The average rates of coastline variation are one of the best indicators to determine the trend of the oscillatory behavior of any part of the coastline over time. The multi-temporal study of the coastline dynamics of the beach segments of Mosqueiro Island, PA, using the Landsat and Sentinel series of satellite imagery, the United States Geological Survey (USGS) and the European Space Agency (ESA) with the aid of the Digital Shoreline Analysis System (DSAS), demonstrated that during the period from 2001 to 2018, the total linear mean change for all beach segments was -81.3 m at a rate of -9.67 m / year. The average linear retreat was - 160.77 m, while the average linear advance was 79.47 m, indicating a clear erosion tendency of the Mosqueiro Island coast. From the 11 beach segments analyzed (Baia do Sol, Paraíso, Marahú, Carananduba, São Francisco, Ariramba, Murubira, Porto Arthur, Bishop / Praia Grande, Bitar), in the western part of the Island, 06 (São Francisco, Ariramba, Murubira, Porto Arthur, Bishop / Praia Grande and Bitar) showed a trend of retreat of their coastlines, presenting average rates of variation from -1.00 m / year to -3.31 m / year, the highest rate belonging to the Bishop segment /Big beach. The segments of Baía do Sol, Paraíso, Marahú, Carananduba and Farol / Chapéu Virado were the only ones that presented a tendency to advance in their coastlines, presenting values of average rates varying from 0.30 m / year to 1.74 m / year. In addition to the study of the behavior of the coastline of the western part of Mosqueiro Island, the classification of the physical vulnerability to the coastal erosion of the Island was carried out. In general, the coastal zones of the island bathed by Guajará Bay, Furo das Marinhas and Furo do Maguari were classified as "high to very high", with the exception of some sectors located in the northwest, northeast and southeast of the island. were classified as "low to moderate" vulnerability. The most localized areas in the center of the island not directly impacted by oceanographic variables were classified as "very low to moderate"vulnerability, in addition to some contiguous areas that were classified as "high" vulnerability.
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