Adult Sockeye Migrations: Challenges to
Complete the Journey and Spawn
Scott Hinch
University of British Columbia
Vancouver, BC, CANADA
Outline of Presentation
1.  Ocean conditions matter for freshwater migrations
2. Populations are unique
3. Entry timing and physiological condition
4. Warming temperatures and climate change
•  Fraser sockeye
starting upriver
migration are
heavier when
ocean food more
abundant
Hinch et al 1995
•  Fraser sockeye starting
upriver migration have
higher energy reserves
when ocean
temperatures are cool
and upwelling is strong
Crossin et al 2004
•  spawner to recruit survival
is lower when coastal
temperature is warmer
Hinch et al 1995
Outline of Presentation
1.  Ocean conditions matter for freshwater migrations
2. Populations are unique
3. Entry timing and physiological condition
4. Warming temperatures and climate change
Fraser River Sockeye Salmon
~ 150 stocks which differ in:
•  spawning migration distance (100 – 1,200 km)
•  annual spawning abundance (100’s – 1,000,000’s)
•  adult morphometry, energy density, fecundity,
swimming performance, heart morphology
Adaptations for completing
river migration and spawning
Adults with long distance or
high elevation spawning
areas have:
-small torpedo shaped
bodies
-high body energy
-few and small eggs
-high maximum swimming
speeds
-more efficient hearts
-large and broad ‘metabolic
scope’
‘Difficult Migrations’
-built for high performance
and energy conservation
‘Easy Migrations’
Swimming performance and metabolic limits
•  Swim tunnel respirometry studies
Metabolic scope & temperature
Maximum
scope
Oxygen
consumption
(Mo2)
Maximum
Mo2
Zero
scope
Metabolic scope
Topt
Routine Mo2
(Q10 effect)
Tcrit
Temperature
Metabolic scope = O2 available for activities other than routine
and is temperature-dependant
Metabolic scope (mg O2 kg-1 min-1)
Metabolic scope temperature profiles for 3 Fraser salmon stocks
12
A
10
8 Gates Creek
Sockeye
6
4
Topt
Gates Creek
2
(summer-run sockeye)
0
B
Weaver Creek
10
(late-run sockeye)
8 Weaver Creek
Sockeye
Chehalis River
6
(fall-run coho)
Tcrit
4
Topt
2
0
Key points
C
10
•  Topt and Tcrit vary among stocks
8
Chehalis
Coho
6
•  Only 6-7oC between Topt and Tcrit
4
•  Maximum scope varies among stocks in
2
Topt
relation to migration difficulty
0
0
5
10
15
20
25
Lee et al. 2003
Temperature ( oC)
Historical Lower Fraser River thermal conditions
E. Stuart
Early Summer Summer
Temperature (°C)
22
Late Summer
20
18
1 SD
16
1940-2000
average
1 SD
14
12
26
3 10 17 24 31 7
14 21 28 4
11
Jun Jul Jul Jul Jul Jul Aug Aug Aug Aug Sep Sep
Date
temperature frequency distribution
Metabolic scope (mg O2 kg-1 min-1)
Metabolic scope temperature profiles for 3 Fraser salmon stocks
12
16%
A
10
12%
8 Gates Creek
Sockeye
6
8%
4
4%
2
Gates Creek
(summer-run sockeye)
0
0%
B
10
Weaver Creek
12%
(late-run sockeye)
8 Weaver Creek
Sockeye
6
8%
Chehalis River
(fall-run coho)
4
4%
2
0
0%
C
10
12%
Key point
8
Chehalis
Coho
•  Topt is coincident with
6
8%
historic river temperature profile
4
4%
during the migration period
2
0
0%
0
5
10
15
20
25
Farrell et al. 2008
)
Temperature (oC
Outline of Presentation
1.  Ocean conditions matter for freshwater migrations
2. Populations are unique
3. Entry timing and physiological condition
4. Warming temperatures and climate change
Early Migration of Late run stocks
•  1995 to present – segments of all late run stocks have
migrated upriver 4-6 weeks early than usual
•  In recent years late runs have nearly completely eliminated
their estuarine holding behaviour
•  correlated with early migration has been extremely high
mortality in freshwater
Weaver Sockeye Timing and Mortality
270,000 fish
Migration Mortality
(% total run)
100
80
60
165,000 fish
2001
2000
490,000 fish
1999
1998
2003
2006
2007
2004
1996 1997
1995
2005
2002
1995 - 2007
40
1974 - 1994
20
0
Up-River Migration Date
(50% past hydroacoustic facility near river mouth)
Inter-university / Inter-agency research began 2002
Questions:
Why are they migrating early?
