foraging patterns of northern fulmars (fulmarus glacialis) in alaska inferred from fatty acid...
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Foraging patterns of Northern Foraging patterns of Northern Fulmars (Fulmars (Fulmarus glacialisFulmarus glacialis) in ) in Alaska inferred from fatty acid Alaska inferred from fatty acid
signature analysissignature analysis
Shiway W. Shiway W. WangWangUniversity of Alaska University of Alaska Fairbanks USGS, Alaska Fairbanks USGS, Alaska Science CenterScience Center
Sara J. IversonSara J. IversonDalhousie University, Dalhousie University, CanadaCanada
Alan M. Alan M. SpringerSpringerUniversity of Alaska University of Alaska FairbanksFairbanks
Scott A. HatchScott A. HatchUSGS, Alaska Science USGS, Alaska Science CenterCenter
GoalGoal
Describe foraging characteristics and Describe foraging characteristics and diet of Northern Fulmarsdiet of Northern Fulmars
Assess trophic pathways of marine Assess trophic pathways of marine ecoregions in Alaskaecoregions in Alaska
Why fulmars?Why fulmars?
opportunistic, generalist predators
major colonies located in distinct ecoregions
largest component of seabird bycatch in AK
are they sensitive to ecosystem change?
Pribilofs Pribilofs (outer shelf-shelf (outer shelf-shelf
break)break)80,000 birds80,000 birds
no obvious trendno obvious trend
Chagulak Chagulak (Aleutian (Aleutian
Archipelago)Archipelago)½ million birds½ million birds
popn trend unknownpopn trend unknown
Semidis Semidis (Alaska Coastal (Alaska Coastal
Current)Current)440,000 birds440,000 birdspopn stablepopn stable
St.Matthew- St.Matthew- Hall Hall (middle shelf)(middle shelf)
450,000 birds450,000 birdspopn trend unknownpopn trend unknown
Why fatty acids?Why fatty acids? foraging patterns, diets foraging patterns, diets
of marine mammals and of marine mammals and seabirdsseabirds
non-lethal, less invasive non-lethal, less invasive
diet over time vs. last diet over time vs. last mealmeal
FA carbon chain length ≥ FA carbon chain length ≥ 14 pass into tissues 14 pass into tissues relatively intactrelatively intact
FA signatures conserved FA signatures conserved through the food chain, through the food chain, act as indicators of dietact as indicators of diet
To compare the adipose tissue To compare the adipose tissue FA signatures of adult fulmars FA signatures of adult fulmars
1.1.among coloniesamong colonies
2.2.between years within between years within coloniescolonies
3.3.between seasons within between seasons within coloniescolonies
ObjectiveObjective
Adipose tissue fatty acids will varyAdipose tissue fatty acids will vary
1.1. among colonies among colonies - located in distinct oceanographic habitats- located in distinct oceanographic habitats
2.2. between years within colonies between years within colonies - response of prey popn to inter-- response of prey popn to inter-annual environmental changesannual environmental changes
3.3. between seasons within colonies between seasons within colonies - life history traits of prey- life history traits of prey
PredictionsPredictions
St. GeorgeSt. George
ChagulakChagulak
ChowieChowiett
MayMay
2003 n = 30 2003 n = 30 2004 n = 252004 n = 25
AugustAugust
2003 n = 27 2003 n = 27 2004 n = 312004 n = 31
JuneJune
2003 n = 29 2003 n = 29 2004 n = 302004 n = 30
AugustAugust
2003 n = 9 2003 n = 9 2004 n = 262004 n = 26
JulyJuly
2004 n = 302004 n = 30
Storage: glass vials Storage: glass vials with Teflon-lined caps with Teflon-lined caps w/chloroform + 0.01% w/chloroform + 0.01%
BHT (antioxidant)BHT (antioxidant)
NoosepoNoosepolele
dip netdip net
adipose adipose tissuetissue
Lab AnalysisLab Analysis
lipid extractionlipid extraction
transesterification to transesterification to fatty acid methyl fatty acid methyl estersesters
gas chromatographygas chromatography (e.g. Iverson et al. 1997)
Diets differed among Diets differed among coloniescolonies
1st discriminant function
- 4 - 2 0 2 4
2nd
dis
crim
inan
t fu
ncti
on
- 4
- 2
0
2
4
St. GeorgeChowiet
Chagulak
Means ± SE Means ± SE 1st 6 functions (p < 0.0001), 69% of the variation, 76% correctly classified
Diets differed among Diets differed among coloniescolonies
