The study of diet and trophic relationships through natural abundance 13C

Measurement of the natural abundances of stable carbon atoms (δ13C) is a powerful way to study the dietary organization of an entire ecosystem. In some cases, it is often the only tool available for distinguishing and tracing different food sources. However, like all methods, it has certain limitations; care must always be taken in designing the experiment and in interpreting the results. This chapter covers all of these aspects of the method. Section 1 gives examples of specific areas in which the technique is valuable, a general discussion of its limitations and how to work around them, and finally some examples of particular studies that are used to illustrate the different procedures. Section 2 enumerates the various factors important for both experimental design and for interpretation of results. Section 3 describes the particular steps necessary to obtain, process, and preserve samples. General techniques and principles are given that can be applied to all ecosystems. Specific methods for marine plankton illustrate how the principles can be applied