Beneath 50 m of NW Pacific water: Coral reefs on the Benham Bank Seamount off the Philippine Sea

The benthic habitats on the Philippine (Benham) Rise were unknown until the joint University of the Philippines Marine Science Institute (UPMSI)/University of the Philippines Los Baños (UPLB)/Department of Agriculture-Bureau of Fisheries and Aquatic Resources (DA-BFAR) cruise of May 2014 when extensive coral reefs were discovered on the summit of the Benham Bank Seamount. Short observational surveys of five stations at depths up to 55 m revealed that the reefs were pristine and with excellent cover mostly by tiered, thick, rigid and foliose plate-forming Porites (Synaraea) rus. The voucher specimen collections indicated that there are at least 11 reef-building and two solitary coral species in the reef communities. The fish visual census and random hook-and-line fishing surveys recorded 62 species, 16 of which were reef health indicators and the rest were commercially exploited species. These short surveys yielded the first records of mesophotic coral reef biodiversity on the Benham Bank, albeit incomplete, and point to the inevitable requisite of further exploring these pristine reefs and their associated benthic habitats, since this Philippine natural heritage serves as an important area for fisheries. © 2017, University of the Philippines Los Banos. All rights reserved