The role of nutrients and their budgets in the Bay of Quinte, Lake Ontario
The Bay of Quinte shows symptoms of cultural eutrophication which are markedly similar to those of Lake Erie. Algal blooms are severe and prolonged, and macroinvertebrate and fish communities are composed of pollution-tolerant species. The bay received about 9,700,000 pounds of nitrogen and 700,000 pounds of phosphorus in 1968. Of these total inputs 89% of the nitrogen and 60% of the phosphorus were attributable to land drainage and the remainder of each nutrient to municipal-industrial sources. Comparison of absolute inputs is shown to be ecologically unsound because low-volume high concentration inputs are compared directly with high-volume, low-concentration river inputs. Comparisons based on "net inputs" are proposed; "net input" is defined as the amount of nutrient contained in an input in excess of the amount of nutrient in the equivalent volume of water displaced at the outlet. In the Bay of Quinte about 50% of the "net input" of nitrogen and 85% of phosphorus were contributed by municipal-industrial sources in 1968. Phosphorus removal from high-concentration, low-volume inputs i.e. municipal-industrial sources, is recommended. The high turnover rate of water in the bay, five times annually, should contribute towards improved water quality by translocating re- suspended nutrients from sediments in shallow water of the inner bay to sediments in deeper waters of the outer bay and Lake Ontario. The estimated cost of nutrient removal, 200,000 dollars per year, is apparently justified in view of the importance of the local tourist trade (about one million visitors in 1968 spent 7.8 millions of dollars) and its future viability in the face of deteriorating water quality conditions.
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