Final answer:
In coral reefs, salinity is an example of an abiotic factor, while the corals themselves are a biotic factor, both crucially impacting the ecosystem's biodiversity and functioning.
Step-by-step explanation:
In a coral reef ecosystem, one example of an abiotic factor would be salinity, which significantly influences the types of organisms that thrive there. On the other hand, a biotic factor from the coral reefs could be the actual coral, which is a living organism serving as a foundation species for the ecosystem. Corals form symbiotic relationships with algae, offering protection and receiving nutrients in return. The presence of diverse fishes, including predators, herbivores, and planktivores, indicates the high biodiversity and richness of coral reef habitats. These factors, both abiotic and biotic, interact to shape the environment and the plethora of life forms within the coral reefs.