Sources and Cycling of Organic Matter within Modern and Prehistoric Food Webs

Abstract

Over the past two decades, analysis of the stable isotopes of carbon, nitrogen, and sulfur has become a widely used and important technique for tracing the flow of organic matter in modern and prehistoric food webs (Miyake and Wada, 1967; DeNiro and Epstein, 1978; Fry, 1981a; van der Merwe, 1982). This approach is based on the observation that the carbon, nitrogen, and sulfur isotopic compositions (δ13C, δ15N, and δ34S,* respectively) of an organism are similar to or vary predictably from those of its food source. As a measure of assimilable material, this type of data offers a unique opportunity to delineate pathways of energy transfer.