A SEASONAL STUDY OF PHOSPHORUS DEFICIENCY IN A EUTROPHIC RESERVOIR

1. Seston elemental composition (C, N, P) and the orthophosphate uptak e rate constant, k(upt), were measured in the epilimnion of the eutrop hic Rimov Reservoir in the period March-August 1989. 2. Seasonal serie s of log C/P, log N/P and log [k(upt)] values were highly correlated ( r(2) in the range 0.84-0.93), but, based on literature-derived criteri a, k(upt) values indicated stronger P deficiency than did the C/P valu es. 3. The results showed moderate to strong phosphorus deficiency in summer, moderate deficiency at the end of the spring peak of phytoplan kton, and no deficiency early in the spring or during the spring clear -water period.