Resumen:
This study represents the first assessment of microplastic (MP) contamination in the coastal area of the Esmer aldas 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 re sults 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
