Dissolved amino acids in the equatorial Pacific, the Sargasso Sea, and Biscayne Bay1

Seawater samples from several depths in the Sargasso Sea and equatorial Pacific and from surface stations in Biscayne Bay were analyzed for dissolved free amino acids and dissolved combined amino acids by a ligand-exchange chromatography technique. Enantiomeric ratios of dissolved total amino acids from Atlantic and Pacific samples were also determined. On the basis of these ratios, a bacterial source is postulated for the origin of the dissolved n-amino acids in seawater. The possible contributions from chemical raccmization are compared to biological production as a source for these n-amino acids. Because of the importance of dissolved amino acids in the marine food chain, the role of these compounds as excretion products and as nutrient sources is being thoroughly investigated in estuarine and nearshore environments ( e.g. Riley and Segar 1970; Wheeler et al. 1974; Crawford et al. 1974; North 1975). The abundance, distribution, and role of amino acids in the open ocean has received much less attention (Pocklington 1972; Lee and Bada 1975). The role of amino acids is not necessarily the same in coastal and open ocean environments, especially considering the much lower (about a tenth) concentrations found