Callahan Reservoir: III. Bottom Sediment-Water-Phosphorus Relationships

ABSTRACT SEDIMENT core samples obtained from a 164 x 103 m3 reservoir in central Missouri showed highly significant correlations between sediment clay content and phosphorus concentrations. Both sediment clay content and phosphorus concentrations increased with distance from the reservoir inlet. No strong correlations between phosphorus concentration and sediment depth were observed. Phosphorus concentrations varied widely between and within core profiles ranging from < 100 ppm to > 1000 ppm and from < 200 ppb to > 3000 ppb for total phosphorus and total soluble phosphorus, respectively. The mean total phosphorus concentration in the reservoir water was 108 ppb. About 25 percent and 10 percent of the total suspended phosphorus was soluble phosphorus and soluble reactive phosphorus, respectively. The reservoir sediments seemed to serve as a phosphorus sink either through chemical adsorption or planktonic and mineral sedimentation..