index

MANGROVES: AN OVERVIEW

The following section contains a number of articles describing both the mangrove ecosystem (including the important social and environmental services it provides), as well as the main problems it is facing. We hope that this will provide readers with the necessary information to understand why so many people are fighting to protect this ecosystem and to encourage them to get involved in this struggle.

Mangroves and their uncertain future

Mangroves are the coastal equivalent of tropical forests on land. There are various types of mangroves: coastal mangroves, growing without the input of fresh water from inland and that can extend for various kilometres, mangroves growing mainly at the mouths of rivers or deltas, that may be very extensive, and coral reef mangroves that grow on coral reefs above sea level. But they all have something in common, they are very special, fragile and endangered "salt water forests".

Mangroves are characterised by the woven maze of trees and roots, that are in fact an orderly forest mass, growing in bands according to their differing degree of resistance to periodic flooding by tides and therefore, to salt.

They grow on protected river estuaries and banks in equatorial, tropical and subtropical coastal zones, adapted to tide flow. At high tide, their canopy is barely apparent above the water. At low tide, their respiratory roots are visible, capturing oxygen and transmitting it to the buried roots. This adaptation enables them to survive in soils without oxygen and with a high saline concentration, their leaves also adapt to the scarcity of fresh water and are able to eliminate excess salt.

Mangroves are an irreplaceable and unique ecosystem, hosting incredible biodiversity and among the most productive ecosystems in the world. They house a wide variety of life: migratory birds, marine creatures and reptiles in addition to associated species of flora.

In spite of the fact that at world level there are some twenty species of mangroves, the basic structure of individual mangroves is usually formed by between 3 and 8 species. A wide variety of representatives of the plant kingdom live on them, over 100 fungus, and under them, up to 70 aquatic plants.

The aerial roots of their trees form a 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 species, many of them of importance as human food, which has made it possible for populations to settle around them, having their subsistence in resources generated by this ecosystem. Herons, cormorants, eagles and kingfishers find their source of food in mangroves.

When the tide goes down, some mammals approach the beach to eat, such as the wild boar and shrimp-eating monkeys. In the canopy, other primates feed on mangrove leaves and they shelter iguanas, parrots, doves and waders such as spoonbills, ibis, etc. that return to the canopy every night to roost.

Mangroves, in addition to protecting the coasts from erosion caused by hurricanes that periodically scourge these tropical zones, have, for many centuries, provided a multitude of resources to the local population. The most common uses of mangroves and their ecosystems are extraction of firewood, material for housing, and more importantly, fishing and harvesting of sea products, including many crustaceans.

However, thousands of kilometres from this unique ecosystem, so rich in biodiversity, at the tables of the European countries, Japan and the United States, we find the origin of the progressive loss of this balance: consumption of shrimps grown in ponds by the shrimp industry. This consumption has risen over the past years and thousands of hectares of mangroves have been transformed into breeding ponds, where created economic interest is very strong.

The shrimp industry benefits from mangrove conditions to breed shrimps, converting into "ponds" millions of hectares of fundamental habitats for local economies and for biodiversity. Thanks to the support of governments and grants from bodies such as the World Bank and with the support of FAO, today shrimp industries are increasingly being installed in tropical countries.

This activity has disturbed the population living off these ecosystems. Mangroves do not produce enough to support extractive activities by artisan fishers and at the same time the shrimp industry that is considerably undermining the ecosystem's capacity for production, in most cases, degrading it in an irreversible way. One single company competes with the resources providing subsistence to a population. Over the years, the shrimp ponds drown in their own contamination, and are subsequently abandoned leaving a destroyed ecosystem and local communities impoverished to extreme limits. (WRM Bulletin Nº 51, October 2001).

  top

Mangroves are life, long live mangroves

At present, mangrove forests cover an area of 181,000 km2, distributed in over 100 countries, but during the past 50 years, over 50% have been lost. Some direct activities are destroying mangroves or are degrading them, including substitution by other activities such as shrimp farming and agriculture, forestry, salt extraction, urban development, tourist development and infrastructure. Furthermore, other impacts include deviation of river water and contamination, caused by heavy metals, oil spills, pesticides and other products.

The establishment of shrimp farms has been the main cause of mangrove loss in many countries over the past 30 years. In Vietnam, a total of 102,000 hectares were converted to aquaculture between 1983 and 1987; in Honduras between 1986 and 1994, over 12,000 hectares were destroyed for the construction of shrimp ponds; in Ecuador over 180,000 hectares of shrimp ponds were built in mangrove areas; in Thailand, between 1961 and 1993, over 80,000 hectares of mangroves were destroyed to turn them into shrimp breeding ponds.

