STOP SEAFRONT PLANTING OF MANGROVES ON SEAGRASS BEDS
J.H. Primavera, Ph.D.
Among others, Typhoon Yolanda in 2013 and the 2004 Indian
Ocean tsunami have highlighted the importance of mangroves in coastal
protection. Of global storm events, the Philippines has the greatest intensity
(maximum score of 5 on the Saifir-Simpson Hurricane Intensity Scale) and number
(one-third). Mangroves have therefore captured the public imagination –
student, NGO, government, religious and business groups plant mangroves
themselves or raise money for others to plant. Even the national government
planned to allocate PhP1 billion for mangrove rehabilitation in Yolanda sites.
Such massive amounts of taxpayers’ and private funds beg the question: Are the planting
protocols science-based?
Ocean tsunami have highlighted the importance of mangroves in coastal
protection. Of global storm events, the Philippines has the greatest intensity
(maximum score of 5 on the Saifir-Simpson Hurricane Intensity Scale) and number
(one-third). Mangroves have therefore captured the public imagination –
student, NGO, government, religious and business groups plant mangroves
themselves or raise money for others to plant. Even the national government
planned to allocate PhP1 billion for mangrove rehabilitation in Yolanda sites.
Such massive amounts of taxpayers’ and private funds beg the question: Are the planting
protocols science-based?
Mangroves are uniquely adapted to withstand harsh conditions
of salty water and tidal inundation – but not more than 30% of the time. Hence
mangroves are not uniformly distributed between high and low tide, but are
found in the middle to upper intertidal levels (at or above mean sea level)
where they remain mostly exposed.
of salty water and tidal inundation – but not more than 30% of the time. Hence
mangroves are not uniformly distributed between high and low tide, but are
found in the middle to upper intertidal levels (at or above mean sea level)
where they remain mostly exposed.
 |
| Fig. 1: Intertidal location of mangroves and recommended planting zones (©J.H. Primavera). |
The 35-40 Philippine mangrove
species are adaped to different substrates (sand, mud), salinity (full
seawater, brackish water), but mainly to water level which determines how much
flooding they can tolerate. Therefore most open seafronts are dominated by
pagatpat Sonneratia alba and piapi Avicennia marina (Fig. 2) whose extensive lateral/cable
roots firmly anchor the tree belowground. Bakhaw Rhizophora, whose aboveground prop/stilt
roots cannot withstand strong wave/wind action, either hide behind the
pagatpat-piapi zone, or line inner tidal rivers and creeks.
species are adaped to different substrates (sand, mud), salinity (full
seawater, brackish water), but mainly to water level which determines how much
flooding they can tolerate. Therefore most open seafronts are dominated by
pagatpat Sonneratia alba and piapi Avicennia marina (Fig. 2) whose extensive lateral/cable
roots firmly anchor the tree belowground. Bakhaw Rhizophora, whose aboveground prop/stilt
roots cannot withstand strong wave/wind action, either hide behind the
pagatpat-piapi zone, or line inner tidal rivers and creeks.
 |
| Fig. 2: Three common mangroves in the Philippines (collage by J.H. Primavera) |
So most bakhaw planted along the seafront are the WRONG
SPECIES IN THE WRONG SITES, as the scientific community has pointed out since
the 1990s. Yet large Rhizophora propagules (or Tusok d Tongki, Cebuano for
“sticking the propagules”) are favored over piapi/pagatpat whose small seeds require
a nursery phase – Planting by Convenience, not by Ecology. This misguided
preference for bakhaw is seen in logos, posters and t-shirts that prominently
feature iconic bakhaw prop roots instead of pencil-/cone-shaped pneumatophores
(arising from lateral roots) of piapi/pagatpat.
SPECIES IN THE WRONG SITES, as the scientific community has pointed out since
the 1990s. Yet large Rhizophora propagules (or Tusok d Tongki, Cebuano for
“sticking the propagules”) are favored over piapi/pagatpat whose small seeds require
a nursery phase – Planting by Convenience, not by Ecology. This misguided
preference for bakhaw is seen in logos, posters and t-shirts that prominently
feature iconic bakhaw prop roots instead of pencil-/cone-shaped pneumatophores
(arising from lateral roots) of piapi/pagatpat.
