Answer:
Increased ocean temperature
Explanation:
Coral reefs provide shelter and protection to many aquatic organisms. It is also a source of protection against coastline erosion.
Climate change results in increased temperature of the oceans which in turn increases the level of carbon dioxide. The increase in carbon dioxide in the oceans will amount to the coral reefs to consume more of the algae that provide it with oxygen in its body. This quick consumption of the algae results to death of coral reefs by bleaching.
