reproductive responses of planktivorous and piscivorous ... · reproductive responses of...

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