Diets differed somewhat in May Diets differed somewhat in May between years for Chowietbetween years for Chowiet
1st discriminant function
- 4 - 2 0 2 4
2nd
dis
crim
inan
t fu
ncti
on
- 4
- 2
0
2
4
Means ± SE Means ± SE
May 04May 04
May 03May 03
Diets differed somewhat in May Diets differed somewhat in May between years for Chowietbetween years for Chowiet
ChowieChowiett
1st discriminant function
- 4 - 2 0 2 4
2nd
dis
crim
inan
t fu
ncti
on
- 4
- 2
0
2
4
May 04May 04
May 03May 03
ChowieChowiett
Means ± SE Means ± SE
Diets similar in Aug between Diets similar in Aug between years for Chowietyears for Chowiet
Aug 03Aug 03 Aug 04Aug 04
1st discriminant function
- 4 - 2 0 2 4
2nd
dis
crim
inan
t fu
ncti
on
- 4
- 2
0
2
4
May 04May 04
May 03May 03
ChowietChowiet
Aug 03Aug 03
Means ± SE Means ± SE
Diets same in June between years Diets same in June between years for St. Georgefor St. George
Jun 03Jun 03
Jun 04Jun 04
Tukey’s: 1 Tukey’s: 1 FA (p < FA (p < 0.003)0.003)
St. GeorgeSt. George
Aug 04Aug 04
1st discriminant function
- 4 - 2 0 2 4
2nd
dis
crim
inan
t fu
ncti
on
- 4
- 2
0
2
4ChowietChowiet
Means ± SE Means ± SE
Diets differed between Diets differed between seasonsseasons
May 03, 0403, 04
Aug 03, 0403, 04
St. GeorgeSt. George
Jun 03, 04 03, 04
ChowietChowiet
ChagulakChagulakJuly 0404
St. GeorgeSt. GeorgeAug 0404
EARLIER
LATER
SummarySummary1.1. Differences in FA signatures Differences in FA signatures
among coloniesamong colonies difference in food web structuresdifference in food web structures
2.2. Little difference in FA signatures Little difference in FA signatures between years within coloniesbetween years within colonies
similar diets and food web pathways similar diets and food web pathways between yearsbetween years
3.3. Differences in FA signatures Differences in FA signatures between seasons within coloniesbetween seasons within colonies
seasonal variability in diets or in food web seasonal variability in diets or in food web pathwayspathways
What are What are fulmarsfulmars eatingeating??
Quantitative Fatty Acid Quantitative Fatty Acid Signature AnalysisSignature Analysis
(QFASA)(QFASA)
Iverson, Field, Bowen & Blanchard (2004) Ecological MonographsIverson, Field, Bowen & Blanchard (2004) Ecological Monographs
Iverson, Field, Bowen & Blanchard (2004) Ecological MonographsIverson, Field, Bowen & Blanchard (2004) Ecological Monographs
Principles of QFASA:Principles of QFASA:1. Marine fishes & invertebrates have characteristic1. Marine fishes & invertebrates have characteristic FA signaturesFA signatures
PC1
- 8 - 6 - 4 - 2 0 2 4 6 8
PC2
- 4
- 3
- 2
- 1
0
1
2
3
4
P. sandfish
SandlanceW. pollockP. jordaniP. pacifica
R. pacifica
C. Melanaster
P. cod
B. milleriN. smoothtongue
L. opalescens
D. theta
Eulachon
P. herring
B. magisterCapelin
T. spiniferaN. lampfish
Zooplankton
P. alberti
Western GOAWestern GOA
Iverson, Field, Bowen & Blanchard (2004) Ecological MonographsIverson, Field, Bowen & Blanchard (2004) Ecological Monographs
1. Marine fishes & invertebrates have characteristic1. Marine fishes & invertebrates have characteristic FA signaturesFA signatures
2. These signatures are deposited in predators 2. These signatures are deposited in predators in a predictable wayin a predictable way
3. Calculate what mix of prey signatures comes 3. Calculate what mix of prey signatures comes closest to matching that of a given predatorclosest to matching that of a given predator
Principles of QFASA:Principles of QFASA:
Validation of QFASA
Validation of QFASA
Common MurreCommon Murre
Red-legged Red-legged KittiwakeKittiwake
QFASA Model: ProceduresQFASA Model: Procedures
4. Calculate shortest statistical 4. Calculate shortest statistical distance between real bird and our distance between real bird and our estimate of that birdestimate of that bird
1. Average (or series of averages) of prey1. Average (or series of averages) of prey signatures signatures
2. Apply calibration coefficients to predator to 2. Apply calibration coefficients to predator to account for metabolism of specific FAs account for metabolism of specific FAs
3. What mix of those prey signatures3. What mix of those prey signatures comes closest to a given (calibrated) bird?comes closest to a given (calibrated) bird?
