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Wetlands: The Endangered Ecological Bridge
by Dr. Ashesh Ambasta
Global aquaculture production has more than doubled in recent years, from 10 million metric tons to 25.5 million between 1984 and 1994. Today this industry, which includes fish farming and coastal fisheries, is worth about $40 billion a year, and the sector contributes nearly 22 percent of the 72 million tons of all marine products bought and sold. It has been among the fastest-growing food sectors, and given current consumption trends, is likely to retain this lead in the years to come.
Because most demand is met through production in the developing parts of
the world,  surely this should have been a cause for celebration, signalling
economic prosperity for the coastal peoples and vastly enlarging sorely
needed foreign exchange reserves in chronically cash-starved nations. But,
as the familiar adage goes, if wishes were horses, beggars indeed would be
kings.
True, poor and rich alike participated in the boom, as global demand
soared and commerce in marine products flourished as never before (though
some accumulated significantly more than the others did).
Unfortunately, the prosperity was short-lived. As the boom led to a
bust, the entrepreneurs, the local elite and the private companies that had
invested when the going was good stampeded to greener pastures. Left
behind were the local inhabitants, surveying devastated landscapes rendered
unproductive and infertile by the short but intensive mining of their
eco-system.
An Industry Under Attack
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The truth of the collapse of aquaculture in most parts of the developing world was not that demand had petered out. Instead, the bust followed acute production failure, as coastal wetlands were subjected to a violent resource-use pattern that was not sustainable. The dynamics of such a production regime tell this story quite eloquently.
Aquaculture farms began mushrooming in the mid-1980's on the coastal fringes of Asia. The farms comprise artificial ponds, stocked with seedfish and shellfish and inundated with brackish water from suitable local sources. To maximise profits, farmers invariably maximise stocking. This requires a commensurate increase in nutrients introduced into the ponds, and a heightened risk of diseases leads to the intensive use of chemicals to thwart the problem. To offset the contamination, more and more water has to be pumped in.
This process implies, first, a rapid draining of coastal wetlands. Secondly, in thousands of farms, pond water saturated with chemicals and nutrients is pumped back into the sea after each harvest, causing irrevocable havoc to coastal life and a progressive decline in harvests.
But the calamity, at least for the coastal people, packs a double punch:
Even as their harvests begin to fail, they come face to face with yet another predator, the mechanised trawlers gathering their catch in ever larger volumes and thus delivering yet another mortal blow to coastal livelihoods.
The Social Effects of Economic Collapse
A deteriorating environment and diminishing livelihood are not the only challenges confronting groups like the Programme for Community Organisation in Kerala and Yadfon in Thailand. As activists like Nalini Nayak and Pisit Chansnoh correctly point out, the process has left in its wake a number of acute social and economic problems.
Many of the people have been deprived of their land. Entire coastal communities, in some cases, have been denied access to village commons once used for drying fish, grazing and subsistence cultivation. Many convert paddy lands into shrimp farms, reducing employment and posing a serious threat to food security. In short, those concerned about coastal communities not only have the daunting task of nurturing back to life a shattered ecosystem, but to do so in a manner that assures local inhabitants of adequate and sustainable livelihoods.
This is a task they have approached with ingenuity, dedication and perseverance, as you shall see in the accompanying articles.
Important as it is to acknowledge the invaluable endeavours of such groups, it is equally relevant to point out that in the larger scheme of things, coastal fringes are but a part of a broader wetlands ecology integrally and intricately linked in an ever-expanding network of ecosystems. Thus, adversely affected wetlands in the deep hinterlands can, and do, have significant effects on coastal systems and hence provide the primary justification for a plea to view wetlands in their totality.
Secondly, shrimp farming is but one cause for the rapid depletion of wetlands. World over, such areas have been used as dumping grounds or drained, channelled or built over until very little remains. And what remains faces a serious ecological crisis in the developed and developing worlds alike. (See Note 1) The crying need now is to understand the critical role wetlands play in maintaining the ecological balance. Only then can we truly comprehend the extent of damage we inflict, knowingly or unknowingly, on these critical eco-bridges between the terrestrial and aquatic ecosystems.
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What Are Wetlands?
Wetlands are what the term suggests: areas saturated with water either permanently or temporarily. It is not necessary for such lands to be completely submerged; water may be present at or near the soil surface, or even within the root zone. Since repeated and prolonged presence of water is the defining characteristic, it follows that this also determines the soil composition and the particular biotic life that develops in such ecological niches. That is, wetlands typically see the efflorescence of hydrophytes, plants adapted to life in hydric soils, which are formed under flooded or saturated conditions.
