Clare Duncan: Mangrove Conservation in the Philippines

Clare is an ecologist studying the world’s natural and restored mangrove forests, focused on the Philippines. To help answer big questions about climate change, Clare is normally knee deep in mud counting carbon and fiddler crabs. Roll up your sleeves and find out more, below.


Name: Clare Duncan

Habitat: Mangrove Forests

Location: Panay island, Philippines

Twitter: @whereisklara

I am an ecologist and currently a PhD Candidate between the Institute of Zoology (IoZ), Zoological Society of London (ZSL) and University College London (UCL). I am specifically interested in climate change impacts and mitigation. After completing my undergraduate degree, I undertook internships at a global carbon cutting initiative and then at the IoZ working on the Sampled Red List Index assessing the extinction risk of freshwater species, followed by a Research Assistant post at IoZ working to explore the impacts of future increases in extreme drought occurrence under potential climate scenarios on the viability of African ungulate populations.

I completed my Masters degree in Ecology, Evolution and Conservation from Imperial College, London in 2013, in which my thesis explored the species-specific and environmental factors controlling carnivore space-use globally.

Hi Clare, your current project is all about mangrove forests – so what are mangroves, and what makes them special?

Mangroves are tropical forests found at the interface between the land and sea, which experience frequent tidal inundation and are thus comprised of more saltwater-adapted tree and shrub species. Mangrove forests are extremely important ecosystems, providing a plethora of important services to people from local to global scales: they provide an important source of food, fuel and fibre, provide nursery habitat for economically important fish stocks, and are an important bulkhead against climate change by affording protection for coastal areas and communities from the impacts of storms, tidal waves and typhoons, as well as being among the most carbon-rich forests in the tropics.

Considering how important mangroves are, how are they faring around the world?

Despite the clear importance of mangroves, they are considered to be among the world’s most threatened biomes, with an estimated loss of 20-35% of their global distribution in the last two decades of the 20th century. The largest threat to mangroves currently is land conversion, particularly clearing for fish pond aquaculture in South-east Asia. However, mangrove ecosystems are also highly vulnerable to climate change processes such as increased intensity and frequency of extreme weather events (storms, typhoons) and sea level rise. In the face of these challenges, it becomes increasingly important to for us to improve our understanding of the factors and conditions shaping mangrove ecosystem health and functioning, in order to enable more effective management and conservation of these vital ecosystems into the future.

So what is being done?

In the past decades, significant effort has begun to be placed on mangrove protection, restoration and management across the world. In particular, many exciting and promising projects have focused on mangrove replanting and rehabilitation within their historical distribution. Since the early 2000s, ZSL has been implementing community-based mangrove replanting and rehabilitation activities across Panay island in the Philippines.

Unfortunately, following recent devastation of many areas during typhoon Yolanda (international name Haiyan) in 2013, it may be that some rehabilitated forests are not currently highly functional in terms of mitigating storm damage, which may be an indicator of low overall functionality. Part of my PhD focuses on examining the factors shaping the relative health and ecosystem services provision of various natural and rehabilitated mangroves across the island, in order to inform future rehabilitation efforts.


TOP: Traversing the waterways in a bamboo raft, or ‘balsa’. BOTTOM LEFT: A ghost crab in the intertidal zone.
" Since the early 2000s, ZSL has been implementing community-based mangrove replanting and rehabilitation activities across Panay island in the Philippines. "

Your fieldwork is centered on the Philippines, can you tell us about the area and what your fieldwork entails?

My field sites consist of natural and rehabilitated mangrove areas spread throughout the coastal zone in the provinces of Iloilo, Capiz and Aklan in Panay island, which I survey for mangrove community structure, carbon storage and higher biodiversity (fiddler crabs). The sites I am studying are very diverse in terms of their size, location and composition, comprising small natural and replanted seafront fringe mangroves, recolonized and replanted fishpond areas and extensive and diverse basin mangroves. It is fantastic to be able to experience and study such a vast array of different mangrove ecosystem types. And all of that means that day-to-day conditions of working at each site are highly variable.

Sadly, the Philippines has historically experienced a dramatic loss and fragmentation of mangrove areas – less than a fifth of their historical 500,000ha now remains – and there is a high density of people inhabiting most of the coastal zone. As a result, access to some small fringe mangrove sites can often be disturbingly easy, requiring simply a short walk from the local community hall. In other sites, ZSL, in partnership with other NGOs and local government units, have worked toward the construction of boardwalks or bamboo footwalks through some of the larger, less accessible ecopark sites. Other more extensive sites can require very long walks through fishpond mudbanks, or access by sea on small fishing vessels and a short swim.

Where I live when in the field depends on a combination of the availability of local accommodation and ease of travel (by local jeepney, tricycle and motorbike) and access to sites – working with the tides in mangrove ecosystems means that field and travel schedules have to be very tight. Places to stay can range from houses in local communities, a college dormitory, a ZSL staff house in Capiz province, to in one case a small seafront resort close by an ecopark site (definitely can’t complain about that one!). In all sites, we are fortunate enough to be fed by the excellent local cooking of community members (huge thanks to Nangs Che Che, Mary Beth, Amor, Precil and Pacit!)!

