Murder of the Salween: Pollution, dams and destructive fishing practices affect Karen communities
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Over the past five years, Ms Mu Tee and her uncle, Mr Saw Ni Say, observed a dramatic decline in their catch due to unregulated fishing practices and pollution.
PHOTO: ANIS NABILAH AZLEE
Zachary Lim and Anis Nabilah Azlee
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MAE SOT, Thailand - About a decade ago, Mr Saw Ni Say recalls being able to catch up to 5kg of fish along the Moei River – a tributary of the Salween.
Today, the corn farmer reels in less than a kilogram if he is lucky, making it harder to feed his family at times.
“When I was young, there were a lot of fish in the river,” said the 65-year-old. “I fish less today because there are fewer fish, and they’re smaller.”
His experience mirrors that of the over 10 million people from at least 13 ethnic groups who rely on the life-giving waters of the Salween River. It spans 2,800km and is Asia’s longest undammed river – so far.
But as discussions on tapping hydropower progress across South-east Asia, dam construction projects, pollution and unregulated fishing are threatening the river, which flows through China, Myanmar and Thailand.
In 2010, the Salween River was among the 10 most polluted rivers in the world, according to the Food and Agriculture Organisation (FAO) of the United Nations.
A family crossing the Moei River by boat from Karen State in Myanmar to Mae Sot in Thailand.
PHOTO: ZACHARY LIM
These river threats have implications for a large proportion of the Karen community in both Mae Sot and Myanmar’s Karen State. The Karen are an ethnic group largely originating from southern Myanmar.
The majority of the Karen community are farmers and fishermen, and rely on the river to irrigate their crops and get their supply of fish, said Mr Saw Hea Say, coordinator of environmental watchdog Karen Rivers Watch.
“Having spent much of their day near the river, many of them have developed a special affinity for, and dependence on the river,” he said.
The Moei and Salween rivers are also home to about 300 species of freshwater fish – though some experts estimate there could be many more others yet to be discovered.
Professor Peter Ng, an adviser at the National University of Singapore’s Lee Kong Chian Natural History Museum who studies marine and freshwater crabs in the Indo-West Pacific, said these rivers are still poorly explored.
He added: “We don’t know very much about them... These are just the numbers of fish species alone, which are considered among the more well-explored groups.
“If you look at other freshwater animals, like insects, probably up to 90 per cent of the fauna there is not known.”
This makes creating comprehensive management and mitigation plans by the relevant authorities challenging due to the overall ambiguity of the ecosystem, said Prof Ng.
River life on the line
The Moei River is mainly fed by rainfall, surface run-off and treated wastewater.
Its headwaters – streams of water that merge near the source of a river – meet in the highlands of Phop Phra, in Mae Sot.
During the rainy season between June and September every year, rubbish that is discarded along either side of the river gets swept into the Moei River, said Mr Saw Ni Say, the corn farmer.
During rainy seasons, the Moei River often overflows its banks, sweeping improperly discarded rubbish nearby into its channel.
PHOTO: ANIS NABILAH AZLEE
“About two years ago, I saw along the riverside in Myawaddy, every day around 4pm to 5pm, people would throw rubbish like food boxes and packaging carelessly into the river. Even the rubbish truck would dump garbage into the river,” he added.
River life is also threatened by unregulated fishing practices, which include the use of explosives and electricity to kill or stun a large number of fish. Such practices often result in the death of more fish than is required by the fishermen.
The collective impact of the multitude of stress factors has resulted in a drastic drop in both numbers and sizes of the fish native to the river, said the Karen River Watch’s Mr Saw Hea Say.
“These methods kill the baby fish – which they do not want, and leave adult fish unable to reproduce,” he added.
While data on the decline of biodiversity in the basin is scant, environmental non-profit International Rivers noted that damming activity alone is likely to disrupt the freshwater fish ecology and threaten one-third of fish species in the river.
The construction of large dams would also lead to new roads being built, which would facilitate the movement of poachers, loggers and other resource users, thereby threatening the ecological integrity of the area, it added.
While the Thai authorities have introduced regulations such as fines of up to 10,000 baht (S$400) for the improper disposal of rubbish and irregular fishing practices, locals say they are not actively enforced.
Mr Saw Hea Say added that political tensions in Myanmar and Thailand have pushed environmental issues off the national agendas of both countries.
“It is concerning because these issues are affecting the bigger Salween River, which is already one of the world’s most polluted rivers... The river is our home. We must protect it. If it is damaged, we are damaged,” he said.
Damming and displacement
These threats affect more than just the biodiversity of the Salween River and its tributaries. The Karen community, too, faces displacement from dam projects.
Over the past two decades, companies, enterprises and the authorities across China, Myanmar and Thailand have been planning to erect dams along the Salween River to harness the channel’s hydropower potential, according to a 2011 report by the FAO.
This includes the Electricity Generating Authority of Thailand and Chinese hydropower company Sinohydro, which has proposed building seven dam projects – one of which, the Hatgyi dam, is to be situated in Karen State’s Hpapun district.
Progress on the project, first announced in 2006, has stalled, most likely due to post-coup instability and strong resistance from locals, as reported by multiple sources including the climate diplomacy arm of German environment consultancy Adelphi Global.
In September 2016, Myanmar’s Border Guard Force collectively displaced some 5,000 Karen from their villages near the proposed dam site, the Karen Rivers Watch said, citing information from villagers.
In 2023, villagers filed a landmark lawsuit to halt a different initiative – the Salween Water Diversion Project. The project aimed to pipe large amounts of water from the Moei and Yuam, another tributary of the Salween, to irrigate central Thailand’s rice-producing region.
There is currently no set completion date for the project.
Karen youth push back
Despite the call by Karen Rivers Watch for a moratorium on damming activities until peace is established in the conflict zone, construction has persisted.
In response, activist organisations like the Karen Students’ Network Group have partnered the environmental watchdog since 2016 to protest against damming activity every year on March 14 – the International Day of Action for Rivers.
The student group provides Karen students with a platform to tackle a variety of societal issues through education and publicity efforts.
The group’s social and relations officer Joseph Lah said: “A lot of our Karen people plant rice, beans and vegetables. So, if the river is stopped by a dam and not flowing as usual, then both sides will face heavy impact on their agriculture.”
He believes that the media attention on these movements has helped delay parts of the hydropower project timeline in recent years.
Beyond protests, the students organise clean-up drives, tree-planting programmes, and community dialogues to help with river conservation, promoting environmental responsibility.
“But it’s hard to change (people’s waste disposal habits sometimes),” Mr Lah said. “It’s been ingrained in many people’s minds, and it’s what they are used to doing. No one is stopping them, either.”
For Mr Saw Hea Say, cross-border cooperation and law enforcement are necessary to protect the river. “Rivers should flow freely... but that can be done only if Thailand and Myanmar work together,” he said.
“More research about the area, and education on responsible waste and fishing practices are needed. The authorities need to enforce regulations much more actively as well, so that our future generations can enjoy a healthy flowing river too.”
Zachary Lim and Anis Nabilah Azlee are final-year communication studies students at Nanyang Technological University’s Wee Kim Wee School of Communication and Information in Singapore. Their report is part of the school’s Going Overseas For Advanced Reporting, or Go-Far, module.

