RELATIONSHIPS BETWEEN PHOSPHORUS IN SHALLOW SEDIMENTS AND IN THE TROPHOGENIC ZONE OF 7 ALBERTA LAKES

Relationships between phosphorus (P) in bottom sediments, soluble reactive P in lakewater just above the sediment (LWP), and total P in the trophogenic zone (TZP) were investigated in seven meso-eutrophic to eutrophic Alberta lakes in 1986. Sediments, porewater and overlying water were collected from two to four shallow sites within the trophogenic zone (≤ 10-m depth) at each lake. The amount of P in particulate sediments or porewater was not correlated with TZP (P > 0.05). LWP was positively correlated with TZP (r = 0.86, P < 0.05). Principal component analyses of porewater and particulate sediment parameters resulted in two principal components (PC), which separated the study lakes from each other. Average factor scores of the second PC (a mobile porewater P component) were correlated with LWP (r = 0.75, P < 0.001) and TZP (r = 0.77, P < 0.05). This study indicates that P in shallow sediments may be an important source of P to the trophogenic zone. © 1990.