Photos showing thousands of dead fish floating on the Kameng River after its water suddenly turned black on Saturday have emerged online, triggering outcry from locals in the village of Seppa in the Indian state of Arunachal Pradesh.
After investigating the river, officials from the district's fisheries found a high level of total dissolved substances (TDS) – a measure of the dissolved combined content of all inorganic and organic substances present in a liquid in molecular, ionised, or micro-granular suspended form – which they believe blackened the river and suffocated the fish.
Locals claim the dangerously high level of TDS is due to construction activities by China across the border.
The TDS in the Kameng River was recorded at 6,800 mg per litre – much higher than the normal range of 300-1,200 mg per litre, District Fisheries Development Officer (DFDO) Hali Tajo said.
Tapuk Taku, an Indian politician from Arunachal Pradesh, has appealed to the government to immediately set up an expert committee to find the cause of the poisoning.
"If it continues for more than a few days, the aquatic life from the river will be totally eliminated," Taku told PTI.
In 2017, the Siang River in Arunachal Pradesh's Pasighat district also reportedly turned black.
At that time, Congress politician from Arunachal Pradesh – Ninong Ering – blamed a massive tunnel project in China and appeal to Indian Prime Minister Narendra Modi to intervene. The construction work diverted water from Arunachal Pradesh's Siang district to the Xinjiang province in China's Taklamakan Desert. However, Beijing denied the allegations.