KodiakArchipelago

Alaska

Area of detail

42 20 0 0 0

Kilometers

N

Kenai River

Kamishak Bay

Barren Islands

ChugachIslands

Kachemak BayHomerLower

CookInlet

1995

GullIsland

ChisikIsland

Fig. 7.1. Routes for hydroacoustic surveys of fish and seabird censuses conducted in lower Cook Inlet during August, 1995. Triangles indicate location of seabird colonies.

Alaska

Area of detail

Kenai River

Kamishak Bay

Barren Is.

ChugachIslands

LowerCookInlet

1996

GullIsland

ChisikIsland

42 20 0 0 0

Kilometers

N KodiakArchipelago

HomerKachemak Bay

Fig. 7.2. Routes for hydroacoustic surveys of fish and seabird censuses conducted in lower Cook Inlet during late July, 1996. Triangles indicate location of seabird colonies. Zig-zag lines near shore are coastal transects added in 1996.

Alaska

Area of detail

Kenai River

Kamishak Bay

Barren Islands

ChugachIslands

LowerCookInlet

1997-1999

GullIsland

ChisikIsland

42 20 0 0 0

Kilometers

N KodiakArchipelago

HomerKachemak Bay

Fig. 7.3. Routes for hydroacoustic surveys of fish and seabird censuses conducted in lower Cook Inlet during July-August, 1997-1999. Triangles indicate location of seabird colonies. Zig-zaglines near shore are coastal transects added in 1996.

Fig. 7.4. Fish density in all waters and in waters <30 m deep near Chisik, Gull and Barren islands, 1995-1999.

Fish Density - All Waters

0.0

0.1

0.1

1995 1996 1997 1998 1999

g/m

3

Chisik

Gull

Barren

Fish Density - All Waters <30 m

0.0

0.1

0.1

1996 1997 1998 1999

g/m

3

Chisik

Gull

Barren

Fig. 7.5. Fish density in inshore and offshore waters near Chisik, Gull and Barren islands, 1995-1999.

Fish Density - Inshore Transects

0.0

0.1

0.1

1996 1997 1998 1999

g/m

3

Chisik

Gull

Barren

Fish Density - Offshore Transects

0.0

0.1

0.1

1996 1997 1998 1999

g/m

3

Chisik

Gull

Barren

Fig. 7.6. Fish density by 20 m depth strata near Chisik, Gull and Barren islands, 1995-1999.

Barren Is lands

0.0

0.1

0.2

0.3

0.4

0.5

0.6

5-20 20-40 40-60 60-80 80-100

Depth (m )

g/m

3

1999

1998

1997

1996

Kachemak Bay

0.0

0.2

0.4

0.6

0.8

1.0

5-20 20-40 40-60 60-80 80-100

Depth (m )

g/m

3

1999

1998

1997

1996

Chis ik Is land

0.0

0.1

0.1

0.2

5-20 20-40 40-60 60-80 80-100

Depth (m )

g/m

3

1999

1998

1997

1996

Fig. 7.7. Frequency of occurrence of different densities of fish in 10-min by 5 m blocks near Chisik, Gull and Barren islands, 1995-1999.

0

10

20

30

40

50

-7 -6 -5 -4 -3 -2 -1 0

Log (Acous tic B iomass in g/m 3)

% F

req

ue

nc

yB arr 95

Barr 96

Barr 97

Barr 98

Barr 99

0

10

20

30

40

50

-7 -6 -5 -4 -3 -2 -1 0

Log (Acous tic B iomass in g/m 3)

% F

req

ue

nc

y

K ach 95

Kach 96

Kach 97

Kach 98

Kach 99

0

10

20

30

40

50

-7 -6 -5 -4 -3 -2 -1 0

Log (Acous tic B iomass in g/m 3)

% F

req

ue

nc

y

Chis 95

Chis 96

Chis 97

Chis 98

Chis 99

Fig. 7.8. Distribution of acoustic backscattering signals in lower Cook Inlet, 6-30 m strata.

1995 1996

1997 19991998

Sum of sa by interval, log +1 scale:

0.5

1.0

10.0

100.0

1036.15

Depth layer 6-30 m

Fig. 7.9. Distribution of acoustic backscattering signals in lower Cook Inlet, 31-60 m strata.

