 1977 99 7.9% 102 20.0%• 1978 101.3 9.11% 102.1 12.1%
• Steelhead trout • 1977 158.0 172.0• 1978 164.4 165.1
• Chum salmon escapement biomassBiomass Biomass
• 1976 0.037 0.217• 1977 0.014 0.122• 1978 0.037 0.362• 1979 0.003 0.069• 1980 0.012 0.464
UPSHOT• Nutrients, as delivered by spawning
salmon, are critical• Quality habitat, including appropriate
flows, access to stream reaches, habitat complexity, are equally critical
STEELHEAD ESCAPEMENT GOAL• Harvest rate on wild stock no more than 10% in
total.• Coho escapement target of at least 0.15 kg per
square metre• Pink escapement goal of at least 0.63 kg per
square metre• Chum escapement goal of 0.5 kg/square metre• Fall Chinook escapement goal of 0.63 kg per
square metre to match pinks• Spring Chinook goal of 0.15 kg per square metre to
match coho
SOOS CREEK ESCAPMENT GOAL
• For Chinook (7.97 kg) and chum (4 kg), target only the mainstem of Big Soos Cr, 104,479 square metres
• For coho (2.27 kg) use entire basin, 249,057 square metres
• Chinook=8,250• Chum=16,450• Coho=16,450