A Comparison of Photosynthetic Yields in the Maumee River, Steidtmann's Pond, and Urschel's Quarry under Natural Conditions

Abstract

A study of photosynthetic rates under natural conditions in the Maumee River, Steidtmann's Pond, and Urschel's Quarry, computed from pH and O2 measurements in the natural habitat at 4- to 6-hr intervals, revealed average rates of 1.4 to 20.9 /xmol CO2 absorbed petliter of water per hour, and 0.27 to 1.32 ^mol CO2 absorbed per /xliter of plant matter per hour, with 0.1 to 35.0 /imol O2 evolved per liter of water per hour, and about 0.012 to 2.22 yumol O2 evolved per pliter of plant matter per hour. These values lie within the range of values for ponds, quarries, lakes, and streams reported in the literature. They are much lower than published values for clear flowing streams. It seems likely that poor light supplies resulting from suspended silt particles cancel any ecological advantage the turbulence of flowing water might provide. The ratios of O2 production to CO2 absorption were close to unity except during the spring flood period when ratios below 0.1 were observed, similar to ratios found in a shallow pond near Bowling Green.