Worse, the practice of seagrass planting continues to this
day. In 2003, the Philippine Association of Marine Science called on the
Department of Environment and Natural Resources to stop planting on seagrasses,
a call repeated and disseminated to DENR field staff in 2005 and 2007. Yet 10
years later, seagrass beds in Cordova, Cebu were again planted to bakhaw (Fig.
3) financed by Oil Spill funds. According to National Scientist Edgardo Gomez,
(some) foresters argue that If grasses can be planted to forests, likewise
seagrasses can become mangroves, a well-meaning but unscientific
transformation. Current mangrove programs also prefer to reforest the
ecologically difficult but low- to no-conflict, open access seafront. It should
prioritize the biophysically easier but sociopolitically challenging reversion
of abandoned ponds, where mangroves used to thrive.
day. In 2003, the Philippine Association of Marine Science called on the
Department of Environment and Natural Resources to stop planting on seagrasses,
a call repeated and disseminated to DENR field staff in 2005 and 2007. Yet 10
years later, seagrass beds in Cordova, Cebu were again planted to bakhaw (Fig.
3) financed by Oil Spill funds. According to National Scientist Edgardo Gomez,
(some) foresters argue that If grasses can be planted to forests, likewise
seagrasses can become mangroves, a well-meaning but unscientific
transformation. Current mangrove programs also prefer to reforest the
ecologically difficult but low- to no-conflict, open access seafront. It should
prioritize the biophysically easier but sociopolitically challenging reversion
of abandoned ponds, where mangroves used to thrive.
 |
| Fig. 3: Common seagrass planting along seafront, e.g., seagrass beds in a) Divilacan, Isabela (Cagayan Valley Environment Update, 2014) and d) Cordova, Cebu (photo by R.B. Sadaba) has mostly high mortality in b) Iloilo and c) Palawan. |
A more worrisome practice has emerged – the Tongki
Protocols, by which money is siphoned off reforestation budgets by unscrupulous
parties. To switch from easy-to-source and easy-to-plant bakhaw to
nursery-reared piapi/pagatpat will affect the modus operandi (and flow of
money). Moreover, many mangrove programs are driven by Guinness and/or photo
ops. In 2012, around 7,000 volunteers planted one million mangrove propagules
in El Verde, Camarines Sur, targetting the Guinness Book of Records. Another
million mangrove planting event in Quezon province was named 2014 Galing Pook
awardee. Nothing wrong with planting in the morning, posting Facebook photos in
the evening, and print/TV media coverage the next day so long as planting is
science-based. Unfortunately, the focus on initial planting forgets the
endproduct – the mature forest. Like graduation ceremonies, tree planting is
only the commencement, yet media rarely report, if at all, the massive
mortalities of failed plantings.
Protocols, by which money is siphoned off reforestation budgets by unscrupulous
parties. To switch from easy-to-source and easy-to-plant bakhaw to
nursery-reared piapi/pagatpat will affect the modus operandi (and flow of
money). Moreover, many mangrove programs are driven by Guinness and/or photo
ops. In 2012, around 7,000 volunteers planted one million mangrove propagules
in El Verde, Camarines Sur, targetting the Guinness Book of Records. Another
million mangrove planting event in Quezon province was named 2014 Galing Pook
awardee. Nothing wrong with planting in the morning, posting Facebook photos in
the evening, and print/TV media coverage the next day so long as planting is
science-based. Unfortunately, the focus on initial planting forgets the
endproduct – the mature forest. Like graduation ceremonies, tree planting is
only the commencement, yet media rarely report, if at all, the massive
mortalities of failed plantings.
Tracking down mangrove survival rates in Camarines Sur via
dozens of text/email exchanges with local officials has been fruitless.
