LOS BAÑOS, Laguna, Philippines – The country’s sea surface temperatures (SST) have been rising over the past decades, a University of the Philippines Diliman scientist noted.
During the past 20 to 30 years, the SST in the country’s southern part increased by 0.20 degrees Celsius per decade, reported Laura T. David, a professor at the UP Marine Science Institute (MSI) and member of the National Academy of Science and Technology (NAST) technical committee on climate change.
On the other hand, the SST in the country’s northern part increased by 0.30 degrees Celsius per decade.
These fluctuations in temperature have a significant impact on the marine environment, David said in a report titled “Risk in Fisheries due to Climate Variability.”
A synthesis of the scientific paper was published by the Philippine government-hosted Southeast Asian Ministers of Education Organization-Regional Center for Graduate Study and Research in Agriculture (SEAMEO SEARCA) under its “Agriculture and Development Notes.”
UP Los Baños-based SEARCA, headed by director Gil C. Saguiguit Jr., is one of 21 regional centers of SEAMEO, an inter-government treaty body that promotes cooperation among Southeast Asian nations in science, education and culture.
In addition to the fluctuations in SSTs, “typhoon-induced wave action and high sedimentation may lead to the corals’ brittleness and increased sensitivity to siltation. As a result, seagrass may die,” David said.
She further emphasized that damage to these ecosystems results in loss of nursery grounds for fish and support systems for endangered species.
An MSI study showed that hotter water fuels typhoons. Consequently, change in the amount of rainfall may lead to potential loss of stenohaline mangrove species, or those that thrive only within a narrow range of saltwater concentration.
Sea level rise, as another threat to the marine ecosystem, also affects the wavelength and amount of light that reaches seagrass and corals, explained David, also a corresponding member of the International Geosphere Programme Land Ocean Interaction in the Coastal Zone, a research program that studies the phenomenon of global change.
In mangroves, she said, establishing propagules (buds) becomes difficult when they are submerged owing to inability to photosynthesize. Consequently, the United Nations estimates that by the year 2100, 30 percent of mangroves will be drowned.
David further explained that typhoons and sea level rise may also lead to coastal erosion, causing destruction of habitats of thousands of marine species. Animal species that move to different habitats through their life stages are the most vulnerable.