A type of fragile ecosystem characterized by a high level of biodiversity is a coral reef ecosystem. These ecosystems are formed by coral polyps that build calcium carbonate structures, providing habitat for a vast array of marine species. Coral reefs support fish, invertebrates, and other marine organisms, playing a critical role in maintaining marine biodiversity. However, they are particularly vulnerable to threats such as climate change, pollution, and overfishing, necessitating conservation efforts to protect these vital ecosystems.