Microplastics in the fish Dormitator maculatus from the Alvarado Lagoon, Veracruz, Mexico

This work analyzed the presence of microplastics (MP) in the gills and digestive tract of the fish Dormitator maculatus and its relationship with biological parameters in the Alvarado Lagoon (AL). In 127 organisms, 1,134 MP were found: 561 in the digestive tract and 573 in the gills, with an average of 8.9 MP per individual. Central tendency, Mann-Whitney, Kruskal-Wallis, and linear regression tests were performed to examine the relationship between the number of MP and the biological parameters of D. maculatus. A slight correlation was found between the number of MP in the gut and gills. The biological parameters analyzed - weight, length, condition index, and gut fullness - lacked a relationship between the amount of MP present in the gut and gills. The MPs were classified by color and type: fibers, pellets, films, and fragments. All fish analyzed presented MP in digestive tracts and gills, which indicates a uniform distribution of contamination and suggests that it originates from nearby populations, resulting from daily activities such as washing synthetic clothes and fishing. Fibers were the most dominant material (97.53%), comprising 62% blue and 12% transparent fibers. The presence of these is a threat to the health of both fauna and humans.