The nearshore water quality of Nottawasaga Bay 1980

Abstract

During the 1980 ice-free period, nearshore water quality between Cape Rich and Cedar Point in Nottawasaga Bay was surveyed. Only two localized areas showed clear signs of eutrophication, one at the mouth of the Nottawasaga River and the other at the mouth of Collingwood harbour; these affected areas did not extend to the Mary Ward Shoals, a major fish spawning ground susceptible to growth of the attached alga Cladophora. Oligotrophy characterized the open bay and the remainder of the nearshore, although differences between these two zones were apparent. Slightly elevated nutrient levels and the presence of bloom—forming algae in the remote, nearshore may represent initial signs of eutrophication.