Spatial and Temporal Patterns of Hydrogen Peroxide in Lake Waters

Depth profiles of H 2 O 2 concentration were measured at three stations in Lake Erie, one in Lake Ontario and in Jacks Lake. Epilimnetic concentrations followed changes in solar radiation suggesting that the formation resulted from photochemical or perhaps photoautotrophic processes. Mid-day H 2 O 2 concentrations of 100–200 nM were observed at all locations. Dark decay of H 2 O 2 , determined at several depths at two locations, followed apparent first order kinetics with half lives from 10–22 h. H 2 O 2 may be useful as a tracer for short term mixing processes and as a powerful oxidizing agent can influence metal speciation, degradation of some organic pollutants, as well as the survival and behavior of organisms.