Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
Reproductive responses of planktivorous and piscivorous
seabirds to climate variability in the northern Sea of Okhotsk
Alexander Kitaysky1 & Elena Golubova2
1Institute of Arctic BiologyUniversity of Alaska Fairbanks, U.S.A.
2Institute of Biological Problems of the NorthMagadan, Russia
Inter-annual oceanographic change
Seabird reproductive performance
Causal links between reproduction and climate variability on small and large geographic scales
Change in diet composition: over time and inrelation to climate variability
Bering Sea (1960s-1990s)• decline in populations of
piscivorous seabirds Springer 1992 Hunt & Byrd 2000
• increase in populations of planktivorous seabirdsPiatt et al. 1990 Konyoukhov 1991
Sea surface temperature in the Bering Sea
YEAR
SST
AN
OM
ALY
(o C)
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
1957 1962 1967 1972 1977 1982 1987 1992
COLD phase
planktivorous increased
piscivorous declinedWARM phase
Study area: Talan Island1987-2001
Kitaysky & Golubova 2000;& in preparation
Talan I. Sea of Okhotsk1987-2003
Longitude (degrees East)La
titud
e (d
egre
es N
orth
)148 149 150 151 152
58
59
60
Talan I.
Kuril current Jamskoe currentC
oast
al w
ater
s
Tauyskaya Bay
10-14oC
5-8oC10-14oC
Cold-core eddy
Sea of Okhotsk Kam
chat
kaSiberia
Shelik
hov B
ay
Tauyskaya Bay
Kuril Isl
ands
Study hypothesis:environmental change causes
contrasting trends inreproductive performance of
planktivorous and piscivorousalcids
Rep
rodu
ctiv
e su
cces
s
0.00
0.25
0.50
0.75
1.00
1986 1987 1988 1989 1990 1991 1992 1993 1994
Year
SS
T (J
uly
1 - A
ugus
t 30)
o C
7.5
8.5
9.5
10.5
11.5
1986 1987 1988 1989 1990 1991 1992 1993 1994
no data
Tufted puffinHorned puffinParakeet aukletCrested auklet
long-term SST = 9.3o
Rep
rodu
ctiv
e su
cces
s
0.00
0.25
0.50
0.75
1.00
1986 1987 1988 1989 1990 1991 1992 1993 1994
Year
SS
T (J
uly
1 - A
ugus
t 30)
o C
7.5
8.5
9.5
10.5
11.5
1986 1987 1988 1989 1990 1991 1992 1993 1994
no data
Tufted puffinHorned puffinParakeet aukletCrested auklet
long-term SST = 9.3o
“WARM” PHASE “COLD” PHASE
Sea-Surface Temperature
Date
July
-- A
ugus
t SS
T an
omal
y (o C
)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
0 10 20 30 40May 1 May 10 May 20 May 30 June 10
19891990
1991
1994
1993
19881992
1987
Dates of permanent ice disappearance
“WARM” PHASE
“COLD” PHASE
PlanktivorousaukletsPiscivorouspuffins
OCEANOGRAPHIC REGIME
Rep
rodu
ctiv
e su
cces
s (%
)
0
20
40
60
80
100
COLD WARM
Kitaysky & Golubova 2000
Talan I.Sea of Okhotsk1987-1994
“COLD”regime
“WARM”regime
Distribution of adult euphausiids Thysanoessa rashii(major prey of planktivorous auklets)
“COLD”regime
“WARM”regime
Distribution of Acartia and calanoid copepods(major prey of small “forage” fish)
-80
-40
0
40
80
-2 -1 0 1 2
-80
-40
0
40
80
-2 -1 0 1 2
Sea-surface temperature ANOMALY (oC)
Rep
rodu
ctiv
e su
cces
s( d
evia
tion
from
long
-ter
m m
ean)
piscivorous:Tufted puffins
Black-legged kittiwakes
planktivorous:
Crested auklets
Talan I.1987-2001
Conclusion:Environmental change affects trophic level linkages in marine ecosystems
• Alternations in distribution of zooplankton are driven by local inter-annual oceanographic change
• Reproductive performance of planktivorous and piscivorous seabirds reflects these changes
Arctic Oscillation Index
Is reproduction of birds in the northern Sea of Okhotskrelated to climate variability on
a large geographic scale?
