The Canadian Mineralogist
Volume 34, pages 667-675 (1996)

BIOAVAILABILITY OF RIVERINE, SEWAGE PLANT, AND SEDIMENT PHOSPHORUS IN THE BAY OF QUINTE, LAKE ONTARIO

PHILIP G. MANNING
Lakes Research Branch, National Water Research Institute, P.O. Box 5050, Burlington, Ontario L7R 4A6

Abstract

The loadings of bioavailable nonapatite inorganic phosphorus in riverine suspended solids, sewage effluent and bottom sediments to the eutrophic Upper Bay of Quinte, Lake Ontario, are reported. The form and magnitude of all three sources are seasonally dependent. Increasingly over the summer, diffusional reflux from in-place sediments becomes the dominant source of bioavailable phosphorus. Values of the ratio phosphorus:ferrous iron show that most of the load of riverine inorganic phosphate ion is not deposited in the organic sediments within Upper Bay. It is considered to be weakly bioavailable, as it is transported through the Bay in oxic suspension. Remedial action to control eutrophication hinges on reduction of the rate of accumulation of nonapatite inorganic phosphorus in the bottom sediments. This means additional controls on sewage effluent, and a reduced loading of riverine phosphorus.