Quantifying and Characterizing Microplastic Marine Debris Loads in the Mississippi River

Two people taking a water sample from a boat.

Scientists collected and studied water samples from 11 locations along the Mississippi River and quantified and characterized microplastic debris that may eventually flow into the Gulf of Mexico.

Type of Project: Research

Region: Gulf of Mexico/Mississippi River

Project Dates: June 2016 – Jan 2019

Who is involved?

Scientists from Texas A&M University Corpus Christi, St. Louis University, University of Central Florida, Louisiana State University, and The National Great Rivers Research and Education Center, with support from the NOAA Marine Debris Program, worked to adapt riverine water sampling methodologies, collected water samples along the Mississippi River and tributaries, and studied water samples to determine and characterize the microplastic loads along the Mississippi River.

What is the project and why is it important?

The Mississippi River is the fifth largest river in the world and the largest river in North America. It passes through agricultural lands and urban centers where it is influenced by various sources of plastic debris: surface runoff and effluent discharges. It is home to 72 million people, drains nearly half (40%) of the country (2.98 million km2) and receives final effluent from over 7,400 wastewater treatment discharges. The microplastic loads likely impact coastal ecosystem health in the Mississippi River Delta, home to some of the most productive fisheries in the world. To our knowledge, there have been no comprehensive studies to date that have analyzed microplastic debris loads along the Mississippi River. This study sought to fill this critical knowledge gap. They quantified microplastic loads throughout the Mississippi River watershed and produced baseline data for one of the largest and most populated river catchments in the world. Researchers worked to obtain surface and sub-surface water samples at 11 locations along the Mississippi River watershed, which included above and below the confluence of where major tributaries enter the Mississippi River. Water samples were processed in a laboratory at Texas A&M where microplastic particles were isolated, quantified, and characterized. This information will help guide future studies on impacts to aquatic organisms and sources of microplastics to the Gulf of Mexico.