Biology | Ecology and Evolutionary Biology

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Tropical coral reefs are one of the most impressive and diverse ecosystems on the face of the earth. Found in warm, tropical waters around the globe, these reefs are major supporters of the immense biodiversity of the area. The health of coral reefs is highly influential on the overall health of the entire ecosystem. In recent years, intensifying climate change has resulted in an accelerated rise in seawater temperatures and the frequency and severity of coral bleaching. Coral bleaching occurs in response to harsh environmental conditions that cause corals to enter a period of extreme stress. During this time, corals expel their algal symbionts – ending the symbiotic relationship with the zooxanthellae. Corals are especially vulnerable to permanent damage in this bleached state. As major supporters of the success of marine ecosystems and coastal communities alike, it is imperative that ecosystems are rehabilitated and protected from future harm. Coral polyps have long generation times, making them unable to keep up with the rate at which the climate is currently changing. Without human intervention, coral reefs will not survive the next century. Studies have indicated that the introduction of thermotolerant strains of Symbiodinium, the algal symbiont associated with corals, improves the heat tolerance of corals. This review examines the use of thermotolerant algal symbionts as a potential long-term rehabilitation and mitigation strategy. The thermal tolerance of zooxanthellae has been shown to transfer to coral species, making these species of corals more resilient to the increasing ocean temperatures and harsher conditions associated with climate change. Experimentally implanting thermotolerant strains of Symbiodinium may serve as a viable solution to the problem of corals’ slow adaptation times. Additional mitigation strategies may be required during the conservation of coral reefs to ensure the overall health of the reef for years to come. Climate change has shown no indication of slowing down in future years. It is critical that mitigation efforts are implemented immediately to identify feasible, long-term solutions to assist vulnerable corals in beating the heat.