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Marine Biology

, 163:220 | Cite as

Lipid removal and acidification affect nitrogen and carbon stable isotope ratios of beluga whales (Delphinapterus leucas) and their potential prey species in the Beaufort Sea ecosystem

  • Emily S. Choy
  • James D. Roth
  • Lisa L. Loseto
Original paper

Abstract

Carbon and nitrogen stable isotope ratios are ecological tracers that can provide insights into the diets of marine mammals. As a generalist predator, beluga whales (Delphinapterus leucas) consume a variety of prey; however, differences in lipid content and the presence of inorganic carbon in prey may cause variability in the δ13C signal that is not related to food sources. We examined the effects of carbonate and/or lipid removal in beluga and potential prey and tested whether the C:N ratio was a valid indicator of lipid content. The C:N ratio was a good predictor of the change in δ13C after lipid removal in capelin (Mallotus villosus), octopus (Cirroteuthis muelleri), green shrimp (Argis dentata), and circumpolar eualid (Eualus gaimardii). Despite relatively low C:N ratios, lipid removal significantly increased δ13C values, but also affected δ15N. Removal of carbonates from invertebrate samples significantly decreased δ13C values and had variable effects on δ15N. Overall, the variability in δ13C within a species decreased after removing lipids and carbonates. Variability in δ15N did not change for species requiring only lipid removal, but increased after acidification. We also evaluated the effect of these sample preparation methods on niche dispersion metrics. After lipid and carbonate treatments, centroid locations differed significantly in all species except beluga muscle, and niche breadth and mean distance to the centroid decreased. Failure to remove lipids and carbonates for δ13C values may lead to incorrect interpretations for isotopic niche, which may have major ecological implications, such as predicting the impacts of invasive species or determining the dietary linkages of beluga whales.

Keywords

Lipid Content Niche Breadth Stable Isotope Ratio Carbonate Removal Isotopic Niche 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

This project was supported by a Natural Science and Engineering Research Council (NSERC) Doctoral Scholarship, UNESCO-L’Oreal Women in Science PhD Fellowship, E. Scherer Memorial Scholarship, Lorraine Allison Memorial Scholarship, Arctic Institute of North America (AINA) Grant-in-Aid Program, and the Association of Canadian University for Northern Studies (ACUNS) W. Garfield Weston Northern Research Award to EC. Project funding was provided by Fisheries and Oceans Canada, Fisheries Joint Management Committee, Northern Science Training Program and the Northern Contaminants Program. We would like to thank Shannon MacPhee for coordinating the BREA benthic program and Laure de Montety for identifying the invertebrate samples. We would also like to thank Sheila Atchison and Andy Majewski for collecting the capelin samples, as well as beluga monitors Frank Pokiak, John Day, and Brandon Green for collecting muscle and liver tissues. Maps of the beluga hunting camps and BREA transects were provided by Mark Ouellette. We are grateful for the support and partnerships of the Hunters and Trappers Committees of Inuvik, Tuktoyaktuk, and Paulatuk. We would like to thank our reviewers for their valuable feedback.

Supplementary material

227_2016_2992_MOESM1_ESM.pdf (177 kb)
Supplementary material 1 (PDF 177 kb)