Why are they dying at such high levels in-river?
Relevance to other runs and species?
Study methods:
•  destructive sampling of fish captured along ocean and
freshwater migratory routes for physiological and genomics
work (~4,000 fish sampled)
•  radio and acoustic telemetry with biopsy assessments on
individual fish (~2,000 fish tracked)
•  swimming performance and simulated migration experiments
Acoustic receiver
Radio receiver and antennae
Acoustic transmitter
i-button temperature logger
Radio transmitter
Transmitters inserted down throat into stomach on migrating adults
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then insert it again.
Mechanisms of mortality: searching for physiological answers with
‘biopsy’ telemetry
•  Gross somatic energy assessed by microwave energy meter
•  blood sample to examine range of plasma
ions, reproductive and stress hormones
•  tissue removed from first gill arch
ionoregulatory function and for
functional genomics assessments
•  small muscle plug also taken for
functional genomics
Cooke et al. 2005.
Cooke et al. 2008.
Telemetry lines, stations and adult salmon tagging sites
- Partnership with POST, Kintama, and LGL Ltd
Biopsy telemetry results reveal that early migrants are:
i) physiologically stressed
ii) more reproductively mature
iii) dysfunctional ion regulation
Causes of early migration not yet resolved:
•  evidence supporting environmental, physiological and behavioural
hypotheses
•  advanced maturation suggests changes to internal and/or external
migratory cues and an ‘open ocean’ link (or earlier)
•  en-route mortality is associated with higher than usual river
temperatures
Cooke et al. 2006a,b
Crossin et al. 2009
Hinch 2009
Outline of Presentation
1.  Ocean conditions matter for freshwater migrations
2. Populations are unique
3. Entry timing and physiological condition
4. Warming temperatures and climate change
Potential causes of thermal-based migration mortality
•  metabolic
collapse
Fast processes (hours-days)
-critical temperature limits
•  stress
•  disease
•  energy depletion
Slow processes (days-weeks)
-accumulated degree-day limits
Collapse of metabolic scope occurs in warm years
2004 temperatures during migration - red bars
D
80%
60%
40%
20%
0%
100% E
80%
60%
40%
20%
0%
0
temperature frequency distribution
100%
Percentage of maximum aerobic scope
25%
20%
15%
10%
5%
0%
25%
20%
15%
10%
5%
0%
25
30%
Gates
Weaver
Temperature (oC)
10
15
20
Key findings
•  River temperature can exceed Tcrit
for some sockeye stocks
•  in 2004, expect high mortality for
segment of Weaver run that
experienced temperatures ≥ 20 C
•  telemetry confirmed > 70% of total run
perished that year
Farrell et al. 2008
Mathes et al. 2010
Laboratory thermal holding experiments
•  collect migrating fish as they enter the Fraser and hold in lab
for their migratory period under different temperatures
•  simulate migrations under different thermal and stress
conditions
Lab experiments with adult late run sockeye
Mortality (%)
100
90
80
70
60
50
40
30
20
10
12oC
18oC
Importance of
thermal refuges?
18oC
20oC
0
12oC
8 oC
15-16oC
0
5
10
15
20
25
River migration duration
Days
30
35
Stefan Larsson unpub. data
Crossin et al. 2008
Migratory Disease Issues
•  parasites, bacteria and fungal infections are temperature dependent
•  bacterial infections – e.g. Columnaris disease (Flavobacterium columnare)
•  fungal infections – e.g. (Saprolegnia sp.)
2004
Columnaris infection in Weaver / Harrison Sockeye in 2008
Parasite infections - e.g. Parvicapsula minibicornis
•  kidney infection in lab held Weaver Creek sockeye increased rapidly
when individuals had accumulated ~ 370 degree days
Maximum score of 25
In kidney glomeruli
Severity of infection
25
20
15
10
5
0
0
100
200
300
Degree days
400
500
600
Wagner et al. 2006
Mortality in relation to accumulated degree days
•  Weaver Creek sockeye captured at river entry (24 days at 18 ºC)
•  mortality begins ~ 300 degree days (spawning ground arrival)
•  70% mortality at ~ 500 degree days
60
25
50
20
40
15
30
10
20
5
10
0
Severity of infection
Cumulative mortality (%)
70
0
90
180
270
360
450
540
Accumulated degree days ºC
Wagner et al. 2006
Crossin et al. 2008
How important are cool water refuges?