1995 1996

1997 19991998

Sum of sa by interval, log +1 scale:0.5

1.0

10.0

100.0

342.93

Depth layer 31-60 m

Fig. 7.10. Distribution of acoustic backscattering signals in lower Cook Inlet, 61-100 m strata.

1995 1996

1997 19991998

Sum of sa by interval, log +1 scale:

0.5

1.0

10.0

100.0

264.23

Depth layer 61-100 m

Fig. 7.11. Distribution of acoustic backscattering signals in lower Cook Inlet, all strata.

1995 1996

1997 19991998

Sum of sa by interval, log +1 scale:1.0

5.0

10.0

100.0

1044.10

All depth layers

All Murres

5 birds

1 bird

10 birds

75 birds

157 birds

1995 1996

1997 19991998

Figure 8.1. Distribution and abundance of Common Murres in lower Cook Inlet, 1995-1999.

Black-legged Kittiwakes

5 birds

1 bird

25 birds

100 birds

300 birds

1995 1996

1997 19991998

Figure 8.2. Distribution and abundance of Black-legged Kittiwakes in lower Cook Inlet, 1995-1999.

Pigeon Guillemots

3 birds

1 bird

6 birds

9 birds

12 birds

1995 1996

1997 19991998

Figure 8.3. Distribution and abundance of Pigeon Guillemots in lower Cook Inlet, 1995-1999.

Horned Puffins

5 birds

1 bird

10 birds

15 birds

20 birds

1995 1996

1997 19991998

Figure 8.4. Distribution and abundance of Horned Puffins in lower Cook Inlet, 1995-1999.

Tufted Puffins

5 birds

1 bird

25 birds

100 birds

300 birds

1995 1996

1997 19991998

Figure 8.5. Distribution and abundance of Tufted Puffins in lower Cook Inlet, 1995-1999.

All Cormorants

2 birds

1 bird

5 birds

15 birds

29 birds

1995 1996

1997 19991998

Figure 8.6. Distribution and abundance of Cormorants (spp.) in lower Cook Inlet, 1995-1999.

Glaucous-winged Gulls

5 birds

1 bird

10 birds

25 birds

81 birds

1995 1996

1997 19991998

Figure 8.7. Distribution and abundance of Glaucous-winged Gulls in lower Cook Inlet, 1995-1999.

Marbled and Brachyramphus Murrelets

2 birds

1 bird

5 birds

15 birds

27 birds

1995 1996

1997 19991998

Figure 8.8. Distribution and abundance of Marbled and Brachyramphus Murrelets in lower Cook Inlet, 1995-1999.

Kittlitz's Murrelets

2 birds

1 bird

5 birds

8 birds

11 birds

1995 1996

1997 19991998

Figure 8.9. Distribution and abundance of Kittlitz's Murrelet in lower Cook Inlet, 1995-1999.

Fish Feeders and Divers

All Terns All Loons

AncientMurrelets

RhinocerousAuklets All Jaegars

1996 1996

1996 19961996

13 Terns

2 Loons

33 Ancient Murrelets

1 Rhinocerous Auklet

2 Jaegars

Maximum Flock Sizes:

(includes flying jaegars)

(includes flying terns)

Figure 8.10. Distribution and abundance of various fish-eating or diving seabirds in lower Cook Inlet, 1996.

Plankton and Surface Feeders

Maximum Flock Sizes:

AllShearwaters

Fork-tailedStorm-Petrels

NorthernFulmars

AllPhalaropes Mew Gulls

1996 1996

1996 19961996

6000 Shearwaters

100 Fork-tailed

22 Northern Fulmars

125 Phalaropes

12 Mew Gulls

Storm-Petrels

Figure 8.11. Distribution and abundance of various plankton- or surface-feeding seabirds in lower Cook Inlet, 1996.

Figure 11.1. Pigeon Guillemot colonies studied during 1995-1999 in Kachemak Bay. Colony name abbreviations as follows: OS = Outer Seldovia Bay, IS = Inner Seldovia Bay, HS = Hesketh I., YU = Yukon I., NE = Neptune Bay, MH = Moosehead Pt., HC = Halibut Cove.

