The dissolved organic nitrogen occurring in the sea has so far received the least attention of all the nitrogen-containing fractions. As Krogh (1) has pointed out, it is present in relatively large amounts but is apparently unavailable for use by living organisms. The present investigation was carried out to test the practicability of a more extensive study of the distribution and significance of the dissolved organic N in the sea.
Brand, Theodor v., and Norris W. Rakestraw. 1941. "The determination of dissolved organic nitrogen in sea water." Journal of Marine Research 4, (1). https://elischolar.library.yale.edu/journal_of_marine_research/583