lower homer cook inlet - usgs homer cook inlet 1995 ... pigeon guillemots 3 ... 12 birds 1995 1996...
TRANSCRIPT
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.