UN World Ocean Assessment Expert: 'Seagrass Meadows Most Threatened Ecosystem'

The only Filipino in the 25 experts who wrote the First Ocean Assessment Report for the United Nations revealed that seagrass meadows are the most threatened ecosystems on earth.

Dr. Hilconida P. Calumpong, who is a professor at the Institute of Environmental and Marine Sciences in Silliman, said that one-third of all the seagrass areas recorded around the world in the 1870s have disappeared. The rate of destruction has been at 110 square kilometers per year, since 1980.

Currently, the highest declines are reported in the China-Japan region due to heavy coastal development, such as building of airports, water resorts and extensive reclamation. Other causes around Asia are aquaculture and watershed siltation.

“All the forests we are cutting, all the soil goes down and cover our seagrass beds,” Dr. Calumpong told journalists at the seminar “Biodiversity 101” February 29 at the American Studies Resource Center of the Robert B. and Metta. J. Silliman Library. The seminar was organized by the ASEAN Centre for Biodiversity and Young Southeast Asian Leaders Initiative (YSEALI) in cooperation with the SU Research and Environmental News project, and was funded by the US Embassy Manila. 

According to Dr. Calumpong, plastics thrown into the ocean form another threat. Plastics break into very tiny particles, competing with microscopic organisms that serve as food for larger marine animals and blocking the sunlight needed for the seagrass to survive.

She said seagrass loss is a critical problem because they provide essential “goods and services”, such as oxygen production and absorption of carbon dioxide.

“Carbon dioxide are very small molecules, they form a film around the earth (trapping the heat). Any increase, even 0.0001 percent increase, really affects the amount of heat that is trapped,” she explained.

Because of carbon dioxide, the heat can come in but it has no way out. “If the carbon sink is reduced, more carbon dioxide in the atmosphere, more heating in the oceans, the climate becomes more and more extreme,” she said.

Seagrass loss puts coastal residents, their livelihoods and food production at risk. Fishermen, such as the ones in Bais City, are dependent on seagrass and will lose their livelihood, such as sales from danguit, a popular form of dried fish.

Dr. Calumpong added that seagrass loss will affect populations of large marine animals that feed on them, including manatees, dugongs and green turtles which already have poor conservation status.

Some 115 marine species that live on seagrass beds, including some invertebrates, fishes, sea turtles, and marine mammals are being listed as threatened by the International Union for the Conservation of Nature.

Reefs and mangrove ecosystems will also be affected since many fish and invertebrate species found in coral reefs and mangroves have been reported to spend their juvenile stages in seagrass beds.

Dr. Calumpong stressed that the ocean is a complex system that is interconnected, and that a wrong action done in one part of the ocean will affect the whole. She emphasized that integration management is needed not just to sustain seagrass meadows, but also to preserve other ecosystems.

To drive her point, she said: “The oceans can exist without humans, but humans cannot exist without the oceans.” (Andrea Dawn E. Boycillo, SU Research and Environmental News Service)