 The goal of this paper was to examine the stoichiometry of the nutrient loads in the water delivered to the Gulf of Mexico from the Mississippi Chafalaya River Basin. The paper also examined spatial and temporal patterns in nutrient stoichiometry among four large sub-basins of the Mississippi River, the Upper Mississippi, the Ohio Tennessee, the Missouri, and the combined Arkansas Red Rivers. I used discharge and nutrient load data collected by the U.S. Geological Survey from 1979 through 2015, along with a stoichiometric index called the Indicator of Coastal Utrification Potential, or ICEP. The ICEP estimates the potential for production by non-solicious algal groups, particularly cyanobacteria. Nitrogen and phosphorus loading can shift nutrient ratios to conditions that favor cyanobacteria over diatoms, and often this results in harmful algal blooms. Some key points from the paper include, one, there were clear differences among the subbasins in the stoichiometry of the nutrient loads, and the degree to which the conditions favored cyanobacteria. In particular, the Upper Mississippi Subbasin, where land use is predominantly row crop agriculture, had a disproportionately large influence on the stoichiometry of the freshwater inputs to the Gulf of Mexico. Second, over the 1979 to 2015 time period, conditions have become increasingly favorable for cyanobacteria throughout most of the Mississippi River basin, and this result is consistent with anecdotal reports of increasing frequency and severity of harmful algal blooms. Third, there was significant seasonal variation in the stoichiometry of nutrient inputs to the Gulf of Mexico. Inputs favored non-solicious algae in spring and early summer, but favored diatoms in late summer and autumn. There are additional results and details in the paper, and I hope you will give it a read.