jellyfishjellyfishP.codP.cod
shrimpshrimpsandfishsandfish
sandlancesandlanceamphipodsamphipods
eulachoneulachonn.lampfishn.lampfish
n.sm.tonguen.sm.tonguemyctophidaemyctophidae
pollockpollockzoopzoop
0.5
0.4
0.3
0.2
0.1
0
% ofdiet
Chowiet (Semidi Is)Chagulak (Aleutians)St. George (Pribilofs)
Preliminary QFASA Preliminary QFASA Estimates of Fulmar DietsEstimates of Fulmar Diets
ConclusionConclusion
Fatty acid signature analysis is a powerful Fatty acid signature analysis is a powerful tool in comparing and describing the tool in comparing and describing the diets of fulmars and other predators, diets of fulmars and other predators,
and will provide additional insight into and will provide additional insight into the structure and variability of marine the structure and variability of marine
food webs in Alaska.food webs in Alaska.
FUNDINGFUNDING
USGS-SCEP, AK Science USGS-SCEP, AK Science Center Center
NPRB/ReFERNPRB/ReFERDalhousie UniversityDalhousie University
Logistical SupportLogistical Support
Alaska Maritime NWR/USFWS Alaska Maritime NWR/USFWS
M/V Tiglax, F/V Big Valley M/V Tiglax, F/V Big Valley
USCG Kodiak Air StationUSCG Kodiak Air Station
photos: S.Wang, C.Warbelow, M.Shultz, V.Gillphotos: S.Wang, C.Warbelow, M.Shultz, V.Gill
Field WorkField Work
A.Larned, E.Naughter, M.Nielson, A.Larned, E.Naughter, M.Nielson, N.Bargmann, A.Ramey, D.Mulcahy, N.Bargmann, A.Ramey, D.Mulcahy,
T.KitayskyT.Kitaysky
Thanks!Thanks!Lab Analysis & EquipmentLab Analysis & Equipment
S.Lang & S.Temple (Dalhousie) S.Lang & S.Temple (Dalhousie) S.Henrichs, C. Stark (UAF)S.Henrichs, C. Stark (UAF)
Suggestions & SupportSuggestions & Support
UAF/Dalhousie Grad StudentsUAF/Dalhousie Grad Students
Additional Committee MembersAdditional Committee Members
Loren Buck (SFOS/UAF) Loren Buck (SFOS/UAF)
Sasha Kitaysky (IAB/UAF)Sasha Kitaysky (IAB/UAF)
Prey CollectionPrey Collection
E.Chilton, A.Abookire, D.McKelvey, M.Wilkins, K.Williams, M.Wilson E.Chilton, A.Abookire, D.McKelvey, M.Wilkins, K.Williams, M.Wilson (NOAA/NMFS)(NOAA/NMFS)
B.Holladay & B.Norcross (UAF)B.Holladay & B.Norcross (UAF)
T.Kline (PWSSC)T.Kline (PWSSC)
Would you Would you like fries like fries with your with your kittiwake?kittiwake?
Will work for money… or Will work for money… or food..food..