timing of entry, distribution, and condition of chum salmon juveniles in western alaska nicola...
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Timing of entry, distribution, Timing of entry, distribution, and condition of chum salmon and condition of chum salmon
juveniles juveniles in western Alaska in western Alaska
Nicola Hillgruber Nicola Hillgruber Christian E. ZimmermanChristian E. Zimmerman
Sean E. BurrilSean E. Burril
OutlineOutline
► Introduction & BackgroundIntroduction & Background►MethodsMethods►ResultsResults
Fish catches and timing of Fish catches and timing of outmigrationoutmigration
Distribution Distribution Size and conditionSize and condition Otolith microchemistryOtolith microchemistry
►ConclusionsConclusions
MethodsMethods
Kuskokwim Bay, western Kuskokwim Bay, western AlaskaAlaska
Quinhagak
Eek
Bethel
Ishkowik River
Kwethluk River
Sampling StationsSampling Stations
0 20 4010 Kilometers
9
8
7
6
5
4
3
2
1
21
20
19
18
17
16
15
14
13
12
11
10
MethodsMethods
Sampling TripsSampling Trips
20032003 20042004
June 23-25June 23-25 Week 1: May 16-22Week 1: May 16-22
July 24-26July 24-26 Week 2: May 23-29Week 2: May 23-29
August 26-30August 26-30 Week 3: May 30-Week 3: May 30-June 5June 5
Week 4: June 6-12Week 4: June 6-12
ResultsResults
Fish abundance Fish abundance
and timing of outmigrationand timing of outmigration
Catch summary in 2003 and 2004Catch summary in 2003 and 2004
Species 2003 2004 Total Fork length [mm]
Oncorhynchus keta 68 1,245 1,313 31-66
Oncorhynchus kisutch 1 200 201 70-170
Oncorhynchus tshawytscha 5 50 55 78-125
Oncorhynchus nerka 0 38 38 63-124
Oncorhynchus gorbuscha 4 76 80 32-53
Ammodytes hexapterus 0 739 739
Clupea pallasii 2,035 1 2,036
Osmeridae 1,810 22,778+
24,588
Gasterosteidae 1,117 1,432 2,549
Others 10 104 114
Mean CPUE (Mean CPUE (±SE)±SE) of juvenile chum of juvenile chum salmon at the head of Kuskokwim Bay salmon at the head of Kuskokwim Bay
(station 1-3) (station 1-3)
0
1
2
3
4
5
6
May-19 May-26 Jun-2 Jun-9 Jun-24 Jul-25 Aug-27
Week
Ln
(CP
UE
+1
) 2003
2004
0
1
2
3
4
May-19 May-26 Jun-2 Jun-9 Jun-24 Jul-25 Aug-27
0
1
2
3
4
May-19 May-26 Jun-2 Jun-9 Jun-24 Jul-25 Aug-27
0
1
2
3
4
May-19 May-26 Jun-2 Jun-9 Jun-24 Jul-25 Aug-27
0
1
2
3
4
May-19 May-26 Jun-2 Jun-9 Jun-24 Jul-25 Aug-27
Mean CPUE for juvenile salmonids Mean CPUE for juvenile salmonids at the head of Kuskokwim Bay at the head of Kuskokwim Bay
(station 1-3)(station 1-3)
2004 2003
Coho Pink
Chinook Sockeye
ResultsResults
Environmental factors and Environmental factors and juvenile chum salmon juvenile chum salmon
distributiondistribution
SST and SSS in 2004SST and SSS in 2004
6/06-6/12
5/16-5/22
Legend
6 - 7
7 - 8
8 - 9
9 - 10
10 - 11
11 - 12
12 - 13
13 - 14
14 - 15
15 - 16
Legend
0 - 5
5 - 10
10 - 15
15 - 20
20 - 25
25 - 30
Temperature
Salinity
Surface density [mSurface density [m-3-3] of small copepod in ] of small copepod in 20042004
Legend
2
3 - 75
76 - 120
121 - 222
223 - 9000
5/16-5/22
5/23-5/29
5/30-6/05
6/06-6/12
Chum salmon CPUE in 2004Chum salmon CPUE in 2004
E
EE
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
Legend
E 0.000000
0.000001 - 0.010000
0.010001 - 0.100000
0.100001 - 1.000000
1.000001 - 10.000000
10.000001 - 30.000000
No Chum
0 - 0.01
0.01 - 0.1
0.1 - 1.0
10.0 – 30.0
1.0 – 10.0
5/16-5/22
5/23-5/29
5/30-6/05
6/06-6/12
Chum salmon CPUE by SSSChum salmon CPUE by SSS
Week 1
0 5 10 15 20 25 30 35
ln C
PU
E +
1
0
2
4
6
8
10
Week 2
0 5 10 15 20 25 30 35
ln C
PU
E +
1
0
2
4
6
8
10
Week 3
0 5 10 15 20 25 30 35
ln C
PU
E +
1
0
2
4
6
8
10
Week 4
Sea Surface Salinity
0 5 10 15 20 25 30 35
ln C
PU
E +
1
0
2
4
6
8
10
ResultsResults
Size and conditionSize and condition
Weight and length of chum salmon Weight and length of chum salmon juvenilesjuveniles
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
May 16-22 May 23-29 May 30-June 5 June 6-12
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
June 23-25 July 24-26 August 26-30
0
10
20
30
40
50
60
May 16-22 May 23-29 May 30-June 5 June 6-12
0
10
20
30
40
50
60
June 23-25 July 24-26 August 26-30
Fork Length [mm]Fork Length [mm]
Weight [g]Weight [g]20042004 20032003
18 62 48 162 356
FL = 173.1 mm
(Aug/Sept)Farley et al.
0
Energy content by size and month in Energy content by size and month in 20042004
4500
4700
4900
5100
5300
5500
5700
Takotna 30-39 40-49 50-59 60-69 Shelf
cal/g
dry
we
igh
t
May 2004
June 2004
23 59
Aug/Sept(Farley pers.
comm.)
815 river km
4500
4700
4900
5100
5300
5500
5700
30-39 40-49 50-59 60-69
cal/g
dry
we
igh
t
May 2004
June 2004
58 32 21 58111 3 69
0
ResultsResults
Otolith microchemistryOtolith microchemistry
Determination of saltwater entry for Determination of saltwater entry for Kuskokwim Bay chum and Chinook Kuskokwim Bay chum and Chinook
salmonsalmon
Distance from primordium (microns)
0 100 200 300 400 500 600
Sr/
Ca
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
Chum salmonChinook salmonCollected at
SSS=12
ConclusionsConclusions
► Chum emigration peaked in early/middle Chum emigration peaked in early/middle JuneJune
► Juveniles followed the river plume before Juveniles followed the river plume before moving into the bay moving into the bay
► Length and weight increased with season Length and weight increased with season
► Condition decreased with size, season, Condition decreased with size, season, SSTSST
► No distinct saltwater entry signal for chum No distinct saltwater entry signal for chum salmon juvenilessalmon juveniles
AcknowledgementsAcknowledgements
► Mikhail BlikshteynMikhail Blikshteyn
► Johnny ZutzJohnny Zutz
► Jim PeacockJim Peacock
► Bill WiebeBill Wiebe
► Wendy WhelanWendy Whelan
► Switgard DuesterlohSwitgard Duesterloh