Transcript PowerPoint

Impact of Climate on
Distribution and Migration of
North Atlantic Fishes
George Rose, Memorial University, NL Canada
Table of Contents
• A few platitudes
• Brief history of the North Atlantic
• Where are the fish?
•
•
•
•
“Grouping” analysis of species
“Event” analysis: the 1920-1940 warming
“Species” analysis: capelin
“Ripple” effects: food webs
Fish distributions and migrations
• NOT random
• the result of evolution of
the physiology of the
species
• “tuned to the particular
biotic and abiotic
environment of the stock”
• variable at several time
scales
• early indicator of
ecosystem change
“On the cod highway”
1992
2000
Environmental unit
Abiotic:
depth
temp
salinity
currents
oxygen
spawning
Migration links
Biotic:
fishing
prey
predators
densitydependence
feeding
juvenile
History of North Atlantic
Long-term climate change
Most North Atlantic
species have Pacific origins
(Ekman, 1953)
The gadoids are likely the only major
fish group whose evolutionary center
is the North Atlantic
Where are the fish?
# of species with latitude in N. Atlantic
(data from Briggs, 1974; Cech, 2000)
70
Latitude (N)
60
50
40
30
20
0
100
200
# of species
300
400
Sea temperatures in mid-Atlantic
(data from Ekman, 1953)
80
60
Latitude (N)
40
20
0
-20
surface
100 m
200 m
400 m
-40
-60
-80
-5
0
5
10
15
Temperature (oC)
20
25
30
70
Number of species
60
Depth
50
Depth:
40
30
20
10
0
0
1000
2000
3000
4000
5000
6000
0.07
Species per km2
0.06
0.05
0.04
0.03
Number of
species in
the North
Atlantic
(data from Challenger
cruise, 1800s)
0.02
0.01
0.00
0
1000
2000
3000
Depth (m)
4000
5000
6000
Number of species at depth in North Atlantic
(from 150 species documented in this study)
70
60
50
40
30
Count
20
10
0
250
750
Maximum depth bins
1500
2000
4000
Lower and upper temperature
limits: cumulative # of species
100
# of species
80
60
40
Lower limit
Upper limit
20
0
-2
0
2
4
6
8
10
12
o
Temperature ( C)
14
16
18
20
Spawning temperature limits
35
30
# of species
25
20
15
Lower limit
Upper limit
10
5
0
-2
0
2
4
6
8
10
12
o
Temperature ( C)
14
16
18
20
Spawning salinity limits
35
30
# of species
25
20
15
10
Lower limit
Upper limit
5
0
30
31
32
33
34
Salinity
35
36
37
“Grouping”
analysis
All North Atlantic Species - catalogued 146
Can species be grouped into
response categories?
• Feeding period requirements (temperature,
depth)
• Spawning requirements (temperature,
salinity, depth, timing)
Shallower
Warmer
3
Shad
Principle
Components
Saury
2
FACTOR2
Smelt
Lamprey
1
1: Min and Max
depth
Mackerel
Bf.tuna
Argentine
Mudhake
Stickleback
Arcticcharr
Brookcharr
2: Min and Max
temperature
Lanternfish
Alewife
Salmon
Lf.hake
Softpout
Pollock
Cunner
0
M.sculpin
Winter
-1
Cusk
Haddock
G.sculpin
Herring
Yellowtail
Cod
Alligator
S.sculpin
D.shanny
Unernak
Capelin
-2
-2
-1
Rosefish
Rh.grenadier
Witch
G.halibut
A.sculpin
Arcticcod
Plaice
Eelpout
H.sculpin
0
Spinyskate
1
2
FACTOR1
3
4
Salinity
Deeper
4
G.halibut
Spawning
Components
Factor 2
3
1: salinity
2: depth
3: temp,
timing
2
Cusk
1
Sp.wolf
Rosefish
0
Arcticcod
Pollock
Nwcod
Haddock
Plaice B.tuna
Brookcharr
Herring
Mackerel
Necod
Ice.capelin
NEcapelin
Winter
P.capelin
-1
-3
-2
NWcapelin
Gr.capelin
-1
0
Factor 1
1
2
General limits: F1 with pop’n
doubling time
4
3
2
1
0
n
-1
-
D
I
I
I
N=
21
14
3
q
S
d
F
S
S
u
i
f
g
a
3
9
14
C
0
2
3
1
2
6
I
n
0
1
1
1
0
0
Doubling
time
F
0
6
1
6
9
1
F
2
7
1
7
0
0
F
7
5
1
5
7
7
E
6
6
6
T
0
0
C
8
9
-2
a
R
Spawning limits: PCs and pop’n
doubling time (depth,temp,timing)
n
-
D
I
I
I
S
d
F
S
S
u
i
f
g
a
C
6
3
9
8
1
I
n
0
1
0
7
0
S
2
1
2
0
0
S
0
1
0
2
0
S
4
1
4
2
4
E
4
6
3
T
0
0
C
0
9
a
R
“Event” analysis
An old problem
“there have been certain periods of
years in northern seas with higher
temperatures and simultaneously
increasing occurrence of southern
species, for instance in the years of
about 1820-30, 1840-50, 1870-80,
and 1920-”
Rollefsen and Taning, 1948
A warm water
“event” in the north
Atlantic
1920-1940 (or thereabouts)
According to Taning, 1948
“Simultaneous with this scarcity of ice in the
waters around Iceland the winters have been
exceedingly mild, especially during February
and March, when the mean temperature was
some 4 to 7 oC above the normal”
“This increase of the surface temperature has
amounted to about 0.5-4.0o above the normal”
a)
7
Annual air temperature
o
Temperature ( C)
8
6
5
4
St. John’s, NL
3
o
Temperature ( C)
2
1860
2
1880
1900
1920
1940
1960
1980
2000
b)
1
0
-1
-2
-3
-4
Godthab, Greenland
-5
o
Temperature ( C)
-6
1860
7
1880
1900
1920
1940
1960
1980
2000
c)
6
5
4
3
Akureyi, Iceland
2
1
0
1860
7
1880
1900
1920
1940
1960
1980
2000
o
Temperature ( C)
d)
6
5
4
Bodo, Norway
3
2
1860
1880
1900
1920
1940
Year
1960
1980
2000
The
warm
1930s
midN. Atl.
