Correlation Between the Numbers of Branta canadensis and fecal coliform contamination in the Milwaukee County Parks

Stacy Whitaker

Alverno College

November 7, 2000


Abstract: This research project was done to determine whether there was a correlation between the number of Canada geese (Branta canadensis) near a pond and the number of total fecal coliform and E. coli colonies per 100 mL of water. Six samples were collected from Milwaukee County parks and tested using the Hach membrane filter method. A strong correlation was found between the number of Canada geese inhabiting the area and the total fecal coliforms (r = 0.99) and E. coli (r = 0.98). This indicates that the numbers of geese may be having an adverse affect on recreational water quality in the Milwaukee County Parks.

Key Words: fecal coliform, E. coli, Canada geese, Milwaukee County Parks

Introduction: Fecal coliform is a collection of bacteria living in the intestines of animals. They aid in the digestion of food. Escherichia coli is a member of the collection of intestinal bacteria associated with warm-blooded animals. The presence of fecal coliform in water means that it has become contaminated with the fecal material of man or animals. A body of water identified as "healthy" or when the average dissolved oxygen, pH, nitrate-nitrogen, phosphorus and nitrogen ammonia are within state and federal boundaries, can have elevated amounts of fecal coliform above the regulations (Van Ess & Harding, 1999). Fecal coliform can be an indicator of potential health risks for any individual coming in contact with the water since many pathogens or disease producing bacteria can exist in fecal material. There are standards that exist to protect humans who come into contact with water. The standard refers to how many colonies grow after 100 mL of water is filtered through a membrane and incubated for a certain amount of time. Sources of fecal coliform include overflow of domestic sewage or nonpoint sources such as urban runoff, livestock or agricultural practices and wildlife. It has been shown that the number of roosting waterfowl, specifically ring-billed gulls and Canada geese, did correlate with the fecal coliform levels (r = 0.50) in the Kensico Reservoir in the state of New York (Alderisio & DeLuca, 1999). If geese were contributing to fecal coliform contamination, the bacterial numbers would be greater in areas with higher geese densities. The hypothesis is that total fecal coliform and E.coli will be greater in waters that have greater numbers of B. canadensis living nearby.

Methods: One water sample of 100mL was collected from each pond in six Milwaukee area parks: Jackson Park, Jacobus Park, Wilson Park, Mitchell Park, Whitnall Park and the Milwaukee Medical college campus. The sample was taken directly off the surface of each of the ponds on the same day within two hours, put in a plastic container and stored in the refrigerator overnight. At the same time, the numbers of geese on the park grounds were counted and recorded. The samples were tested the next morning using the Hach membrane filter method using sterile techniques. The samples were then incubated at 35C for 24 hours. The colonies of total fecal coliform and E. coli were counted using a low power light microscope. Finally, a graph was made and the correlation was calculated using Excel for both the colonies of total fecal coliform and the colonies of E. coli.

Results: The results of the experiment are shown below in table one. The colonies of total fecal coliform and E. coli per 100 mL of water did increase when the numbers of geese surrounding the pond increased. There was a strong correlation between the numbers of geese and total fecal coliform per 100 mL of water (r = 0.98) and the number of geese and colonies of E. coli per 100 mL of water (r = 0.99).

Table 1

The numbers of geese and the number of colonies of total fecal coliform and E. coli per 100 mL of water from ponds in Milwaukee County Parks

Park Name

Numbers of Geese

Number of Total Fecal Coliform Colonies per 100 mL water

Number of E. coli Colonies per 100 mL of water









Medical College Campus


















Graph one also shows the correlation between the numbers of geese and fecal contamination. As the numbers of geese rose so did the colonies of total fecal coliform and colonies of E. coli per 100 mL of water.









Discussion: The results of this experiment indicate that the numbers of geese in Milwaukee area recreational parks may contribute to a decrease in water quality. Taking into consideration that the average concentration of fecal coliform bacteria per gram in Canada geese feces is 1.53 x 104, the more geese in the area the more contamination there will be in the parks (Alderisio & DeLuca). People coming in contact with the water may be putting themselves at risk for catching water borne illness coming from the fecal contamination. Swimming and other recreational activities in which the unintentional ingestion of water occurs are known to increase the risk of gastrointestinal illnesses (Van Ess & Harding, 1999).

The next step would be to try and reduce the amount of fecal contamination in the park's waters. Assuming that it is the geese contributing to the problem, measures for controlling the numbers of geese in the area may need to be put into place. Although there was a strong correlation between the geese number and colonies of both fecal coliform and E. coli, it can not be said for sure whether the geese are the sole problem. Further research needs to be done to identify and control the source of fecal contamination. Antibiotic resistance analysis has been shown reliable in identifying nonpoint sources of fecal contamination (Wiggins, et. al., 1999). The Virginia watershed used antibiotic resistance patterns in fecal streptococcus to identify sources of contamination (Hagedorn,, 1999). The researchers found that more than 78% of fecal contamination was coming from cattle. When access of cattle to the watershed was restricted and the test was performed again, fecal coliforms were reduced by an average of 94%. To further support the hypothesis, a longer study would need to be put in place, where more samples would be collected and analyzed and where the numbers of Canada geese were monitored over longer periods of time. Finally, the fecal contamination would need to be connected to the geese using the antibiotic resistance analysis.



Alderisio, K. A. & DeLuca, N. 1999. Seasonal enumeration of fecal coliform bacteria from the feces of ring-billed gulls (Larus delawarensis) and Canada geese (Branta canadensis). Applied and Environmental Microbiology 65:5628-5629.

Hagedorn, Charles, et. al. 1999. Determining sources of fecal pollution in a rural Virginia watershed with antibiotic resistance patterns in fecal streptococci. Applied and Environmental Microbiology 65: 5522- 5531

Van Ess, Eric and Harding, Anna K. 1999. A bacteriological study of natural freshwater swimming areas in western Oregon. Journal of Environmental Health 61:14-20

Wiggins, B. A. 1999. Use of antibiotic resistance analysis to identify nonpoint sources of fecal contamination 65: 3483-3486