A coral’s true colors: Understanding color hues to assess coral health and welfare

Coral reefs are one of the most biodiverse and productive ecosystems on Earth and various methods are utilized to monitor and assess coral health. But there is not a standardized method for quantifying coral health for corals held in captivity in zoos and aquariums. Therefore, a health assessment card using coral color to non-invasively monitor coral health was developed with the Texas State Aquarium (TSA). To quantify coral health, individual corals of each species were photographed in a controlled environment to develop color profiles. Simultaneously, nondestructive measurements of “health” were assessed using Pulse- Amplitude Modulation Fluorometry. These photosynthetic efficiency measurements determine how efficiently the symbiotic algae provides energy to the coral host. This project successfully corresponded photosynthetic efficiency to coral color to develop a Coral Health Assessment Card for all species at TSA. By implementing a standardized assessment of coral health, TSA can effectively and rapidly assess the health of their corals improving overall coral wellness. Consequently, the results of this work support TSA’s mission to support wildlife conservation by promoting education and conservation of coastal and marine ecosystems through their interactive exhibits.