Salween River ecosystem
The Salween River, also known as the Nujiang in China, is a significant waterway in Southeast Asia, extending approximately 1,500 miles (2,400 kilometers) from its source in the Tibetan Plateau to the Andaman Sea. Renowned for its breathtaking scenery, the river flows through rugged mountainous terrain, narrow valleys, and gorges. It supports a rich ecosystem, home to at least 140 fish species, 7,000 plant species, and numerous endangered animals, including the Siamese crocodile and various turtle species. The river's biodiversity thrives in relatively pristine conditions, yet faces growing threats from proposed dam constructions, which could disrupt its natural flow and endanger local wildlife. Human activities such as mining and logging further exacerbate environmental degradation, leading to erosion and habitat fragmentation. Fishing remains a vital source of income and sustenance for many communities in the watershed. Climate change impacts, including altered glacial melt and increased flooding, add another layer of complexity to the river's ecological health. As plans for additional hydropower dams advance, the concerns of indigenous communities and environmental advocates highlight the need to balance development with the preservation of this unique ecosystem.
On this Page
Subject Terms
Salween River ecosystem
Category: Inland Aquatic Biomes.
Geographic Location: Southeast Asia.
Summary: Flowing through rugged, mountainous terrain, the Salween is relatively unspoiled but in jeopardy from mining, logging, and dam construction.
The Salween River of Burma (Myanmar) runs through a rugged, mountainous, north-south series of narrow valleys and gorges; it is approximately 1,500 miles (2,400 kilometers) in length. Glaciers in the eastern highlands of the Tibetan Plateau form the sources of the Salween River. Its path takes it southward through Yunnan Province in China, then along parts of the Burma-Thailand border, and finally into the Andaman Sea.
The Salween begins approximately 13,100 feet (4,000 meters) above sea level. Only one southeast Asian river, the Mekong, is longer than the Salween River. Throughout its history, the Salween has been a free-flowing river, but recent pushes from various governments and commercial interests to add as many as 16 major dams along the Salween could change the river and its ecosystem quickly. Dams remain one of the greatest threats to the wetlands and river.
This great river is known by many names as it courses through China, Thailand, and Burma; the Chinese call it the Nu Jiang, or angry river, perhaps reflecting its rapid flow as it streams through sheer canyons in its upstream segments. Fishing is a primary source of income and food for many human inhabitants of the 105,000-square-mile (272,000-square-kilometer) Salween watershed.
From its beginning in the Qinghai Mountains on the Tibetan Plateau through its terminus at the Andaman Sea in Burma, the river undergoes dramatic changes. Portions of it are known as the Grand Canyon of the East, while other segments water woodland- and agricultural-dominated plateaus and valleys. The Salween is recognized as being in relatively pristine condition, with much of its biome intact.
Recent plans to dam the river have met with fierce resistance in some quarters, especially among indigenous peoples, as such measures would dramatically change both the nature of the river and its biota, endangering many species of flora and fauna that rely upon the Salween’s free-flowing waters, and jeopardizing the livelihood of many humans. Fish spawning grounds and migratory pathways are of particular concern
Biodiversity
Among a diverse flora, montane evergreen forests are spread across many ridges upstream, while mangroves are found near the Salween Estuary.
The Salween River area has been known to support at least 140 species of fish, 7,000 species of plants, and up to 80 different types of endangered species in all. Minnows are by far the most prevalent fish found here. Some endemic (found nowhere else) fish species are Hampala salweenensis and Hypsibarbus salweenensis; up to 50 endemic fish species inhabit the biome.
Larger fauna in the Salween River biome include Siamese crocodiles, Asian small-clawed otters, and the fishing cat. The wild ox, wild donkey, and golden-eye monkey are ensconced along its banks. Turtles are an important component of the ecosystem, and a food source for many. Among the dozen different turtle species found in the Salween River are the Asian leaf turtle (Cyclemys dentata), giant Asian pond terrapin (Heosemys grandis), and big-headed turtle (Platysternon megacephalum).
Threats
Mining, logging, and other disruptive human activities can undermine the high-relief landforms along the Salween River, adding to erosion and exacerbating the damage done by frequent landslides during the rainy season. Flooding, increased siltation and turbidity in the river, and fragmentation of habitats are the typical outcomes. Climate change impacts along the Salween River range from altered glacial melt regimes at the source, to heavier monsoon precipitation and wind across the main segments, to sea-level rise at the mouth. Additionally, some research suggests that dam construction is a net additive to global warming—apart from the destruction of forested areas it necessitates—by creating stagnant reservoirs conducive to algal blooms and rotting plants that release quantities of greenhouse gases. According to a 2019 study published in the book, Knowing the Salween River: Resource Politics of a Contested Transboundary River, the governments of China, Myanmar, and Thailand have plans to construct twenty additional hydropower dams on the river.
Bibliography
Hedley, P., Michael I. Bird, and Ruth A. J. Robinson. “Evolution of the Irrawaddy Delta Region Since 1850.” Geographical Journal 176, no. 2. (2010).
Lamb, Vanessa, et al. “A State of Knowledge of the Salween River: An Overview of Civil Society Research,” Knowing the Salween River: Resource Politics of a Contested Transboundary River, edited by Carl Middleton and Vanessa Lamb. Springer, 2019, pp. 107–120.
Twa, Saw Sein. “The Salween—My River, My Natural Belonging.” Watershed 4, no. 2 (November 1998).
WWF Dams Initiative. Rivers at Risk—Dams and the Future of Freshwater Ecosystems. Washington, DC: World Resources Institute and World Wildlife Fund, 2004.