This loss of mangroves in the tropics has been facilitated on a major scale by international financial support, mainly provided by the World Bank and the Asian Development Bank. The International Financial Corporation approved, between 1997 and 2000, loans amounting to 82 million dollars for the development of aquaculture in Latin America. The "beneficiary" countries have been Belize, Mexico, Honduras, Ecuador and Peru.

One of the forces behind the mass loss of mangroves over the last decade has been the inability of economists to recognise the value of natural products and ecological services produced by this ecosystem. This has led to mangroves being considered as lands with no use, with no value and wasted and therefore subject to conversion to uses such as shrimp farming, generating products with a market value.

However, mangroves generate a wide range of natural resources and ecosystem services. Some of these services, such as protection against hurricanes and floods, reduction of erosion and maintenance of biodiversity, are key functions that sustain economic activities in tropical coastal areas. Forest products from mangroves, such as building materials, charcoal, tanin, drugs and honey are vital to subsistence and provide a commercial base for local and national economies. Coastal subsistence economies in many developing countries are strongly dependent on fishing from mangroves.

It has been established that each hectare of mangrove generates between 1,100-11,800 kgs of fisheries catches. This productivity is much higher than the 10-370 kg/ha/year found for coral reefs. In developing countries, the annual value of the fish market depending on mangroves varies between US$ 900 and US$ 12.400 per hectare of mangrove. It should be stressed that this value is based on a single good from the mangrove, that is to say, only fisheries. Additional efforts to estimate the economic value of forest resources and ecological services generated by mangroves, will demonstrate the significant value of this ecosystem and its support to subsistence and to local and national economies.

While this recognition regarding the value of mangroves and support by the authorities for their conservation is yet to be achieved, over the past few years, coastal communities have gone through one of the most critical times in all their history. Following decades or centuries of use of these ecosystems without any major conflicts, they are now facing the daily fact of seeing how two, twenty or sixty bulldozers, arrive on a "bad day" to destroy, in less than two weeks, what had been their subsistence and economy for generations. At the end of two months, all that is left are memories and an enormous amount of shrimp-breeding ponds.

Mangroves are being lost for ever and with them, the economies of hundreds of coastal communities, mainly coastal artisan fishers. This destruction is being extended day by day through all countries in the world having tropical coasts. In Latin America, from Mexico to Peru and Brazil, the shrimp industry does not stop. The efforts by coastal communities to defend their mangroves have cost the life of various artisan fishers in Mexico, Guatemala and Honduras. Presently grassroot movements are growing and to co-ordinate and detain the scourge, the "Mangrove Network" has been set up, aimed at providing all the coastal communities with a mechanism to co-ordinate efforts. During its first assembly held in September, the Mangrove Network achieved membership from organisations in ten countries of Latin America, with the objective of struggling with a single voice, Mangroves are life, long live mangroves. Justice for mangroves. (By: Elmer López Rodríguez, WRM Bulletin Nº 51, October 2001).

  top

Unsustainable versus sustainable shrimp production

Most people that eat shrimp are unaware of where it comes from and about the impacts its production implies. Most of the commercial shrimp is either caught wild using destructive fishing methods, or produced in industrial shrimp ponds, which constitute the main cause of mangrove destruction.

According to FAO figures, 50% of the world's fisheries are already depleted. Jacques Diouf, General Director of FAO, has just alerted the delegates of more than 70 countries at a conference recently held in Iceland that oceans are over exploited and that it is urgent to guarantee their sustainable use. According to FAO data, in 1950 the total production of fish was 19 million tonnes. Fifty years later, a slightly higher amount (20 million tonnes) was wasted in the process of producing a total of 130 million tonnes.

Shrimp trawlers are among the most wasteful fishing boats in the world: they produce less than 2 % of the world's seafood, but are responsible for a third of the wasted fish bycatch. Up to 14 pounds of fish and other marine life are destroyed and discarded for each pound of shrimp harvested. Shrimp trawlers kill more turtles than all other human means combined in US waters.

This needless destruction is not much better in the case of shrimp farming. Shrimp aquaculture ponds are located in the most biologically productive and undervalued areas on earth: coastal estuaries, mangrove forests and wetlands, where shrimp naturally grows. Pond construction begins by cutting down the mangrove forests and digging diked ponds. Then, they are stocked with post larvae, mostly from hatcheries and nurseries at high stocking densities. In order to force the shrimp to feed continuously, the pond is lit all night. It is fed with formulated protein pellets and supplementary artificial feeds. To prevent from diseases, a number of chemical inputs as antibiotics, pesticides and detergents are also added. Pumped exchanges of water to remove wastes and to add clean oxygenated water is crucial to accommodate the high density stocking. This results in accumulation of wastes and degradation in the surrounding ecosystems leading to severe and irreversible problems.

