THE EXPERIMENTAL DECOMPOSITION AND REGENERATION OF NITROGENOUS ORGANIC MATTER IN SEA WATER

Abstract

An effort was made to reproduce the cycle of decomposition of organic matter and regeneration of nitrogenous constituents of sea water by allowing collected samples of mixed plankton to decompose in sea water of known composition and following the disappearance of N in the suspended plankton fraction and the appearance of ammonia, nitrite and nitrate in the water by periodic analyses. Ammonia appeared very quickly in the water as the "plankton N" diminished, continued to a maximum in 15-20 days, after which its disappearance was accompanied by the appearance of nitrite. The latter rose to a maximum and its decrease was in turn accompanied by the formation of nitrate. Eventually all but a small amount of the "plankton N" was oxidized to nitrate, at which point a portion of the solution was inoculated with a diatom culture which grew until practically all the nitrate in the water was transformed into organic matter. Bacterial counts were made at intervals. The main stages in the decomposition of organic matter are: dead body[long dash]ammonia[long dash]nitrite[long dash]nitrate.