Descent into the Summit: The Benham Bank Seamount Project

Benham Rise is the country’s newest territory, a 13M hectare submarine plateau which rises from the seafloor off the coast of Aurora province.

Around 3,000 meters deep, Benham Rise is a seamount--an underwater mountain. Its biological richness depends on its steep slope which forces seawater to carry nutrients upward, providing food for various marine life.

A marine expert and project leader of the Department of Science and Technology (DOST)-funded, multi-agency program on Benham Rise, Nacorda had dreamed of contributing to the documentation of deep-water biodiversity in the Philippines.

At a depth of 50 meters at the Benham Bank, she knew she and her team had their work cut out for them. The pristine and seemingly endless ecosystem of coral reefs landscape that welcomed them at the summit confirmed that there is a lot to be discovered. “We were barely scratching the surface,” she recalled.

The way to the Rise

In April 2012, Benham Rise was recognized by the United Nations Convention of the Law of the Sea (UNCLOS) as the rightful territory of the Philippines and became an extension of the country’s continental shelf.

The claim inevitably increased the area of the country’s marine bottom habitats. Known to be a rich fishing ground, Benham Rise is considered to be a potential source of oil, natural gas and minerals.

The government thereafter went to work to find the ecological and economic potentials of this newly acquired territory. A program was created through the DOST that would look into the new deep-water habitats.

SESAM was commissioned to lead a project that would assess the benthic resources of the Benham Bank seamount. Its very first activity was to explore and document Benham Bank’s bottom.

Nacorda knew that she would need extra hands for this exploration and used her call-a-friend card. Well, friends for that matter. Colleagues and experts from UP Diliman (Marine Science Institute and National Institute of Geological Sciences), UP Baguio, UP Mindanao, Xavier University, Ateneo de Manila and the Department of Agriculture-Bureau of Fisheries and Aquatic Resources (BFAR) were invited to make up the Benham Bank Expedition Team.

On board MV BFAR, this team of oceanographers; fish, coral, and benthos experts; and marine microbiologists, set sail for Benham Bank in May 2014. “Each and everyone was eager to be one of the first to enter a world still untouched by man,” Nacorda recounted.

Deep challenge

On the way to the Rise, the team was getting ready to dive at 20 meters, a depth well within the limits of safe diving. The people were prepared to work for an hour at the bottom.

However, when the anchor was dropped, they found out that the summit, or the shallowest point, was almost three times deeper. A dive computer and an underwater mini-camera confirmed this depth.

“We had prepared for a maximum dive of 20 meters so we just brought along single tanks. When we got there, it was not 20 (m)! The shallowest we had was 50 (m)! We had to rethink our diving plan,” Nacorda narrated.

After recalculating carefully, the team decided on a new plan. Each one was to take turns diving and spend a maximum time of five minutes at the bottom to do very specific tasks.

To eliminate non-oxygen gases from accumulating in the divers’ bloodstream, decompression stops at different depths on the way up were designated.

The ascent took half an hour for each diver. Assisted by technical divers from the Philippine Navy and Philippine Coast Guard, this diving plan was strictly enforced.

Exploring new territory

Once at the summit, each diver had to focus on his assigned task. Photo and video documentation, fish and coral surveys, and sample collection were some of the tasks distributed among the team. Given very little time, the divers knew they had to get the job done quickly. This proved to be an effort for most of them.

“I was at the bottom and I saw a fish swimming straight at me. The fish was probably thinking, aba, first time may tao dito ah,” Nacorda said, laughing. “It was very hard to focus on the work.”

The bottom, she said, looked surreal. Spreads of plate-like corals were basking in the sunlight penetrating the clear waters. There were corals as far as the eyes could see. But there are also other habitats including sand.

“With Benham Rise, we still have a long way to go. It is very interesting to know that there is life at that depth na pwede natin pag-aralan at alamin ano ang pakinabang nito sa atin,” she added.

Biodiversity potential

From the first expedition in 2014, the reefs were found with excellent cover (75 to 100%) of mostly tiered, thick, rigid and foliose plate-forming Porites rus; over 60 species of bony and cartilaginous fish; and four species of the green algae Halimeda.

With the aid of cutting-edge technology, the team’s second expedition last May 2016 covered 12 research stations and produced many hours of video footage. Additional specimens have been collected and are currently undergoing processing.

Research contributions

Asked on how the project would contribute to society, Nacorda answered: “Scientists are sources of basic information. We are conduits of these information and we play a role in making research useful to industries.”

“For example, if we are able to culture microorganisms found at the Rise and know their bioactivities, it can be something for molecular biologists to look at further. Geologists can look for minerals, changes in the shelf, and possible sources of fuel,” she added.

There are lots of things that can be done. There is a need to study the biodiversity and economic potential of the Rise. The resources there can also be a source of food and would be economically beneficial to nearby provinces. With reefs in pristine condition, entirely different from what we normally see in shallow waters, the rise may also have tourism potentials.

Nacorda also pointed out that research collaborations with BFAR are worth looking into. MV BFAR is a 60m-length research platform, which can bring in students to do research on areas not covered by BFAR. For example, BFAR is currently studying the effectiveness of different kinds of hooks for catching fish. “A lot of fish are being discarded which researchers and students can study. Gut contents of migratory fish, for instance, can be looked at; we will be able to know where these have come from,” Nacorda explained.

Conservation and utilization

The 2014 expedition tbrought significant awareness on Benham Rise. A Technical Working Group (TWG) under the Office of the President is being organized. This will be composed of all related national agencies, research institutions, and NGOs. The TWG will look into the proper bases whether the country should declare Benham Rise as a protected area or capitalize its resources. But to do so, continuous studies should be done.

Nacorda asserted in the end, “Mapping Benham Rise is the first step. We should know what is there to protect and what it is in for us. What we saw was just the tip of the iceberg. Lalalim pa ang maari natin madiskubre.” ■