Coral reefs: Hyperspectral and multiple view angle approaches for the assessment of coral structure and dynamics

In order to conduct effective monitoring and management programs of these complex and fragile biological and geological environments, further research needs to be implemented using a variety of ancillary data sets to provide supplementary information to that obtained from remotely sensed data. As the relative health of corals and algae is related to the existence of photosynthesising pigments, the determination of their presence and density is important in the assessment of reef health and productivity. Chlorophyll a is the primary photosynthesising pigment found within macroalgae, zooxanthellae (corals) and benthic microalgae or BMA. The integration of information relating spectral response, pigment content and photosynthetic capacity is required to assist understanding of the reef environment and processes. By coupling reflectance curves with pigment analysis, additional information can be obtained about the biological composition of the feature, while structural and morphological information may be revealed through studies of the bidirectional reflectance distribution function (BRDF). By determining how corals and algae reflect and absorb light in different wavelengths at the coral scale a sound basis may be provided for using airborne and satellite imaging systems to monitor biophysical properties of coral reefs. The aims of this project were (i) to investigate the nature of the BRDF in a coral reef environment, and (ii) to examine the relationships between spectral response, photosynthetic capacity and pigmentation within and between various coral reef features.