Water Resources Research Act Program

Details for Project ID 2018MS211B

Microplastics in the Mississippi River and Mississippi Sound: concentrations, sources, sizes, types, and loadings to the northern Gulf of Mexico

Institute: Mississippi
Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $36,166 Total Non-Federal Funds: $72,352

Principal Investigators: James Cizdziel

Project Summary: Problem: Microplastics concentrations on the inner shelf of the northern Gulf of Mexico (nGoM) are among the highest levels reported globally.[1] Because their size range overlaps that of zooplankton, they are confused with prey and are accumulating in the food chain.[1] The plastic particles are causing deleterious effects on aquatic organisms, particularly filter-feeders such as oysters.[2] Moreover, plastics attract (sorb) certain contaminants, such as persistent organic pollutants and mercury, and thus their accumulation in biota may be an overlooked source of contaminants to ecosystems. This is a major concern to the state and region because seafood is a vital industry for Gulf Coast states, and because, on average, Gulf Coast residents consume more seafood than other U.S. residents.[3] It is also a national problem because the majority of microplastics in the nGoM originate from the Mississippi River (MR), whose basin encompasses thirty one states. Yet, surprisingly little is known about the concentrations, types, sizes, and loadings of microplastics in the MR and its major tributaries, and along oyster reefs in the MS Sound. This lack of data is hindering our understanding of the magnitude and sources of the problem. Our research will fill key knowledge gaps and improve people’s education around microplastic pollution and its impacts. Our approach to this large-scale problem is both collaborative and long-term (a three year Ph.D project), and is designed around leveraging opportunities for the future. Methods: This Ph.D. research is divided into five parts: (1) student training and method development, (2) a spatial “snapshot” of microplastic pollution in the MR and its major tributaries, (3) monitoring and characterizing microplastics in the lower MR and at oyster reefs in the MS Sound, (4) sorption/desorption behavior of mercury species with microplastics, and 5) determining the prevalence of microplastics in GoM seafood. Details are in the methods section. Briefly, for training, the student will visit the lab of Sherri Mason, an expert on microplastics and a member of the UN Working Group on Plastic Pollution. To assess microplastic pollution in the MR system, we will first take a broad spatial snapshot, collecting multiple samples from the main stem of the River from Grafton, Il. to Natchez, MS, as well as in major tributaries (Illinois, Missouri, Ohio, TN, Arkansas and Yazoo rivers), during summer low-flow (base) conditions. To determine the loading of microplastics delivered to the nGoM, we will collect samples about every two months from a site in the lower MR, including during high-flow (runoff) events. To assess microplastic pollution at oyster reefs in the MS Sound, we will collect samples quarterly in collaboration with the MS Department of Environmental Quality (MDEQ). For sampling the surface, we will use neuston nets, and for the subsurface, Niskin bottles.For analysis, we will use National Oceanic and Atmospheric Administration (NOAA) standardmethods and collaborate with Kathy Conn, who is developing a microplastics lab for the USGS.