Mushroom to manoeuvre? Using photogrammetry to track the movement and survival of free-living corals

Abstract

Mushroom corals can play an important role in tropical reef ecosystems by providing habitat and performing important ecological functions. Unlike most stony corals, free-living mushroom corals can move, both passively and actively, and can use this ability to escape competition or harmful environments. However, as their movement is typically slow, occurs over relatively small scales, and is traditionally hard to measure, their movement ecology is little researched. Nevertheless, quantitative geospatial data on species’ movement, distribution, survival, and interaction can improve mechanistic modelling of community dynamics in various environments. We use ‘structure from motion’ photogrammetry to track 51 individual corals’ 3D movement and survival over one year within an isolated and enclosed lagoon. This technique essentially provides a large-scale quantitative community time-lapse and allows detailed individual level life-history data to be collected over spatial and temporal scales that were previously impractical.