<p>These 15 spectra denote the most common fluorescent emissions we have measured on Caribbean reefs. Note: All of the stony coral functional groups (1–7) also include a chlorophyll component. Fluorescence intensities are plotted in arbitrary units, and the spectra indicate typical peak-to-peak ratios. The spectra also illustrate actual inter-functional-group differences. For example, corals with pigments 486 and 515 (group 4) tend to fluorescence ‘brighter’ than the other groups, and chlorophyll fluorescence in soft corals (group 8) is approximately 4 times more intense than that in green or brown algae (group 9). The spectra used in the classification comparisons included the effects of water-column attenuation and observed peak shifts, as described in the text.</p