In the short term, intensive shrimp farming is highly profitable for the companies. However, it is clearly unprofitable for the local communities living in the area where it is established, which results in major environmental and economic losses for the local people.

This destructive and polluting system can be avoided. Aquaculture has not always inflicted environmental harm. In fact, integrated fish and rice farming has been the backbone of traditional agriculture in Asia for centuries. This traditional system offers enormous potential for local food security and household nutrition. They also take advantage of the services that coastal ecosystems provide, such as filtering and purifying water, cycling nutrients, removing contaminants and buffering the land from coastal storms and severe weather. A study of the Matang mangrove in Malaysia revealed that its value for coastal protection alone, exceeded the value of farmed shrimp by 170 percent.

Silvofishery, an ancient coastal resource management concept might prove invaluable as alternative management. Silvofisheries is a low input sustainable aquaculture form of integrated mangrove tree culture with brackish water aquaculture. This integrated approach to conservation and utilization of the mangrove resource allows for maintaining a relatively high level of integrity in the mangrove area while capitalizing on the economic benefits of brackish water aquaculture.

However, it is important to underscore that the issue is not a technical one and that there are basically two ways of producing shrimp. One is based on the appropriation and destruction of mangrove areas, the pollution of the same and neighbouring areas and high corporate profitability at the expense of local peoples' territories and livelihoods. The other approach aims at the sustainable use of natural resources - among which shrimp is but one - for the benefit of local communities. If environmental protection and social advancement is to have a meaning, the latter system is clearly in the right direction. (WRM Bulletin Nº 51, October 2001).

  top

Environmental, social and economic impacts of shrimp farming

The destruction of mangrove forests implies the loss of unique species. Mangroves link the tropical forests with the coral reefs, providing a critical transition between terrestrial and marine ecosystems. They also protect shorelines from erosion, capture sediments - thus protecting coral reefs - and are the spawning grounds for the majority of tropical commercial fish. They also protect coastal lowland rainforests from tropical storms. They are critical to local biodiversity, harbouring plants and animals totally unique to mangrove ecosystems. They are also used for recreation and tourism. They are extremely biologically productive and for local communities mangroves are an important source of fuel, medicines, food, fodder, etc.

Apart from the fact that vast areas of mangroves are cut, another consequence of industrial shrimp farming is that there is a vast volume of waste produced inside the ponds by the shrimps. Feed eaten by shrimps but not retained in their body ends up as waste. As the waste piles up, bacteria flourish and consume the available oxygen. This can suffocate the shrimps and reduce their growth. Intermediate waste products - both of shrimp and microbes - such as ammonia and nitrite, are toxic to shrimp, fish and other animals. Shrimp weakened by waste and lack of oxygen is more susceptible to disease. In order to avoid this problem, the water from inside the ponds is regularly removed out and the ponds are filled in with clean water. This system results in the pollution of the neighbouring surface waters.

This activity also provokes the salinization of coastal aquifers and agricultural lands. When the ponds are abandoned due to disease or other causes, the area is often left as a wasteland and the soils contain high levels of salinity, acidity and toxic chemicals, which make other uses practically impossible.

Another consequence of industrial shrimp farming is the use of antibiotics, pesticides, fungicides, parasiticides, and algicides. To guard against diseases farmers also use a large amount of antibiotics during production as well as toxic chemicals between harvests to sterilize the ponds. The result is that human consumers of tropical shrimps produced in this way are eating food containing high levels of antibiotics. Many of the substances used in this activity are prohibited in some countries due to their carcinogenic effects. Regarding antibiotics, some of the ones that are used in shrimp farming are the ones used in humans, which might decrease the effectiveness of antibiotics against diseases. It is important to highlight that in many of the producer countries there are no regulations limiting the amount of chemicals used.

In the quest for profits, the idea of using genetically modified shrimps is already being taken on board and Thailand -the world leading producer - has started research in this area. The idea is to develop a super-shrimp. If this were to succeed, consumers - apart from eating antibiotics, pesticides and other chemicals - would be also eating GM Shrimps.

Among the social and economic impacts of this activity, the destruction of mangroves entails the destruction of an ecosystem which is of great importance for local communities, which of course do not share the profits! Aquaculture is said to be a viable response to the problem of food resources especially in the poor countries. This is clearly not the case of shrimp farming. It is also said that it is a source of much needed foreign exchange, enabling shrimp producing countries to import lower cost protein thus ensuring food security. This argument present two problems. Firstly, that there is no evidence that the foreign exchange earned by shrimp farmers will be used to purchase cheap imported protein. The foreign exchange is earned not by the poor but by the rich shrimp farm owners who decide on how to spend it. Secondly, dependence on imported food reduces food security in times of currency instability.

