Microplastics in rivers and coastal waters of the province of Esmeraldas, Ecuador

This study represents the first assessment of microplastic (MP) contamination in the coastal area of the Esmeraldas Province, Ecuador. MPs were quantified in 14 coastal waters in beaches with different urbanization level and in 10 rivers. The most abundant MP types were transparent fibres, brown fragments, grey fragments, transparent fragments, and black fragments, which together represented 84% of the total count. Coastal waters presented significantly higher quantities of MP than rivers. No difference in microplastic abundance was detected between beaches with higher and lower urban occupation, nor between beaches facing North or West. Our results indicate that MP contamination is widespread, and most likely transported from multiple sources. Our results can serve as a baseline for future MP monitoring in the area. •Microplastic (MP) was detected in the coastal and inland waters of the Esmeraldas province, Ecuador.•Higher MP abundance was found in coastal waters rather than in river waters.•Fragments and fibres were the most common MP types found.•No differences were found between coastal urban areas with low or high population, nor between beaches with north or west aspect.•Our results suggest a widespread contamination of MP in the northern coastal zone of Ecuador