The Red Sea is considered to be an environmentally stable (water temperature, salinity, etc.) ecosystem that is filled with coral reefs and seaweed habitats. Here, we investigated the effects of disease on the coral, Stylophora pistillata, using spectral reflectance and fluorescence. Corals provide unique color identification in response to light illumination. For example, a coral may appear yellow-white in natural daylight conditions and appear to have green and red shades when illuminated with a blue light. This color change phenomena is known as fluorescence.

Current remote sensing studies have focused on the separation of coral species from the surrounding environment (e.g., covering sediments, or between species) or the amount of bleaching on coral reefs. In this study, we investigated an in situ proof of concept of the effects of disease on corals, using reflectance and fluorescence excited from a tungsten lamp and colored lasers. The results of this study can support coastal managers in defining environment sensitivity indices (ESI) and possible habitat mapping and monitoring programs using hyperspectral and airborne lidar bathymetry (ALB) surveys.

After visual inspection of the health of individual corals underwater, the color of the corals was measured using different light sources (i.e., white, red, green, and blue). In addition, selected branches from each coral were sampled and brought back to the laboratory for further study. Preliminary results from the field measurement and laboratory work show systematic color differences between healthy and diseased corals.