Phosphorus and Iron Retention in Sediments Measured by Mass Budget Calculations and Directly

Abstract

Retention of phosphorus (P) and iron (Fe) was estimated from mass budget calculations of Bob Lake, Ontario. Ratios of Fe to P in sediment cores were used to test the reliability of the concurrent retention estimated. However, a 300% range in Fe to P ratios measured in vertical profiles in sediments was many times larger than the uncertainty associated with mass budget measurements. Sediment cores showed a near-surface maximum of iron but not phosphorus. There was reasonably good agreement between P retention as computed by mass budget and by sediment accumulation methods, though the latter were slightly higher.