Physiological Responses of Stylophora pistillata in the Red Sea in Response to Elevated Temperatures

Naomi Tsai Colorado College
Faculty Sponsor(s): Shane Heschel Colorado College
Stylophora pistillata in the Gulf of Aqaba (GoA), Red Sea shows exceptional resilience and thermal tolerance when faced with temperatures above the local maximum monthly mean (MMM) (Bellworthy and Fine 2017). This area has been shown to be a type of “coral reef refuge”, with a high bleaching threshold due to natural selection and migration through the warmer southern Red Sea (Krueger et al. 2017, Fine et al. 2013). For this experiment, four colonies of S. pistillata were identified, and 15 to 17 coral fragments were cut from each colony, a total of 64 fragments. Coral samples were exposed to a plus six-degree heating treatment over 23 days in the Red Sea Simulator, an aquaria facility with ongoing monitoring and temperature control. All colonies showed bleaching and zooxanthellae cell loss in the elevated treatment. Statistical analysis showed significant colony treatment differences in three of the four colonies for zooxanthellae cell density. Fv/Fm supported colony effect as well, with significant differences between colonies and treatment in days 11-14. Coral reefs are one of the most vulnerable ecosystems to climate change. They are at risk from both ocean acidification and rising sea surface temperatures, and often face other local stressors (pollution, coastal development, tourism, and overfishing). Rising sea surface temperatures affect the thermal ranges many organisms need to survive, causing ecosystem shifts or loss of species. Mitigating local stressors will be crucial in the GoA. Coastal development, high influxes of tourists every year, and pollution all are threats to the coral reefs.
Oral Presentation

When & Where

10:45 AM
Gallahue Hall 106