There is a tremendous diversity in wetland types, depending on the geography of the sites and whether the water is fresh, brackish or saline. Moreover, since the water levels are in constant flux, wetlands are quite often transient. These difficulties notwithstanding, it is possible to classify all wetlands into two basic types: tidal (coastal) and freshwater (inland). (See Note 2)
Harvesting of fish or shellfish has become the most tangible of benefits that flow from wetlands. But stop to think of the complex processes in wetlands, which lead to the tremendous biodiversity of such formations, which in turn creates the food web in which aquatic fauna can breed, live and grow. In this process wetlands serve several additional functions which, though invisible to our eyes, nevertheless have a crucial bearing on the quality of our lives.
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How Wetlands Contribute to Ecological Balance
The invisible benefits first. First and foremost, wetlands store and regulate the flow of water within watersheds. Most wetlands store water derived from rainfall, from surface runoff and from ground water. Therefore, they first act as reservoirs. The stored water is then slowly released to supply the downstream reaches of rivers, streams and lakes, and to recharge ground water. Like the inland wetlands, the tidal ones slow the flow of water moving through the system and allow the settling of sediment and pollutants. Moreover, by maintaining the water-table level they protect ground water resources against saltwater intrusion. Along with supplying water, wetlands play a crucial role in improving the quality of water
(see Note 3) by trapping or transforming pollutants before they reach the larger water resources.
By virtue of their place in the landscape, wetlands protect shorelines and stream banks against erosion and thus prevent land and soil degradation. Wetland plants hold the soil in place, diffuse the momentum of waves and reduce the velocity of stream or river currents. In urban areas, where the risk of flood damage is considerable because of impervious surfaces, wetlands are particularly valuable for flood protection.
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Moving on to the face of wetlands that we know best: They play a crucial role in providing life support. They are among the most productive ecosystems in the world. Immense varieties of species of microbes, plants, insects, amphibians, reptiles, birds, fish and other wildlife depend in some way on wetlands. Wetland plants provide breeding and nursery sites. Coastal freshwater marshes perhaps support the largest and most diverse bird populations of all wetland habitats by providing critical food and refuge. Decomposed plant matter into the water is important food for many invertebrates and fish.
Wetlands provide critical life support to the local people too: timber, fuel, feed and manure, as well as fisheries. The brackish water and reclaimed mangrove areas are used as fishponds and after the monsoons, they are drained and used as salt pans. The mud from wetlands is periodically removed and used as manure for paddy and coconut plantations.
How Human Action Has Destroyed Wetlands
Just as most benefits of wetlands are derived from their saturated character, the degradation of wetlands begins with changes in hydrology that alter the soil chemistry and thus plant and animal community. Such changes, which we humans have caused, have been wrought historically through all our projects of modernisation and development, be it agricultural growth, industrialisation or urbanisation.
Ever since demographic pressure first extended beyond arable land, humans have expanded the frontiers of agriculture into other habitats. Wetlands and forests have been the major casualties, and thus agriculture until recently has been the major single factor in freshwater and delta wetland losses. Besides depleting the area, wetlands have been violated by fertilisers and animal waste that has upset the balance of nutrients. Similarly, in the coastal areas, subsurface withdrawals of water (for aquaculture farms, for instance) allows saltwater intrusion into freshwater wetlands, modifying these habitats to the extent that it has threatened the billion-dollar fisheries industry.
The more recent culprits include urbanisation and industrialisation. Both bring a concentration of organic matter, wastes, pesticides, fertilisers, heavy metals, hydrocarbons, road salts and debris, all of which are major pollutants. Both create large tracts of impermeable surfaces; because such surfaces prevent rainfall from percolating into the soil, they hasten the flow of these wastes into streams and wetlands. Thirdly, such surfaces raise the temperature of water runoff, thus decreasing its dissolved oxygen. Together, these three factors cause immense stress on all aquatic life and, therefore, the food web.
The final link is a kind of evil synergy, the combined outcome of all these factors. Agriculture, industrialisation and urbanisation entail the clearing of extensive areas, thus intensifying the silt in runoffs. This, coupled with extensive deforestation and overgrazing, strips the land of its natural vegetation cover even more. An undue increase in the silt load can completely clog the root systems of wetlands, smothering vegetation and shellfish beds. Sedimentation also reduces the water storage capacity, reduces the penetration of light and reduces oxygen. In short, it makes wetlands unproductive, with grave consequences on the food chain.
The Challenge of Protecting and Managing Wetlands
But, finally, a narrow focus on environmental deterioration to the exclusion of the people living in these niches can never prove to be a successful strategy. Thus, activists not only must attempt eco-restoration, but must do so in a manner that minimises conflicts between humans and nature, and between local inhabitants and interlopers. The question is the extent to which the social entrepreneurs profiled here address themselves to such a task.
