Bea Gatmaytan of MindaNews and David Ezra Francisquete of SunStar Davao
MATI CITY (MindaNews / 01 May) — Rows of mangrove seedlings line parts of Guang-Guang Mangrove Park and Nursery — a protected landscape and seascape area in Pujada Bay. But not all of them take root: some wither under the heat and other climate problems, while others fail to grow at all despite repeated mass planting efforts.
In the coastal community of Sitio Guang-Guang, Barangay Dahican, an estimated 20 hectares of mangroves (Rhizophora mangle) are seen as a frontline defense againstclimate change.
Yet across many coastal areas, survival rates have raised questions about how these efforts are being carried out.
Amid storm surges and typhoons, the failure of these planting efforts shows that planting mangroves alone is not enough.
Across the park, mangrove rehabilitation has been ongoing for years with millions of seedlings introduced through various programs. Since 2020, Mama Earth Foundation — a non-government organization (NGO) dedicated to restoring mangroves in Mati — has planted five million seedlings, with an estimated survival rate of 70 to 80 percent, according to Amy Ponce, Director of the Regional Integrated Coastal Resource Management Center of Davao Oriental State University (DOrSU).
This leaves a 20 to 30 percent portion that does not survive.
Experts underscore the fundamental issue that not all mangroves can grow everywhere.
“Especially when you are not in science, the concept of, ‘pag magtanim tayo ng kahoy (if we plant trees) is always good,’ but it’s not actually, (because) when you introduce certain species on a certain area, may mga alteration ‘yan (there will be alterations in ecology) … you really need to formulate with experts before you do that,” she said.
As Ponce underscores, mangrove ecosystems depend on precise environmental conditions: soil type, tidal patterns, and wave exposure all determine which species can survive in a given area. Guang-Guang alone contains multiple ecological zones — from mudflats to sand flats — each suited to different mangrove species.
Environmental studies show how mangrove forests are structured by clear zonation patterns driven by tidal elevation, salinity, and flooding frequency, where each species occupies a narrow ecological band shaped by its tolerance to environmental stress. The study shows that even slight changes in surface elevation or hydroperiod can determine whether a mangrove species thrives, survives marginally, or fails entirely — reinforcing the idea that mangrove distribution is tightly controlled by coastal physical conditions.
Costly mistake
Improper planting also affects more than just the mangroves themselves. According to Wetlands International, planting mangroves in mudflats can disrupt the entire ecosystem: open mudflat areas serve as feeding and roosting grounds for migrating bird species, and as key actors in maintaining a coastal sediment balance. Covering these areas with mangroves would deprive these birds of their natural feeding grounds, and alter hydrodynamics — leading to increased erosion elsewhere.
“Seagrass meadows and mudflats have their own ecosystems,” Annabel Cabanban, Country Manager of Wetlands International Philippines, said in an October 2025 article on why planting mangroves in mudflats is a costly mistake. “When you plant mangroves on non-mangrove areas, the mangroves will either die or destroy the entire ecosystem,” she said.
Despite this, however, large-scale planting efforts continue, often driven by campaigns or events with little to no ecological planning. In some cases, according to Ponce, mangroves were planted during the pandemic without proper site matching, leading to damaged or destroyed growth.
The result is a repeated cycle of planting and replanting that does not address the underlying mismatch between species and site.
On the other hand, when science does guide intervention, signs of recovery become clear. In areas where mangrove growth has been properly managed, water quality has improved and juvenile fish populations have increased, according to Ponce.
Experts emphasize that, more than planting a target number of seedlings, successful restoration also requires site assessments, species matching, and long-term monitoring — approaches aligned with ecological mangrove restoration practices. Ponce reiterated that establishing baseline data grounded in sound scientific evidence is essential.
Extreme heat, limited water supply
Extreme heat and limited water supply have dealt a major blow to mangrove rehabilitation efforts in Mati City, leaving most seedlings unfit for planting, Jeomar Senagan, head of the Fisheries Division of the Bureau of Fisheries and Aquatic Resources (BFAR-Mati) said.
Senagan cited prolonged exposure to high temperatures as a key factor.
He recalled that during the first quarter of 2025, only about 10% of the 5,000 Bakhaw (red mangrove) seedlings — equivalent to roughly 500 — survived.
“Naa mi mga stock ng mga seedlings diria, mga 5,000. Atoa ning gina-maintain og dilig unya naabtan pud siya’g guwang sa straight nga init, nangamatay sila (We have a stock of about 5,000 seedlings here. We keep them watered [but] when exposed to direct heat, they die),” Senagan said.
The seedlings were grown for coastal planting, particularly in Guang-Guang Mangrove Park. The remaining stock was set for planting in June.
Improper planting practices also affect coastal communities. Because mangrove forests serve as nurseries for fish, crustaceans, and other marine life, they also support coastal livelihoods — showing how environmental issues are also human issues.
Genieve Monares, 52, of Purok Dapila in Brgy. Dahican began fishing in Pujada Bay in 1993, when fish catch was abundant and mangrove ecosystems were still healthy and stable. She recalled that, past human activities — particularly the “culturization” of coastal resources, such as illegal mangrove cutting and shrimp aquaculture expansion — contributed to environmental disturbance.
Monares noted that mangrove areas are sometimes converted into shrimp ponds, which can undermine conservation efforts.
“Siguro dili malikayan na i-culturized ang product ba, parehas anang mahimo og punong ba,” she said.
According to Ponce, illegal logging was once a major issue in the area due to plans to set up shrimp farms.
“Ngayon na-resolve na ang issue,” said Ponce. “Hindi nag-stop ang shrimp farm but nag-stop lang yung cutting nila — [clearing] the mangroves.” While the shrimp farm plan was carried out, it was done in a way that did not affect the mangroves in the coastal ecosystem.
“Some of the areas, na hindi talaga pwede ang shrimp farm na binuo nila, tinaniman natin ng mga mangroves,” Ponce continued, explaining how areas off-limits to the shrimp farm were since covered with mangroves — properly, and with appropriate scientific assessments.
Rising temperatures and increasing environmental pressures continue to show how mangroves become a critical line of defense for coastal communities. However, their effectiveness depends on how their restoration is carried out.
In tree planting efforts, the assumption of “the more, the merrier” may lead to unintended impacts on the very ecosystems meant to be protected. (Bea Gatmaytan of MindaNews and David Ezra Francisquete of SunStar Davao)
[This story was produced during the Climate Impact and Environment Reporting Workshop for Journalists in Mindanao on April 24 to 27 in Mati City, Davao Oriental. It was organized by the Mindanao Institute of Journalism, publisher of MindaNews, under the Media Impact Philippines project. Media Impact is supported by International Media Support (IMS) and co-funded by the European Union and the Danish International Development Agency (DANIDA)]
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