OPTICAL PROPERTIES INVOLVED IN THE EFFICIENCY OF LIGHT ABSORPTION OF CORAL FAVIA FRAGUM
The structural complexity of corals provides them the capacity to regulate the amount of light they receive, by absorbing a variable fraction of the photons and transmitting, reflecting or scattering the rest. The aim of this study was to describe the optical properties of Favia fragum at two developmental stages with different skeletal thicknesses: 35 juveniles with skeletal thicknesses less than 0.5 cm and 25 adult colonies with skeletal thicknesses greater than 1 cm were used. Measurements of transmittance and reflectance were performed and from these measures absorbances and absorptances were estimated. The number of symbionts, their chlorophyll a content and the chlorophyll a specific absorption coefficients (a*) were determined. The transmittance value recorded in the skeletons of juveniles was close to 3%. Reflectances at 675 nm was 12% in adult colonies and 37% for the juveniles with absorptance values of 88% and 62% respectively. Juveniles had a higher pigment content/symbiont and lower symbiont densities than adults. Comparison of a* values showed that adults are up to 1.6 times more efficient at absorbing light than juveniles. Loss of light by transmittance is reduced with increasing skeletal thickness and is related to the increased light absorption efficiency in adult colonies. The balance between cell density and symbiotic photosynthetic pigments strongly influence the efficiency of light absorption in corals with different skeletal thicknesses.
Mendoza-Quiroz, S., Posgrado en Ciencias del Mar y Limnología, UNAM, Mexico, firstname.lastname@example.org
Iglesias-Prieto, R., Instituto de Ciencias del Mar y Limnología, UNAM., Mexico, email@example.com
Banaszak , A. T., Instituto de Ciencias del Mar y Limnología, UNAM., Mexico, firstname.lastname@example.org
Time: 18:15 - 19:45
Location: Poster/Exhibit Hall
Presentation is given by student: Yes