Understanding the role of solar radiation and sea surface temperature on the allocation of resources

Final Report TITLE Understanding the role of solar radiation and sea surface temperature on the allocation of resources into immune defense, growth and reproduction of Acropora cervicornis. NAME AND AFFILIATION OF RESEARCHERS Dr. Carlos Toledo-Hernandez, Socidedad Ambiente Marino (SAM) Dr. Claudia Patricia Ruiz-Diaz, Sociedad Ambiente Marino (SAM) Dr. Juan Sebastián Ramírez-Lugo, University of Puerto Rico, Río Piedras RESULTS AND FINDINGS FPs and PO analyses On going analyses show that FP increase during seasons were temperature and solar radiation increase. That is, the emission intensity of FPs was relatively higher in fragments placed on farms at 5m water depth, than at 8m and 12m during spring and summer. Temperature and solar radiation were higher during these seasons at all depths when compared to the other seasons i.e. fall and winter. Yet, comparing clones placed at different water depths, FPs emission intensities were similar. Overall, these findings suggest that FPs might have a photoprotective function in corals. On the other hand, PO activity was higher in shallow waters (i.e. 5 m) during spring as compared to the others depth, and them PO activity in fragments placed at 12m depth overpass those fragments placed at 5 and 8m depths. No differences have been observed in PO activity when comparing clones placed at different depths. Growth analyses Coral fragments exhibited higher growth rate and higher rate of branching in farms placed at 5m water depths than at any other depth. Interestingly, growth rate and branching peaked during JanMar, the coldest water temperature periods. These finding were consistent among clones. That is, clones fragments placed at farms in shallower waters showed the highest growth rate and branching when compared to the fragments placed in deeper areas. Furthermore, fragments collected from La Ahoga, exhibited lowest growth rates and branching when compared to the other collection sites. Mortality of fragments Coral mortality was low at all farms, as 23 fragments died during the study period. Mortality was significantly higher at the shallowest farms when compared to the deeper farms. For instance, fragment mortality at the shallower farms were twice as high than at mid depth farms and four times higher than the deepest farms. As in growth and branching measurements, mortality was higher on fragments collected at La Ahoga.