TOP: Replanted mangroves in front of a sea wall in Ermita, Dumangas. Local women behind are harvesting the high abundance of various small bivalves and gastropods.
" Plastic debris is not only unsightly and a threat to the marine system as a whole, but it, as well as occasional thick algal growths, can serve to weight down and push over mangrove seedlings and saplings."

Fieldwork in the Phillipines sounds idyllic, except perhaps for all the mud! What are your highlights?

One of the biggest highlights of working within the mangroves and local communities in Panay is the so very many diverse and wonderful people I have been fortunate enough to meet and work with along the way. The Filipino nation is renowned for the outstanding hospitality and good nature of its people, and I can definitely vouch for it! Members of all of the communities near the sites moreover show a tangible enthusiasm for mangrove ecology, protection and rehabilitation. The engagement of such great communities makes working in Panay even more exciting as a place where I believe that mangrove rehabilitation and conservation has a real chance at big success!

Another major highlight of working in Panay is getting the chance to work in the magnificent Katunggan-It-Ibajay (KII) mangrove ecopark site in Aklan province. This large and diverse ecopark, protected by local government and the two local communities inhabiting its fringes, contains 28 mangrove species (80% of all species found in the Philippines) and is home to some of the largest and oldest individuals of the globally threatened Avicennia rumphiana mangroves in the country. Mangroves are eerily beautiful ecosystems, and working in KII affords some rare and stunning sights, especially during stints of quietly observing the huge diversity of crab species in the area.

Working in this kind of habitat must come with difficulties too, what are the biggest challenges you face?

A challenge to working in Panay island can be language barriers. Across the four provinces of the island, four different regional dialects are spoken, and some of these dialects (for example Akeanon) are vastly distinct from the others and hard for even other locals to understand and speak. A language barrier can be tough, and not fully understanding your research team can make working in these complex environments quite challenging. Taking time to learn at least a reasonable level of the most prevalent dialect or working with at least one team member capable of translation is really important in these cases.

Another challenge can be witnessing on-going conservation issues first hand. While in the field last year, we witnessed some significant cutting of large Rhizophora mucronata trees at one of the sites (in fact within one of my original study plots!), which were being felled to gather fertile substrate for a fishpond being constructed a little further inland. Witnessing this kind of direct threat to the health of your study site and system in motion can be disheartening. However, information-sharing and re-discussion with relevant community members and local government offices of the existence and impacts of these kinds of activities has now resulted in renewed fervour to enforce extraction rules within the area.


TOP LEFT: Me inside the branches of a centuries-old Avicennia rumphiana tree in Katunggan-It-Ibajay ecopark, Aklan. TOP RIGHT: The extensive prop roots of a Rhizophora mucronata tree and a carpet of Avicennia marina pneumatophores. BOTTOM: Cutting a soil core for carbon content and bulk density analysis.

Lastly, what advice can you offer anyone interested in mangrove forest science!?

1) The Tide! The absolute number one rule of working in mangrove forests is that your entire working schedule for each day must be timed perfectly to the day’s tide. A good understanding of the range of surface elevation of your site and inundation depths at different tidal levels, as well as a good hourly tidal calendar, is essential to avoid ruining a day’s surveying or putting the team at risk.

2) As any marine biologist or fisher folk will tell you, saltwater can wreak serious havoc on metal components of equipment. For soil sampling work, repeated exposure can seriously rust coring equipment, and essential parts of other mechanical and electronic equipment can similarly corrode, and your (or others’ – sorry, Trent!) equipment can stop working. A back up plan is really important in these cases.

3) Keeping safe from the elements. Mangrove species are fantastically adapted to their brackish, intertidal environment, but some of these unique adaptations can provide some (very painful!) obstructions to moving around inside mangrove forests. Particularly when working in very dense areas, prop roots (or stilt roots; extensive structures that help support the stems of some mangrove species) and pneumatophores (upward growing roots which serve to help some mangrove species intake oxygen), which can sometimes be coated in very sharp bivalves, can cause quite bad cuts and infection can be rapid to onset in these muddy, hot and humid environments. Long sleeves and trousers are an absolute must, despite the heat! This can definitely be learned the hard way!

4) Take a little time for clean-up as your work. The level of plastic debris in the world’s oceans is alarming, and the high structural complexity of mangrove roots and stems means that a lot of it ends up getting stuck inside mangroves. Plastic debris is not only unsightly and a threat to the marine system as a whole, but it, as well as occasional thick algal growths, can serve to weight down and push over mangrove seedlings and saplings. This can result in increased mortality in rehabilitated areas, as well as for natural mangrove recruits. Removing these hazards is quick work, and can easily be done simultaneously while surveying and sampling is being conducted.

5) Share your research. Mangroves have historically been understudied and underappreciated by comparison with other tropical ecosystems, and as a result local community and government scientific knowledge of them can sometimes be lacking. Ensuring that you take opportunities to discuss what you are up to with local community members will serve to increase awareness, and sharing your findings with communities and local government units ensures that important knowledge can inform relevant future local policy.

Thanks Clare, and good luck!

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