Stable isotopes in aquatic systems: sample preparation, analysis, and interpretaion

This report was written to provide background information for aquatic ecologists interested in using stable isotope analysis (SIA). Ratios of stable isotopes of carbon ( super(13)C/ super(12)C), nitrogen ( super(15)N/ super(14)N), and sulphur ( super(34)S/ super(32)) differ among various substances, and allow for dietary inferences to be made due to the predictability of isotopic relationships between consumers and their food. SIA also has been employed to examine contaminant bioaccumulation in top predators, to identify migrant individuals, and to quantify nutrient sources and their uptake. Potential problems exist, however, that require a researcher's awareness, to avoid potentially erroneous and misleading interpretation of data. SIA is becoming a powerful tool in ecology due to its integrative nature and its potential for non-destructive sampling.