Biological Effects on Sediment-Water Nutrient Interchange

It was found that the different types of sediments varied in their ability to support algal growth and that this was related to the amount of available phosphorus measured in the sediments. Although the amount of phosphorus released from the sediments varied with the type of sediment, it seemed apparent that all of the available phosphorus eventually would be extracted in the 15-cm layer of sediment studied in these microcosms. The development of a thick mat of Oscillatoria caused an increase in productivity due to the increased transfer of phosphorus from the sediment; and, in general, the more productive systems had sediments containing greater amounts of phosphorus. Also, the equilibration of ³²P with stable phosphate occurred more rapidly in the more productive systems, and this rate of equilibration appeared to be associated with the sediments themselves. Hence ³²P exchange with stable P was related to the concentration of available phosphorus in the system.