Philippine maritime waters encompass as much as producing unique and diverse marine life, an important part of the Coral Triangle, a territory shared with other countries. The total number of corals and marine fish species was estimated at 500 and 2,400 respectively. New records and species discoveries continue. The Tubbataha Reef in the Sulu Sea was declared a World Heritage Site in 1993. Philippine waters also sustain the cultivation of fish, crustaceans, oysters, and seaweeds. One species of oyster, Pinctada maxima, produces pearls that are naturally golden in color. Pearls have been declared a "National Gem".