Particulate matter distribution and heating patterns in a small pond

Summary

Biotic and abiotic particulate layers associated with seasonal phytoplankton succession and thermal stratification significantly affect surface and internal heating patterns. These effects were studied in a small eutrophic 1.5 ha farm pond with a mean depth of 1.9 m. A submersible beam transmittance meter was used in conjunction with in situ measurements of standard physicochemical parameters to locate and study the development of phytoplankton and other types of layers. Measurements were made morning and afternoon twice weekly during the stratified period in 1982. Results indicate a rapid successional sequence of phytoplankton layers in April through June with subsequent development of a metalimnetic layer persisting from June until fall overturn in early October. Temperature measurements revealed intense heating in the near surface waters during periods of high surface turbidity and less intense heating to a greater depth when surface turbidity was lower. Greater rates of heating occurred near subsurface layers than in the overlying water, when surface turbidity was low enough to permit light penetration to the deeper layer.