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WEEK TWO: HOW DOES WATER SUPPORT LIFE? | ESSAY ONE

The Mekong: River of the Nine Dragons

The Nine Dragons

This satellite photo shows the nine distinct outlets of the Mekong River Delta. ©NASA

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Flowing 4,880 kilometers (3,030 miles) through six countries before discharging in the South China Sea, the Mekong River is Southeast Asia's

longest river. Its drainage basin is divided into the Upper Mekong (which flows from the Tibetan Himalayas through China's Yunnan Province

and Myanmar [Burma]) and the Lower Mekong (Cambodia, Lao People's Democratic Republic, or Lao PDR, Thailand, and Vietnam). Its

source in the Tibetan plateau was only discovered in 1994. The Mekong Delta drains into the sea through nine outlets, giving the river its

Vietnamese name, Song Cuu Long, or River of Nine Dragons.

An Enormously Variable Natural CycleThe region's typical monsoon climate, with distinct wet (May to November) and dry (December to March) seasons, causes the Mekong River's

flow to vary greatly. In the rainy season, the river floods many areas up to three meters (10 feet) deep for up to five months, while flows drop by

90 percent in the dry season. The river's ecosystem depends on these seasonal variations. Flood pulses fertilize riverbanks with nutrients and

sediments, and allow fish to swim into tributaries and floodplains to spawn and hide from predators. A huge wetland (65,000 square

kilometers/25,000 square miles), the Mekong Delta is crisscrossed by canals and rivers; it continues to grow though sediment deposition. When

river flow is low, saltwater from the South China Sea can intrude upstream, flooding a third of the entire delta. This saline intrusion, like rainfall

and flooding patterns, is an important natural component of the delta ecosystem.

Seasons of Change

The variation of the Mekong is obvious on the shoreline at Nakon Phanom, Thailand: rainy season (left) and dry season (right). ©Michael

Lanty

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An Immensely Productive RiverThe Mekong is the world's third-most-biodiverse inland waterway, after the Amazon and Congo rivers. More than a thousand new vertebratespecies have been discovered in the river basin in just the last decade: 519 plants, 279 fish, 88 frogs, 88 spiders, 46 lizards, 22 snakes, 15mammals, 4 birds, 4 turtles, 2 salamanders and a toad, not to mention thousands of new invertebrate species. The river is home to at least 1,200species of fish, notably a number of very large ones. The river's seasonal rise and fall ensures a nutrient-rich environment, and Mekong fisheriesare extraordinarily productive.

Millions of Livelihoods Revolve Around the MekongThe Mekong River basin is home to 73 million people, a third of whom survive on a few dollars a day. They belong to over 100 different ethnicgroups, making the Lower Mekong River Basin one of the most culturally diverse areas in the world. Most are self-sufficient farmers andfishermen who depend on the river's rich sediment and fish-filled waters for subsistence and commercial fishing, rice production, andagriculture. The vast, swampy delta is one of Asia's greatest rice-growing regions. During the dry winters, most rice-growing areas requireirrigation. Many fish species can be harvested from rice fields; some enter from adjacent bodies of water, while others are deliberately stocked.

Conservative estimates indicate that basin dwellers eat more than 1.5 million tons of fish per year. The fishery provides a livelihood not just forfishers and their families but for thousands more who are employed full- or part-time making and selling food products and fishing gear,repairing boats, and providing hundreds of related services. Aquaculture in the basin relies heavily on introduced species such as the commoncarp and Nile tilapia.

Newly Discovered Species

These are among the species recently discovered in the Mekong River Basin: (clockwise from left) litter frog (Leptobrachiun gunungense),green pit viper (Trimeresurus gumprechti), Kachin woolly bat (Keriboula kachinensis), and shocking pink dragon millipede (Desmoxytespurpurosea). ©Greater Mekong Programme / WWF International

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Crop Irrigation

This is a traditional method of irrigating a rice field in rural Vietnam. ©QT Luong

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Environmental Degradation and Economic DevelopmentMany factors have contributed to degraded water quality and declining fisheries in parts of the Mekong Basin, including the intensive

application of chemical fertilizers and pesticides, urban waste discharge, widespread logging, and the use of explosives and other nontraditional

fishing methods.

The basinÕs native flora and fauna are threatened by invasive species that have escaped or been released into the Mekong Basin, in particular

water hyacinth (Eichornia crassipes) and giant mimosa (Mimosa pigra). First spotted in the Mekong River Delta in 1979, the mimosa is a

spiny shrub native to the Americas that spreads in floodwaters and construction sand, quickly forms dense stands, and out-competes native

plants. The mimosa has taken over several irreplaceable wetlands on which endangered water birds depend for food and shelter. The basin lacks

control, management, and eradication programs for these and other invasive species.

The basin's human population, which has doubled over the last 30 years, continues to increase. As with environmental degradation, the threat

from too much water (e.g. flooding in Cambodia) or too little (water scarcity in Thailand) will become more problematic as the population and

development increase. Lastly, regional economic development is spurring a demand for energy through hydropower.

Invasive Aquatic Weed

Villages relying on fishing and water travel are paralyzed each year when water hyacinth takes over, as seen from a boat in Cambodia's Siem

Reap River. ©Gillian Perrett

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Dam DevelopmentA number of dams have already been built on the Mekong's three major tributaries in Lao PDR, Thailand, and Vietnam, and more than 100 new

ones have been proposed in the last decade. China is building a series of dams on the Mekong itself, two of which rival the scale of the

immense Three Gorges Dam. Support for these dams comes from basin countries that need power for development, from basin countries with

hydropower potential and limited national income, and from the countries and companies that build the dams. Proponents point out that dams

could reduce salinity issues by ensuring greater flow during the dry season and reduce flood damage by stabilizing water levels. All of

Cambodia's major cities, for example, are vulnerable to flooding.

