Marianas Trench Marine National Monument

The Marianas Trench Marine National Monument is the deepest part of the world’s ocean, and includes the second deepest point on Earth, the Sirena Deep, which lies at 35,000 feet below sea level. The monument has been studied for its rare undersea phenomena, such as the largest mud volcanoes on earth and sites where photosynthetic and chemosynthetic communities coexist. The monument supports an ecosystem ranging from the deep sea to coral reefs to recently formed volcanic islands at the ocean’s surface, and scientists have identified new species of sponges, jellyfish, and crinoid within the monument.