Amino acid compound specific δ13C fingerprinting of old vs. young dissolved organic matter: testing new ideas about a microbial nitrogen pump in the North Pacific subtropical gyre

Hope L Ianiri, University of California Santa Cruz, Ocean Sciences, Santa Cruz, CA, United States, Taylor Broek, Lawrence Livermore National Laboratory, Center for Accelerator Mass Spectrometry, Livermore, CA, United States, Yasuhiko T Yamaguchi, Lake Biwa Environmental Research Institute, Otsu, Shiga, Japan, Thomas P Guilderson, LLNL, Livermore, CA, United States and Matthew D. McCarthy, University of California Santa Cruz, Ocean Sciences Department, Santa Cruz, CA, United States