Do soluble organic nitrogen compounds cause unusual algal blooms in seawater?
Hammer KD Ordinariat für Hygiene, Universität Hamburg. Up to now the nature and importance of the macromolecular forms of organic nitrogen in the marine environment is poorly understood. There is no doubt on the capacity of phytoplankton to utilize low molecule weight dissolved organic nitrogen compounds competitively with bacteria. In marine ecosystems the members of the plankton community show a complex close coupling with biological substances. In spite of trace concentrations the high dynamics in uptake and release processes cause strong fluxes of these compounds. In the case of inorganic nutrient deprivation or reduced photosynthesis under light deficiency algal utilization of organic nitrogen becomes noteworthy. Even under high nitrate supply an algal development occurred which was mainly triggered by amino acid uptake as was demonstrated during field experiments in the German Bight. The consumption of amino acids is controlled by several uptake systems, which are specified for t