Although the potential ecological impacts of these proposed dams are not well understood, existing dams are already blamed for a decline in

fishery yields and habitats for endangered species. All of the river's large fish species are in serious decline. One species of freshwater dolphin,

the Irrawaddy dolphin (Orcaella brevirostris), was once common in the whole of the Lower Mekong but is now very rare. Dams impede fish

migration routes, inundate spawning grounds, and eliminate the seasonal flooding that provides nutrients for agriculture, especially rice

farming. Existing dams are estimated to have displaced tens of thousands of rural people, and new construction would displace many tens of

thousands more.

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A significant concern is the possibility that dams upstream will disrupt the annual flood pulse throughout the Delta and into Cambodia's Great

Lake, or Tonle Sap, which was designated a UNESCO Biosphere Reserve in 2001. When monsoon rains arrive, a tributary of the Mekong

River reverses directions, flowing backward and causing this lake to swell to around 10,360 square kilometers (4,000 square miles) from 2,700

square kilometers (1,050 square miles). The depth increases to 9 to 14 meters (30 to 45 feet) from 1 to 3 meters (3 to 10 feet). The millions of

fish that surge in with the floodwaters are key to the livelihood of the 80,000 people who live around the lake. When the dry season returns, the

flow reverses. This entire process is believed to provide nutrients and habitat necessary for these fisheries and nurseries to survive. The least

developed of the basin nations, Cambodia, is completely dependent on the river, and Tonle Sap in particular, for food and other resources.

Endangered Species

The Irrawaddy dolphin and giant Mekong catfish are increasingly threatened by alterations to their habitats. ©CITES

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At present, environmental and human costs are taking a back seat to development pressures. In addition to dams for hydropower, large

irrigation projects are under consideration. Another point of controversy is a Chinese-initiated project to blast rapids, shoals, and rocks in the

upper Mekong, allowing passage for bigger ships and opening a trade route to Vietnam.

Landlocked Lao PDR hopes that a shipping route will help lift its people out of subsistence farming and poverty. Reefs in the area, some as

long as two kilometers, are the breeding ground for many migratory fish. The biggest freshwater fish in the world, the endemic giant Mekong

catfish, which can grow to over three meters, hatches its eggs just south of where a first phase of blasting was completed in 2003.

Managing the Mekong: A Brief History

Attempts to promote cooperative river basin planning began in 1957, when the United Nations led one of its first efforts to study a project's

social, economic, and organizational aspects in advance of construction. In April 1995, the four lower basin countries (Cambodia, Lao PDR,

Thailand, and Vietnam) signed the Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin in Chiang Rai,

Thailand, establishing the Mekong River Commission (MRC). They committed to developing, conserving, and using the river in a cooperative

and sustainable manner. (Other agreements between the six riparian countries focus primarily on economic development.) The MRC is the

governing body for cooperative river basin management.

Along with other cooperative organizations, the MRC provides a forum for dialogue. Its achievements include improved understanding of the

ecology of the Mekong River system and the development of a flood forecasting system. Dam construction, long forestalled by political

instability in the region, is taking environmental and social impacts into consideration. In the spring of 2009, the MRC launched a wide-ranging

assessment of the impact of hydropower development along the river in Lao PDR, Cambodia, and on the Lao-Thailand border.

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Construction on the Mekong

As of 2008, 12 new dams are under construction on the Mekong River and its tributaries, with another 80 dams awaiting approval. ©MekongRiver Commission

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The Challenges AheadThe MRC clearly recognizes the interconnectedness of upstream and downstream stakeholders. With a clear understanding of threats, a sharedaction plan, and broad participation, this type of framework can be critical to sharing a resource sustainably. Yet sustainable management of theMekong River Basin faces serious obstacles, which include poor water-use planning, insufficient data and data-sharing, poor institutionalcoordination, lack of skilled personnel, poor communication, and weak regulatory frameworks and enforcement mechanisms. The MRC ishampered by its small size and limited resources, and by the region's extreme poverty. Donor funding, which provides 90 percent of the budget,impedes riparian country ownership of the MRC and its governance mechanisms.

Some local communities do not bring their concerns to the MRC, and its role as an advisor at the national level is hampered by limitedparticipation and engagement. China and Myanmar do not belong, and China undercut the MRC's authority when it established separate tieswith the four lower basin countries in order to blast the navigation channel. Economic development has greatly suppressed environmentalconcerns. Countries that are developing more quickly, like China and Thailand, have different incentives and disincentives than other basincountries. Participation is seen as a constraint to further development, despite the MRC's limited charter. While the organization does havepolicy-making authority that binds the participating countries, it does not currently have the ability to set a basin-wide agenda, nor do countriesrelinquish sovereignty simply by participating in the MRC.

Despite these challenges, the organization has made progress in establishing a foundation for integrated management across the four membercountries. A strong environmental movement has formed in Thailand, and Cambodia is beginning to develop one. China is also taking a greaterinterest in regional development, which may translate to greater cooperation. The MRC continues to support dialogue on the most effectiveway to manage the basin and to encourage participation by all stakeholders at all levels.

Related Links

Mekong River Commission »

Gain insight into current programs and management practices going on within the Mekong River Delta.

Mangrove Action Project »

This nonprofit is dedicated to reversing the degradation and loss of mangrove forest ecosystems worldwide. Its main goal is to promote therights of traditional and indigenous coastal peoples, including fishers and farmers, to manage sustainably their coastal environs.

Mangroves for the Future »

This is a global initiative to promote investment in coastal ecosystem conservation for sustainable development.

CBC: Mainland Southeast Asia »

Learn about the rare and endemic species that the Museum's Center for Biodiversity and Conservation researches in the greater Mekong region.