Complex sentence: The national park and the rest of the Philippine archipelago is part of the Coral Triangle, recognized as the global center of marine biodiversity containing 75% of the described coral species but is under a grave threat due to overfishing and destructive fishing practices.
Split into simpler sentences: The national park and the rest of the Philippine archipelago is part of the Coral Triangle. The area is under a grave threat due to overfishing and destructive fishing practices.