Oxygen Depletion in the Central and Eastern Basins of Lake Erie, 1970

Abstract

The hypolimnetic oxygen depletion rate is required to be measured to an accuracy of approximately 3% if major changes in the trophic state of Lake Erie are to be documented within about 5 yr of the change commencing. Depletion rate measurements of this level of accuracy require a knowledge of the reoxygenation of the Central and Eastern basin hypolimnia and the transport of oxygen between the hypolimnia. A model is described here that enables an estimate of the degree of hypolimnetic reoxygenation to be made. The transport of oxygen between the hypolimnia was estimated by means of a hydrodynamic model. The resultant calculations gave areal hypolimnetic depletion rate values of 0.43 and 0.87 g O₂ m⁻² day⁻¹ for the Central and Eastern basins, respectively, and volumetric depletion rates of 0.13 and 0.057 g O₂ m⁻³ day⁻¹, respectively, for these basins during 1970.