What unique conditions make coral reefs so highly productive?

Coral reefs thrive in warm, shallow waters with ample sunlight, which supports the growth of symbiotic algae called zooxanthellae. These algae perform photosynthesis, providing essential nutrients to corals while benefiting from the corals' waste products. The intricate structure of reefs also creates diverse habitats that support a variety of marine life, enhancing productivity through complex food webs. Additionally, nutrient recycling within the reef ecosystem further boosts its overall productivity.