The Economist
December 30, 2003

THE SWEET SERPENT OF SOUTH-EAST ASIA

How much longer will the Mekong remain the world's last great unspoilt
river?

Every October, on the night of the full moon, small globes of light
rise from the Mekong river along the border of Laos and Thailand. One
theory holds that methane drawn from the riverbed by the gravitational
pull of the moon causes the "Naga fireballs", as locals call the
phenomenon. The devout, on the other hand, consider it a sort of
spiritual firework display to celebrate the end of Buddhist Lent, while
sceptics say that it is all a hoax, perpetrated by Laotian monks to put
the fear of god into their flock.

The event is emblematic of the Mekong in general. It may rank only
eighth among the world's rivers in terms of flow, 12th in length and
21st in the size of its basin, but few can top it for sheer
peculiarity. More conventional rivers, for example, content themselves
with flowing in a single direction all year round. Not the Tonle Sap, a
branch of the Mekong that runs through central Cambodia. For half the
year, it flows south-east towards the South China Sea. But as run-off
from South-East Asia's monsoon raises the water level, the river
reverses course, and begins flowing north-west into the Tonle Sap lake.
When the rains slacken and the river falls, the current changes course
once more, carrying its diminished flow back down to the sea.

Then there are the bizarre creatures that navigate these shifting
currents: catfish the size of cows, dome-headed dolphins, crocodiles
with a taste for royal blood - and relatively few people. Uniquely for
such a big river in the heart of tropical Asia, the biggest city along
the Mekong's banks - Phnom Penh - has a mere 1.1m inhabitants. That makes
the river unusual in another respect: the pressure of a burgeoning
population and fast economic growth is only just beginning to make its
mark on the Mekong. But the outcome could be all too familiar: a poor
compromise between conservation and development.

For centuries, the Mekong has disappointed those who have dreamed of
turning it into a major artery of trade and industry. At times,
overland routes have rivalled maritime ones as a conduit for east-west
trade in Asia, but the sea has always provided the simplest way of
getting from north to south. Thus Marco Polo probably crossed the
Mekong on his way home to Europe from China in the 13th century, but
did not travel along it. At any rate, he considered the river so
inconsequential that he did not mention it in his account of the
journey.

About the same time, 1,600km (1,000 miles) to the south, the only major
civilisation to be built around the Mekong, the empire of Angkor, was
reaching its apogee. Its Cambodian heartland sustained a population of
at least 1m through rice farming along the shores of the Tonle Sap, and
fishing in its waters. But the Mekong played a part in the empire's
trade only in so far as it provided an outlet to the sea. The Chinese
merchants and ambassadors who visited Angkor in its heyday came by boat
from China's coast and then up the Mekong from the delta, not downriver
from the Chinese province of Yunnan.

FOUR THOUSAND OBSTACLES

They did so in part because the Mekong is not navigable much beyond
Phnom Penh. In the dry season, when the river is low, boats must dodge
endless jagged reefs and shifting sandbars. Even when the water level
crests, the many rapids of Si Phan Don, or "Four Thousand Islands", in
what is now southern Laos, form an insurmountable obstacle to shipping.
Over a stretch of 30km, the Mekong divides into a muddled network of
streams and channels, tumbling over cascades and shoals.

But the main reason this huge river has always been such a commercial
backwater is the scanty population along its course. The biggest
expanse of flat, well-watered and fertile land in the basin lies around
Tonle Sap lake, but the devastating annual flood makes intensive
agriculture difficult there. Depending on the strength of the rains,
the surface area of the lake can swell to up to ten times its normal
size during the monsoon. But the water recedes quickly when the rains
stop, so the land is alternately flooded and parched.

No wonder, then, that the most powerful countries in the region took
shape in more hospitable river basins: China on the Yangtze and Yellow
rivers, Thailand on the Chao Phraya, Vietnam on the Red, and Burma on
the Irrawaddy, leaving the lower Mekong to much-diminished Cambodian
kingdoms. North of Cambodia, the Mekong flows through the periphery,
not the centre, of all these countries.

European explorers, who began snooping around the Mekong in the 16th
century, took hundreds of years to work that out, though. In the 1590s
a party of Iberian conquistadors overthrew the Cambodian king and set
themselves up as governors in the Mekong delta. A Dutchman, Gerritt van
Wuysthoff, struggled upriver as far as Vientiane in 1641. But as late
as the 1860s, when France conquered Vietnam and Cambodia, colonial
officials knew nothing of the river's northern reaches. They still
hoped that it might provide a lucrative back door to China, and in 1866
sent an expedition to explore both the Mekong's course and its
commercial potential.

The leader of the expedition died en route, and the survivors brought
back grim reports of impassable rapids and lawless hinterlands. But the
optimists pressed on. They seized control of Laos in 1893, and tried to
turn the Mekong into a thoroughfare linking all their colonies in
Indochina. To get round the rapids in Si Phan Don, they built a railway
across the river's two southernmost islands, Khon and Det, close to the
Laos-Cambodia border. Goods could be shifted from boat to train at the
southern terminus of the railway on Khon, below the rapids, and carried
to a vessel above them, at the northern end of Det.

