State Water Resources Research Institute Program (WRRI)

Details for Project ID 2007LA51B, 2007

Discerning nutrient limitations to phytoplankton growth in rivers and bayous on the North shore of Lake Pontchartrain, Louisiana

Institute: Louisiana
Start Date: 2007-03-01 End Date: 2008-02-29
Total Federal Funds: $19,245 Total Non-Federal Funds: $41,807

Principal Investigators: Sarah Fearnley

Abstract: Rapid urbanization and intensive agricultural practices on the north shore of Lake Pontchartrain in south east Louisiana has resulted in increased nutrient concentrations in surface waters that flow into Lake Pontchartrain. The primary sources of nutrient contamination in this area are dairy farm wastes, agricultural fertilizers, and sewage outflow both from municipal treatment systems and individual septic systems. Current research at the University of New Orleans has discovered that surface waters in some roadside storm water ditches and rivers on the north shore of Lake Pontchartrain are phosphorus limiting, in spite of the fact that the Lake Pontchartrain estuary as a whole is primarily nitrogen limiting. Other investigators have determined that excess nitrogen loading from anthropogenic sources often increases phosphorus disproportionately to nitrogen, causing the limiting nutrient to phytoplankton growth to shift. Discerning the limiting nutrient to phytoplankton growth on the north shore is critical to managing water quality in Lake Pontchartrain. This project will measure the nutrient concentrations in six rivers and bayous on the north shore of Lake Pontchartrain to determine the limiting nutrient to phytoplankton growth in this area.