Diverse marine life recorded in Benham Rise expedition

Posted on June 07, 2016

AN array of soft and hard corals, fish, algae, and sponges comprised some of the biological diversity documented by marine scientists from the Bureau of Fisheries and Aquatic Resources (BFAR), University of the Philippines (UP), and Oceana Philippines during a week-long expedition to Benham Rise in May.

In a statement released yesterday, Oceana Philippines reported that scientists observed 100% coral cover in several sites, with a wide variety of colorful branching and plate corals. At least 200 fish species including surgeonfish, hawkfish, and damselfish, and large predators such as tiger shark were recorded along with green algae and soft sponges.

“We saw terraces of corals, as far as the eye could see. It’s so exciting to know that we have such a vast and pristine coral reef ecosystem within Philippine territory,” said Marianne Pan-Saniano, marine scientist for Oceana Philippines.

Benham Bank is the shallowest portion of Benham Rise, which includes an outer section recognized by the United Nations’ Commission on the Limits of the Continental Shelf as the Philippines’ newest territory in 2012. The vast seamount lies off the eastern coast of Luzon.

During the first science expedition to Benham Bank in 2014, scientists were able to cover five stations and dive for 25 minutes.

Two years later, with the aid of new technology, scientists in the 2016 expedition were able to extensively study the underwater terrain of Benham Bank, covering 12 research stations and analyzing many hours of video footage daily.

On board the government research vessel MV DA-BFAR, the expedition team left for Benham Bank on May 23, and returned May 31.

Fisheries and algae experts, microbiologists, oceanographers, and ecologists from BFAR, UP Marine Science Institute, UP Los Baños School of Environmental Science and Management, and Oceana joined the trip to study the biophysical composition of Benham Bank.

For the first time, scientists were able to use data from a remotely operated vehicle (ROV) that took underwater photos and videos for two hours on a daily basis. They also deployed equipment called the baited remote underwater video system (BRUVS), that explored deeper parts of the ocean and took five hours’ worth of footage, to determine fish diversity and biomass.

Technical divers from the Philippine Navy and the Philippine Coast Guard assisted the researchers in collecting samples from Benham Bank’s seabed.

The expedition team documented a vast mesophotic reef ecosystem -- coral reefs found at depths of up to 150 meters (492 feet). Scientists believe such deep sea reefs can serve as a potential refuge for shallow reef fishes that could be affected by climate change.

“Collectively, among the decades of experience studying the ocean that we have aboard the ship, no one has ever seen reefs like this. Benham is indeed a special place,” said Margot Stiles, Oceana’s director of science and strategy.

“Benham Bank holds tremendous potential for discovering more unique species and outstanding samples of marine resources. Based on the huge success of this expedition, and the inspiring collaboration among the partners, we foresee government and stakeholders working together to protect and sustainably manage this extraordinary natural heritage which is now part of our territory,” said lawyer Gloria E. Ramos, vice-president for Oceana Philippines.

The 2016 expedition was funded by the Philippine Council for Agriculture and Natural Resources Research and Development, while BFAR contributed the use of the research vessel.

Oceana provided the ROV and BRUVS, as well as technical divers who took photographs and videos of marine life in the deep sea reefs.