Apo Reef in Occidental Mindoro is the largest atoll-like reef in the Philippines and the second largest non-contiguous reef on Earth. It covers 34 square kilometers and boasts of two impressive lagoon systems. The area exhibits a wide variety of habitat types and hosts a high diversity of corals, fishes, invertebrates and other fauna. After Tubbataha, Apo Reef became the country's second Marine Protected Area (MPA) where fishing in all its forms is completely banned.

Apo Reef National Park (ARNP) is composed of a diverse assemblage of shallow tropical marine habitats that provide food and shelter for a plethora of invertebrate fauna and fish life. The relatively large distance of the reef complex from the main island of Mindoro is seen as a major factor in helping minimize the negative impacts typically associated with a reef's proximity to man – the most significant of which would include overfishing, sedimentation and pollution. With the reclassification of ARNP as a strict protection zone in 2007, illegal fishing activities have been dramatically reduced. This management intervention was cited as one of the main reasons for the increase in fish abundance within and around ARNP.

WWF continues to support the Protected Area Office of Apo Reef through the maintenance of the patrol boats, coral monitoring, and capacity building.