Photograph of a typical pond that can be found anywhere in the northern hemisphere. Woodland, freshwater ponds teem with an amazing variety of microbial life. The pond in the above photo, from which all of these samples were collected, is located in Epping Forest, approximately 10 miles from the center of London. Such ponds contain numerous ecological niches that result from variations in oxygen content, temperature, pH, mineral composition, light intensity, nutrient availability, and associated life forms. Each unique habitat is populated by organisms selected through the evolutionary process for characteristics that ensure an optimal chance of survival in a particular environment. Microbes can, by their quantity and species, be used to identify ecological niches and changes in environmental variables, and to detect the presence of pollutants. As ponds undergo both seasonal and short-term (rain, drought, water fowl, etc.) changes that impose selective pressures on the inhabitants, they offer a rich opportunity for the study of a variety of ecological issues. For those lacking access to a pond or birdbath, a small puddle or jar of water with some straw placed in the water, will exhibit many types of microbes that can be studied.

The following pages provide further information on specific organisms observed in the pond.
Links to Microbial Inhabitants of Freshwater pages:
Amoeba proteus
Campanella
Euplotes, a common ciliate
Hyladiscus, a rare ameba
Vaginicola

Reference

I'd like to thank Dr. Ron Hurlbert of Washington State University for his help and advice.