1. Foraging patterns of Northern Fulmars (Fulmarus glacialis) in Alaska inferred from fatty acid signature analysis Shiway W. Wang University of Alaska Fairbanks USGS, Alaska Science Center Sara J. Iverson Dalhousie University, Canada Alan M. Springer University of Alaska Fairbanks Scott A. Hatch USGS, Alaska Science Center

2. Goal Describe foraging characteristics and diet of Northern Fulmars Assess trophic pathways of marine ecoregions in Alaska

3. Why fulmars?   opportunistic, generalist predators   major colonies located in distinct ecoregions   largest component of seabird bycatch in AK   are they sensitive to ecosystem change?

4. Pribilofs (outer shelf-shelf break) 80,000 birds no obvious trend Chagulak (Aleutian Archipelago) ½ million birds popn trend unknown Semidis (Alaska Coastal Current) 440,000 birds popn stable St.Matthew- Hall (middle shelf) 450,000 birds popn trend unknown

5. Why fatty acids?  foraging patterns, diets of marine mammals and seabirds  non-lethal, less invasive  diet over time vs. last meal  FA carbon chain length ≥ 14 pass into tissues relatively intact  FA signatures conserved through the food chain, act as indicators of diet

6. To compare the adipose tissue FA signatures of adult fulmars 1.among colonies 2.between years within colonies 3.between seasons within colonies Objective

7. Adipose tissue fatty acids will vary 1.among colonies - located in distinct oceanographic habitats 2.between years within colonies - response of prey popn to inter-annual environmental changes 3.between seasons within colonies - life history traits of prey Predictions

8. St. George Chagulak Chowiet May 2003 n = 30 2004 n = 25 August 2003 n = 27 2004 n = 31 June 2003 n = 29 2004 n = 30 August 2003 n = 9 2004 n = 26 July 2004 n = 30

9. Storage: glass vials with Teflon-lined caps w/chloroform + 0.01% BHT (antioxidant) Noosepole dip net adipose tissue

10. Lab Analysis  lipid extraction  transesterification to fatty acid methyl esters  gas chromatography  gas chromatography (e.g. Iverson et al. 1997)

11. Diets differed among colonies

12. St. GeorgeChowiet Chagulak Means ± SE 1 st 6 functions (p < 0.0001), 69% of the variation, 76% correctly classified Diets differed among colonies

13. Diets differed somewhat in May between years for Chowiet

14. Means ± SE May 04 May 03 Diets differed somewhat in May between years for Chowiet Chowiet

15. May 04 May 03 Chowiet Means ± SE Diets similar in Aug between years for Chowiet Aug 03 Aug 04

16. May 04 May 03 Chowiet Aug 03 Means ± SE Diets same in June between years for St. George Jun 03 Jun 04 Tukey’s: 1 FA (p < 0.003) St. George Aug 04

17. Chowiet Means ± SE Diets differed between seasons 03, 04 May 03, 04 03, 04 Aug 03, 04 St. George 03, 04 Jun 03, 04 Chowiet Chagulak 04 July 04 St. George 04 Aug 04 EARLIER LATER

18. Summary 1.Differences in FA signatures among colonies  difference in food web structures 2.Little difference in FA signatures between years within colonies  similar diets and food web pathways between years 3.Differences in FA signatures between seasons within colonies  seasonal variability in diets or in food web pathways

19. What are fulmars eating? Quantitative Fatty Acid Signature Analysis (QFASA) Iverson, Field, Bowen & Blanchard (2004) Ecological Monographs

20. Principles of QFASA: 1. Marine fishes & invertebrates have characteristic FA signatures FA signatures Western GOA

21. Iverson, Field, Bowen & Blanchard (2004) Ecological Monographs 1. Marine fishes & invertebrates have characteristic FA signatures FA signatures 2. These signatures are deposited in predators in a predictable way in a predictable way 3. Calculate what mix of prey signatures comes closest to matching that of a given predator closest to matching that of a given predator Principles of QFASA:

22. Validation of QFASA

23. Common Murre Red-legged Kittiwake

24. QFASA Model: Procedures 4. Calculate shortest statistical distance between real bird and our estimate of that bird 1. Average (or series of averages) of prey signatures signatures 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 signatures comes closest to a given (calibrated) bird? comes closest to a given (calibrated) bird?

25. jellyfish P.cod shrimp sandfish sandlance amphipods eulachon n.lampfish n.sm.tongue myctophidae pollock zoop 0.5 0.4 0.3 0.2 0.1 0 % of diet Chowiet (Semidi Is) Chagulak (Aleutians) St. George (Pribilofs) Preliminary QFASA Estimates of Fulmar Diets

26. Conclusion Fatty acid signature analysis is a powerful tool in comparing and describing the diets of fulmars and other predators, and will provide additional insight into the structure and variability of marine food webs in Alaska.

27. FUNDING USGS-SCEP, AK Science Center NPRB/ReFER Dalhousie University Logistical Support Alaska Maritime NWR/USFWS M/V Tiglax, F/V Big Valley USCG Kodiak Air Station photos: S.Wang, C.Warbelow, M.Shultz, V.Gill Field Work A.Larned, E.Naughter, M.Nielson, N.Bargmann, A.Ramey, D.Mulcahy, T.Kitaysky Thanks! Lab Analysis & Equipment S.Lang & S.Temple (Dalhousie) S.Henrichs, C. Stark (UAF) Suggestions & Support UAF/Dalhousie Grad Students Additional Committee Members Loren Buck (SFOS/UAF) Sasha Kitaysky (IAB/UAF) Prey Collection E.Chilton, A.Abookire, D.McKelvey, M.Wilkins, K.Williams, M.Wilson (NOAA/NMFS) B.Holladay & B.Norcross (UAF) T.Kline (PWSSC)

28. Would you like fries with your kittiwake? Will work for money… or food..