AP BIOLOGY

Detailed explanation-1: -The variety of species living on a coral reef is greater than in any other shallow-water marine ecosystem, making reefs one of the most diverse ecosystems on the planet.

Detailed explanation-2: -They are made up not only of hard and soft corals, but also sponges, crustaceans, mollusks, fish, sea turtles, sharks, dolphins and much more. Competition for resources such as food, space and sunlight are some of the primary factors in determining the abundances and diversity of organisms on a reef.

Detailed explanation-3: -Because of strict environmental restrictions, coral reefs generally are confined to tropical and semi-tropical waters. Reef-building corals cannot tolerate water temperatures below 64° Fahrenheit (18° Celsius).