Textural characteristics and abundance of microplastics in Tecolutla beach sediments, Gulf of Mexico.

Abstract

Abundance of microplastics in coastal sediments is considered an emerging pollution problem worldwide. In Mexico, studies focused on microplastics in coastal sediments are little. In this study, we analyzed the textural characteristics and investigated the abundance of microplastics in the Tecolutla beach sediments, SW Gulf of Mexico. The extraction of microplastics in sediments was done by density separation. Microplastics were identified by stereomicroscope and scanning electron microscopy, and were classified based on their morphology, color, length, texture, and abundance. Among 181 microplastics, fiber type is predominant (number of microplastics n = 166; 92%) and followed by film (n = 12; 6%) and fragment (n = 3; 2%) types. The most abundant color of microplastics is black (n = 81; 45%) and second dominant color is blue (n = 65; 36%); most of them are fiber type. Based on the textural characteristics of sediments, it was observed that microplastics were derived from the fluvial contribution of the Tecolutla River and were deposited in the coastal environment by ocean currents. This study revealed that the abundance of microplastics was high in fine-grained sediments and was directly proportional to skewness. The results of this study can act as a reference for understanding the abundance of microplastics in the Gulf of Mexico coastal sediments.