Talan SST vs composite indices of climate in the North Pacific1986-2003
r=+0.53P<0.04
r=+0.78P<0.001
r=-0.54P<0.04
Talan I.
SSTAugust
AOannualmean
NPIJan-April
mean
PDOannualmean
Talan I.1987-2003
Talan I.1987-2003
Talan I.1987-2003
Conclusion:Environmental change affects trophic level linkages in marine ecosystems
• Alternations in reproduction of piscivorous and planktivorous seabirds in the northern Sea of Okhotsk are driven by inter-annual oceanographic change on large geographic scale
Arctic Oscillation Index
Are DIETs of birds in the northern Sea of Okhotskrelated to changes in climate phenomena
on a large geographic scale?
Diet composition of puffin chicks on Talan I.1987-2003
6 spp1% biomass
29 spp99% biomass
HornedPuffin
N=6 years
7 spp2% biomass
37 spp98% biomass
TuftedPuffin
N=9 years
InvertebratesFish
Talan I.1987-2003
Horned puffinTufted puffin
Change in diet composition, SANDLANCE 1987-2003
YEAR
% B
IOM
ASS
, wet
0
20
40
60
80
100
1988 1992 1996 2000 2004
Talan I.1987-2003
HERRINGCAPELIN
Change in diet composition, Tufted puffin, 1987-2003
YEAR
% B
IOM
ASS
, wet
0
20
40
60
80
100
1988 1992 1996 2000 2004
Talan I.1987-2003 Change in diet composition, Tufted puffin, 1987-2003
YEAR
%B
IOM
ASS
, wet
0
1
2
3
4
5
1988 1992 1996 2000 2004
Pacific lamprey
Talan I.1987-2003
Age 1+Saffron codAge 0+Walleye Pollock
Change in diet composition, Tufted puffin, 1987-2003
YEAR
%B
IOM
AS
S, w
et
0
10
20
30
40
50
60
70
1988 1992 1996 2000 2004
Arctic Oscillation Index
Are DIETs of birds in the northern Sea of Okhotskrelated to climate variabilityon a large geographic scale?
Diet (% biomass) vs composite indices of climate in the North Pacific1986-2003
r=-0.95P<0.01pollock
r=-0.74P=0.090gadids
r=+0.91P<0.011gadids
HornedPuffinN=6
r=-0.60P=0.088Saffron
cod
r=+0.66P=0.055Saffron
cod
TuftedPuffinN=9
AOannualmean
NPIJan-April
mean
PDOannualmean
Diet (% biomass) vs reproductive performance of puffins on Talan I.1986-2003
r=-0.89P<0.02
Flatfish
r=-0.94P<0.01
r=-0.97P<0.01
r=-0.80P=0.057
Repr. successHornedPuffin
N=6 years
SquidPoachersPollock
Summary1. Local oceanographic conditions in the northern
Sea of Okhotsk are driven by large-scale oceanographic patterns
2. Availability of forage fish and consequently seabird reproduction are determined by these patterns
3. The same oceanographic event has opposite consequences for planktivorous and piscivorous birds
4. Whether these relationships are specific to the Sea of Okhotsk or apply to other arctic regions remains to be seen
• Thanks to:– A. Andreev, J.F. Piatt, and all the Russian and
American colleagues and students who participate in this ongoing project
• Funding: – Russian (Soviet) Academy of Sciences– Institute of Biological Problems of the North
(Magadan)– EVOS– NPRB– Institute of Arctic Biology, UAF