Distribution and Characteristics of Microplastics in the Mangrove Sediments of Guyana, South America

In Guyana, mangroves are vital for coastal protection, mitigating erosion, and supporting local fisheries. However, these ecosystems are threatened by marine pollution, particularly plastic debris. The fragmentation and biodegradation of these plastic items introduce microplastics in marine environments such as mangrove ecosystems. This study investigated the presence and characteristics of microplastics in sediments collected in the landward (the area farthest from the sea), middle (the area between landward and seaward zones), and seaward (the area closest to the seas) zones of three mangrove locations in Guyana. Microscopic examinations were done under a spectroscopic microscope to identify and count the microplastics' characteristics. All mangrove sediment samples examined were contaminated with microplastics. Two thousand and sixty-five microplastic items/kg of sediment were collected from three mangrove locations. The Kruskal-Wallis test revealed significant differences (p < .05) between the microplastic abundance in the landward, middle, and seaward zones. Fibers, films, and fragments were observed, with fibers being the most common. The observed microplastics were blue, green, red, black, and brown, with blue most common. The identified shapes of plastic items indicated that the microplastics were from secondary sources. Our findings confirm the presence of microplastics in Guyana's mangroves, and emphasize the urgent need for targeted local policies to manage waste and reduce plastic pollution.