The scheme was more a triumph of engineering than of economics,
however. Chinese merchants still found it cheaper to send goods to Laos
overland via Thailand. After the second world war, the railway--the
only one in Laos - fell into disuse. By now, villagers on Khon have
prised up most of the tracks for use as fencing. Water buffalo graze on
the grass that has sprouted on the old railway bridge linking Det and
Khon. Not far off, a rusty French locomotive lies abandoned in a bog.

In the 1950s and 1960s, America, too, dreamed of harnessing the Mekong
to enrich Indochina, and thus dent support for the region's communist
insurgents. Its allies in the region, Thailand, Laos, Cambodia and
South Vietnam, set up an agency called the Mekong Committee to
co-ordinate joint development projects. Plans were drawn up to dam the
Mekong, and engineers got as far as surveying several sites before the
ever-intensifying Vietnam war put an end to such schemes.

Thanks to all these disappointments, the Mekong remained almost
untouched until the 1990s. The first dam on the river, at Man Wan, in
China, was not completed until 1993. The first bridge across the lower
Mekong (ie, outside China) was built a year later, between Vientiane in
Laos and Nong Khai in Thailand. To this day, much of the river feels
deserted. Between the town of Stung Treng, in northern Cambodia, and
the Laotian border, hardly a house can be seen. There is so little
traffic on the road that runs parallel to the river north of the border
that "you could sleep on it," as one local remarks. Farther north
still, along some stretches of the river near Luang Prabang, only odd
patches of cultivated land give any hint of human settlement.

But that is changing fast. The population of Cambodia is growing by
2.6% a year, and that of Laos by 2.3% - among the highest rates in Asia.
Growth is lower in the Thai and Vietnamese parts of the basin, but they
have long been more densely populated. Economic growth is even faster:
5-6% in 2003 in Thailand, Laos and Cambodia, 7-8% in China and Vietnam.

BUILD AND DESTROY

To accelerate this trend, the Asian Development Bank (ADB) is promoting
a scheme to integrate the economies of the "greater Mekong sub-region".
Two north-south highways are under construction to link China and
Thailand, one via Laos and the other via Myanmar. So are five east-west
routes linking Thailand and Vietnam, three via Laos and two via
Cambodia. A tie-up of electricity grids and telecoms networks is also
getting under way.

The ADB may find it as difficult to make the region boom as the French
and Americans did. But one element of the current development drive is
bound to leave its mark on the Mekong: dam-building. According to the
International Rivers Network, an anti-dam group, some 100 large dams
are proposed for the Mekong basin.

China has already completed two on the Mekong itself, has started work
on a third, and plans at least four more. By the time the Mekong enters
Vietnam, it has already formed a delta, leaving no opportunity for
dam-building - so the government is building five dams on the one big
tributary that strays across its mountainous border with Cambodia
instead. Thailand, too, has dammed the main tributaries that flow
across its territory. The biggest dam enthusiast of all is dirt-poor
Laos, which hopes to enrich itself by building enough hydropower
projects to become the battery of South-East Asia.

This barrage of dams generates valuable electricity, aids irrigation
and regulates flooding - but in the process does irreparable damage to
what was, until recently, the Mekong's most valuable resource: its
fisheries. The Mekong and its tributaries yield more fish than any
other river system. The annual harvest, including fish farms, amounts
to about 2m tonnes - or roughly twice the catch from the North Sea. The
Mekong is home to over 1,200 different species of fish, more than any
other river save the Amazon and the Congo. Over 1m people in Cambodia
depend solely on fishing to make a living, while in Laos 70% of rural
households supplement their income by fishing.

The abundance of fish stems from the Mekong's seasonal ebb and flow.
During the monsoon, when the plains around the river and its
tributaries flood, the habitat for fish suddenly increases by as much
as ten times. Moreover, much of the flood-plain is actually forest,
which provides a particularly nutritious array of rotting leaves for
the fish to feed on. Many species in the Mekong have evolved to take
advantage of this delectable smorgasbord. They spawn at the end of the
dry season, so that the coming floods can carry the fry to the
flood-plain. The bigger the flood, the greater the feast on offer, and
so the fatter and more numerous the fish.

More dams, however, mean smaller floods. Most hydroelectric plants aim
to generate the same amount of energy year-round. That requires a
consistent flow through the turbines, which in turn requires rainwater
to be held in a reservoir for use in the dry season. The same drawback,
of course, applies to dams designed for flood control. Dams for
irrigation, meanwhile, have a doubly damaging impact on fisheries: they
not only hold back water, but also encourage the conversion of forest
to farmland in the flood-plain.

