Answer: Alligators living in a pond is an example of natural habitats
Destruction of coral reefs would cause an imbalance in the ecosystem. Some species could be driven to extinction.
Coral reefs are the base of the most diverse marine ecosystem in the world. They are often referred to as the ‘rainforest’ of the oceans and seas. They provide shelter for cnidarians, sponges, crustaceans, and etcetera and provide hiding grounds from predators.
No system is closed off by it surroundings.