Date of Award
Climate change can indirectly affect the level of predation on soft corals. As sea temperatures rise, more and more bleaching events are occurring, which can affect the production of chemical defenses and the concentrations of the biochemical constituents that make up the soft corals. These changes may make the soft corals more attractive to predators. This phenomenon is suggested by the environmental stress theory (EST), which states that under stressful conditions, more of an organism's energy is allocated to survival rather than to other factors, such as reproduction or predator deterrence. To test the effect of predation on already bleached soft corals, an array of different cage types was placed over the soft coral Sinularia polydactyla to show how the cages affected biochemical constituents in the soft corals. Percent carbohydrates were highest in uncaged soft corals, suggesting a cage effect because the cage did not block any sunlight or slow the rate of photosynthesis in these individuals. Percent protein was highest in caged soft corals, suggesting a predation effect because the cage inhibited predators from feeding on the soft corals. In contrast, there was no significance between the treatments for percent lipid or percent ash. In conclusion, climate change has caused an increasing number of bleaching events, and although only the decreased protein concentration appeared to be a direct effect of predation, carbohydrates are also indirectly affected by predation and directly affected by loss of the coral's zooxanthellae symbionts due to bleaching.
Cole, Carley Elizabeth, "Effects of Predation on the Biochemical Constituents of the Bleached Soft Coral Sinularia polydactyla" (2018). Honors Theses. 160.