Figure 17. Annual cycle of dissolved-oxygen concentrations at the Klamath River at Miller Island Boat Ramp site, Oregon (U.S. Geological Survey station 420853121505500, top). Concentrations are near saturation early in the year, then supersaturated from March through July, owing probably to photosynthesis. Dissolved-oxygen concentrations decrease to low levels in mid- to late summer as a result of large oxygen demands and slowly recover as summer ends and fall leads to cooler temperatures.

First posted July 14, 2011