COLONIZATION RATE OF FORAMINIFERA IN THE INDIAN RIVER, FLORIDA

A cage containing azoic sand was placed on the seabed (1 m water depth) at Link Port, Florida on 17 March 1988. Beginning one week after emplacement, four replicate cores were taken inside the cage and outside every week for six weeks. From each of the eight cores 5 ml of sediment was removed from each cm to a depth of three cm. The number of living (stained) individuals for Quinqueloculina, Ammonia, Elphidium and Ammobaculites were enumerated. These data were analyzed by two-way ANOVA testing for differences between time, cms and their interaction. Inside, all taxa had significantly lower densities at the first two sampling times and had significantly lower densities in the second and third cms. Outside, only Elphidium had a significant difference with time, the fifth sampling time had lower densities. Quinqueloculina had significantly higher densities in the first cm and Ammobaculites in the first two cms. These results indicate that colonization is rapid and occurs in the same rank order as the ambient fauna. Densities stabilize inside within about three weeks after emplacement. The top cm is colonized initially followed by the second and third cms. No density peak was observed after the initial colonization, nor was there any succession of species.