What are the main threats to Bonaire’s reefs?
Coral bleaching. Reef-building (also called “hermatypic”) corals have a symbiotic relationship with one-celled algae, called zooxanthellae. The presence of zooxanthellae in the coral tissue explains the common tan or green color of coral colonies. It also explains why hermatypic corals need sunlight, because the algae (plants) need light for their photosynthesis. The symbiotic relationship between the coral polyps and the algae is a mutually beneficial one: both algae and polyps not only recycle some of each other’s waste products, the algae also create a chemical environment that promotes the deposition of calcium carbonate, the building material for the coral skeleton. The coral cannot survive without the algae. Periodically coral colonies expel all or part their zooxanthellae; the coral animals, called polyps, become transparent, the color of their white skeleton shows through them and they appear white. This phenomenon is known as bleaching. Scientists have demonstrated that stress
