Coral reefs are formed by the accumulation of calcium carbonate skeletons secreted by tiny marine invertebrates called coral polyps.

Patch reefs are not a distinct type of coral reef, but rather small, isolated coral formations found within larger reef systems.

Coral polyps and photosynthetic algae engage in a mutually beneficial relationship, where the algae provide the coral with nutrients through photosynthesis, and the coral provides the algae with a protected environment.

Coral bleaching is a symptom of stress experienced by corals, often caused by elevated water temperatures or pollution. It is not a direct threat to coral reefs, but rather a consequence of other stressors.

The Great Barrier Reef, located off the coast of Australia, is the largest coral reef system in the world, stretching over 2,300 kilometers.

Dolphins are not typically found in coral reef ecosystems, as they prefer deeper waters and open ocean habitats.

Calcification is the process by which coral polyps use calcium and carbonate ions from seawater to build their hard skeletons.

Competition is not a major factor contributing to the biodiversity of coral reef ecosystems, as these ecosystems are characterized by a high degree of cooperation and mutualism among species.

Coral degradation refers to the damage or destruction of coral reefs caused by human activities such as pollution, overfishing, and coastal development.

Introducing invasive species is not a conservation measure implemented to protect coral reefs, as it can disrupt the delicate balance of the ecosystem and harm native species.

Coral restoration refers to the process of actively restoring damaged or degraded coral reefs through various techniques such as coral transplantation and fragmenting.

Coral reefs do not play a major role in regulating ocean currents, as they are primarily responsible for providing habitat, protecting coastlines, and contributing to biodiversity.

Coral adaptation refers to the process by which coral reefs adjust and evolve over time to cope with changing environmental conditions such as rising sea temperatures and ocean acidification.

Natural disasters, such as hurricanes and tsunamis, can cause damage to coral reefs, but they are not considered a major threat to their survival compared to human-induced stressors like climate change and pollution.