Africa: The huge value
of mangroves for communities
Africa is richly endowed with
mangroves, which cover over 3.2 million hectares, extending from
Mauritania to Angola on the Atlantic coast and from Somalia to
South Africa along the Indian Ocean.
Mangrove forests have a huge
value for coastal communities that derive their livelihoods from
them. Although commonly defined as “poor”
in official statistics, communities living in healthy mangrove
areas have what many urban people lack: diverse and abundant food.
Mangroves provide for many of their needs, usually complemented
with other productive activities such as farming, poultry, bee-farming
and so on. Mangrove wood is a multi-purpose resource for fish stakes,
fish traps, boat building, boat paddles, yam stakes, fencing, carvings,
building timber, fuel and many other uses.
The Rufiji River Delta mangroves
provide a good example on the above. Located in southern Tanzania,
it is the largest delta in Eastern Africa and contains the largest
estuarine mangrove forest on the eastern seaboard of the African
continent. The Delta region is home to over thirty thousand people
who live, farm and fish in its fertile agricultural lands and
rich fishing grounds. The latter produce over 80 per cent of
Tanzania's prawn exports with the entire catch being wild prawns.
The importance of mangroves
for local communities becomes even clearer when they are degraded
or disappear. In the case of Senegal, oysters, shrimp, tilapia,
barracuda and catfish are among the many fish species that live
in Casamance’s mangrove forests, but now, as a result of
mangrove degradation
"you can only find big fish, as well as shrimps and oysters,
but you can no longer find catfish or other varieties, while there
used to be plenty."
The depletion of fish stocks
has particularly affected women who sell fish in bulk: "Women
are closely involved in the fishing economy in this region. We
sell fish, shrimp and oysters in the market and can earn up to
US$20 a day from this, which greatly benefits our families. Now
it is difficult for fish-sellers in Ziguinchor markets to earn
even US$4 a day because there is so little fish left to sell."
The disappearance of mangroves
harms other crops as well. Fewer mangroves means increased salt
content of the water, which impedes the growth of paddy rice. "When
we plant the rice now, it doesn't grow because there is so much
salt in the water."
Regarding biodiversity, mangrove
forests have few tree species to show (6 to 10), which may lead
people to think that they are biodiversity-poor. In fact, they
are exactly the opposite: mangroves are an irreplaceable and
unique ecosystem, hosting incredible biodiversity and ranking
among the most productive ecosystems in the world. The aerial
roots of their trees form a complex web, hosting a multitude
of animal species (fish, molluscs, crustaceans) and they operate
as zones for mating, refuges and nursery areas for a large number
of other species. The enormous quantities of fish and invertebrates
that live in these coastal waters, provide an abundance of food
for monkeys, turtles, and aquatic birds and they serve as an
important migratory point for many birds.
Many species of animals use
the Baly Bay’s 7200 hectares of mangroves as nesting, roosting
and feeding areas. Located to the West coast of Madagascar, the
bay’ mangroves constitute an important habitat for crab
and shrimp species.
By some estimates, over 60%
of fishes caught between the Gulf of Guinea and Angola breed
in the mangrove belt of the Niger Delta. Mangroves have been
sustainably managed by the many generations of communities living
there. Sustainable use has been possible because of their profound
knowledge about this ecosystem, passed on from generation to
generation.
However, a number of changes
have taken place over the last few decades that have resulted
in mangrove destruction or degradation in many countries. Two
different processes (frequently related) affecting mangroves
can be observed: total destruction or degradation.
In some cases their total destruction
may be due to urbanization, large-scale tourism undertakings,
rice production or their eradication to give way to commercial
shrimp farming. According to the FAO, Africa has lost about 500,000
hectares of mangroves over the last 25 years.
In other cases, partial deforestation
is further aggravated by mangrove degradation
– where most trees may remain standing – due to activities
such as oil exploitation or mining. That is to say, the installation
of pipelines, seismic exploration and open cast mines cause deforestation;
while oil-spills, gas flaring and waste dumping pollute the water
and the air and seriously degrade the ecosystem as a whole. Another
important cause of “invisible” degradation is the use
of agro-toxics in nearby agricultural production, where toxic chemicals
end up in this ecosystem, thus resulting in severe impacts on mangrove
biodiversity and peoples’
livelihoods.
In terms of degradation, major
oil spills have occurred that have devastated rivers, killed
mangroves and coastal life and affected the health and livelihoods
of millions of inhabitants. Although this has happened in several
countries in both Eastern and Western Africa, the case of the
Niger Delta is probably the worst. As denounced by Amnesty International,
the local communities living there rely on “the land and
natural waterways for their livelihood and sustenance. Now, they
have to drink, cook with and wash in polluted water and eat fish
contaminated with toxins. They have lost farming land and their
incomes from oil spills and breathe air that reeks of oil, gas
and other pollutants.”
A further form of mangrove
degradation results from overexploitation of its resources –both
the trees themselves or the fish and other aquatic life forms
that live there. In Africa, excessive mangrove wood extraction
has been linked to fish smoking, building materials, fuelwood
and charcoal production.
Within that context, efforts
should be made to ensure sustainable use of existing mangroves,
to restore degraded areas and to replant mangrove forests whenever
possible and viable.
For the above to be possible,
the necessary starting point is to identify and address all the
direct and underlying causes of mangrove loss and degradation.
In this respect, it is important to note that while most of the
former have already been identified, the underlying causes are
still a matter of debate that needs to be studied much further.
Such analysis is fundamental in order to avoid the easy solution
of putting the blame on “poverty” or “population
growth”, while obscuring the role of governments, international
institutions and corporations in mangrove loss and degradation.
While existing problems are
addressed, it would be wise to prevent the development of new
ones. In this respect, policies should be adopted and implemented
to stop the expansion of unsustainable industrial shrimp farming,
which is now looking at Africa’s mangrove areas as a new
business opportunity to be exploited with little regard to the
ecosystem. The negative social and environmental impacts of this
activity are already well documented in all the countries where
it has established itself, particularly in Latin America and
Asia. The result, in country after country, is that industrial
shrimp farming destroys mangroves, biodiversity and local peoples’
livelihoods. The impacts of the few existing cases of industrial
shrimp farming in Africa should also serve as a basis for convincing
governments on this issue.
African mangroves should be
allowed to continue to play the role they have traditionally
played: to ensure local peoples’ livelihoods through the
conservation and wise use of their rich biodiversity.
Summarized version of “African
mangroves: their importance for people and biodiversity”,
by Ricardo Carrere, editorial of “The relevance of mangrove
forests to African fisheries, wildlife and water resources”,
Nature
& Faune Volume 24, Issue 1. The full article with footnotes,
quoted sources and references is available at ftp://ftp.fao.org/docrep/fao/012/ak995e/ak995e00.pdf
