One Step Closer to Non-Invasive: Quantifying Coral Zooxanthellae Pigment Concentrations Using Bio-Optics

• Main Author: Hancock, Harmony Alise
• Format: Others
• Published: NSUWorks 2012
• Subjects: Zooxanthellae; photosynthetic pigments; bio-optical modeling; reflectance; corals; high performance liquid chromatography; partial least squares regression; Marine Biology; Oceanography and Atmospheric Sciences and Meteorology
• Online Access: http://nsuworks.nova.edu/occ_stuetd/189; http://nsuworks.nova.edu/cgi/viewcontent.cgi?article=1208&context=occ_stuetd

Due to the invasive nature of quantification techniques, baseline pigment data for coral-dwelling zooxanthellae are not known. In an attempt to develop a model for non-invasive estimation of zooxanthellae pigment concentrations from corals, field samples were taken from Porites rus and P. lutea in Apra Harbor, Guam. In-situ reflectance spectra (R400-R800) from 22 coral colonies were collected. “Coral truthing” was accomplished by extracting corresponding tissue core samples. Subsequent analysis to quantify the concentrations of 6 zooxanthellae pigments (µg cm-2) was performed using HPLC. Trials of multiple linear regressions were attempted (EJ Hochberg) and found inappropriate, despite previous success. The multivariate calibration technique partial least squares regression (PLS-R) is an excellent tool in the case of co-linear variables. Thus, PLS-R was attempted for chlorophyll c2 and peridinin after demonstration of co-linearity. This may be an appropriate approach for development of bio-optical models to estimate zooxanthellae pigment concentrations. Further, the dinoflagellate diagnostic pigment peridinin may be of great value for reef-scale remote sensing of changes in coral status in the future.