One of our members sent us her concerns this month about goose droppings and their effects on our chain of lakes. We deferred the question to the Iowa DNR, and they have sent us this response:

Response by MARK GULICK
NW District Wildlife Supervisor

Thank you for your inquiry regarding the health and other issues associated with Canada goose droppings at Pikes Point State Park on West Okoboji. We recognize that goose and other wild animal (i.e. gull, duck, etc.) and pet droppings are unsightly and cause people to have legitimate health and water quality concerns. With regards to health issues, the jury is sort of out with definitive conclusions. The Animal and Plant Health Inspection Service (APHIS) of the U.S. Department of Agriculture reports that there is no direct link between goose feces and human health concerns, but there is increasing evidence that human virulence determinants are present in Canada goose (many other human and animal) feces. The Centers for Disease Containment and Prevention state that many germs that might be found in bird droppings can infect humans. Both agencies, as well as many other health groups advise using normal hygiene and caution when recreating or in the presence of any animal feces.

Regarding water quality, which is also or extreme importance in the Great Lakes area and other parts of Iowa, nutrient loading from Canada geese appears to be negligible compared to other nutrient inputs from rural and urban watershed sources. In a study conducted at Clear Lake in NW Iowa in about 2002, the Iowa Waterfowl Biologist developed a model to predict nutrient loading from geese. He considered the number of geese present annually (from about 30 in summer to nearly 900 in fall); the amount of time they spent on the lake, the amount of droppings/goose, the contributions of phosphorus (P) and nitrogen (N) (the 2 nutrients most responsible for algal blooms in surface water), etc. and then compared this to watershed loadings of these nutrients. In a nutshell, the annual contribution of P Canada geese was about 28kg compared to 7,719 kg from watershed sources. For nitrogen the annul goose contribution was 91 kg compared to 104,092 kg from watershed sources. This equates to Canada geese at Clear Lake contributing less than ½ of 1% of the phosphorus and slightly more than 1% of the nitrogen; pretty negligible in the grand scheme of things.

With that said, we do try to manage Iowa’s Canada goose flocks for those that appreciate them and those that do not. Many Iowans view Canada geese, which were extirpated (i.e. no longer present) from Iowa in the early 1900’s, as a valued resource either through hunting, viewing, or the dollars these activities bring into rural communities. Furthermore, in kind of an ironic way, Canada geese and other waterfowl actually help us to make huge gains in water quality on our state’s lakes and wetlands. Through the North American Waterfowl Management Plan and the associated NA Wetlands Conservation Act, states and local communities are able to request grant dollars from the federal government to convert highly erodible farmland and other landscapes into restored wetlands and prairies. These conversions improve water quality by holding soils in place and reducing or eliminating pesticides, herbicides, and other pollutants; as well as provide excellent habitat for wildlife and recreational areas for humans. Because of the importance of water quality to the Iowa Great Lakes, millions of these waterfowl-orientated dollars have been spent in this watershed.

As mentioned above, we use several strategies to manage Canada geese at a tolerable level. Our resident geese and migrant geese from temperate, sub-artic, and arctic areas are an international resource that are cooperatively managed by Canada and many US. States. Through controlled hunting, we are able to exert or relax mortality pressure on various segments of the continental goose population, depending on population goals. For example, in some situations we are able to have September hunting seasons that put harvest pressure on locally raised Canada geese at a time prior to the arrival of migrant geese. We have used these seasons before in Iowa, but at present are not using them due to the stabilization of the population at all but a few areas. We also have the ability to remove/kill problem populations of Canada geese in urban areas. This method requires young geese be hauled to a distant area prior to them learning to fly. Adult geese must be killed (and donated to a good shelf at the expense of the community), as extensive research shows that adult geese, no matter how far removed from their nesting sites, will return. Before the goose removal/kill can be done, the local community must hold a public meeting outlining the steps needs, and then petition the Director of the DNR for a permit to carry out the operation. Based on recent observations, it is difficult to complete a removal/kill operation, as in a given community there are oftentimes as many people who like the geese as do not, and word of such pending operations spreads to other areas and states, resulting in significant pressure to not carry out the operation.

So what are we doing or can we do to address your specific concern of goose droppings on area beaches? DNR-Parks recently acquired a machine designed to pick up goose droppings from beaches, and perhaps grassed areas, and will be using it extensively.

I apologize for the length of this response. I hope that by providing this detailed information you have a better understanding of the value of this international resource and the steps we take to maintain goose populations levels that are acceptable to those who life them and those that do not.