Plastic never fully disappears, but instead breaks into smaller pieces referred to as microplastics (< 5 mm length). Microplastics are common worldwide, and more studies are needed to understand the accumulation and diversity of microplastics found in various environments. In this study, six locations were sampled for one year in the Guana River Estuary, a partially impounded system with heavily urbanized headwaters. This study was conducted in conjunction with the Guana Tolomato Matanzas National Estuarine Research Reserve (GTM NERR) and the Florida Fish and Wildlife Conservation Commission (FWC) at their water sampling stations. The objectives of this study were to investigate: 1) distribution patterns across sample sites over time, 2) the color, size, and shape of microplastics found, and 3) polymer composition. Water samples were collected from surface waters in 1-L bottles, with five replicates at each site. Sampling occurred once a month, at the beginning of each month from August 2020-August 2021. Samples were analyzed for abundance and characteristics of microplastics using a dissecting microscope and the polymer composition was determined using Fourier-transform infrared spectroscopy. No pattern was found in the distribution of microplastics from north to south or over time. Variations in plastic color, size, and polymer composition suggests that there are multiple sources of pollution into the Guana River Estuary.

Thesis (M.S.)--Florida State University, 2005. / Advisor: Dr. Robert Deyle, Florida State University, College of Social Sciences, Dept. of Urban and Regional Planning. Title and description from dissertation home page (viewed June 13, 2005). Document formatted into pages; contains ix, 70 pages. Includes bibliographical references.