FEATURE - Dams threaten Cambodia's "floods of fortune"
Date: 16-Oct-02
Country: CAMBODIA
Author: Ed Cropley
"It was this big," the 71-year-old said, his dark eyes lighting up and leathery arms stretching out to indicate the size of the giant cat-fish he once caught as a young man.
"But that was over 30 years ago, even before the Khmer Rouge came," he said, recalling the glory days of Cambodia's Tonle Sap, southeast Asia's biggest lake whose bountiful waters, ebbing and flowing with the seasons, support some 1.2 million fishermen.
"Now, the fish I catch are getting smaller and smaller. There are so many fishermen they catch fish faster than they breed," he said, pointing to the hundreds of little house-boats that make up this bustling floating village.
For thousands of years, the chocolate brown waters of the Tonle Sap, rising and falling in a unique annual cycle, have supported countless generations of fishermen, bringing fame and fortune to this small southeast Asian nation.
Legend has it the stunning temple complexes of Angkor, built by the mighty Khmer civilisation which ruled supreme in Indochina 1,000 years ago, were built on wealth netted from the lake.
Today, Cambodia, an impoverished international minnow of just 13 million people, lands over 400,000 tonnes of fresh-water fish a year, ranking it only behind China, India and Bangladesh.
Some two-thirds of this comes from the Tonle Sap, providing vital income and food for a nation slowly emerging from three decades of war.
DAM IT
For all the familiar doom and gloom of the fishermen, scientists fear the future of the lake, and in particular the annual floods so crucial to its fisheries, could be at risk.
Every spring, as glacial melt-waters from China and Tibet flow down the Mekong, the lake swells to five times its dry season size, covering some 15,000 sq km (5,800 sq mile) - nearly as big as Lake Ontario in North America.
Come November's dry season, the level of the mighty river falls back down and the lake slowly drains away again.
Fish follow these "floods of fortune", as locals call them, in their billions to feed in the rich waters of the mangrove swamps and inundated woodlands around the lake's shores.
But experts who have studied old Mekong records from Laos - Cambodia's data was destroyed by the Khmer Rouge - are worried the ever-growing number of dams in the river's upper reaches are smoothing out the annual ebb and flow and reducing the floods.
"Not only are dams decreasing the water flow, they also cut off access for fish larvae to their spawning areas," said Nicolaas van Zalinge, a Mekong River Commission biologist who says the river level has dropped some 12 percent since the 1960s.
In China, one huge dam, soon to be joined by a second, already spans the Mekong and some 25,000 other minor irrigation projects, many of them built with U.S. aid in northeast Thailand during the Vietnam war, are dotted throught its watershed.
With more massive projects planned for coming years - including a cross-Mekong dam at Sambo in central Cambodia - van Zalinge urges politicians to pause for reflection.
"For a long time there has been a push for the building of dams and irrigation systems driven by the big banks," van Zalinge said. "Governments must consider their effects when investing in irrigation and other schemes."
FISH OR RICE?
Van Zalinge believes the lake's fisheries are sustainable at current levels of flooding and fishing - but only if the delicate ecosystem is protected from a host of other threats.
With the increased destruction of ancient rainforest across the region and the consequent rise in erosion, it is debatable whether the lake will be there at all in the long term, or whether it will have completely silted up.
"The level of siltation is very minimal but we should be concerned about the amount of deforestation upstream and around the lake," said Nao Thuok, director general of Cambodia's Department of Fisheries.
"Maybe in 100 years' time there will be one very shallow or two separate lakes," he said.
