DECOMPOSITION OF ORGANIC MATTER IN SEA WATER BY BACTERIA

III. FACTORS INFLUENCING THE RATE OF DECOMPOSITION

¹ From the Woods Hole Oceanographic Institution and Department of Soil Microbiology, New Jersey Agricultural Experiment Station

1. Investigations are reported on the decomposition of organic matter in sea water placed under controlled laboratory conditions. It has been found that, under these conditions, the organic matter in the water, both in suspension and in solution, can undergo rapid decomposition. It is quite possible that a change in temperature, resulting from the sudden warming up of the water, may bring about not only an increase in the biological reactions, but also a change in their very nature; this limitation need not invalidate the results obtained, since these results are not a measure of what actually happens in nature under different conditions, but what may happen under any one set of conditions.

2. The abundance of readily decomposable organic matter in sea water was measured by the rate of oxygen absorption in the water, incubated under uniform conditions. The rapidity of libenation of nitrogen in the decomposition of the organic matter can be measured by the rate of decomposition of glucose added to the water.

3. The amount of organic matter in sea water readily attacked by bacteria varies with the rate of production of the organic matter, with photosynthesis and with the water mass; at the surface of the water, it falls off as one goes southward.