Microplastics were found in sediments and in the tissues of two commercially exploited mangrove species, Anadara tuberculosa (black ark) and Ucides occidentalis (mangrove crab), in the Tumbes mangrove ecosystem in Peru. Sediment samples contained an average of 726 ± 396 microplastics/kg, while the black ark had 1.6 ± 1.1 items/g and the mangrove crab had 1.9 ± 0.9 items/g. Microplastics were more abundant in the gills than in the stomachs of the crab. Human consumption of microplastics from these species in Tumbes is estimated at 431 items per capita per year. The study highlights the widespread contamination of the mangrove ecosystem with microplastics, posing a risk to the marine food web and food security. Microplastics were identified in various forms, including microbeads, fragments, fibres, and films. The study also found that microplastics in the sediments did not show a significant correlation with microplastics in the organisms. The presence of microplastics in the mangrove ecosystem is likely due to anthropogenic activities such as tourism, aquaculture, and improper waste disposal. The study underscores the need for further research and monitoring to assess the long-term impacts of microplastics on the mangrove ecosystem and the health of the local population.Microplastics were found in sediments and in the tissues of two commercially exploited mangrove species, Anadara tuberculosa (black ark) and Ucides occidentalis (mangrove crab), in the Tumbes mangrove ecosystem in Peru. Sediment samples contained an average of 726 ± 396 microplastics/kg, while the black ark had 1.6 ± 1.1 items/g and the mangrove crab had 1.9 ± 0.9 items/g. Microplastics were more abundant in the gills than in the stomachs of the crab. Human consumption of microplastics from these species in Tumbes is estimated at 431 items per capita per year. The study highlights the widespread contamination of the mangrove ecosystem with microplastics, posing a risk to the marine food web and food security. Microplastics were identified in various forms, including microbeads, fragments, fibres, and films. The study also found that microplastics in the sediments did not show a significant correlation with microplastics in the organisms. The presence of microplastics in the mangrove ecosystem is likely due to anthropogenic activities such as tourism, aquaculture, and improper waste disposal. The study underscores the need for further research and monitoring to assess the long-term impacts of microplastics on the mangrove ecosystem and the health of the local population.