Corals face serious worldwide population declines due to global climate change in combination with direct anthropogenic impacts. Global climate change is difficult to manage locally, but policy makers can regulate the magnitude of local stressors affecting reefs. The objective of this experiment is to investigate if reducing sedimentation will enable reef corals to better endure global climate change. It has been shown that some coral species can handle climate change stress when provided with additional energy resources. Here I tested if the capacity of corals to cope with climate change can be improved when their ability to feed and photosynthesize was not compromised by increased sedimentation. Sedimentation can impede coral feeding and their ability to photosynthesize due to direct polyp blocking and increased turbidity, which reduces light availability. To evaluate the potential of enhancing coral ability to tolerate climate change by reducing a local stressor, I examined the survival and growth of brooding coral Porites astreoides juveniles when exposed to ambient and elevated water temperatures under differing sedimentation rates. I also assessed if sediment composition has significant impacts on these results. I used sediment from a reef and sediment from a boat basin within a port to mimic natural and anthropogenic sediment types and processes (e.g. dredging). Experiments were conducted to quantitatively assess the synergistic effects of sediment concentration and composition, along with increased temperature on the survival and growth of juvenile P. astreoides. The most detrimental effects were observed with anthropogenic sediment, when both sediment concentration and water temperatures were high. However, increased natural reef sediment was found to be beneficial to juvenile corals. More interestingly, I found that corals capacity to deal with higher temperatures is improved when anthropogenic sedimentation is maintained at minimal levels and turbidity resulting from sedimentation was low. Therefore, this information will aid managers in making decisions that regulate dredging and construction activities to minimize sedimentation, which will contribute to increase coral survival under climate change.

The purpose of this study was to collect baseline data of juvenile scleractinian coral density, spatial variability, size variability, and species composition across the linear shore parallel hard bottom coral communities offshore Broward County, Florida. Adult coral population data was also collected and compared with that of the juvenile coral population to better understand the local coral demographics and potential factors that influence the population structure. The juvenile and adult coral data from the Broward County coral communities was then compared to a second study region 50 kilometers south to identify latitudinal changes in the coral population structure. The results of this study found that the densities and the list of coral species observed within the Broward County study region did fall within the range of densities found in other studies completed along the southern portion of the Florida Reef Tract and the Caribbean. Despite having similar species richness to other Caribbean studies, there was an overwhelming dominance of only a few species. This was also found in the adult coral population in the Broward study region. The densities of both the juvenile and adult coral populations were significantly positively correlated as well as their number of species observed across the sites in the Broward County study region. Additionally, the highly dominant species found in the juvenile population were in the adult population. Despite increasing coral density and diversity with decreasing latitude found in other studies conducted along the Florida Reef Tract, the results from this study were not as clear. Density of corals and the number of coral species did increase from north to south on the Outer reef however there was a significant decrease in the depth of the sample sites. On the Pavement habitat the density of juvenile corals increased from north to south however the number of coral species did not increase. The density and number of species of adult corals did not increase on the Pavement habitat with decreasing latitude as well making the results unclear.