What are the characteristics of a healthy coral reef?

A healthy coral reef is characterized by clarity of water and stable temperatures, making this answer particularly relevant. Clear water allows sunlight to penetrate effectively, which is essential for the photosynthetic organisms, such as zooxanthellae, that live within the coral and provide them with energy. Stable temperatures are crucial since corals are sensitive to temperature variations; extreme changes can lead to coral bleaching, where the corals lose their symbiotic algae, resulting in stress and potential mortality.

In contrast, low biodiversity and high sediment levels, high levels of pollution and warm water, as well as a lack of sunlight and limited species diversity, contribute to environmental degradation and stress on coral systems, leading to their decline rather than promoting a healthy ecosystem. Thus, clarity of water and stable temperatures are fundamental to the resilience and vitality of coral reefs, supporting a diverse marine life and functioning ecosystem.