An integrated model of H and O isotope composition in vertebrate muscle and its spatially explicit prediction: implications for migration studies

CHESSON, LESLEY A; VALENZUELA, LUCIANO O; O'GRADY, SHANNON P; CERLING, THURE E; EHLERINGER, JAMES R

Buenos aires

Congreso; IV Reunión Binacional de Ecología, XXIV Reunión Argentina de Ecología, XVII Reunión de la Sociedad de Ecología de Chile; 2010

The use of stable hydrogen and oxygen isotopes for migration studies and region-of-origin assignment is a growing field due to the predictable geographic variations in the isotope values of hydrogen and oxygen within meteoric water. Research thus far has used correlational inference to predict the isotope values of animal tissues based on the isotopic composition of drinking water. An obvious limitation to this approach is that it cannot easily be adapted to new geographic areas and different species. We present a semi-mechanistic model for the incorporation of hydrogen and oxygen atoms into muscle tissue of vertebrates. Our model includes isotopic contributions from local water, food, metabolic water and diatomic oxygen. To test our model we used muscle from cows and freshwater-fish sampled across a large isotopic range. We also present a South American isotope landscape (isoscape) for beef based on predictions derived from our model. The model and the isoscape are a first attempt to generate a spatially explicit prediction of hydrogen and oxygen isotope ratios in vertebrate tissues that will be useful in research related to animal movements such as migration studies, as well as region-of-origin assignment of invasive species and animal-derived products (for cases of illegal trafficking).