EXPLORING PLASTIC DIVERSITY AND POLLUTION PATTERNS AT PLAYA LAS GOLODRINAS, PUERTO RICO

Plastic pollution is a pressing global issue, particularly in marine shore environments. Playa Las Golodrinas, a popular tourist destination centrally located on the northern coast of Puerto Rico, provides an excellent opportunity to study plastic pollution due to its high level of human activity. During mid-April 2023, a small collection of macroplastic fragments of various types was obtained from the beach berm to assess plastic diversity.

Macroplastics were investigated using an ASD FieldSpec 4 spectroradiometer with a spectral range of 350 to 2500 nm, using a contact probe. Reflective spectra show a wide range of diversity with average overall relative reflectivity varying from 0.17 to 0.75 and numerous adsorption features. Common adsorption features that are strong in many samples include ~1210 nm, ~1727 nm and ~1764 nm. Some samples showed absorption features at 2350 nm, interpreted as being associated with the presence of calcium carbonate, a constituent of the plastic manufacturing process. Other spectral features were indicative of carbon-carbon bonds, functional groups, or inclusions of oxyhydroxides/phyllosilicates within the polymers. Reflective spectra of these plastics are distinct from the Playa Las Golodrinas sand. Major adsorption features observed in sands occur at approximately 1413 nm, 2212 nm, 2255 nm, and 2339 nm. These features are consistent with the dominant siliciclastic nature of the sands indicated by light microscopy and scanning electron microscopy and are broadly similar to detailed reflective spectroscopy studies of other siliciclastic sands.

The preliminary findings suggest that hyperspectral remote sensing approaches can distinguish plastics from the sediment at the site. This initial investigation provides a foundation to study the nature of plastic pollution in the region more broadly, attempt to assess the sources of pollution, and create remote sensing tools to monitor changes in plastic pollution trends at a large scale.