Figure 11.2. Pigeon guillemot colony census sites in western Kachemak Bay. Site names as follows: 1 = Guillemot Meadows, 2 = Naskowhak Pt., 3 = Lemon Cliffs, 4 = Gray Cliffs, 5 = Seldovia Bay, 6 = Sub-Seldovia, 7 = Seldovia Pt., 8 = Kasitsna Cliffs, 9 = Hesketh I., 10 = SW Yukon, 11 = Yukon I., 12 = Sub-Yukon.

Figure 11.3. Pigeon guillemot colony census sites in eastern Kachemak Bay. Site names as follows: 13 = S. Neptune Bay, 14 = N. Neptune Bay, 15 = China Poot Bay, 16 = Moosehead China Poot Side, 17 = Moosehead N. Side, 18 = Moosehead Peterson Side, 19 = E. Peterson, 20 = The Nose, 21 = Peterson Pt., 22 = Ismailof I., 23 = Sea Cliff Manor, 24 = Triangle Rock, 25 = Goshawk, 26 = Mallard Bay.

Figure 12.1. Linear regression of Horned Puffin chick age on wing length (n=67 chicks)

0

10

20

30

40

50

0 25 50 75 100 125 150 175

Wing length (mm)

Age

(day

s)

Figure 12.2. Horned Puffin bill measurements. A= cutting edge, B= bill depth, C= culmen, D= bill width.

Figure 12.3. Horned Puffin chick diet composition (% number of all prey items (n=2658) collected in 1995-1999).

sand lance

capelin

Salmonid

other

1999

050

100150200250300350400450

23-May

29-May

4-Jun10-Jun

17-Jun

24-Jun

2-Jul9-Jul

16-Jul

23-Jul

29-Jul

8-Aug

14-Aug

21-Aug

27-Aug

2-Sep

9-Sep

date

Mea

n pu

ffin

num

bers 1st chick

1998

0

50

100

150

200

250

300

350

400

450

26-May

31-May

5-Jun11-Jun

16-Jun

21-Jun

27-Jun

2-Jul7-Jul

12-Jul

18-Jul

23-Jul

31-Jul

6-Aug

15-Aug

23-Aug

29-Aug

3-Sep

Date

Mea

n pu

ffin

num

bers

1997

050

100150200250300350400450

27-Jun4-Jul11-Jul18-Jul25-Jul1-Aug8-Aug15-Aug22-Aug29-Aug

Date

Mea

n pu

ffin

num

bers

RaftersLandTotal

Figure 12.4. Seasonal colony attendance of Horned Puffins at Duck Island.

0

50

100

150

200

250

5:0

0

7:0

0

9:0

0

11

:00

13

:00

15

:00

17

:00

19

:00

21

:00

Time

Me

an

pu

ffin

nu

mb

ers

Rafters

Loafers

Total

Figure 12.5. Diurnal attendance patterns of Horned Puffins in North Cove, Chisik. Average attendance on 8, 9 and 10 July, 1997.

Acoustic Fish Biomass

0.00

0.02

0.04

0.06

0.08g

/ m3

Trawl CPUE

10

100

1000

10000

100000

Fis

h / k

m

Seine CPUE

10

100

1000

10000

95 96 97 98 99 95 96 97 98 99 95 96 97 98 99

Chisik Gull Barrens

Fis

h / s

et

Figure 14.1. Summary of fish abundance indices (acoustic biomass, trawl CPUE, seine CPUE) observed around Chisik, Gull and Barren islands, Cook Inlet, during 1995-1999.

