PARENT SESSION
Oral Session #23: Aquatic Ecology: Salt marshes, estuaries, ephemeral wetlands.
Presiding: D. Childers
Monday, August 5. 1:00 PM to 3:45 PM. Palo Verde Room, Radisson.

Thermal stratification in temporary ponds and Its potential implications for resident species.

Boeckman, Chad^*,1, Schwartz, Steven^*,1, ¹ Oklahoma State University, Stillwater, OK

ABSTRACT- Although the limnology of permanent lakes is well documented, a basic knowledge of the same properties fails to exist for shallow temporary habitats. Even though these ponds are less than 0.5 m deep, thermal stratification can occur. While collecting water samples in Payne County, Oklahoma we observed stratification in a highly turbid temporary pond. We tested the hypothesis that increased total suspended solids (TSS) would significantly decrease the depth of the thermocline. Water was taken from Cemetery Pond (TSS = 12.0 g/L) and used to fill two 40L fish aquaria. A 250 Watt 120 volt heat lamp attached to the side of the tank heated the water. Thermal probes placed at the surface, 2, 4, 6, 8, 10, and 20 cm below the surface recorded the temperature in 15-minute increments for 2 hours. Distilled water (TSS = 0 g/L) served as a control. There was no significant difference in temperatures between tanks with the same TSS value. ANOVA revealed differences in the change in temperature between depths for each tank, however no significant difference occurred in the depth of the thermocline among all tanks. Mean temperature values from each depth differed between TSS values. I argue this micro-scale stratification drives other chemical processes, namely dissolved oxygen, pH, total organic carbon, nitrates, and phosphates hence has tremendous effects on the biological community within that system.

KEY WORDS: temporary ponds, total suspended solids, thermal stratification, limnology