Thermal experience of an Adams sockeye 2006
from its recovered temperature logger
Tagged
Spawning
grounds
Hourly Temperature C
20
17
14
BC
USA
100 km
11
Key findings:
-  No thermal refuges in
lower Fraser
8
Ocean
5
21-Aug
31-Aug
Fraser R.
10-Sep
Thompson R. Thompson R.
Kamloops L. Shuswap L.
20-Sep
30-Sep
10-Oct
Adams R.
20-Oct
-  Adams sockeye use
lakes as thermal refuges
Weaver Creek migration
•  directed swim up Fraser River (5-6 days in August/September)
•  1-30 day migration / holding in Harrison River or Lake
•  spawning begins in early October
Harrison
Lake
Weaver
Creek
Harrison
River
Vancouver
N
10 km
Fraser River
Canada
USA
Hourly depth profiles for 4 Weaver sockeye ‘holding’ in Harrison Lake
Fraser River migration thermal issues:
1. Since 1940s, ~ 2 ºC increase in peak summer water temperature
2. Recent years have had extreme (record) high temperatures
3. Since 1996, Late-run sockeye enter river 4-6 weeks earlier than
normal and thus encounter temperatures ~ 5 C warmer
4. Climate models predict at least a 2 C increase in summer water
temperatures
10
12
Temperature ( oC)
14
16
18
20
Since 1940s, ~ 2 ºC increase in peak summer water temperature
1950
1960
1970
1980
Years
1990
2000
Dave Patterson, DFO Env. Watch Program
Historical Lower Fraser River thermal conditions
E. Stuart
Early Summer Summer
Temperature (°C)
22
Late Summer
20
18
1 SD
16
1940-2000
average
1 SD
14
12
26
3 10 17 24 31 7
14 21 28 4
11
Jun Jul Jul Jul Jul Jul Aug Aug Aug Aug Sep Sep
Date
Recent years have had extreme (record) high temperatures
E. Stuart
Early Summer Summer
Temperature (°C)
22
Late Summer
2004
20
18
16
60-y ave
14
12
26
3 10 17 24 31 7
14 21 28 4
11
Jun Jul Jul Jul Jul Jul Aug Aug Aug Aug Sep Sep
Date
Historical Lower Fraser River thermal conditions
E. Stuart
Early Summer Summer
Temperature (°C)
22
Late Summer
2004
20
18
16
60-y ave
14
12
26
3 10 17 24 31 7
14 21 28 4
11
Jun Jul Jul Jul Jul Jul Aug Aug Aug Aug Sep Sep
Date
What about future conditions in the Lower Fraser River?
E. Stuart
Early Summer Summer
Late Summer
Temperature (°C)
22
2004
20
18
16
60-y ave
14
12
26
3 10 17 24 31 7
14 21 28 4
11
Jun Jul Jul Jul Jul Jul Aug Aug Aug Aug Sep Sep
Date
•  2004: 50-80% migration mortality across all runs
•  the future for Fraser River sockeye?
E. Stuart
Early Summer Summer
Temperature (°C)
22
Late Summer
2004
20
Future
60-80 yr
average
18
16
14
12
26
3 10 17 24 31 7
14 21 28 4
11
Jun Jul Jul Jul Jul Jul Aug Aug Aug Aug Sep Sep
Date
Model-averaged
survival rate
Survival rates (+/- CI) to natal rivers of fish with transmitters in
relation to encountered Fraser River temperature (2002-2007)
1.0
1.0
0.9
0.9
0.8
0.8
0.7
0.7
0.6
0.6
0.5
0.5
0.4
0.4
0.3
0.3
0.2
0.2
0.1
0.0
0.1
Chilko
15
16
0.0
17
18
19
20
Quesnel
15
16
Model-averaged
survival rate
Temperature (oC)
1.0
0.9
0.9
0.8
0.8
0.7
0.7
0.6
0.6
0.5
0.5
0.4
0.4
0.3
0.3
0.2
0.2
0.0
Stellako-Late Stuart
15
16
17
18
19
Temperature (oC)
18
19
20
Temperature (oC)
1.0
0.1
17
20
0.1
0.0
Adams
13
14
15
16
17
18
19
Temperature (oC)
20
Martins et al. 2010
Predicting future migration survival with climate change models
Temperature (oC)
Summer-run
Late-run (Adams)
early-timed
~2 oC
~1 oC
normal-timed
normal-timed
Quesnel
Survival rate
~5 oC
early-timed
Stellako-Late Stuart
~1%
~16%
~15%
Martins et al. 2010
Hague et al. 2010
Climate change summary:
•  warmer, less productive northeast Pacific ocean
•  reduction in preferred marine thermal habitat
•  poorer ocean survival
•  smaller mature fish with less energy
•  warmer river temperatures, more frequent ‘extreme’ years
•  higher rates of river migration mortality