COMU Density at Sea

0

5

10

15

Bird

s / k

m2

COMU Hatching Success

0.00

0.50

1.00

Chi

cks

/ egg

laid

COMU Fledging Success

0.00

0.50

1.00

Fle

dged

/ ha

tche

d

COMU Breeding Success

0.00

0.50

1.00

95 96 97 98 99 95 96 97 98 99 95 96 97 98 99

Chisik Gull Barrens

Chi

cks

/ pa

ir

COMU Attendance at Incubation

60

70

80

90

Bird

-min

/ hr

COMU Attendance at Chick-rearing

60

70

80

90

95 96 97 98 99 95 96 97 98 99 95 96 97 98 99

Chisik Gull Barrens

Bird

-min

/ hr

COMU Chick Feeding Rate

0.0

0.1

0.2

0.3

0.4

0.5

Mea

ls /

nest

/ hr

COMU Foraging Trip Duration

0

100

200

300

Min

utes

/ tr

ip

COMU Fledgling Body Condition

0.00

2.00

4.00

Mas

s / w

ing

leng

th

COMU Adult Body Mass

0

500

1000

1500

Mas

s (g

)

Figure 14.2. Summary of Common Murre breeding and behavioral parameter values observed at Chisik, Gull and Barren islands, Cook Inlet, during 1995-1999.

BLKI Density at Sea

0

5

10

Bird

s / k

m2

BLKI Clutch Size

0.0

1.0

2.0

Egg

s / n

est

BLKI Laying Success

0.0

0.5

1.0

Egg

s la

id /

pair

BLKI Hatching Success

0.0

0.5

1.0

% n

o. /

egg

laid

BLKI Brood Size at Fledging

0.0

0.5

1.0

1.5

No.

chi

cks

BLKI Fledging Success

0.0

0.5

1.0

% n

o. /

egg

hatc

hed

BLKI Breeding Success

0.0

0.4

0.8

95 96 97 98 99 95 96 97 98 99 95 96 97 98 99

Chisik Gull Barrens

Chi

cks

/ nes

t

BLKI Attendance at Chick-rearing

45

50

55

60

65

70

Bird

-min

utes

/ hr

BLKI Chick Feeding Rate

0.0

0.1

0.2

0.3

Mea

ls /

nest

/ hr

BLKI Foraging Trip Duration

0

100

200

300

400

Min

utes

/ tr

ip

BLKI Alpha Chick Growth Rate

0

5

10

15

20

25

g / d

ay

BLKI Adult Body Condition

0.0

0.5

1.0

1.5

2.0

95 96 97 98 99 95 96 97 98 99 95 96 97 98 99

Chisik Gull Barrens

Mas

s / w

ing

leng

th

Figure 14.3. Summary of Black-legged Kittiwake breeding and behavioral parameter values observed at Chisik, Gull and Barren islands, Cook Inlet, during 1995-1999.

COMU Breeding Success

0.00.10.20.30.40.50.60.70.80.91.0

0 0.02 0.04 0.06 0.08

Forage Fish Density (g/m3)

Chi

cks/

pair

r2 = 0.02NS

COMU Hatching Success

0.00

0.20

0.40

0.60

0.80

1.00

Chi

cks

/ eg

g la

id

r2 = 0.11NS

COMU Fledging Success

0.00

0.20

0.40

0.60

0.80

1.00

Chi

cks

fledg

ed /

hatc

hed

r2 = 0.001NS

COMU Density at Sea

0

2

4

6

8

10

12

14B

irds

/ km

2

r2 = 0.70p=0.017

COMU Discretionary Time at Incubation

60

65

70

75

80

85

90

Bird

-min

/ h

r

r2 = 0.54p=0.04

COMU Discretionary Time at Chick-rearing

60

65

70

75

80

85

90

0 0.02 0.04 0.06 0.08

Forage Fish Density (g/m3)

Bird

-min

/ hr

r2 = 0.65p=0.008

COMU Chick Feeding Rate

0.15

0.20

0.25

0.30

0.35

0.40

Mea

ls /

nest

/ hr

r2 = 0.41p=0.011

COMU Foraging Trip Duration

r2 = 0.49p=0.005

60

110

160

210

260

Min

utes

/ tr

ipCOMU Chick Body Condition

2.8

2.9

3.0

3.1

3.2

3.3

Mas

s / w

ing

leng

th

r2 = 0.71p=0.044

COMU Adult Body Mass

950

1000

1050

1100

1150

Mas

s (g

)

r2 = 0.04NS

Figure 14.4. Functional response of Common Murre breeding and behavioral parameters to variation in food supply.

