West Philippine Sea Coral Reef Imagery Using ARRAS Technology

The Automated Rapid Reef Assessment System (ARRAS), which is a towed platform composed of an underwater camera and echosounder with a stitching algorithm called Kiko&Stitch, were utilized to quantify the coral reef extents of the Kalayaan Island Group (KIG) in the West Philippine Sea (WPS) for its resource valuation where impacts of both natural and anthropogenic activities are investigated. This efficient and inexpensive system allows for optimized sampling specially in cases that require rapid assessments at a limited time frame, a case in point is the WPS where geopolitical tensions are present. Portions of the geotagged stitched images from the captured videos that were classified into corals, seaweed, seagrass, rubble, and sand and extents were assigned as training and validating sets in classifying satellite imagery using semi-automated classification algorithm. This created a habitat map of the KIG reefs validated with a mean accuracy of 0.56. The total calculated area for the 32 identified reef systems in KIG is 3,179 sq km, 40% of which are primarily dominated corals, 32% are seaweed/macroalgae/CCA, 18% are rubble/rock, and 10% are sand.