References

  1. Bligh EG, Dyer WJ (1959) A rapid method of total lipid extraction and purification. Can J Biochem Physiol 37:911–917. doi: 10.1139/o59-099 CrossRefGoogle Scholar
  2. Boecklen WJ, Yarnes CT, Cook BA, James AC (2011) On the use of stable isotopes in trophic ecology. Annu Rev Ecol Evol Syst 42:411–440. doi: 10.1146/annurev-ecolsys-102209-144726 CrossRefGoogle Scholar
  3. De Lecea AM, Smit AJ, Fennessy ST (2011) The effects of freeze/thaw periods and drying methods on isotopic and elemental carbon and nitrogen in marine organisms, raising questions on sample preparation. Rapid Commun Mass Spectrom 25:3640–3649. doi: 10.1002/rcm.5265 CrossRefGoogle Scholar
  4. DeNiro M, Epstein S (1977) Mechanism of carbon isotope fractionation associated with lipid synthesis. Science 197:261–263. doi: 10.1126/science.327543 CrossRefGoogle Scholar
  5. Ehrich D, Tarroux A, Stien J, Lecomte N, Killengreen S, Berteaux D, Yoccoz NG (2011) Stable isotope analysis: modelling lipid normalization for muscle and eggs from arctic mammals and birds. Methods Ecol Evol 2:66–76. doi: 10.1111/j.2041-210X.2010.00047.x CrossRefGoogle Scholar
  6. Elliott KH, Elliott JE (2016) Lipid extraction techniques for stable isotope analysis of bird eggs: chloroform–methanol leads to more enriched 13C values than extraction via petroleum ether. J Exp Mar Biol Ecol 474:54–57. doi: 10.1016/j.jembe.2015.09.017 CrossRefGoogle Scholar
  7. Folch J, Lees M, Stanley GHS (1957) A simple method for the isolation and purification of total lipids from animal tissues. J Biol Chem 226:497–509. doi: 10.1007/s10858-011-9570-9 Google Scholar
  8. Jackson AL, Inger R, Parnell AC, Bearhop S (2011) Comparing isotopic niche widths among and within communities: SIBER—Stable Isotope Bayesian Ellipses in R. J Anim Ecol 80:595–602. doi: 10.1111/j.1365-2656.2011.01806.x CrossRefGoogle Scholar
  9. Jackson MC, Donohue I, Jackson AL, Britton JR, Harper DM, Grey J (2012) Population-level metrics of trophic structure based on stable isotopes and their application to invasion ecology. PLoS One 7:1–12. doi: 10.1371/journal.pone.0031757 Google Scholar
  10. Jacob U, Mintenbeck K, Brey T, Knust R, Beyer K (2005) Stable isotope food web studies: a case for standardized sample treatment. Mar Ecol Prog Ser 287:251–253. doi: 10.3354/meps287251 CrossRefGoogle Scholar
  11. Kidd K, Fagan K-A, Koops MA, Arts MT, Power M (2011) Assessing the utility of C:N ratios for predicting lipid content in fishes. Can J Fish Aquat Sci 68:374–385. doi: 10.1139/F10-119 CrossRefGoogle Scholar
  12. Kiljunen M, Grey J, Sinisalo T, Harrod C, Immonen H, Jones RI (2006) A revised model for lipid-normalizing δ13C values from aquatic organisms, with implications for isotope mixing models. J Appl Ecol 43:1213–1222. doi: 10.1111/j.1365-2664.2006.01224.x CrossRefGoogle Scholar
  13. Layman CA, Arrington DA, Montana CG, Post DM (2007a) Can stable isotope ratio provide for community-wide measures of trophic structure? Ecology 88:42–48. doi: 10.1890/0012-9658(2007)88[42:CSIRPF]2.0.CO;2 CrossRefGoogle Scholar
  14. Layman CA, Quattrochi JP, Peyer CM, Allgeier JE (2007b) Niche width collapse in a resilient top predator following ecosystem fragmentation. Ecol Lett 10:937–944. doi: 10.1111/j.1461-0248.2007.01087.x CrossRefGoogle Scholar
  15. Lesage V, Morin Y, Rioux È, Pomerleau C, Ferguson SH, Pelletier É (2010) Stable isotopes and trace elements as indicators of diet and habitat use in cetaceans: predicting errors related to preservation, lipid extraction, and lipid normalization. Mar Ecol Prog Ser 419:249–265. doi: 10.3354/meps08825 CrossRefGoogle Scholar
