Global Warming Impact on Coral Reefs

• Coral reefs are biodiverse ecosystems providing ecological and economic benefits.
• Coral reefs face numerous threats, including global warming.

Global Warming and Coral Bleaching

• Global warming significantly affects coral growth by increasing sea temperatures, leading to coral bleaching.
• Rising sea temperatures are linked to more frequent and severe mass coral bleaching events.
• Fiji's coral reefs are vulnerable to bleaching during El Niño events due to significant sea temperature increases.
• Coral bleaching occurs when corals expel symbiotic algae due to high-temperature stress.
• Expulsion of symbiotic algae leads to a loss of color and weakened coral health, making them more susceptible to disease and death.
• Global warming exacerbates the frequency and severity of bleaching events, critically degrading coral reefs

Ocean Acidification and Reef Degradation

• Global warming leads to ocean acidification, undermining coral growth and structural integrity.
• Increased CO₂ emissions from global warming lower ocean pH.
• Lower ocean pH makes it difficult for corals to build calcium carbonate skeletons.
• Ocean acidification reduces the availability of aragonite, a key mineral for coral skeleton formation.
• Reduced aragonite leads to weaker and slower-growing reefs.
• Ocean acidification directly and negatively impacts coral growth, further reinforcing global warming as a primary threat.

Combined Effects of Climate Change

• The combined effects of global warming compound threats to coral reefs, including sea-level rise and increased storm intensity.
• Cyclones and storm surges caused by global warming can physically damage coral reefs and increase sedimentation in Fiji.
• Sea-level rise can lead to deeper waters, reducing light availability for coral growth.
• These create a multi-faceted threat to coral reefs, making it difficult for them to recover from damage.
• Global warming exacerbates multiple stressors that degrade reef health.

Local Human Activities and Pollution

• Local human activities, such as overfishing and pollution, are significant threats to coral reefs, independent of global warming.
• Overfishing has disrupted the ecological balance, leading to algal overgrowth in Fiji.
• Pollution from agricultural runoff and sewage increases nutrient levels in the water, promoting harmful algal blooms.
• These directly impact coral health by reducing water quality and disrupting the reef ecosystem.
• Local human activities significantly contribute to degradation.

Effective Local Management Strategies

• Effective local management strategies can mitigate some impacts of global warming on coral reefs.
• Closing Thailand's Maya Bay to tourism allowed the reef to recover from human-induced stress.
• Integrated coastal management and marine protected areas in Fiji have shown success in conserving coral reefs.
• Local conservation efforts can be effective in protecting reefs, even in the face of global warming.
• Local management strategies play a crucial role in coral reef conservation.

Conclusion

• Global warming significantly affects coral growth through coral bleaching, ocean acidification, and other climate-related stressors.
• Local human activities such as overfishing and pollution also pose significant threats to coral reefs.
• Effective conservation strategies must address both global and local factors to ensure the survival of coral reef ecosystems.
• Fiji and Thailand’s Maya Bay highlight the importance of integrating global and local solutions in coral reef conservation efforts.