Temporal and Seasonal Variations of Hydrogen Peroxide Levels in Estuarine Waters

Hydrogen peroxide variability on the Patuxent River at both estuarine and freshwater locations are reported. Estuarine peroxide ranged from 11 to 350 nM and exhibited both diel and seasonal variability. Upriver, high organic, freshwaters showed similar H2O2profiles to those observed in the estuary. These are the first H2O2data reported for this estuarine environment. Concentrations are similar in magnitude and range to values reported in both fresh and marine systems. The diel H2O2variability presented here is similar in structure to marine and freshwaters with an amplitude intermediate between the former and the latter. Possible implications for submicromolar levels of this chemically and biologically labile species in estuarine systems are also discussed.