Irrigated rice-farming, which is two or three times more productive
than the rain-fed sort, is growing rapidly throughout the basin, albeit
from a low base. In Laos alone, the area under irrigation increased
eightfold in the 1990s. Meanwhile, the Mekong River Commission, the
latter-day successor to the Mekong Committee, calculates that flood
levels have fallen by almost 11% since 1965.

Fishermen all along the Mekong are already complaining of falling
catches. For now, at any rate, the problem stems more from the growing
number of fishermen than from falling numbers of fish. The Mekong River
Commission calculates that the fish catch actually doubled in Cambodia
between the 1940s and the 1990s. But over the same period, the number
of fishermen (along with the population as a whole) has more than
tripled, leading to a decline of 44% in the amount each one takes home.

To make matters worse, even if the catch as a whole is stable, certain
species are clearly dying out. The Siamese crocodile, which used to
pluck picnicking princesses off the riverbank, according to French
explorers, has already disappeared from the main river. Perhaps a few
hundred remain in the forested highlands of Laos and Cambodia - but they
too are threatened by hunting and habitat loss.

A similar fate awaits the Irrawaddy dolphin. According to Isabel
Beasley, an academic, there are only about 70 of these dark grey,
snoutless creatures left in the entire Mekong basin. These few
survivors, she explains, follow the fish in the dry season to deep
pools in the bed of the river near Kratie, in Cambodia. Despite their
scarcity, they can easily be spied at these spots, breaking the surface
in gentle arcs in pods of three or four. But fishermen also follow the
fish, and often snag the dolphins unintentionally in the large-mesh
nets they leave unattended for days at a time. As mammals, they need to
come to the surface to breathe at intervals of roughly 20 minutes. So
any that are caught in nets have usually drowned long before the
fishermen return to inspect their catch.

SUFFERING CATFISH

The reasons behind the dramatic decline in other species are murkier.
Take the giant catfish, the world's largest freshwater fish, which can
grow up to 3 metres (10 feet) in length and weigh up to 300kg (660lb).
It used to be found throughout the Mekong basin, but has completely
disappeared from most areas. In Chiang Khong, traditionally a prime
fishing ground, the catch declined from 69 in 1990 to two in 2000, and
none since. Unlike smaller species, which reach reproductive age within
a year, giant catfish take about seven years to mature, and so are
seven times more vulnerable to over-fishing. They also migrate upstream
to spawn, though no one knows where, exactly, they go, and therefore
whether the proliferation of dams is playing a part in their demise.

In general, the Mekong is so little studied that the effects of any
development project are hard to predict. China, for example, is paying
for a scheme that involves blowing up reefs in Laos, Myanmar and
Thailand, to provide a navigable channel for ships of up to 150 tonnes.
But halfway through the blasting, the Thai government has suspended the
project, for fear that the faster flow of an unimpeded current would
increase erosion and thus alter the midstream boundary with Laos.
Fishermen also worry that, since the reefs may be prime
breeding-grounds for fish, including the giant catfish, the catch of
all species will plummet if their habitat is destroyed.

That fear is not far-fetched. Something similar happened in 1994, when
Thailand, with money from the World Bank, completed a hydropower dam on
the Mun river, a major tributary of the Mekong. Since then, the fish
catch directly upstream has declined by 60-80%, according to a study by
the World Commission on Dams. The same study argued that, thanks to
cost overruns and lower-than-expected generation at peak times, it
would have made more sense to build a gas-fired plant.

To avoid a similar fiasco, the World Bank is insisting on umpteen
studies and safeguards for the Nam Theun II, a big dam it is financing
on a tributary of the Mekong in Laos. But the authoritarian rulers of
China, Myanmar and Vietnam do not always mull over big projects so
carefully, and no cost-benefit analysis at all is made of the thousands
of small dams, irrigation schemes and land clearances that are
undertaken each year throughout the basin. Anyway, governments in
upstream countries are unlikely to give much thought to the impact of
projects on lowly fishermen or farmers beyond their borders.

In theory, that is the job of the Mekong River Commission. Its members,
Vietnam, Cambodia, Laos and Thailand, are slowly drawing up pacts on
the exploitation of the Mekong and its tributaries. In 2001 they agreed
to exchange data on water flows. A pledge to notify one another about
big projects came next, and then a system to check up on such
declarations. Next year, if all goes according to plan, they will fix
the minimum amount of water each country must discharge downstream and,
in 2005, rules on water quality.

But none of these pacts will amount to much so long as China and
Myanmar refuse to join the Mekong River Commission. Officials from
downstream countries - somewhat hypocritically - say that China's
dam-building schemes threaten the whole basin. But for upstream
countries, of course, membership of the commission would bring many
restrictions and few benefits.

China has, however, been keen to rid itself of the image of a budding
regional bully, and has courted South-East Asian countries with trade
concessions. It also needs the acquiescence of downstream countries in
schemes such as the reef-blasting. In 2001 it agreed to the minimal
step of sharing data on water levels with the commission, to provide an
early-warning system for floods. After all, say officials at the
commission, co-operation among the riparian states, like the river
itself, should flow in both directions.[End]