By Migo Gonzalvo
Illustration by Kristi Seredica
Published 2020 December 26
Thelma in 1991, Pablo in 2012, Haiyan in 2013, Rolly in 2020—these are just some supertyphoons the Philippines has faced the last 3 decades; yet only the Filipino people seem to be getting credit for braving through them. Resiliency has always been tagged on the Filipino People’s capability to withstand up to 20 typhoons every year, however, many argue that this label has been excessively and inappropriately used—so let’s shift this resiliency tag onto something that has biologically adapted and evolved to be resilient against the country’s harsh weather—Mangroves.
Mangroves are one of those things that you know are good for the environment, but likely do not understand why—maybe you’re not even sure what they look like—I am the same way. However with the recent typhoons striking the Philippines and the potential of mangroves in protecting coastal areas, I had to finally figure out ‘what exactly are mangroves and what’s so special about them?’.
What are Mangroves?
Mangroves are defined as trees that grow along coastlines and in brackish water (where freshwater meets saltwater), specifically in intertidal zones . These are the areas below the beach forest and above sea grass/coral reefs. Most trees wilt and die here since saltwater is naturally desiccating. With this, they have to come up with unique saltwater adaptations. One saltwater adaptation is creating a barrier that filters out more than 90% of the salt from saltwater. The alternative saltwater adaptation is to expel the salt out of their system—allowing visible salt crystals to form on the surface of their leaves—yes, some mangroves have visibly salty leaves.
They also have to adapt to the loose and low-oxygen soil of intertidal zones—again making their habitat uninhabitable by most other species. The stereotypical mangroves most would imagine would have a web of roots lifting the trunk above water called prop roots, but there are other kinds such as the buttress roots, which resembles the diagonal structure used in architecture to support a wall, fitting as frontliners for storm-heavy coastal communities; knee roots, which grow up then down resembling a bent knee; and pneumatophores, which are roots that grow above water levels similar to a snorkel, perfect for areas with changing tides such as estuaries (where river meets sea).
These go to show just how unique, yet biodiverse this one group of trees actually is. In fact, out of the 80 species found in the world, about 38 are found in the Philippines, and out of the 38, five of them are near threatened while one is endangered.[1,2]
What makes them special
Mangrove forests play such a crucial role in the Philippine ecosystem. According to the Philippine Information Agency, they provide “breeding habitats for about 75% of fish species caught in the oceans”. This is crucial considering there are almost one million Filipinos involved in fishing, and that many species are already showing signs of overfishing.[6,7] To add to that, mangroves play a big role in reducing carbon in the atmosphere, the main contributor to global warming. Mangrove forests are considered as “Blue Carbon Ecosystems”, meaning that they are able to take in and store carbon even after they die—something to take note of as we are amidst a climate emergency.
They have adapted to our tropical and typhoon-stricken climate. Time and time again, they have proven to not only survive, but even dampen the effects of typhoons along coastal communities. One instance was in the town of Palompon, Leyte, where the locals credited the mangrove forest for reducing the impact of the storm surges brought by Haiyan in 2013. Mangroves do this through their complex root system. Their root system reduces the wave energy in the water, reducing erosion and increasing sedimentation—in other words their roots stabilize the soil effectively.  They have also been known to adapt to the rising sea levels by building up the soil through organic matter, or simply growing their roots.
They slow down climate change and adapt to its effects—talk about hitting two birds with one stone.
However, these are just general reasons to keep them around, if you look up specific species you would likely find other specific reasons to care for these trees. I was specifically intrigued by the Nypa fruticans, commonly known as Nipa or Sasa, a palm tree turned mangrove, which can produce higher yields of biofuel from its sap compared to other commonly used crops. [3,4]
Mangrove Rehabilitation in the Philippines
Unsurprisingly, the real reasons mangroves in the Philippines have decreased in number are because of harmful human activities coupled by lack of strict policies protecting them. Just this year land reclamation projects such as the 700-billion-peso New Manila Airport, which replaces numerous mangrove forests along the coastal areas of Bulacan, continue to be approved.
