One of the major differences is a tendency for more algae-eating fish to inhabit the sites in agricultural basins. Fecal coliform bacteria live in the intestines of warm-blooded animals. The presence of these bacteria in water is indicative of contamination by fecal matter. Sources of these bacteria include animal manure, wastewater-treatment plants, and septic tanks. Poultry production is an extremely important industry in northwestern Arkansas, southwestern Missouri, and northeastern Oklahoma.
Poultry litter can be a substantial source of nutrients and bacteria to water.
Beef and dairy cattle, which are important to the economy of the Ozarks, also are sources of nutrients and bacteria. Forested areas protect water quality and are an economic and recreational asset for the Ozarks. Nutrient concentrations in streams are higher in areas with greater agricultural land use or downstream from wastewater-treatment plants than in forested areas. These higher concentrations may result in increased algal growth in streams. Nitrate concentrations generally increase as the percentage of agricultural land use increases.