  16. Logan JM, Lutcavage ME (2008) A comparison of carbon and nitrogen stable isotope ratios of fish tissues following lipid extraction with non-polar and traditional chloroform/methanol solvent systems. Rapid Commun Mass Spectrom 22:1081–1086. doi: 10.1111/j.1365-2656.2008.01394.x CrossRefGoogle Scholar
  17. Logan JM, Jardine TD, Miller TJ, Bunn SE, Cunjak RA, Lutcavage ME (2008) Lipid corrections in carbon and nitrogen stable isotope analyses: comparison of chemical extraction and modelling methods. J Anim Ecol 77:838–846. doi: 10.1111/j.1365-2656.2008.01394.x CrossRefGoogle Scholar
  18. Loseto LL, Stern GA, Deibel D, Connelly TL, Prokopowicz A, Lean DRS, Fortier L, Ferguson SH (2008) Linking mercury exposure to habitat and feeding behaviour in Beaufort Sea beluga whales. J Mar Syst 74:1012–1024. doi: 10.1016/j.jmarsys.2007.10.004 CrossRefGoogle Scholar
  19. Loseto LL, Stern GA, Connelly TL, Deibel D, Gemmill B, Prokopowicz A, Fortier L, Ferguson SH (2009) Summer diet of beluga whales inferred by fatty acid analysis of the eastern Beaufort Sea food web. J Exp Mar Biol Ecol 374:12–18. doi: 10.1016/j.jembe.2009.03.015 CrossRefGoogle Scholar
  20. Marcoux M, McMeans BC, Fisk AT, Ferguson SH (2012) Composition and temporal variation in the diet of beluga whales, derived from stable isotopes. Mar Ecol Prog Ser 471:283–291. doi: 10.3354/meps10029 CrossRefGoogle Scholar
  21. Matley JK, Fisk AT, Dick TA (2015) Foraging ecology of ringed seals (Pusa hispida), beluga whales (Delphinapterus leucas) and narwhals (Monodon monoceros) in the Canadian High Arctic determined by stomach content and stable isotope analysis. Polar Res. doi: 10.3402/polar.v34.24295 Google Scholar
  22. Mintenbeck K, Brey T, Jacob U, Knust R, Struck U (2008) How to account for the lipid effect on carbon stable-isotope ratio (δ13C): sample treatment effects and model bias. J Fish Biol 72:815–830. doi: 10.1111/j.1095-8649.2007.01754.x CrossRefGoogle Scholar
  23. Monson KD, Hayes JM (1982) Biosynthetic control of the natural abundance of carbon 13 at specific positions within fatty acids in Saccharomyces cerevisiae. Isotopic fractionation in lipid synthesis as evidence for peroxisomal regulation. J Biol Chem 257:5568–5575Google Scholar
  24. Murry BA, Farrell JM, Teece MA, Smyntek PM (2006) Effect of lipid extraction on the interpretation of fish community trophic relationships determined by stable carbon and nitrogen isotopes. Can J Fish Aquat Sci 63:2167–2172. doi: 10.1139/f06-116 CrossRefGoogle Scholar
  25. Parnell AA, Jackson A (2013) SIAR: Stable Isotope Analysis in R. R package version 4.2.2. https://CRAN.R-project.org/package=siar
  26. Peterson BJ, Fry B (1987) Stable isotopes in ecosystem studies. Annu Rev Ecol Syst 18:293–320. doi: 10.1146/annurev.es.18.110187.001453 CrossRefGoogle Scholar
  27. Pomerleau C, Winkler G, Sastri A, Nelson RJ, Williams WJ (2014) The effect of acidification and the combined effects of acidification/lipid extraction on carbon stable isotope ratios for sub-Arctic and Arctic marine zooplankton species. Polar Biol 37:1541–1548. doi: 10.1007/s00300-014-1540-8 CrossRefGoogle Scholar
  28. Post DM, Layman CA, Arrington DA, Takimoto G, Quattrochi J, Montaña CG (2007) Getting to the fat of the matter: models, methods and assumptions for dealing with lipids in stable isotope analyses. Oecologia 152:179–189. doi: 10.1007/s00442-006-0630-x CrossRefGoogle Scholar