Reluctance to share bakhaw monitoring data suggests high mortality rates. Not
surprisingly the National Greening Program and other projects define reforestation
success as the % of target area or number of seedlings actually planted, rather
than survival rates (which remain unreported). Yet mangroves and other trees
are living beings whose measures of success are growth and survival.
dozens of text/email exchanges with local officials has been fruitless.
Reluctance to share bakhaw monitoring data suggests high mortality rates. Not
surprisingly the National Greening Program and other projects define reforestation
success as the % of target area or number of seedlings actually planted, rather
than survival rates (which remain unreported). Yet mangroves and other trees
are living beings whose measures of success are growth and survival.
Moreover, such commonplace mortality has led to the dubious
but profitable practice of replacement planting, with payment based on number
planted. The more plants that die, the more are replaced and, expectedly, the
more money is paid. In contrast, No Pay Planting is promoted by the Zoological
Society of London, an Iloilo-based NGO, on the premise that labor contributed
by fisherfolk entitles them to mangrove ownership. Instead, the ZSL
Community-based Mangrove Rehabilitation Project assists communities in applying
for tenure, e.g., the Community-Based Mangrove Forest Management Agreement. As
owners and de facto managers, coastal folk are obligated to nurture the
mangroves to maturity.
but profitable practice of replacement planting, with payment based on number
planted. The more plants that die, the more are replaced and, expectedly, the
more money is paid. In contrast, No Pay Planting is promoted by the Zoological
Society of London, an Iloilo-based NGO, on the premise that labor contributed
by fisherfolk entitles them to mangrove ownership. Instead, the ZSL
Community-based Mangrove Rehabilitation Project assists communities in applying
for tenure, e.g., the Community-Based Mangrove Forest Management Agreement. As
owners and de facto managers, coastal folk are obligated to nurture the
mangroves to maturity.
Even when successful, bakhaw plantings on seagrass beds are
one ecosystem’s gain and another’s loss. Conversion to mangrove forests will
deprive mudflats and seagrass fauna, e.g., danggit (rabbitfish), dugong, crabs
and birds of their habitats. At the least, white sand substrates turn dark
muddy-sand. Interestingly, Philippine mangrove area increased from only
~140,000 ha in 1987-88 to ~250,000 ha in 2003. How many of over 100,000
hectares of new mangroves are former seagrass beds? The DENR and other agencies
must account for such conversions, e.g., in Molacaboc, Negros Occidental and
Olango, Cebu.
one ecosystem’s gain and another’s loss. Conversion to mangrove forests will
deprive mudflats and seagrass fauna, e.g., danggit (rabbitfish), dugong, crabs
and birds of their habitats. At the least, white sand substrates turn dark
muddy-sand. Interestingly, Philippine mangrove area increased from only
~140,000 ha in 1987-88 to ~250,000 ha in 2003. How many of over 100,000
hectares of new mangroves are former seagrass beds? The DENR and other agencies
must account for such conversions, e.g., in Molacaboc, Negros Occidental and
Olango, Cebu.
To all Mangrove Planters/Conservationists: 1) Do not plant
bakhaw on seagrass beds and mudflats; 2) Plant pagatpat/piapi in the
middle-upper intertidal; and 3) Government agencies should report % surviving
mangroves rather than % of target seedlings/area planted.
bakhaw on seagrass beds and mudflats; 2) Plant pagatpat/piapi in the
middle-upper intertidal; and 3) Government agencies should report % surviving
mangroves rather than % of target seedlings/area planted.
J.H. Primavera is Chief Mangrove Scientific Advisor of the
Zoological Society of London, co-Chair of the IUCN Mangrove Specialist Group,
Scientist Emerita of the SEAFDEC Aquaculture Department, and Pew Fellow in
Marine Conservation. She will cover mangrove reversion of abandoned ponds in asequel.
Zoological Society of London, co-Chair of the IUCN Mangrove Specialist Group,
Scientist Emerita of the SEAFDEC Aquaculture Department, and Pew Fellow in
Marine Conservation. She will cover mangrove reversion of abandoned ponds in asequel.