A recent scientific study from the University of the Philippines Marine Sciences Institute has identified Benham Bank, located off the eastern coast of Luzon, as one of the richest deep coral ecosystems in the Philippines, with pristine reefscapes and high coral biodiversity despite the area’s frequent exposure to typhoons.

Published in the journal Coral Reefs, the study titled “Benthic structuring of the mesophotic coral ecosystem on the Benham Bank seamount in the Philippines” revealed the presence of at least 11 hard coral genera across various morphotypes, with four sites exhibiting near 100 percent coral cover. Researchers also documented 10 genera of soft corals, four genera of macroalgae, and arborescent sponges.

Located 50 meters below sea level, Benham Bank is an underwater seamount taller than Mt. Apo. Its hard coral cover averages 30 percent across depths of 50 to 80 meters—substantially higher than typical mesophotic coral ecosystems (MCEs) found in isolated seamounts or those closer to the mainland.

“Benham Bank is in a way resilient to physical and thermal stress,” said researcher Joey P. Cabasan.

He attributes the area’s resilience to water stratification, where an upper 40-meter water layer acts as a protective barrier against thermal and physical stressors.

According to co-author Dr. Cesar Villanoy, low nutrient levels and clear water conditions allow sunlight to penetrate deeper, enabling coral and algae growth.

The study also identified eight distinct habitat types in the area’s MCE, ranging from macroalgae-dominated zones to rocky and sandy environments. These classifications could support better legislative zoning, protection, and sustainable use of the area.

The findings reinforce the significance of the Benham Bank, which was declared a “protected food supply exclusive zone” in 2017. Despite its depth and distance—around three days by ship from the mainland—the area supports traditional small-scale fishing and hosts over 60 species of reef-associated fish, including commercially important snappers, groupers, trevallies, and tuna.

Benham Bank’s location also plays a strategic ecological role. Affected by the North Equatorial Current, it may serve as a source of coral larvae for other reefs, supporting regional coral reef recovery.

The research team, composed of marine biologists, oceanographers, and geologists, emphasized the need for future studies to explore seasonal variations and conduct connectivity research to better understand larval dispersal and reef interdependence.

Only 5% of the world’s seamounts are protected. Researchers stress that continued scientific efforts are essential to preserving the bank’s ecological richness amid growing natural and manmade threats.