  29. Quakenbush LT, Suydam RS, Bryan AL, Lowry LF, Frost KJ, Mahoney BA (2014) Diet of beluga whales (Delphinapterus leucas) in Alaska from stomach contents, March–November. Mar Fish Rev 77:70–84. doi: 10.7755/MFR.77.1.7 CrossRefGoogle Scholar
  30. R Core Team (2015) R: a language and environment for statistical computing. R foundation for statistical computing, Vienna, Austria. https://www.R-project.org/
  31. Ryan C, McHugh B, Trueman CN, Harrod C, Berrow SD, O’Connor I (2012) Accounting for the effects of lipids in stable isotope (δ13C and δ15N values) analysis of skin and blubber of balaenopterid whales. Rapid Commun Mass Spectrom 26:2745–2754. doi: 10.1002/rcm.6394 CrossRefGoogle Scholar
  32. Ryan C, Berrow SD, Mchugh B, O’Donnell C, Trueman CN, O’Connor I (2014) Prey preferences of sympatric fin (Balaenoptera physalus) and humpback (Megaptera novaeangliae) whales revealed by stable isotope mixing models. Mar Mammal Sci 30:242–258. doi: 10.1111/mms.12034 CrossRefGoogle Scholar
  33. Schlacher TA, Connolly RM (2014) Effects of acid treatment on carbon and nitrogen stable isotope ratios in ecological samples: a review and synthesis. Methods Ecol Evol 5:541–550. doi: 10.1111/2041-210X.12183 CrossRefGoogle Scholar
  34. Soreide JE, Tamelander T, Hop H, Hobson KA, Johansen I (2006) Sample preparation effects on stable C and N isotope values: a comparison of methods in Arctic marine food web studies. Mar Ecol Prog Ser 328:17–28. doi: 10.3354/meps328017 CrossRefGoogle Scholar
  35. Sotiropoulos MA, Tonn WM, Wassenaar LI (2004) Effects of lipid extraction on stable carbon and nitrogen isotope analyses of fish tissues: potential consequences for food web studies. Ecol Freshw Fish 13:155–160. doi: 10.1111/j.1600-0633.2004.00056.x CrossRefGoogle Scholar
  36. Stenroth P, Holmqvist N, Nyström P, Berglund O, Larsson P, Granéli W (2006) Stable isotopes as an indicator of diet in omnivorous crayfish (Pacifastacus leniusculus): the influence of tissue, sample treatment, and season. Can J Fish Aquat Sci 63:821–831. doi: 10.1139/f05-265 CrossRefGoogle Scholar
  37. Svensson E, Schouten S, Hopmans EC, Middelburg JJ, Sinninghe-Damsté J (2016) Factors controlling the stable nitrogen isotopic composition (δ15N) of lipids in marine animals. PLoS One. doi: 10.1371/journal.pone.0146321 Google Scholar
  38. Sweeting CJ, Polunin NVC, Jennings S (2006) Effects of chemical lipid extraction and arithmetic lipid correction on stable isotope ratios of fish tissues. Rapid Commun Mass Spectrom 20:595–601. doi: 10.1002/rcm.2347 CrossRefGoogle Scholar
  39. Turner TF, Collyer ML, Krabbenhoft TJ (2010) A general hypothesis-testing framework for stable isotope ratios in ecological studies. Ecology 91:2227–2233. doi: 10.1890/09-1454.1 CrossRefGoogle Scholar
  40. Wilson RM, Chanton JP, Balmer BC, Nowacek DP (2014) An evaluation of lipid extraction techniques for interpretation of carbon and nitrogen isotope values in bottlenose dolphin (Tursiops truncatus) skin tissue. Mar Mammal Sci 30:85–103. doi: 10.1111/mms.12018 CrossRefGoogle Scholar
  41. Yurkowski DJ, Hussey NE, Semeniuk C, Ferguson SH, Fisk AT (2014) Effects of lipid extraction and the utility of lipid normalization models on δ13C and δ15N values in Arctic marine mammal tissues. Polar Biol 38:131–143. doi: 10.1007/s00300-014-1571-1 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Emily S. Choy
    • 1
  • James D. Roth
    • 1
  • Lisa L. Loseto
    • 1
    • 2
  1. 1.Department of Biological SciencesUniversity of ManitobaWinnipegCanada
  2. 2.Freshwater InstituteFisheries and Oceans CanadaWinnipegCanada

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