Sedimentary records of microplastics pollution from coastal Louisiana and their environmental implications

Keywords: Microplastics, sedimentary record, coastal wetlands, plastic pollution, Louisiana
Session Type: Virtual Poster Abstract
Day: Friday
Session Start / End Time: 2/25/2022 03:40 PM (Eastern Time (US & Canada)) - 2/25/2022 05:00 PM (Eastern Time (US & Canada))
Room: Virtual 49

Abstract

Global plastic production and widespread use began rapidly expanding in 1950, with production increasing exponentially from 2 million tons in 1950 to 380 million tons in 2015. Plastic waste has also increased since 1950, with an estimated 5.25 trillion particles of microplastics currently in the surface oceans. However, this represents only 0.1% of annual global production. Therefore, most of the plastic waste is likely sequestered elsewhere, such as in coastal and estuarine sediments. While studies on microplastics in the surface ocean and river waters are plentiful, few studies are available on the sedimentary record of microplastics in coastal wetlands. This study examines two coastal salt marsh sites in southern Louisiana and compares microplastic quantities present in the sedimentary record. One site, Little Lake, is a marsh downstream from New Orleans. The other is Bay Champagne, adjacent to Port Fourchon and its industrial facilities. Following methods and guidelines set forth by NOAA, microplastics were isolated and quantified from sediment cores taken at each site. Multiple morphotypes of microplastic (e.g. fibers, fragments, and sheets) have been discovered in both samples. A downcore microplastic quantity curve will be presented for both sites, plotted against radiometrically determined age and compared to known high energy oceanographic events to show trends in microplastic pollution over time for southern Louisiana. Additionally, this study will address the possibility of downcore sediment acting as a sink and sequestration area for otherwise ocean bound microplastic.