Physical Sciences: Free Amino-acids dissolved in North Atlantic Ocean Waters

Abstract

THE “dissolved” fraction of the organic matter in sea water is conventionally defined as that which has passed through a 0.45 µm filter¹ (which excludes zooplankton and phytoplankton and most marine bacteria, but not colloidal particles). An acceptable figure² for the mean concentration of this material in surface water is 1.2 mgC l.⁻¹ and in deeper water is 0.5 mgC l.⁻¹. Attention was focused on the amino-acids in seawater because, although they are the most difficult chemical problem because of their polar nature, the free amino-acid “pool” in the oceans is probably one of the best indicators of the state and rate of biogeochemical interactions³.