Global Warming and Coral Reefs

• Coral reefs are biodiverse ecosystems that provide ecological and economic benefits.
• Coral reefs are facing numerous threats, including global warming.
• Global warming is often considered a primary factor affecting coral growth.

Global Warming and Coral Bleaching

• Global warming significantly impacts 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 rises.
• Coral bleaching occurs when corals expel symbiotic algae because of high-temperature stress, resulting in loss of color and weakened health.
• Bleached corals are more susceptible to disease and death.
• Global warming exacerbates the frequency and severity of bleaching events, making it a critical factor in coral reef degradation.

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 has a direct and negative impact on coral growth.

Combined Effects of Climate Change

• The combined effects of global warming, including sea-level rise and increased storm intensity, compound the threats to coral reefs.
• Cyclones and storm surges caused by global warming can physically damage coral reefs in Fiji and increase sedimentation.
• Sea-level rise can lead to deeper waters, reducing light availability for coral growth.
• These combined effects create a multi-faceted threat, making it difficult for coral reefs 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 in Fiji has disrupted the ecological balance, leading to algal overgrowth that smothers corals.
• Pollution from agricultural runoff and sewage increases nutrient levels, promoting harmful algal blooms.
• Local stressors directly impact coral health by reducing water quality and disrupting the reef ecosystem.

Effective Local Management Strategies

• Effective local management strategies can mitigate some of the impacts of global warming on coral reefs.
• The closure of Thailand’s Maya Bay to tourists 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.
• Effective conservation strategies must address both global and local factors.
• Integrating global and local solutions is important in coral reef conservation efforts, as highlighted by the case studies of Fiji and Thailand’s Maya Bay.