Mangroves can help protect coastal areas from typhoons
Text and Photos by Henrylito D. Tacio
In November 2013, the Philippines was hit by super typhoon Yolanda (international name: Haiyan), which killed around 6,300 people. The Visayas were severely damaged by the typhoon, particularly the islands of Samar and Leyte. According to reports, the typhoon affected almost 11 million people, many of whom were left without a place to live.
However, because of the robust mangroves that jutted out along their shoreline and functioned as protective barriers, some affected regions were spared from the extensive damage that happened to other areas.
This was discovered by Dr. Moises Neil V. Seriño, a professor in the economics department and the current vice president for planning at Visayas State University in Leyte, following a study he and co-researchers did on the aftermath of Yolanda.
“Our study shows that mangrove vegetation reduced the number of deaths and damaged houses during the Yolanda incident,” Dr. Seriño said. “This property and lifesaving effects of mangrove is robust. Mangroves can protect us (our lives, livelihood and properties) from damaging effects of typhoons.”
Dr. Seriño and his team collected data from the areas where typhoon Yolanda passed through, particularly in Samar, Leyte, Bohol, Cebu, Negros, Panay, and Palawan. “We focused on mangroves because mangroves have suffered degradation in the past decades and these mangrove ecosystems have been doing a very important job of protecting coastal communities from damaging effects of typhoons,” he explained.
“Coastal communities with substantial mangrove cover suffered fewer or less casualty and less housing damages as compared to coastal communities with reduced mangrove cover,” he added.
Dr. Severino Salmo III, an associate professor at the Institute of Biology at the University of the Philippines Diliman, agrees. “Mangroves, in general, will really protect coastal communities against typhoons,” he said.
But he clarified that “it is not as straightforward as that.” As he puts it, “The types of mangroves, the length/extent, and the structural complexity will matter more than the simple presence.”
To put it simply, Dr. Salmo explained: “If you restore a mangrove today, and there’s a typhoon tomorrow, do not expect that it will protect the coast compared to mangroves that are more mature. Alternatively, even if you have a 30-year-ol old mangroves but these are too sparse and not diverse, the protection will be practically limited to none.”
This is one of the reasons why the Economic World Forum (EWF) urged that old-growth mangroves should be protected from denudation. “The sturdy root systems of mangrove trees help form a natural barrier against violent storm surges and floods,” it said.
Another reason: mangrove forests are carbon sinks. “Coastal forests help the fight against global warming by removing carbon dioxide from the atmosphere, most of which is stored within the plant,” EWF said. “When mangrove tree roots, branches and leaves die they are usually covered by soil, which is then submerged under tidal water, slowing the breakdown of materials and boosting carbon storage.”
According to several studies, coastal mangroves perform better than most other forests in terms of their ability to store carbon. An analysis of 25 mangrove forests in the Indo-Pacific area revealed that they contained up to four times as much carbon per hectare as other tropical rainforests.
Still another reason: mangroves provide livelihoods. “Mangroves provide a livelihood for a large number of people who live in and near them,” the EWF stated.
The mangrove trees are a reliable source of wood for construction and fuel, which is prized for its hardy resistance to both rot and insects. However, in some areas, the wood has been harvested commercially for pulp, wood chip and charcoal, raising concerns about sustainability.
But more importantly, the mangrove forest provides local fishermen with a rich supply of fish, crabs and shellfish to sell for income. Dr. Rafael D. Guerrero III, an academician with the National Academy of Science and Technology, considers mangroves as “fish factories.” More than 3,000 fish species are found in mangrove ecosystems.
“Failure to preserve mangrove ecosystems can lead to carbon emissions and negatively impact the livelihoods of communities that depend on them,” wrote Analiza C. Diaz, of the S&T Media Services of the Department of Science and Technology (DOST).
The Mariano Marcos State University (MMSU) in Ilocos Norte knows this. So much so that MMSU forged recently a collaboration with DOST’s Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) to mitigate coastal risks in vulnerable areas of the province.
Dr. Arlene Gonzalez, the project leader, said the collaboration aims to enhance mangrove ecosystem resilience by implementing green engineering solutions in the project sites.
Among the challenges in mangrove restoration and mangrove plantation establishment, according to Dr. Gonzales, are poor hydrological conditions, which significantly hinder the growth of young propagules. Technology-assisted plantations can be key to successfully establishing mangrove areas even in challenging conditions. Various green technologies will be showcased by the project in the municipalities of Badoc and Currimao, Ilocos Norte.
“The mangrove ecosystem is vital for the environment and the livelihoods of many local communities, especially in the Ilocos region. Through (this project), we aim to restore and sustain this ecosystem, ultimately enhancing the resilience of the communities that rely on them,” said Noel A. Catibog, director of PCAARRD’s Technology Transfer and Promotion Division.
Diaz wrote of the collaboration: “Given the current climate change impacts, the project is both timely and relevant. It stands out among the many programs successfully implemented by MMSU in Ilocos Norte, aiming to serve as a model for other areas in the country.”
