Analyzing the Variation in Microplastic Intake of Waterhyacinth and Pennywort in Lake Okeechobee

Analyzing the Variation in Microplastic Intake of Waterhyacinth and Pennywort in Lake Okeechobee

Alvin Sherman Library

The Florida Everglades ecosystem faces many threats, including municipal pollution and agricultural runoff. This study compares the microplastic intake of two types of floating vegetation in Lake Okeechobee. Water hyacinth (Pontederia crassipes) has a greater root mass and surface area than its native equivalent pennywort (Hydrocotyle umbellate). We hypothesize that water hyacinth would have greater microplastic intake due to its increased capillary action. Our project was conducted using three guiding questions: which plant type had the greatest microplastic intake, did accumulation vary with location, and did concentration vary among roots, stems, and leaves in each plant type. Plants were collected from four sites in Lake Okeechobee and dissolved in a potassium hydroxide solution. After vacuum filtration, microplastic particles were placed onto a slide and stained with Nile Red for fluorescence microscopy to indicate the presence of microplastics. Next, the filter was soaked in Fenton's Reagent to degrade the organic material. Raman Spectroscopy further characterized microplastic types. Finally, we conducted Pyrolysis GC/MS, which identifies and quantifies specific microplastics. The water surrounding both plants was tested in order to form a baseline of environmental contaminants. The initial findings indicate the presence of microplastics in both plants. Our protocol shows promise and allows for fine-scale quantification of microplastic retention of these plants. This data assists in understanding microplastic contamination in the Florida Everglades, to compare the effects of native and invasive plants, and leads to improvements in remediation strategies of microplastics in freshwater ecosystems.