Testing the use of compound specific isotopic in trophic ecosystemstud aiensalysis of amino acids

Ph.D. University of Hawaii at Manoa 2013.Includes bibliographical references.The use of stable isotopes in studying ecological systems has a wide range of applications, from comparing food webinteractions to tracing nutrient flow through an organism or an environment. Compound specific isotopic analysis of amino acids (AA-CSIA) has recently emerged as a technique which resolves some of the shortcomings of bulk tissue stable isotope analysis, yielding information for estimating trophic position and tracingtheδ15N values ofbaseline nutrients from a single sample. However, the application of AA-CSIA to food web studies requires a more in-depth understanding of amino acid isotopic incorporationand fractionation. This dissertation focuses on the preliminary steps toward global application of AA-CSIA in ecosystem studies. The research presented here provides measurements ofsome of the first incorporation rates of individual amino acid nitrogenisotopes (Chapter 2) and the largest known dataset of AA-CSIA in marine teleosts for determining fractionation patterns across trophic positions (Chapter 3). The latter portion of the dissertation describes an understudied ecosystem in Hawaii, the mesophotic reefs, and uses AA-CSIA to compare the trophic ecology of the resident fish population to those in a shallow water coral reef environment (Chapters 4 & 5). The results of this dissertation provide critical first steps toward further developing AA-CSIA asa tool within ecosystem studies and in the process reveal that the biochemical processes controlling isotopic fra