BLKI Density at Sea

0

2

4

6

8

10

12

Bird

s / k

m2

r2 = 0.80p<0.001

BLKI Clutch Size

r2 = 0.009NS

1.001.101.20

1.301.401.50

1.601.701.80

1.90

Egg

s / n

est

BLKI Laying Success

r2 = 0.00NS

0.00

0.20

0.40

0.60

0.80

1.00

Egg

s la

id /

pair

BLKI Hatching Success

0.00

0.20

0.40

0.60

0.80

1.00

Egg

s ha

tche

d / l

aid

r2 = 0.53p=0.049

BLKI Brood Size at Fledging

1.0

1.1

1.2

1.3

1.4

No.

chi

cks

r2 = 0.59p=0.084

BLKI Fledging Success

0

0.2

0.4

0.6

0.8

Chi

cks

/ egg

hat

ched

r2 = 0.89p<0.001

BLKI Breeding Success

0.0

0.2

0.4

0.6

0.8

0.00 0.02 0.04 0.06 0.08

Forage Fish Density (g/m3)

Chi

cks

/ nes

t

r2 = 0.64p=0.009

BLKI Attendance at Chick-rearing

r2 = 0.22NS

40

45

50

55

60

65

Bird

-min

utes

/ hr

BLKI Chick-feeding Rate

0.10

0.14

0.18

0.22

0.26

Mea

ls /

nest

/ hr

r2 = 0.71p=0.045

BLKI Foraging Trip Duration

150

200

250

300

350

400

Min

utes r2 = 0.61

p=0.008

BLKI Alpha Chick Growth Rate

11

121314

1516171819

20

g / d

ay

r2 = 0.73p=0.012

BLKI Adult Body Conditionr2 = 0.03NS

1.0

1.1

1.2

1.3

1.4

1.5

1.6

0.00 0.02 0.04 0.06 0.08

Forage Fish Density (g/m3)

Mas

s / w

ing

leng

th

Figure 14.5. Functional response of Black-legged Kittiwake breeding and behavioral parameters to variation in food supply.

Common Murre Productivity

(n=96 colony-years)

0

10

20

30

40

0.2 0.4 0.6 0.8 1.0

Chicks/site

Fre

quen

cy

Figure 14.6. Frequency of different levels of breeding success for Common Murres and Black-legged Kittiwakes in Alaska. (Data from Hatch et al. 1993, Dragoo et al. 2000, Kettle et al. 2000, and this study).

K it t iwak e P roduc t ivity (n= 232 c o lony -y ears )

020

4060

80100

120

0.0-0 .2 0.2-0 .4 0.4-0 .6 0.6-0 .8 0.8-1 .0 1.0+

Chic k s /pa ir

Fre

quen

cy

Common Murre Productivity

(n=96 colony-years)

0

10

20

30

40

0.2 0.4 0.6 0.8 1.0

Chicks/site

Fre

quen

cy

Kitttiwake (red)y = -80.3x + 118

r2 = 0.77

Murre (blue)y = -134x + 114

r2 = 0.790

30

60

90

120

0.00 0.20 0.40 0.60 0.80 1.00 1.20

Chicks/Pair

CV

(%

)

Figure 14.7. Variability in breeding success versus breeding success in Common Murres and Black-legged Kittiwakes around the world.

Variability in Kittiwake Parameters

Among Colony-Years

0 20 40 60 80 100

BLKI % Time Adult Present with Chick

BLKI Adult Body Condition

BLKI Clutch Size

BLKI Alpha/Singleton Chick Growth Rate

BLKI Brood Size at Fledging

BLKI Beta Chick Growth Rate

BLKI Foraging Trip Duration

BLKI Chick Feeding Rate

BLKI Laying Success

BLKI Hatching Success

BLKI Density at Sea

Forage Fish Biomass

BLKI Fledging Success

BLKI Breeding Success

Coefficient of Variation (%)

Variability in Murre Parameters

Among Colony-Years

0 20 40 60 80 100

COMU Adult Body Condition

COMU Chick Body Condition

COMU Chick Age at Fledging

COMU Chick Feeding Rate

COMU Hatching Success

COMU Foraging Trip Duration

COMU Fledging Success

COMU Breeding Success

COMU Discretionary Time at Incubation

COMU Discretionary Time at Chick-rearing

COMU Density at Sea

Forage Fish Biomass

Coefficient of Variation (%)

Figure 14.8 Ranked variability (Coefficient of Variation) in breeding and behavioral parameters for Common Murres and Black-legged Kittiwakes among colony-years in Cook Inlet.

