A preliminary investigation of the variation of vitamin B₁₂in oceanic and coastal waters

Abstract

The presence in the sea of vitamin B 12 , or of its analogues, has been found necessary for the growth of several species of unicellular plants (e.g. Provasoli & Pintner, 1953; Droop, 1954, 1955). Bioassays of the quantities in inshore waters during winter have been made by Lewin (1954) and by Droop (1954). The present investigation, carried out in 1955, was designed to extend this study and compare different seasons of the year.