Regarding employment generation shrimp aquaculture - due to its industrial nature - employs fewer people than agriculture or other fishing activities.

In many cases, shrimp farming has resulted in serious human rights violations, including murder, physical injuries, eviction of villagers, detention of workers in shrimp farms, violation of shrimp farm workers' rights, and confiscation of land, forest and water resources.

Displacement of local communities is common in shrimp exporting countries, where politically connected investors turn highly productive complex ecosystems into a single use private domain. The many poor people who depend on mangrove and coastal fisheries for their livelihoods are eventually displaced. Conflict over land tenure rights are at the core of the conflicts related to shrimp farming.

Shrimp farming is a profitable business for a small group of people, and it is profitable because liberalized trade does not take into account the so called "externalities". This means that those who make the profits do not pay for the destruction of the ecosystem, while tremendous costs are being unwillingly absorbed by local communities at whose expense the industry makes its profits.

In sum, industrial shrimp farming is not only not a solution, but aggravates socioeconomic disparities within the framework of environmental destruction. (WRM Bulletin Nº 51, October 2001).

  top

The pillars of increased global shrimp trade

Globalisation has encroached upon our table. Foods are trailed all along the seas, from South to North and from East to West. The farther, the better (for transnational companies) because that implies trade, packing, conservation processes, tariffs, importers, exporters, and so on.

Nowadays, there are tropical fruits available in cold countries' markets, or fish and seafood in landlocked regions. And the list goes on. This is shown as a sign of progress and more choices for the people... Actually, it's just global trade. More precisely, the internationalisation of "free" trade, with reduced tariffs, quotas and non-tariff trade barriers to provide exotic products to lucrative markets. And the World Trade Organization (WTO) -the global institution chartered to regulate global trade - together with international agencies and banks (FAO, World Bank, etc.) behind all that, fostering an intensive production-demand pattern. Developing countries become the suppliers through increased loans and credits from lending institutions, which typically finance intensive monoculture production systems.

Such is the case of the shrimp trade. Shrimp consumption is quite expanded in the US, Europe and in some Asian countries. The landings of wild shrimp from "capture" fisheries have hovered between 2 to 3 million tons a year. For some developing countries, the trade in seafood products is greater than that of coffee, tea, rubber, and banana combined.

In the 1980s, the development of shrimp aquaculture - which has meant the conversion of huge parts of tropical mangrove forests into aquaculture ponds - allowed a dramatic increase of shrimp consumption as well as plummeted shrimp prices. For example, many US restaurants now offer cheap all-shrimp menu and all-you-can-eat shrimp bars of what was once an expensive delicacy.

Intensive export-led shrimp farming - with a short term, high rate of return on investment - and cheap supply - at the expense of degraded environment, displaced communities, loss of traditional livelihoods, human rights violations - are then the pillars of a global shrimp trade which on the other hand has also implied overfishing and depletion of the seas. In between there is a full battery of vested corporate interests.

The promoters of global trade maintain that trade is neutral with respect to the environment, society, sustainable management and economic efficiency. Nothing more distant from reality. Trade can have positive or negative effects but cannot be sustainable without sustainable production. Export-oriented industrial shrimp farming has already proven to be socially and environmentally unsustainable and must therefore be stopped before it results in further damages to people and their coastal ecosystems. (WRM Bulletin Nº 51, October 2001).

  top

Shrimp aquaculture in international environmental treaties

The ecological and social impacts of shrimp aquaculture have been brought to the attention of two international environmental treaties that have been developing policies and programmes for the sustainable management of coastal and other ecosystems. These are the RAMSAR Convention on Wetlands and the Convention on Biological Diversity (CBD).

The Forest Peoples Programme, an ISA Net (Industrial Shrimp Action Network) member organisation, made an intervention highlighting the impacts of shrimp farming on coastal and marine ecosystem and local communities at the Conference of the Parties 4 (COP4) of the CBD in May 1998 in Slovakia.

The following year several ISA Net members participated in the 7th Conference of the Parties of RAMSAR and at a workshop on Indigenous Peoples and Local Communities' Participation in Wetland Management during the 13th meeting of the Global Biodiversity Forum (GBF) which preceded the RAMSAR meeting (San José, Costa Rica, 7-18 May, 1999). The presentations made by four representatives of local communities were well received at the GBF and ISA Net's recommendations were discussed at the RAMSAR Conference. As a result, a paragraph was added to one of the final resolutions (Resolution VII.21, Enhancing the conservation and wise use of intertidal wetlands), calling for the suspension of the promotion, creation of new facilities, and expansion of unsustainable aquaculture activities harmful to coastal wetlands until measures aimed at establishing a sustainable system of aquaculture that is in harmony with the environment and local communities are identified.

