Geese Feces and Phosphorus levels within the Wingra Watershed
Dan Rubash and Jessica Loomer

Introduction
Materials & Methods
Results
Discussion
Reference

Abstract
   
    Lake Wingra is a huge characteristic within Madison. Our main focus was to go gain more information about the Wingra Watershed’s    biggest feature, Lake Wingra and how excessive nutrients affect the lake from the large population of geese. In order to gain insight of the varying phosphorus levels within the feces and its affects on the lake, we needed to have two controls, with one known phosphorus level and a control of de-ionized water. We gained information on the levels of phosphorus but also learned of the high bacterial rates, and the constant pH levels within all three samples.

Introduction
   
    Geese are a huge population of the waterfowl along the Lake Wingra shore. Problems include lake eutrophication which spreads excessive dissolved nutrients that allow unwanted growth of plant life, which decreases a percentage of oxygen.

“In the Madison area, including the Lake Wingra watershed, the numbers of resident and wintering geese have increased dramatically since the 1980s.”

    When examining what factors affect Lake Wingra, it is important to look at the composition of geese feces. Phosphorus is key nutrient within geese feces and we focused on how this nutrient affected the environment of Lake Wingra and the Lake Wingra watershed. If we measured a high amount of phosphorus within the feces solution, we then noticed the affects of phosphorus within the Wingra watershed.
“Fertilizers normally contain a mix of nutrients, including nitrogen, phosphorus and potassium. Rainwater runoff from lawns treated with fertilizers flows to storm drainage systems and into the lakes where the phosphorus from many sources causes excessive algae growth, and decreases water clarity, often turning lakes green. Decaying algae also depletes oxygen in the water, so that fish can no longer thrive.”  With this knowledge we are able to know that this also minimizes the fish population and alters how the fish live and breed within the altered environment.
    Another factor that we focused on is the fate of the nutrients from the feces. Did the goose feces soak into the ground after rainfall or did it get washed into the water of the lake? From the feces that were soaked into the ground, it is important to measure how deep it soaks in and how this affects our soil. The affects of phosphorus within the Wingra watershed is significant factor when determining the overall situation of the environment and how each organism interacts within that environment.

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Materials and Methods
   

    In October of 2005, we collected various samples randomly within Vilas Park. We then mixed each sample, which included moist, somewhat dry and dry; this created a homogenous sample.. Once completely mixed we split the amount of feces mixture and placed half of the mixture in an appropriate container and dried the remainder for two to three days at 103° C.
    We filled three cylinders (91 cm tall, 20 cm diameter) with an equal amount of playground sand (64 cm tall, 20 cm diameter). We placed cheese cloth over the three ports. Cheese cloth is a porous cloth which allows water to filter through, yet will retain the sand from exiting. We then attached a tube to each of the three portals on each cylinder for the water to flow out. We made three liters of feces solution, phosphorus solution, and distilled water.
    We began pouring three liters of the phosphate solution at a constant rate of 1L /10 seconds into cylinder 1 and then we took measurements after two hours. We did this same procedure for the other two cylinders, with cylinder 2 having the phosphorus solution and cylinder 3 having the distilled water.
    Then using the HACH Phosphate Testing Kit – Test N Tube, we were able to test the levels of phosphorus. We did this for all of the nine samples and then evaluated the phosphate levels.
We also took conductivity tests, pH level tests, and bacteria tests.

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Results
 

    As the solutions were measured deeper within the sand the conductivity increased. The feces solution had a significant increase compared to the P-standard and the de-ionized water. This pattern did not follow through for the feces solution, because the middle port had a higher conductivity than the rest. As the solution came to the bottom all the conductivity was similar.
                                                                                                                                       Measure of Conductivity Table 1

PH levels
It was interesting to find that all PH levels matched throughout each column. The middle port was closest to being neutral with a measurement of 6.5. This displays much consistency as the solution filters through the sand.

                                                                                                                                Measure of pH levels Table 2

Final water levels
    Both the P-standard and the de-ionized solution had similar characteristics of water output within the top and middle ports. The significant difference between the feces solution was that the bottom port’s output was much lower with an output less than 900 mL. Especially comparing this to the P-standard solution, this had an output greater than 1000 mL.

Bacteria Tests
    E.Coli and total coliform bacteria levels were determined using an EPA-approved enzyme assay test (Colilert®). Through this test we noticed that the sample that contained actually feces had exceeded the range within the bacteria levels.

Phosphorus level
    There is a vast difference between all solutions and the top port. The feces solution had the highest level of phosphorus which was clearly expected. Once the solution flowed through the sand, settled and filtered through the bottom port it is relevant to state that the phosphorus levels were similar.

                                                                                                Measure of the Phosphorus level present within each solution Table 3

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Discussion

    Conductivity measures the amount of dissolved ions that are in the water. The conductivity test results were expected and consistent except for the exceptionally low level of the top of the feces cylinder. This fact could happen because of the excess or remaining feces that settled on the top of the sand.
The phosphorus levels decreased exponentially with depth. Apparently, as a solution goes through the soil, the sand filters out the phosphorus. The feces had a higher level of phosphorus, yet became constant once it hit the bottom port. The best recommendation would be to perform the experiment for a second time to be able to compare data for consistency.
    As far as errors are concerned we could have had numerous errors that could have occurred within the experiment. During the beginning of the experiment 2 liters were poured into the de-ionized water column. As we observed the water filtering during the first five minutes we realized that two liters of water was not sufficient and we delayed adding the last liter. All other columns received three liters at one time.
    In a rain fall, water falls at varying rates and this correlates to the procedure in which the solutions were poured into the cylinders. This is important because each solution could have been poured at various rates, not making it consistent as in nature.
While adding the three liters of feces solution into column two it was noticed that the solution was not mixed enough which resulted in remaining feces left over in the container, which means that not all feces was distributed evenly.
  
Factors that contributed to this include the following:
            o The temperature, including the land, air, and water
            o The sediment, the texture of the ground (sand)
            o The weather, depending on the amount of rainfall received, and the texture of the ground

    Testing in different areas with different soil types and different environments, to get a better idea of how this occurs within nature would have greatly improved our project and our results.
An interesting fact experiment is to study the difference of how long each solution sat within the particular containers. For example, the feces solution sat within the container for approximately 30 minutes. While the feces solution sat for this amount of time so did the other containers. A conclusion we could ask would be, “Does the amount of time each solution sits within their containers have an affect on the phosphorus levels?” Another question to ask is, “Does the material of the container already include phosphorus?”

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Reference

Giant Canada Geese within the Wingra Watershed." Friends of Lake Wingra. 27 May 2003. 20 Feb. 2006 <http://lakewingra.org/library/docs/1117595700-canada_geese.pdf>.

"Phosphorus Control in Dane County." Office of Lakes & Watersheds. 22 Feb. 2006 <http://www.danewaters.com/management/phosphorus.aspx.>.

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