Determining Recovery Success in Anthelia sp. After Exposure to Varying Levels of Thermal Stress

Abstract

Coral bleaching is a phenomenon caused by anthropogenically increased ocean temperatures, and may lead to the eventual death of massive reef systems. Bleaching is the result of corals expelling dinoflagellate endosymbionts in order to compensate for thermal stress. However, the loss of symbionts leads to a subsequent reduction in fluorescence intensity emitted by the coral. Substantial research has been done on coral bleaching due to environmental stressors, but little knowledge has been acquired about coral recovery after thermal stress. The present study aimed to determine how Anthelia species recover after being exposed to varying levels of temperature stress. Corals were exposed to varying levels of heat stress and subsequently brought back down in temperature to promote recovery. Using fluorescence microscopy, a relatively new method of quantifying coral health, and health-colour indices, recovery ability after thermal stress was determined. Analyses concluded that corals were able to successfully recover after thermal stress of 31°C, and exhibit a thermal compensation point around 30°C. However, beyond 31°C, recovery was not achievable. The findings of this study are beneficial to the larger coral research field because they indicate that corals do possess recovery ability up until reaching a fatal thermal maximum.

Presented in absentia on April 27, 2020 at "Student Research Day" at MacEwan University in Edmonton, Alberta. (Conference cancelled)

Faculty Mentor: Ross Shaw

Department: Biological Sciences