ISA Net members also participated in discussions and amendments of the Guidelines for establishing and strengthening local communities' and indigenous peoples' participation in the management of wetlands, which were eventually adopted as Resolution VII.21 and VII.8 of the COP.

Getting useful language into international conventions, however, can only be considered an achievement if they become effective tools to be used by local organisations in their efforts to protect their environment and livelihoods. NGOs and CBOs in Ecuador and Honduras have so far tried to use the paragraph on aquaculture of RAMSAR Resolution VII.21 in order to stop further expansion of shrimp farming in ecologically sensitive coastal ecosystems. So far, it seems that the RAMSAR language might have been helpful in supporting the effort of Ecuadorian NGOs trying to stop the introduction of new policies that would have included the privatization of parts of the coastline for the benefit of shrimp farmers. On the other hand, it does not seem to have been particularly useful in the Gulf of Fonseca, Honduras, despite the fact that part of the Gulf is a RAMSAR site. Effective follow-up needs to be organised to make sure that language developed in RAMSAR does not remain empty words.

Meanwhile, a programme under the CBD, namely the Jakarta Mandate on Coastal and Marine Biodiversity, has developed a 3-year work plan for the conservation and sustainable use of marine and coastal biological diversity. This includes a section (programme element 4) on mariculture, whose main operational objective is to assess the consequences of mariculture for marine and coastal biological diversity and promote techniques that minimise adverse impact. How effective the work plan is going to be still remains to be seen. (By: Maurizio Farhan Ferrari, WRM Bulletin Nº 51, October 2001).

  top

Tropical prawns versus mangroves

The Ramsar Convention on Wetlands was signed in the city of Ramsar, Iran, in 1971 and entered into force in 1975. Ramsar is the only environmental convention that addresses a specific ecosystem, that of the wetlands. Wetlands, as recognised by the Ramsar Convention, fulfil essential ecological functions, as regulators of hydrological regimes and as habitats for a very rich biodiversity and are a resource of great economic, cultural, scientific and recreational importance that must be preserved.

Mangroves, coastal forests located in tropical and equatorial areas of the world, are part of these wetlands. They are presently seriously threatened. According to FAO, over 50% of the mangroves have already disappeared. Today the main cause of mangrove loss is the expansion of the shrimp industry, breeding shrimps or tropical prawns in coastal areas of poor countries to export them to rich countries such as Spain, the United States or Japan. In fact, most of the prawns found today on the market are a product of the destruction of coastal ecosystems in the countries of the South and of the displacement of local populations.

Resolution VII.2, taken at the Seventh Conference of the Parties to the Ramsar Convention on Wetlands (Costa Rica, 1999), recognises the economic, social and environmental value of the wetlands such as mangroves for fishing, biodiversity, coastal protection, leisure activities, education and water quality. It recognised that the subsistence of a considerable number of populations depends on the productivity and value of wetlands located in inter-tidal zones and also showed concern over the advanced process of degradation that is to be found in many coastal wetlands, mainly as a result of unsustainable aquaculture and contamination.

In view of the above, the Convention urged the Contracting Parties -- that is to say, the States -- to suspend the promotion and creation of new facilities for unsustainable aquaculture activities, damaging to coastal wetlands, including the expansion of already existing facilities, until measures aimed at establishing a sustainable aquaculture system, in harmony with the environment and local communities can be identified, by means of environmental and social impact assessments on such activities and through appropriate studies.

Unfortunately, this resolution is not being implemented. For this reason, Greenpeace and the Mangrove Network (Redmanglar) (a network gathering NGOs from Ecuador, Honduras, El Salvador, Guatemala, Mexico, Brazil and Colombia working in defence of mangroves) will submit a very concrete demand regarding mangroves: a moratorium on the expansion of the shrimp industry, to the Eighth Conference of the Parties to the Ramsar Convention, to be held in November, in Valencia (Spain).

Without this stoppage, we will be unable to save these ecosystems and we will prevent the local populations that depend on them from having a different opportunity -- other than poverty or migration. Perhaps the Eighth Conference of the Parties to the Ramsar Convention is one of the last opportunities to curb the destruction of the only forests that can live with their roots in the sea. (By: Eva Hernández, WRM Bulletin Nº 64, November 2002).

  top

next page