The role of Mississippi River discharge in offshore phytoplankton blooming in the northeastern Gulf of Mexico during August 2010

Between July 9 and September 8, 2010, the discharge of the Mississippi River exceeded the 20-year mean. During this time, the northeastern Gulf received an estimated excess volume of approximately 8.3 × 109 m3 relative to the 20-year mean. Together with findings from a particle trajectory model, we conclude that nutrients and other materials (e.g., sediments) from the excessive discharge of the Mississippi River and adjacent marshes and wind-driven currents likely contributed to the anomalous bloom observed during August 2010 and to the anomalously high organic matter sedimentation rates observed in the northeastern Gulf of Mexico in the aftermath of the Deepwater Horizon oil spill.