The Caspian Sea is the largest enclosed inland body of water in the world, home to a unique range of biodiversity. It supports various species, including the Caspian seal, which is the only marine mammal native to the sea. Additionally, the sea is rich in fish species, such as the sturgeon, known for producing valuable caviar. The diverse ecosystems of the Caspian Sea include coastal wetlands and unique habitats that support both aquatic and terrestrial life. However, this biodiversity faces threats from pollution, overfishing, and habitat loss, making conservation efforts essential for maintaining the health of the ecosystem.