Chisik Island1

2

3

4

5

1970 1975 1980 1985 1990 1995 2000

Ln (

num

ber) BLKI - 4.3 %

COMU - 8.9 %

Gull Island2.5

3.5

4.5

1970 1975 1980 1985 1990 1995 2000

Ln (

num

ber)

COMU + 9.1%

BLKI + 8.8 %

Barren Islands

3

4

5

1970 1975 1980 1985 1990 1995 2000

Ln (

num

ber)

BLKI + 5.2 %

COMU + 4.4 %

Figure 14.9 Population trends for populations of Common Murres and Black-legged Kittiwakes at Chisik, Gull and Barren islands. Data for Gull and Chisik from this study, and historical data reported in Zador et al. 1997. Data for Barrens from Roseneau et al. 1998, Kettle et al. 2000.

BLKI Productivity at Chisik Island

0.0

0.2

0.4

0.6

0.8

1.0

70 72 74 76 78 80 82 84 86 88 90 92 94 96 98

Chi

cks

/ site

0 0 0 0 0 0 0

BLKI Productivity at Gull Island

0.0

0.2

0.4

0.6

0.8

1.0

70 72 74 76 78 80 82 84 86 88 90 92 94 96 98

Chi

cks

/ site

BLKI Productivity at Barren Islands

0.0

0.2

0.4

0.6

0.8

1.0

70 72 74 76 78 80 82 84 86 88 90 92 94 96 98

Chi

cks

/ site

Figure 14.10. Historical productivity of Black-legged Kittiwakes atChisik, Gull and Barren islands, 1970-1999. Data from this study, and as reported in Zador et al. 1997, Kettle et al. 2000, Dragoo et al. 2000.

Chisik Island

-1.0

-0.5

0.0

0.5

1.0N

orm

aliz

ed D

evia

tion

Gull Island

-1.0

-0.5

0.0

0.5

1.0

Nor

mal

ized

Dev

iatio

n

mean: +0.24

Barren Islands

-1.0

-0.5

0.0

0.5

1.0

Nor

mal

ized

Dev

iatio

n

mean: +0.09

mean: -0.37

Figure 14.11. Normalized deviations from average of seabird breeding and behavioral parameters at Chisik, Gull and Barren islands, 1995-1999. Deviations have been arbitrarily ranked by magnitude from most positive (left) to most negative (right). Barrens data from Kettle et al. 2000.

Parameter Index vs Population Change

r 2 = 0.85p=0.008

-15

-10

-5

0

5

10

15

-0.6 -0.4 -0.2 0.0 0.2 0.4

Parameter Index

Pop

ulat

ion

Cha

nge

(% p

.a.)

COMU

BLKI

Figure 14.12. Average parameter index (from Fig. 14.11) versus population trend (from Fig. 14.9) for Common Murres (COMU) and Black-legged Kittiwakes (BLKI) at Chisik, Gull and Barren islands.

GOABS

Unlimited

Limited

Deprived

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.701970'sKittiwake Productivity(n=36 colony-years)

GOABS

Unlimited

Limited

Deprived

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.701990'sKittiwake Productivity(n=115 colony-years

GOABS

Unlimited

Limited

Deprived

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.701980'sKittiwake Productivity(n=81 colony-years)

Figure 14.13. Historical breeding success (bs) of Black-legged Kittiwakes in the Gulf of Alaska (GOA) and Bering Sea (BS), categorized by functional relationships with food supply as "Deprived" (bs<0.015 chicks/pair), "Limited" (0.015<bs<0.46 chicks/pair), and "Unlimited" (bs>0.46 chicks/pair). Data from Hatch 1993, Zador et al. 1997, Dragoo et al. 2000, Kettle et al. 2000.