Bangkok Post
January 26, 2003

Villagers and environmentalists along the lower Mekong say the fish stocks have decreased dramatically in the past years. Despite the potentially devastating consequences, no-one else seems much concerned.

In Khong Jiam district in Ubon Ratchathani, the Mekong River curves as it leaves Thailand and enters Laos. Thailand’s portion of the Mekong River leaves national territory at the border village of Woenbuek.

The little fishing community has less than 100 families, most of which depend on fish from the Mekong. The village is about half an hour by boat from the Khong Jiam town district.

“I have been fishing the Mekong River for half a century,”said Buasi Kaewsai, 60. Talking as he weaved repairs into his fishing net, he recalled that he was in elementary school when he caught his first fish on the Mekong.

Buasi said he earns about 200 baht a day from his catch these days, much less than before. Pla nua on or bleekeri lost 70 baht a kilo. Pla jog or holdier river barb is 90 baht per kilo,” he said. In Bangkok markets, the fish sell for between 120 baht and 150 baht a kilo.

“I used to catch about six kilogrammes of fish a day,” he said. “Now I am lucky to catch two kilos.”

Buasi blames the Pak Moon dam for the decline of fish in the river. The dam was built on a tributary of the Mekong, the Mae Moon, which flows into the Mekong upstream from Woenbuek.

“Now we catch less fish than before the dam was built. The dam causes unnatural fluctuations in the Mekong’s water level,” he said. “That’s the reason for the declining catch.” Others say the large dams built along the upper Mekong in the Yunnan province of China have a greater
effect.

Buasi admits that he does not know how the dams affect the river in terms of its ecology. “I know only that there are less fish. If this goes on, we will have no income, and we will end up going to Bangkok in search of work.”

Wichian Pungpa, a 31 year-old fish trader in Woenbuek district, echoed the old fisherman’s worries.

He said that in the past he used to buy an average of two tonnes of Mekong fish from both Thai and Laotian fishermen each week. “Today, I can buy only one or two tonnes.

“I think in the future there will be even less fish in the Mekong River,” said the fish trader.

The opinions in this fishing village are indicative of the general alarm sounding up and down the Mekong.

The Mekong River at Woenbuek is only 300 metres wide. Thai and Laotian communities on opposite banks of the river share a good relationship.

Laotian fishermen cross the river to buy construction materials and food from the Thai side, after selling their fish to Wichian in Woenbuek.

Sunday Perspective has made the river trip from Chiang Khong, Chiang Rai in northern Thailand to Kokpadaek Village in southern Laos. Everywhere, fishermen say the same thing:
“There are less fish in the Mekong River.”

A villager in Kokpadaek said: “The fish hauls continue to decline. Thirty years ago we used to haul up to 100 kg of fish daily. By 1996 we caught a mere three to four kg a day.”

The big picture is mostly out of their control, but villagers in Kokpadaek and elsewhere in Laos are doing what they can to preserve their livelihood as well as the ecology of the river. In 1997, they set up a fish conservation area in a 300-square-metre river pool, with great success (see sidebar). Today, there are 76 fish conservation zones along the Mekong river in the Khong District of southern Laos alone.

River feeds millions

The Mekong is the largest river in southeast Asia, and the twelfth largest in the world.

An estimated 1,700 species of fish are believed to inhabit the Mekong’s waters, including the endangered Mekong giant catfish. Another endangered Mekong species is the freshwater Irrawady dolphin.

The Mekong River Commission (MRC) says the Mekong basin supports about 60 million, but no one has estimated the number of people depending on the river directly or indirectly for their income. Fish is by far the greatest source of protein for most of the 60 million people around
the basin.

The Mekong supports one of the largest inland fisheries in the world. The total annual catch of the lower areas (Cambodia, Laos, Thailand and Vietnam) alone is conservatively estimated at about 1.8 million tonnes, worth approximately US$1.4 billion. The Tonle Sap Lake in Cambodia contributes up to 400,000 tonnes a year.