Given the myriad forces that affect wetlands, it is important first and foremost to develop and implement strategies for the long-term protection of these ecosystems so that their existing functions can endure. This implies a two-pronged strategy: buffering wetlands from damaging human adaptations, and simultaneously maintaining natural processes in surrounding lands that affect wetlands.
All three projects address this issue squarely by allowing the natural process of regeneration to take place, or actively abetting eco-restoration (through afforestation of mangroves in Thailand, for instance); by minimising large-scale and intensive mining of natural resources (in both Thailand and Kerala), and by replacing these with ecologically sustainable land-use practices, even invoking the virtues of traditional farming methods in this context. In Bengal, Dr. Dhrubajyoti Ghosh has gone a step further by using wetlands for wastewater treatment (ecological engineering), thus converting a potential threat into a distinct advantage.
Central to all three projects has been an overriding concern for the people. Thus care has been taken that the livelihoods of these communities do not come under threat. Yadfon and P.C.O. in Kerala have managed this by effectively mobilising the people affected against those elements that threaten their livelihood and by making them participants in the eco-restoration process. Similarly, by converting wastewater into nutrient pools, Dr. Ghosh has augmented the supply of natural fertilisers for both fisherfolk and farmer.
To conserve, use sustainably and share benefits in dealing with biological diversity is a hard-learned lesson and one that we should cherish. This is indeed the guiding principle of the three social entrepreneurs profiled here.
Ashesh Ambasta is a development economist.
Note 1:
Extent of Wetland Degradation in the U.S.A.
Between the mid-1970's and the mid-1980's, approximately 4.4 million
acres of inland freshwater wetlands and 71,000 acres of coastal wetlands
were destroyed. Inland forested wetlands were hurt most during the
mid-1970's to the mid-1980's, with a loss of 3.4 million acres.
Approximately 900,000 acres were converted from forested wetlands to
other wetland types. Conversion to agricultural usage of land was
responsible for 54 percent of the losses of both freshwater and coastal
wetlands, drainage for urban development for 5 percent and "unspecified
usage" for 41 percent. This is in contrast to the mid-1950's to
mid-1970's, when agricultural drainage of wetlands was responsible for 87
percent of the losses and urban development for 8 percent.
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Note 2:
The Diversity of Wetlands
Coastal Wetlands
In the coastal areas marine wetlands are constantly inundated by the high water of spring tides, rendering them extremely saline. Estuarine wetlands, on the other hand, are not as exposed to the seas and oceans and, in fact, are frequently diluted by freshwater run-off from the land. As a result, water salinity is considerably lower.
Thus, while marines wetlands are dominated by seaweeds and grasses, the estuarine areas see a luxuriant growth of shrubs and trees. Common to both, however, is that salinity is the major stress factor, limiting species to those that have evolved the necessary adaptive mechanisms: Salt-tolerant species, halophytes, dominate the plant life.
The largest estuarine formations are the mangroves which, because of their profusion, are also known as tidal forests. Not only are they storehouses of great biological diversity; they also serve as natural defences against erosion.
The second in importance are the tidal freshwater wetlands that form in the upstream of estuaries where the water, though influenced by tides, is predominantly fresh. These wetlands receive considerable water and nutrients from upstream sources as well as from runoff and precipitation.
Inland Wetlands
The most important, extensive and perhaps most degraded, formations in the inland areas are the riverine systems, comprising all wetlands and deepwater habitats contained within the channels of rivers and streams. These wetlands are particularly productive ecosystems, receiving large inputs of water and nutrients from upstream sources. The resulting increase in soil fertility has been the primary factor in the large-scale conversion of such systems for agricultural use.
All other inland wetland systems (fens, vernal pools, bogs, marshes, swamps, wet meadows, etc.) fall under the general heading of palustrine wetlands. Marshes are the broadest category, formed in depressions, as fringes around lakes and along slow-flowing streams and rivers. Although characterised by shallow water, they are constantly inundated, both from surface water (flooding and runoff) and groundwater. Since nutrients derived from surface water are considerable, marshes are highly productive and harbour the greatest biological diversity.
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Note 3:
How Wetlands Improve Water Quality
Several studies have shown that wetlands reduce nitrogen and phosphorous
concentrations in runoff and flood water to a significant extent by
transforming them and releasing them into the atmosphere. High proportions
of suspended solids (sediment and organic matter) are trapped in wetlands,
thus preventing a source of water cloudiness from entering downstream
ecosystems. Moreover, several pollutants affecting water quality are often
absorbed onto these suspended solids, thus removing pollutants from water,
while the sediment depost itself provides multiple benefits to downstream
water quality.
Certain wetlands play an important role in removing metals from other
runoff and ground water. All soils contain low concentrations of metals,
but in some locations, human activities have raised metal levels high
enough to cause health or ecological risks.
