The stony road to understand isotopic enrichment and turnover rates: insight into the metabolic part
|Author(s)||Lefebvre Sebastien1, Dubois Stanislas2|
|Affiliation(s)||1 : Univ Littoral Cote dOpale, Univ Lille, CNRS, UMR 8187,LOG, F-62930 Wimereux, France.
2 : IFREMER, DYNECO, LEBCO, Technopole Brest Iroise,BP 70, F-29280 Plouzane, France.
|Source||Vie Et Milieu-life And Environment (0240-8759) (Observatoire Oceanologique Banyuls), 2016 , Vol. 66 , N. 3-4 , P. 305-314|
|WOS© Times Cited||18|
|Keyword(s)||stable isotopes, growth rates, diet-tissue discrimination, dynamic energy budget, trophic fractionation, catabolism|
Trophic enrichment factors (TEF) are essential to properly and fruitfully explore stable isotope analysis in ecology. And so is the time window of food source integration, usually estimated with the turnover rates (lambda) of isotopic incorporation. On the road to provide ecologists with a general and reliable method to obtain TEF and turnover rates for diet reconstruction, isotopists start realizing that those two parameters are ultimately linked with the physiological state of organisms and that metabolic pathways are of primary importance to understand the large ranges in TEF values. In this study, we used a diet-switching experiment for seven small marine invertebrates. Changes in isotopic compositions were fitted to an exponential decay model to estimate TEF and. values. We then partitioned the growth and the catabolism components of the turnover rate and tested how these components are correlated to the TEF among species. Results showed a significant linear negative relationship between TEF and growth values for both C and N. This ultimately means that the increase in body mass over a time window can be used to estimate the TEF values for a given species.