But except from the fishermen and a few environmentalists, there is no cry of alarm along the Mekong about the decline of fish in the river. No organisation or country has gone so far as to study the Mekong’s progressive decline of fish stocks, its causes, or ways to stop it.

Chavalit Witdhayanon, an aquatic biologist at the Thai Department of Fisheries, said there has been no study or research specifically investigating the declining stocks of fish in the Mekong River.

“Such research takes time, manpower and a lot of budget,” said Chavalit, a lecturer at Kasetsart University.

Environmentalists say the decline of fish stocks is caused by many factors such as deforestation, riverbank environmental changes, and not least the construction of dams on the upper Mekong in Yunnan.

“Cutting trees affects the Mekong and its tributaries because it reduces fertility, fish food, and fish breeding” said Chavalit.

Overfishing and the use of modern fishing equipment are partly responsible for the decline of fish in the Mekong River, and fish fry are destroyed by fishermen who use explosive bombs as well.

The increasing human population also depletes the fish stock of the Mekong. Fishing does not stop during the breeding season.

Many environmentalists have claimed that dams in China confuse the breeding habits of fish in the river, but no investigation has focused on the types of fish sensitive to water level changes.

Chavalit explained how the fluctuations in the Mekong’s water levels – caused by dams in China – could affect the number of fish in the Mekong.

“Many fish breed according to seasonal lows and highs in water level. If the water level changes unusually, they may not lay their eggs. Or if they do lay eggs the survival rate of the fish fry may be low.

“All the dams along the Mekong affect the fish,” he said.

Though no research has been done on the affects of dams on fish in the Mekong, the usual catch of up to 40 giant catfish a year is now so dramatically less that alarms cannot be ignored.

Chavalit pointed out that the bigger the dams are, the more they impact fish breeding and nurseries.

The history of the Pak Moon Dam in the Mae Moon – a tributary of the Mekong – shows how dams affect fish in rivers. The dam prevents fish from the Mekong from breeding and spawning in the Mae Moon River.

Dams biggest threat

Environmentalists in Laos also believe that Chinese dams negatively affect fisheries downstream the Mekong.

They say that fish populations are threated not only by dams but also by overfishing, destructive fishing, pollution –  factories, household, agricultural – rapids blasting,  destruction of wetlands and floodplain habitats, riverbank  erosion, as well as river bank stabilisation projects.

“There are many threats, but dams may be the biggest, as they cause permanent and long term hydrological changes that have huge ecological implications,” said a fish conservationist in Laos speaking on anonymity.

Chinese dams will cause unusual hydrological conditions which are contrary to requirements of various fish species and other aquatic animals that have evolved their migrations and spawning behaviour to the natural hydrological conditions of the Mekong, said the scientist.

For example, primary food production (algae) in the Mekong River requires photosynthesis. The sun’s rays must pass through the water so that algae can grow on rocks in the dry season. Many fish migrate to eat this algae in the dry season.

If there is more water in the dry season, the sun will not be able to easily reach the rocks below, so there will be less algae for fish and other aquatic animals.

It is difficult to speculate on fish production over the next ten years, said the fish conservationist.

“China’s dams and rapids blasting may continue to cause declines, although fish will not entirely disapper from the Mekong.

“However, the people must do something to ensure larger quantities of fish in the years to come,” said the fish conservationist.

The future will depend on whether people are committed to protecting the Mekong or not, he said.

“If the governments of the region support community fish conservation along the Mekong, there is a chance that fish populations could actually increase.”

A detailed study by the Mekong-connected governments and concerned organisations which prescribes preventive measures is imperative to protect the ecology of the river, unless
they intentionally want the fish populations to decline.

If fish populations do continue to decline it will eliminate many riverine jobs, causing people to migrate to the big cities, as Buasi is afraid will be the only choice for his children.