The phosphorus budget of Cameron Lake, Ontario: The importance of flushing rate to the degree of eutrophy of lakes1

The total phosphorus budget of Cameron Lake is described for two 12‐month periods. Although the phosphorus loadings were high (1.70 and 2.21 g m −2 yr −1 ), the lake is not cutrophic because a high flushing rate counteracts the high loading. A plot of L(1–R)/ ρ, where L is phosphorus loading, R is the retention coefficient of phosphorus in the lake, and ρ is the hydraulic flushing rate, vs. (z), the mean depth, is suggested as a means of relating lake trophic state to phosphorus loading. This formulation accurately predicted that nearby Four Mile Lake would be almost identical to Cameron Lake in terms of degree of cutrophy despite the fact that Four Mile Lake’s phosphorus load is 20 times less than that of Cameron Lake.