Combining PIT Tags with Scale Reading to Better Understand the Life History of Snake River Fall...
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Combining PIT Tags with Scale Reading to Better Understand the Life History of Snake River Fall Chinook Salmon Douglas Marsh and William Muir - NOAA Fisheries Dr. William Connor - US Fish and Wildlife Service
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Transcript of Combining PIT Tags with Scale Reading to Better Understand the Life History of Snake River Fall...
Combining PIT Tags with Scale Reading to Better Understand the
Life History of Snake River Fall Chinook Salmon
Douglas Marsh and William Muir - NOAA Fisheries
Dr. William Connor - US Fish and Wildlife Service
Background – The early years
• Mid to late 1990’s– USFWS & NOAA
Background – The early years
• Mid to late 1990’s– USFWS & NOAA– Production fish behavior different from natural fish
Background – The early years
• Mid to late 1990’s– USFWS & NOAA– Production fish behavior different from natural fish– Small hatchery fish (~70mm) performed much like
natural fish (surrogate-size)
Background – The early years
• Mid to late 1990’s– USFWS & NOAA– Production fish behavior different from natural fish– Small hatchery fish (~70mm) performed much like
natural fish (surrogate-size)– 1998 – USFWS began collecting adults at LGR for
scales
Background – The age of expansion
• Early to Mid-2000’s– 2001-2004 NOAA transport studies conducted
Background – The age of expansion
• Early to Mid-2000’s– 2001-2004 NOAA transport studies conducted– Attempted to use surrogate-sized hatchery fish
Background – The age of expansion
• Early to Mid-2000’s– 2001-2004 NOAA transport studies conducted– Attempted to use surrogate-sized hatchery fish– Tag numbers ranged from 50-100,000 per year
Background – The age of expansion
• Early to Mid-2000’s– 2001-2004 NOAA transport studies conducted– Attempted to use surrogate-sized hatchery fish– Tag numbers ranged from 50-100,000 per year– 2004 - No hatchery fish available, tagged at LGR
Background – The age of expansion
• Early to Mid-2000’s– 2001-2004 NOAA transport studies conducted– Attempted to use surrogate-sized hatchery fish– Tag numbers ranged from 50-100,000 per year– 2004 - No hatchery fish available, tagged at LGR– Connor et al. showed a more complicated life history
than expected
Background – The age of expansion
• Early to Mid-2000’s– 2001-2004 NOAA transport studies conducted– Attempted to use surrogate-sized hatchery fish– Tag numbers ranged from 50-100,000 per year– 2004 - No hatchery fish available, tagged at LGR– Connor et al. showed a more complicated life history
than expected– 2005 - NOAA joined with USFWS in the scale
sampling effort and in transport evaluations
Number of juvenile tag codes in SbyC database
• 2005
307,663• 2006
454,972• 2007
936,854• 2008
849,337• 2009
1,416,344• 2010
1,942,691• 2011
2,202,585
2009 – Targeted 1,416,344 NOAA, USFWS, & NPT
Determine age-at-ocean-entry
Scales read byWashington
Department of Fishand Wildlife
S 0.1…SRR 1.2…RR 1.0…
Scales
#123A
09/25/07
3D9.1BF234E5FA
Juvenile detection
historyAge at ocean
entry
Life History
Age-at-Ocean-Entry by Return Year
Summer
Fall Spring Summer
Fall Winter Spring Un-known
Fall-T -
20.0
40.0
60.0
80.0
100.0
Age-0Age-1
Pe
rce
nt
of
tota
l
Transport Migrant
Age-at-Ocean-Entry by Migration path
Age-at-Ocean-Entry by Migration path and River
Summer
Fall Spring Summer
Fall Winter Spring Unk Summer
Fall Spring Summer
Fall Winter Spring Unk -
20.0
40.0
60.0
80.0
100.0
Age-0
Age-1
Pe
rce
nt
of
tota
l
Transport MigrantTransport MigrantSnake River Clearwater River
Migration timing vs. Return rate (SAR)
Jun Jul Aug Sep Oct Holdovers0
10
20
30
40
50
60
0
1
2
3
4
5Juveniles
SAR
Last observation
Perc
en
t o
f M
igra
nts
SA
R
Adult age class distribution vs. Age-of-Ocean-Entry
1 2 3 4 50.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
Age-0Age-1
Adult age (Brood Year)
Pe
rce
nt
of
tota
l re
turn
Adult length vs. Age-of-Ocean-Entry
1 2 3 4 50
100
200
300
400
500
600
700
800
900
1,000
Age-0
Age-1
Adult age (Brood Year)
Fo
rkle
ng
th (
mm
)
• Snake River Fall Chinook Salmon employ a wide range of juvenile life histories
Conclusions
• Snake River Fall Chinook Salmon employ a wide range of juvenile life histories– Ocean-type salmonids typically enter the ocean as
subyearlings; can take a year
Conclusions
• Snake River Fall Chinook Salmon employ a wide range of juvenile life histories– Ocean-type salmonids typically enter the ocean as
subyearlings; can take a year– Summer passage - > 90% age-0 ocean entry
Conclusions
• Snake River Fall Chinook Salmon employ a wide range of juvenile life histories– Ocean-type salmonids typically enter the ocean as
subyearlings; can take a year– Summer passage - > 90% age-0 ocean entry– Fall passage - >80% age-1 ocean entry
Conclusions
• Snake River Fall Chinook Salmon employ a wide range of juvenile life histories– Ocean-type salmonids typically enter the ocean as
subyearlings; can take a year– Summer passage - > 90% age-0 ocean entry– Fall passage - >80% age-1 ocean entry– Passage after October - 100% age-1 ocean entry
Conclusions
• Snake River Fall Chinook Salmon employ a wide range of juvenile life histories– Ocean-type salmonids typically enter the ocean as
subyearlings; can take a year– Summer passage - > 90% age-0 ocean entry– Fall passage - >80% age-1 ocean entry– Passage after October - 100% age-1 ocean entry
• Snake and Clearwater similar except for never detected fish
Conclusions
• The later a fish outmigrates, the higher the SAR
Conclusions (cont.)
• The later a fish outmigrates, the higher the SAR• Age-at-ocean entry affects adult characteristics
(based on brood year)
Conclusions (cont.)
• The later a fish outmigrates, the higher the SAR• Age-at-ocean entry affects adult characteristics
(based on brood year)– Adult age class distribution – Age-1 adults tend to be
older
Conclusions (cont.)
• The later a fish outmigrates, the higher the SAR• Age-at-ocean entry affects adult characteristics
(based on brood year)– Adult age class distribution – Age-1 adults tend to be
older– Adult size at return – Age-1 adults are smaller
Conclusions (cont.)
