METHODS FOR UNDERWATER FIELD SURVEYS (ROV) & PHOTOGRAMMETRY FOR MAPPING COASTAL MARINE ENVIRONMENTS: A CASE STUDY IN BONAIRE, CARIBBEAN NETHERLANDS ANTILLES

We evaluated the use of both an underwater remotely operated vehicle (ROV) for mapping shallow coastal marine environments of the reef systems surrounding the island of Bonaire, Caribbean, Netherlands Antilles. The objectives were to test various underwater field survey strategies, and to evaluate different equipment and equipment configurations, in order to find the most effective and efficient mapping methods from shore to water deeper than ~90 feet. Field survey transects were started from established boat mooring sites, and the boat provided a platform for the remote pilot in command, controller, and ROV connection line operator. A team of snorkelers was distributed on the surface to monitor the ROV connection line and for communication for ROV guidance in location. The ROV and a mounted GoPro Hero 4 on the bottom of the ROV collected video data in the field and were processed in Pix4D software through a frame by frame extraction of videogrammetry to photogrammetry, and were then stitched together to create high-resolution orthophotomosaic maps. This study includes evaluating the methods of data collection, refining data capturing, and processing to create the highest resolution orthophotomosaic maps of the reefs of Bonaire. The data will be shared with Bonaire's marine authority, STINAPA. Capturing the reefs through video and photogrammetry will act as a base for collecting underwater data for the fringing reefs of Bonaire.