EXPLORATION OF SEM AND RAMAN ANALYTICAL TECHNIQUES TO DETERMINE MICROPLASTIC INCORPORATION IN FORAMINIFERA

Agglutinated species of foraminifera, single-celled marine organisms, are known to build their tests out of particulates and other material found within their environment. Many of these species demonstrate an affinity for particulates of specific sizes and/or compositions. Microplastics are also ubiquitous throughout the global oceans, and it may be possible for foraminifera to incorporate this plastic into their tests if it is an appropriate size and/or shape. Two recent studies described microplastic particles incorporated into foraminifera sampled from the Mediterranean and suggested that agglutinated foraminifera could be early indicators of microplastic pollution (Birarda et al., 2021; Roman et al., 2023). The goal in this research is to determine (1) if similar microplastic incorporation is happening within the foraminifera of the South Carolina coastal and (2) what types of plastics are represented in this uptake using several chemical analysis techniques. Samples were collected from marsh and beach locations from four Charleston County parks. While both Birarda et al. (2021) and Roman et al. (2023) used Fourier Transform Infrared Spectroscopy (FTIR) in their analysis of microplastics in foraminifera, we will be attempting different analyses in this study. The elemental analyzer of the Hitachi SU5000 VP-SEM will be used to detect the main elemental composition of sections of the tests. Composition should be dominated by calcium, silica, or aluminum, representing calcium carbonate, quartz sand, and clays that would be incorporated into the tests. Theoretically, if microplastics had been incorporated into the test material, the SEM would detect a high presence of carbon (while lacking in calcium) in the areas where microplastics are present due to the polymer chains. Further analysis will be done via the Renishaw inVia Qontor Raman spectrometer in targeted areas of foraminiferal tests indicating high carbon composition. Should this methodology prove feasible, it may allow future work to determine the primary source of plastics in the Charleston area, which could lead to preventative and/or remedial measures along these coastal environments.