MANILA, Philippines (June 2024) – Scientists have discovered that the Benham Bank, an underwater mountain east of Luzon taller than the Philippines’ highest peak, harbors one of the country’s most pristine coral ecosystems despite sitting in the path of devastating typhoons.
The seamount, located 50 meters below the surface near Luzon’s eastern coast, boasts coral coverage rates of nearly 100% in some areas. This finding challenges expectations for a region regularly battered by Pacific storms.
“Benham Bank is in a way resilient to physical and thermal stress,” said researcher Joey P. Cabasan, whose team published their findings in Coral Reefs journal. “There is stratification or layers with different water properties, which perhaps protected the Benham Bank from the effects of stress.”
The underwater mountain creates natural barriers through water stratification. The upper 40-meter layer prevents mixing with lower depths, shielding corals from environmental damage.
Filipino fishers from Infanta, Quezon already know the area’s value. They travel three days by boat to reach waters the government designated as a “protected food supply exclusive zone” in 2017.
The research team documented remarkable biodiversity during their expedition. They found 11 types of hard coral, 10 varieties of soft coral, and multiple species of seaweed and sponges across eight distinct habitat zones.
Dr. Cesar Villanoy, study co-author, explained why life thrives at such depths. “The water at Benham Bank is very clear. Since there are no major sources of nutrients like large rivers, nutrients and chlorophyll in the water column are low, and light is able to penetrate to greater depths.”
The seamount’s strategic location in the North Equatorial Current means it could serve as a breeding ground for coral recovery across the Pacific. The current flows northeast toward the Philippines before splitting to form the Kuroshio Current toward Japan and the Mindanao Current southward.
Commercial fishing surveys from 2014 recorded more than 60 reef fish species, including large snappers, groupers, and tuna. Many specimens were adults, suggesting the area functions as both breeding ground and nursery.
The three-day journey to reach Benham Bank requires six months of planning and coordination between institutions. Researchers can only study the area outside monsoon season, limiting scientific access.
“This biodiversity emphasizes the need to be proactive towards continued research, especially since current studies serve as a baseline for understanding the area,” Cabasan noted.
Only 5% of the world’s seamounts receive protection status. The team recommends immediate studies on seasonal variations, fish communities, and connectivity patterns to other Pacific reefs.
Filipino scientists urge continued research and protection measures for Benham Bank as climate change threatens marine ecosystems worldwide. The pristine underwater mountain could hold keys to coral reef recovery across the Pacific region.
