Development and application of a video–mosaic survey technology to document the status of coral reef communities, Environmental Monitoring and Assessment

Abstract The recent decline in the condition of coral reef communities worldwide has fueled the need to de-velop innovative assessment tools to document coral abundance and distribution rapidly and effectively. While most monitoring programs rely primarily on data collected in situ by trained divers, digital photographs and video are used increasingly to extract ecological indicators, provide a permanent visual record of reef condition, and reduce the time that divers spend under-water. In this study, we describe the development and ap-plication of a video-based reef survey methodology based on an algorithm for image registration and the estimation of image motion and camera trajectory. This technology was used to construct two-dimensional, spatially accurate, high-resolution mosaics of the reef benthos at a scale of up to 400 m2. The mosaics were analyzed to estimate the size and percent cover of reef organisms and these ecological indicators of ree