Shoreline changes between 1954 and 2007 in the marine protected area of the Rosario Island Archipelago (Caribbean of Colombia)

Aerial photography and satellite imagery analysis (1954–2007) have enabled the assessment of the changes in the net insular zones and the morphological adjustment processes of the Rosario Island Archipelago over last 50–55 years (Grande Island, Rosario Island, and Tesoro Island). Significant erosion was observed (>3% of the initial area) as a result of the morphodynamic imbalance of the insular system. The Grande, Rosario, and Tesoro Islands have lost 6.7%, 8.2%, and 48.7% of their territory, respectively. Data indicate an inverse relationship between the size of the island and the magnitude of the erosion. Erosive processes were detected along ∼85% of coastline exposed directly to NNE–NE waves. The erosive activity on the archipelago has been constant for the last 50 years as consequence of continual wave action and rising sea levels. However, anthropogenic intervention has caused significant changes to the geomorphologic setting of the coast, which creates different morphologic outputs for the erosive processes.

► The Rosario Island Archipelago has been consistently eroded over the past 50 years. ► Anthropogenic intervention has caused significant changes to the geomorphologic setting of the coast. ► Data indicate an inverse relationship between the size of the island and the magnitude of the erosion. ► Between 1954 and 2007, Grande, Rosario, and Tesoro Islands experienced a total reduction of 8.6% of their original area.