Using watershed-scale results and litigation to manage nutrient problems

Litigation is an important process for establishing environmental policy that relies on watershed-scale information.  The Oklahoma Attorney General recently filed suit against the poultry industry for contaminating the Illinois River Watershed (IRW) and Lake Tenkiller in eastern Oklahoma.  Models show a substantial contribution of phosphorus in the IRW originates from poultry operations, particularly from application of manure to fields in the watershed.  Nutrients from poultry waste cause aesthetics problems with algae and injuries to the biological condition of fish, invertebrates, and diatoms.  Direct and indirect effects of nutrients on benthic macroinvertebrates were greater during the spring 2007 than during the summer 2006.  During summer 2006, some metrics responded opposite of predicted responses.  For example, the percent of insects, percent EPT, and percent Ephemeroptera were positively correlated with algal biomass.  Many invertebrate metrics were related as predicted to filamentous algal cover of the stream bottom, standard deviation in DO, and maximum pH during spring 2007.  These responses show deviations from reference conditions that violate benchmarks for Oklahoma’s fish and wildlife propagation uses.