•  effects will be stock-specific
•  thermal refuges will be key to survival of migrating sockeye in
a ‘warming’ Fraser River particularly for stocks with lower Tcrit or
disease thresholds
Thanks to:
•  several past and current grad students, post-docs,
technicians and colleagues
•  funders: NSERC, Pacific Salmon Commission, Fisheries
and Oceans Canada
All references can be found at:
http://faculty.forestry.ubc.ca/hinch/
Research Team
Ecology
Physiology /
Genomics
Behaviour /
Movement
Parasitology
Oceanography
Scott Hinch (Univ. BC)
Steve Cooke (Carleton Univ)
Glenn Crossin (Univ. BC)
Jeff Young (Univ. BC)
Todd Mathes (Univ. BC)
Tony Farrell (Univ. BC)
Glenn Wagner (Univ. BC)
Mark Shrimpton (Univ. Northern BC)
Glen Van Der Kraak (Univ. Guelph)
Kristi Miller (Can. Dept. Fish. Oceans)
Michael Healey (Univ. BC)
David Welch (Kintama and Pacific Ocean Shelf Tracking Project)
Karl English (LGL Ltd.)
Simon Jones (Can. Dept. Fish. Oceans)
Stefan Larsson (Swedish Agricultural University)
Rick Thomson (Can. Dept. Fish. Oceans)
Fisheries Management
Dave Patterson (Can. Dept. Fish. Oceans)
Mike Lapointe (Pacific Salmon Commission)
Take home messages:
•  Critical temperature limits (e.g. metabolic issues) and accumulated degree
day limits (e.g. disease issues) can explain migration mortality
•  Provides mechanistic approach and understanding (predicting) potential
effects of current and further climate change
•  Applying critical temperature or accumulated degree day limits will likely
require stock- or run-specific information
•  Other relevant thermal related critical limits not presented:
•  Stress – e.g. plasma lactate > 18 mmol/L
•  Energy – e.g. somatic concentration < 4 MJ/kg
•  En-route thermal refuges are key to survival of migrating sockeye in a
‘warming’ Fraser River particularly for stocks with lower Tcrit or disease
thresholds
Biotelemetry of 2004 Weaver Creek sockeye
Capture and tagging Harrison River
Fraser River
Tcrit
Topt
Todd Mathes
M.Sc. thesis
Key field findings - Critical temperature Issue
•  0% survival of fish which experienced temperatures ≥ Tcrit
•  10-30% survival of fish which experienced ‹ Tcrit › Topt
•  50-80% survival for fish which experienced temperatures ~ Topt
Capture and tagging dates
Fraser River
to spawning grounds
Tcrit
Topt
Estimated degree-day accumulation for 83 Weaver sockeye from Fraser entry to
spawning grounds based on telemetry and temperature reconstruction
Degree-day accumulated (oC)
a
b
b
c
Early-river
Early-lake
Normal-river
Timing and Residency Groups
Normal-lake
Percent of time spent at depth for
6 adult sockeye in Harrison Lake
Key Result – 80% of residency
time spent at depths > 50 m and
temperatures ~ 6-7 C
Temperature manipulation field experiment
•  test hypothesis that high temperature-exposed fish (> 500 DD)
survive poorly during migration compared to cool temperatureexposed fish (< 400 DD)
•  captured newly arrived, normal-timed, river migrants and held
under different thermal regimes in captivity for three weeks,
prior to release downstream of capture location
Harrison
Lake
Weaver Ck.
capture
Harrison
River
release
10 km
Fraser River
Cold treatment (8 °C)
24 days
327 accumulated degree days
N = 31
Warm treatment (18 °C)
24 days
510 accumulated degree days
N = 17
•  migration mortality higher in warm treated fish
70
•  mortality rates reflect those of ‘early’ and ‘normal’ timed
migrants
Mortality (%)
60
50
510 degree days
40
30
327 degree days
20
10
0
78
80
Harrison
Harrison Fraser
Fraser
Confluence
Confluence
82
84
86
88
90
Distance from release site (km)
92
Spawning
Spawning
Grounds
Grounds
94