Assessing microplastic pollution along the Caribbean coast of La Guajira, Colombia.

Microplastic pollution has become a global environmental issue, severely impacting marine ecosystems. In Colombia, understanding of marine microplastic pollution remains limited, necessitating targeted efforts for prevention and conservation. This study presents the first assessment of microplastics along 125 km of the Caribbean coast of La Guajira region in Colombia. Sediment samples from seven beaches (Palomino, Dibulla, Camarones, Riohacha, Valle de los Cangrejos, Mayapo, and Jimatsu) were analyzed for microplastic during two sampling periods, encompassing color, morphology, and polymer composition determined by Fourier transform infrared spectroscopy. Microplastics were found at Dibulla, Camarones, Riohacha, and Mayapo beaches during the two sampling periods (2.4 ± 0.6 to 12 ± 2 particles/m² in one period, and 3.2 ± 0.8 to 22 ± 7 particles/m² in the other). Filaments from fishing activities predominated, with microplastics mostly light-colored and composed of polypropylene, polyethylene, and polystyrene. While microplastic concentrations varied among beach use, differences between the two sampling periods were not statistically significant.