Raja Ampat Reef, Indonesia

Raja Ampat Reef holds the highest marine biodiversity ever recorded, with over 1,500 fish species and 75% of all known coral species, a concentration 30% denser than the Great Barrier Reef (#1). This remote Indonesian archipelago in West Papua remains relatively pristine, but its corals face rising threats from warming waters. A 2023 study found that 85% of its reef areas show signs of thermal stress, yet its diversity outperforms the typical Indonesian reef by 40%, offering a critical genetic bank for future restoration.