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THE storm surge that devastated villages in Irrawaddy
at the height of cyclone Nargis would have been less destructive if
there were mangroves in the estuaries and mudflats of the delta.
Mangroves are among the best
natural defense of sheltered coastlines against wind and water
during storms. This is one of the lessons of the tragedy in Myanmar
that we should not overlook.
There were, at one time,
according to the World Mangrove Atlas (International Society for
Mangrove Ecosystems, Okinawa, Japan, 1997), more than 200,000 square
kilometers of mangrove forests in tropical and subtropical
coastlines all over the world. They have been disappearing at the
rate of one percent to 2 percent a year or at about the same rate as
the disappearance of coral reefs and rainforests. The rate of loss
is faster in developing countries where in the last 25 years 35
percent to 86 percent of mangrove forests have been destroyed,
according to the Food and Agriculture Organization (FAO) of the
United Nations.
In the Philippines, the rate of
destruction, extrapolated from international data sources, is
between 40 percent and 45 percent in the last 10 years. Mangrove
areas in Bulacan, Davao, Palawan, the two Mindoros, Bohol, Samar and
Zamboanga have shrunk, putting their long-term survival at risk. If
this rate of loss is not reversed, we would have no mangrove stands
by the middle of the century.
Mangrove destruction is due
mainly to human settlement and aquaculture but as the pace of
urbanization quickens, reclamation and pollution will begin to take
their toll.
Mangrove forests are ecosystems
that sustain unique plant and animal species, many of which we still
have to discover and study. It’s possible that many of them have
become extinct with unforeseen effects on fragile mangrove ecology.
Loss of functional diversity is particularly serious because
mangrove ecosystems are species-poor. The FAO reports that in 26 of
120 countries, mangroves are critically endangered or fast becoming
extinct. (“Status and trends in mangrove area extent worldwide,”
FAO, 2003).
What are the known consequences
of mangrove deforestation?
Mangrove ecosystems are an
integral part of terrestrial and marine food webs. Their destruction
will have an immediate effect on fishery productivity.
Mangroves also protect seaweed
beds and coral reefs against river-borne silts and serve as breeding
ground of certain species of fish that thrive in brackish water.
They also maintain salt marshes
as filters of industrial and household wastes.
Certain species of mangrove are
sources of fibers, chemicals and medicine. Palawan mangroves, for
example, are raw materials for Japan’s chemical industries.
Mangrove forests function both as
an atmospheric CO2 sink and a source of ocean carbon. They are
important in the effort to slow down global warming. (E. McLeod and
R.V. Salm, Managing Mangroves for Resilience to Climate Change, IUCN,
2006)
Finally, as said earlier,
mangrove forests protect human settlements near coastlines from
rising seas, storm surges and tsunamis. Myanmar, Thailand, Indonesia
and India are object lessons.
In light of all this, there’s
an urgent need to conserve, protect and renew the mangrove trees and
shrubs in sheltered coastlines and tidal wetlands. The endemic
species—Rhizophora mangle, Avicenna nitida, and the Sonneratia
varieties —are relatively easy to propagate.
Effective and enforceable
policies and education strategies have to be implemented right away
to reverse the loss of mangrove forests.
The Department of Agriculture,
the Department of Environment and Natural Resources and UP Los Baños
should lose no time in putting together a plan to save and to expand
the mangrove forests of the Philippines.
opinion@manilatimes.net.
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