Wetlands also have an important role in protecting surface water from
pathogens that enter through sewage, urban stormwater, leaking septic tanks
and agricultural runoff.
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Wetlands Ecosystems - Bibliography
Bibliographical Notes
The most comprehensive attempt at classification of wetlands is to be found in the National Wetlands Inventory homepage (U.S. Fish and Wildlife Service, Division of Habitat Conservation). Specifically, refer to the following essay (the typologies of wetlands discussed in this paper draws upon this article):
Classification of Wetlands and Deepwater Habitats of the United States. Cowardin, Lewis M. and Golet, Francis C. December, 1979. U.S. Department of the Interior, Fish and Wildlife Service, Office of Biological Services. 26 Sept. 1998 .
A very detailed and comprehensive discussion of the value and functions of wetlands and the human interventions that are destroying such habitats can be found in the following Web sites:
Information on Wetlands. Aug. 1998. North Carolina State University Water Quality Group. 26 Sept. 1998
Wetlands and Nature. U.S. Environmental Protection Agency Office of Water. 26 Sept. 1998
This paper has drawn a great deal from these two sites, especially in the discussion on the function and destruction of wetlands.
Other References Used
Bailey, Conner (1984): 'Fisheries Resource Conflict and Political Resolution: Indonesia's 1980 Trawl Ban', in Rural Sociological Society (RSS) Association-Paper
Bhattacharya, P.C. (1998): 'Assam - Taken for granted', in The Hindu, Survey of the Environment '98, Chennai.
Bhattacharyya, S. (1998): 'Sunderban - Dying a slow death', in The Hindu, Survey of the Environment '98, Chennai.
Gulati, Leela (1982: 'Impact of Technological Change in the Fishing Industry on the Lives of Women in Three Indian Villages', Centre Development Studies, Trivandrum
Kurien, J. (1997): 'Environmental Issues Along the Coastal Zone', in Agarwal, A. (ed.), The Challenge of the Balance - Environmental Economics in India, Centre For Science and Environment, Delhi.
McGoodwin, J.R. (1987): 'Mexico's Conflictual Inshore Pacific Fisheries: Problem Analysis and Policy Recommendations', in Human Organization, Vol. 46 No. 3:221-232.
McMullan, J.L., Perrier, D.C. & Okihiro, N. (1993): 'Regulation, Illegality and Social Conflict in the Nova Scotia Lobster Fishery', in Journal of Legal Pluralism and Unofficial Law, Vol. 33:121-146.
Meynen, Wicky (1989): 'Fisheries Development, Resources Depletion and Political Mobilization in Kerala: The Problem of Alternatives' in Development and Change Vol. 20 No. 4:735-770
Mishra, M. (1998): 'Chilika - In distress', in The Hindu, Survey of the Environment '98, Chennai.
Norr, J.L., & Norr, K.L. (1982): Impact of Urban Growth: Change in a South Indian Fishing Community from 1965 to 1980', Ethnology Vol. 21 No. 2:111-123.
Pal,Amar Nath (1992): 'Development of Brackish Water Shrimp Farming and Pauperisation of Tribal People in Sundarban: An Interplay of Ecology, Economy and Politics' in Journal of the Indian Anthropological Society Vol. 27 No. 1:70-77.
Parasuraman,S. (1995): 'Economic Marginalisation of Peasants and Fisherman Due to Urban Expansion: The JNP Project of New Bombay, India', in Pakistan Development Review Vol. 34 No. 2:121-38.
Pendse, Sandeep (1984): 'The Struggle of Fisherfolk in Goa', Development Vol. 2:30-36
Pharo,Helge (1987): 'Conflict and Cooperation in the Indo-Norwegian Fisheries Project 1952-1972', in Dewey, Clive (ed.), The state and the market: Studies in the economic and social history of the third world, Riverdale,
Saleth, R.M. (1997): 'Sustainable Management of Mangrove Resources in India: Strategies and Options', in Agarwal, A. (ed.), The Challenge of the Balance - Environmental Economics in India, Centre For Science and Environment, Delhi.
Trisal, C.L. (1998): 'Kashmir - Fast disappearing' in The Hindu, Survey of the Environment '98, Chennai.
Untawale, A.G. & Jagtap, T.G. (1998): 'Mangroves - No Wastelands', in The Hindu, Survey of the Environment '98, Chennai.
Vivekananda, V. & Kurien, J. (1998): 'Aquaculture: Where greed overrides need', in The Hindu, Survey of the Environment '98, Chennai.
Webster, Neil (1993): 'Cooperation, Cooperativism and Cooperatives in Rural Production, West Bengal', Journal fur Entwicklungspolitik, Vol. 9 No. 3:309-328
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