Luckily there are renowned scientists such as Dr. Jurgenne Primavera, a Time’s Heroes of the Environment for 2008, organizations such as Zoological Society of London (ZSL), and everyday volunteers who put their best efforts in rehabilitating Philippine mangrove forests (which have been reduced to as much as 50%). Dr. Primavera along with ZSL, create field guides that explicitly tell you what mangroves are best fit for your coastal community and how to grow them. Recently, one town in Cagayan, heavily flooded by Ulysses, planted 280 mangrove seedlings through the project #greenwallofalcala, in hopes of avoiding future floods. This is an example of conservation efforts based on research.
Although the tides have yet to settle, efforts are beginning to show fruit. Mangrove forests were mainly advertised and studied in Mindanao and Palawan only, but recent trends have started opening up mangrove forests as eco parks in Nasugbu, Bohol, and Panay (to name a few). Ecotourism projects such as these allow us to interact and appreciate mangroves without harming them. Not only are we seeing a rise in the number of the trees itself, we are also seeing a rise in appreciation for these trees—and a rise in appreciation for their overall functionality and resilience.
- US Department of Commerce, National Oceanic, Atmospheric Administration. What is a mangrove forest? 2009 [cited 2020 Nov 29]; Available from: https://oceanservice.noaa.gov/facts/mangroves.html
- List and status of Philippine mangrove species [Internet]. Mangroveecology.com. 2015 [cited 2020 Dec 8]. Available from: https://mangroveecology.com/resources/list-and-status-of-philippine-mangrove-species/
- Community-based Mangrove Rehabilitation Training Manual. Zoological Society of London – Philippines. Available from: https://www.zsl.org/sites/default/files/media/2015-06/Field%20Guide%20to%20Phil.%20Mangroves.pdf
- Malaysian company to produce ethanol from Nypa fruticans [Internet]. Mongabay.com. [cited 2020 Dec 8]. Available from: https://global.mongabay.com/news/bioenergy/2006/12/malaysian-company-to-produce-ethanol.html
- Mangroves [Internet]. Ocean.si.edu. [cited 2020 Dec 8]. Available from: https://ocean.si.edu/ocean-life/plants-algae/mangroves
- Conservation of mangrove diversity in ASEAN as climate action and boost to economy [Internet]. Gov.ph. [cited 2020 Dec 8]. Available from: https://pia.gov.ph/news/articles/1048648
- Philippine Fisheries Profile 2018. Bureau of Fisheries and Aquatic Resources. ISSN: 2704-4246. 2019. Available from: https://www.bfar.da.gov.ph/files/img/photos/FisheriesProfile2018forWeb.pdf
- Spalding M, McIvor A, Tonneijck FH, Tol S and van Eijk P. Mangroves for coastal defence. Guidelines for coastal managers & policy makers. Published by Wetlands International and The Nature Conservancy. 2014.
- Rehabilitating Mangroves in the Philippines [Internet]. Zsl.org. [cited 2020 Dec 8]. Available from: https://www.zsl.org/conservation/regions/asia/rehabilitating-mangroves-in-the-philippines
- Buitre M, Zhang H, Lin H. The mangrove forests change and impacts from tropical cyclones in the Philippines using time series satellite imagery. Remote Sens (Basel). 2019;11(6):688.
- Lozada D. A town saved by mangroves [Internet]. Rappler. 2014 [cited 2020 Dec 8]. Available from: https://www.rappler.com/moveph/palompon-leyte-mangroves-saved-lives-yolanda
- coastph. What are mangroves? [Internet]. Coast.ph. [cited 2020 Dec 8]. Available from: https://www.coast.ph/ccef-news/04/mangroves-a-link-between-the-land-and-the-sea/
- de Santos J. Taliptip: A long goodbye where the sea will soon meet the sky. The Philippine Star [Internet]. 2020 Oct 15 [cited 2020 Dec 13]; Available from: https://www.philstar.com/headlines/2020/10/14/2049252/taliptip-long-goodbye-where-sea-will-soon-meet-sky