Document Type
Article
Publication Date
2-2021
Keywords
allochthonous subsidies, Arctic Char, compound-specific stable isotopes, diet tracing, energy flow, fatty acids, lake, mesocosms, trophic ecology
Abstract
Tracing the flow of dietary energy sources, especially in systems with a high degree of omnivory, is an ongoing challenge in ecology. In aquatic systems, one of the persistent challenges is in differentiating between autochthonous and allochthonous energy sources to top consumers. Bulk carbon stable isotope values of aquatic and terrestrial prey often overlap, making it difficult to delineate dietary energy pathways in food webs with high allochthonous prey subsidies, such as in many northern temperate waterbodies. We conducted a feeding experiment to explore how fatty acid stable isotopes may overcome the challenge of partitioning autochthonous and allochthonous energy pathways in aquatic consumers. We fed hatchery-reared Arctic Char (Salvelinus alpinus) diets of either benthic invertebrates, terrestrial earthworms, or a mixture of both. We then compared how the stable carbon isotopes of fatty acids (δ13CFA) distinguished between diet items and respective treatments in S. alpinus liver and muscle tissues, relative to bulk stable isotopes and fatty acid profiles. Although a high degree of variability of fatty acid stable carbon isotope values was present in all three measures, our results suggest that the ability of this method to overcome the challenges of bulk stable isotopes may be overstated. Finally, our study highlights the importance of further experimental investigation, and consideration of physiological and biochemical processes when employing this emerging method.
Publication Title
Ecosphere
Volume
12
Issue
2
DOI
https://doi.org/10.1002/ecs2.3360
Recommended Citation
Chiapella, A. M., Kainz, M. J., and Strecker, A. L.. 2021. Fatty acid stable isotopes add clarity, but also complexity, to tracing energy pathways in aquatic food webs. Ecosphere 12( 2):e03360. 10.1002/ecs2.3360
Subjects - Topical (LCSH)
Food chains (Ecology; Fish hatcheries
Appendix S1
Genre/Form
articles
Type
Text
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Language
English
Format
application/pdf
Included in
Aquaculture and Fisheries Commons, Environmental Sciences Commons, Fresh Water Studies Commons
