High-resolution imagery of the coral reefs of Gorgona Island, Colombian Pacific Ocean: an improved view for monitoring and research

Abstract

The shape and size of a coral reef are both key factors influencing its ecology and biodiversity. These parameters play a fundamental role in the creation of specific habitats that support rich biodiversity. They also greatly influence a coral reef's resilience to climatic events and external influences. Here we present a practical example of photogrammetric reconstruction of the best developed coral reefs of the Colombian Pacific, located at Gorgona Island. Using unoccupied aerial vehicles (drones) and Geographic Information Systems (GIS), we produced high resolution orthophotomosaics and precise contour maps of four reefs and updated estimates of reef areas. We illustrate the improved accuracy of these maps in comparison with maps obtained from satellite imagery and conclude by highlighting the usefulness of drones to locate, measure, and monitor small coral reefs.