IS THE HIGH MPN OF THE ZOO’S POND WATER TIED TO ITS GROWING WATERFOWL POPULATION?

Within the last 40 years, Indiana has seen a substantial growth in its population of Canadian Geese. This rise in population may mean that a larger amount of fecal matter is being produced, and may be detrimental to the water quality and other pond inhabitants. To test this hypothesis, water samples were taken from a pond in a Midwestern city zoo, where a substantial growth in goose population has been observed, and compared to a retention pond of roughly the same shape and size with a much lower waterfowl population. The water samples, for the zoo pond and the residential pond were tested using the most probable number test (MPN), and both samples were then tested for E. coli using eosin methylene blue (EMB) agar. The water from the pond in the zoo had a very high bacterial count (240/ 100ml) and tested positive for E. coli. The water from the residential pond with a substantially smaller waterfowl population had a very low bacteria count (43/100ml) and the E. coli test was negative. Although it is an ongoing project, the current results seem to point to the fact that larger populations of waterfowl may have a negative effect on the water quality of the ponds they frequent.