This map allows for the visualization of the swine densities for several population categories of swine in concentrated animal feeding operation (CAFO) livestock production. Use the dropdown menu on the right to select the swine density category to display on the choropleth map below. Please only select one of the first four swine categories to display on the choropleth map. A parallel coordinates plot (PCP) allows visualization of the relationship between the density of the different swine categories and the montly changes in E.coli concentration. The bottom value of -100,000 MPN/100ml in the columns represents monthly changes in E. coli concentration corresponding to watersheds with null values, or watersheds where no sampling was done. The swine categories included in this data are explained below:
CAFOs are important to examine in relation to microbial concentrations due to the amount of antibiotics used in CAFOs to not only to treat infections, but to promote growth and prevent any potentially future infections (Chee-Sandford et al, 2009, Woolhouse et al, 2015). The overuse of antibiotics creates a highly selective environment for microbes, resulting in increased concentrations of antibiotic reisitant bacteria (ARB) and genes (ARG) in manure and wastewater from these locations (Pruden et al, 2006). Its been shown that a proportion of environmental ARBs and ARGs originate from sources such as hospitals, waste water treatment plants, CAFOs, site of manure application, aquaculture, and industry (Kraemer et al, 2019).
Although the map below only shows concentrations of E. coli, not specifically antibiotic resistant E.coli, it provides a general picture of how the temporal changes in E. coli concentrations in Iowa Watersheds may be related to the swine density from CAFOs in each watershed. Additionally, seperating the swine population into categories based on the production step, can provide insight into specific processes that may be more directly correlated with increased E.coli levels.
To examine certian patterns pertaining to high or low values within a particular category, value ranges can be selected on the PCP by clicking and dragging the mouse. The first column represents the huc8 watershed ID and the next four columns correspond to the swine categories listed above. Although there is a pattern when first observing the PCP and associated choropleth map, when selecting the range of increased values in any of the four swine density categories, an even clearer pattern can be seen. With the expection of watershed units with missing values (-100,000), all lines either are at or close to zero. This indicates that simply looking at the swine density in relation to E.coli concentration isn't enough and that additional factors that are not accounted for may play a larger role in the monthly changes in E.coli concentrations.