Species distribution changes
(data from Saemundsson, 1932; Taning, 1948; Fridriksson, 1948; Rollefsen, 1948; others)
new
N
species expand
S
S
spawn
contract expand change
Greenland
5
7
2
2
5
Iceland
9
23
3
0
3
Norwegian skrei fishery landings,
Lofoten (N) and More (S)
(data from Nakken, 1994)
50
Lofoten
More
Numbers (millions)
40
30
20
10
0
1900
1910
1920
1930
Year
1940
1950
1920s
Warming: fish change
No warming:
No fish change
Species analysis
A keystone species:
Capelin
The dispersal of capelin from their north Pacific origin
(from Vilhjalmsson, 1994)
Present distribution of capelin
(from Vilhjalmsson, 1994)
Documented capelin shifts
Stage
Spa
Mechanism
Area
Year
km
T
Reference
No
drift
Faroes
1991
778
Yes
drift
GOA
1978-79
278
No
Temperature
Iceland
1960-80
444
3
Vilhjalmsson, 1994
Trans-
Pleistocene
12000
6
Vilhjalmsson, 1994; Sarnthein et al., 2003
wn
larval
adult
Jakupsstovu and Reinert, 2002
Doyle et al., 2002
(currents, food)
Yes
Temperature
Arctic
Yes
Temperature
Barents
1972-83
509
2
Ozhigin&Luka, 1984; Gjosaeter&Loeng, 1987
Yes
Temperature
Scotian
1990-
556
2.
7
Frank etal., 1996
(food)
Shelf
Temperature
NE NL
1990-
500
1.
5
O'Driscoll&Rose, 2000: Lilly 1994; Shackell
et al., 1994
Flemish
1990-
445
1.
7
Frank et al., 1996
2.
7
Frank et al., 1996
Yes
(food)
Temperature
Cap
Yes
Temperature
GOSL
1990-
889
Yes
Temperature
BOF
1915-19
1200
Bigelow&Schroeder, 1953
Yes
Temperature
BOF
1965-68
1200
Tibbo&Humphreys, 1966
Yes
Temperature
Trans-
4000 BC
6000
Arctic
6
Vilhjalmsson, 1994; Sarnthein et al., 2003
warm
cold
Extension of capelin spawning grounds from
cold period (1900-1920) to warm period
(1920-1940); from Vilhjalmsson 1997
Capelin: distance moved and temperature change
Distance (km)
100000
10000
1000
100
0
1
2
3
4
5
Temperature change (oC)
6
7
Capelin: distance moved and persistence
Distance (km)
100000
10000
1000
100
1
10
100
1000
Persistence (yr)
10000
100000
Ripple effects
North Atlantic food web
Capelin is key to:
• Many fishes (e.g., cod, greenland
halibut, salmon, charr, winter
flounder)
• Seabirds
• Marine Mammals
Templeman, 1948, on
Newfoundland caplin
“not only does it provide the
nourishment on which the great
bulk of inshore running codfish
recover condition in June and
July after spawning, but it is very
likely in the main responsible for
the attraction of the huge shoals
of cod to the coast”
warm
cold
Extension of capelin spawning grounds from
cold period (1900-1920) to warm period
(1920-1940); from Vilhjalmsson 1997
warm
cold
Extension of cod spawning grounds from cold
period (1900-1920) to warm period (19201940); from Vilhjalmsson 1997
Hamilton Bank
Flemish Cap
Grand Banks
Capelin movements late 1980s
Northern cod movements early 1990s
Cod and capelin
on
Newfoundland
shelf in early
1990s
(from O’Driscoll & Rose, 2001)
Effects of lack of capeln: weight
of cod in winter: Iceland data from Vilhjalmsson, 2002
8
Newfoundland-Labrador (NO capelin)
Iceland (low capelin)
Iceland (high capelin)
Whole weight (kg)
6
4
2
0
5
6
7
Age (years)
8
Northern cod liver index and
capelin availability (from Rose & O’Driscoll, 2002)
100
80
Liver index anomaly
60
40
20
0
-20
-40
-60
-80
-100
1
10
100
1000
Capelin availability
10000
100000
Cod stock historical range and
biomass (from Robichaud & Rose, in press)
10000
Range (km)
1000
100
10
1
0.1
1
10
100
1000
Biomass (1000 t)
10000
100000
Conclusions
• Distribution changes important - early
indicator of ecosystem change
• Response differences (pelagics faster;
demersals slower, some maybe not at
all)
• Capelin fast - “canary in the mine”
• Ripple effects: capelin changes affect
many species