Lipid corrections in carbon and nitrogen stable isotope analyses: comparison of chemical extraction and modelling methods
Article first published online: 16 MAY 2008
© 2008 The Authors. Journal compilation © 2008 British Ecological Society
Journal of Animal Ecology
Volume 77, Issue 4, pages 838–846, July 2008
How to Cite
Logan, J. M., Jardine, T. D., Miller, T. J., Bunn, S. E., Cunjak, R. A. and Lutcavage, M. E. (2008), Lipid corrections in carbon and nitrogen stable isotope analyses: comparison of chemical extraction and modelling methods. Journal of Animal Ecology, 77: 838–846. doi: 10.1111/j.1365-2656.2008.01394.x
- Issue published online: 16 MAY 2008
- Article first published online: 16 MAY 2008
- Received 21 November 2007; accepted 28 January 2008Handling Editor: Joseph Rasmussen
- chemical tracer;
- energy transfer;
- trophic ecology
- 1Lipids have more negative δ13C values relative to other major biochemical compounds in plant and animal tissues. Although variable lipid content in biological tissues alters results and conclusions of δ13C analyses in aquatic food web and migration studies, no standard correction protocol exists.
- 2We compared chemical extraction and mathematical correction methods for freshwater and marine fishes and aquatic invertebrates to better understand impacts of correction approaches on carbon (δ13C) and nitrogen (δ15N) stable isotope data.
- 3Fish and aquatic invertebrate tissue δ13C values increased significantly following extraction for almost all species and tissue types relative to nonextracted samples. In contrast, δ15N was affected for muscle and whole body samples from only a few freshwater and marine species and had a limited effect for the entire data set.
- 4Lipid normalization models, using C : N as a proxy for lipid content, predicted lipid-corrected δ13C for paired data sets more closely with parameters specific to the tissue type and species to which they were applied.
- 5We present species- and tissue-specific models based on bulk C : N as a reliable alternative to chemical extraction corrections. By analysing a subset of samples before and after lipid extraction, models can be applied to the species and tissues of interest that will improve estimates of dietary sources using stable isotopes.