Traders are searching for fish scales.

Ms. Nguyen Thi Huong, owner of a dried fish processing facility in Khanh An commune, An Phu district, An Giang province, said that her facility currently processes about 10 tons of snakehead fish for drying each day. The amount of scales discarded is equivalent to 600 kg.

"More than two years ago, someone came and offered to buy all the fish scales for 1,200 dong per kilogram, so I sold them instead of throwing them away," Ms. Huong said, adding that a truck would come to weigh and transport the scales every 4-5 days. She said they sold everything, but when asked what they did with them, they wouldn't say.

Many other households in the dried fish village of Khanh An commune also sell to traders from other places who come to buy them at a price of 1,500 - 2,000 VND per kg.

Mr. Cao Xuan Dieu, Chairman of the People's Committee of Khanh An commune, confirmed that traders are buying snakehead and catfish scales from dried fish processing villages in the area. "Through working with some dried fish processing facilities, they said they sell the fish scales to traders for use as fertilizer," Mr. Dieu said.

Mr. Pham Thanh Tam, Deputy Head of the Agriculture Department of An Phu District, said that traders buying this type of waste helps increase people's income and reduce environmental pollution. "The local authorities will investigate where they are transporting it and what they are using it for," he said.

According to nutrition experts, fish scales contain a lot of lecithin, which helps improve brain memory and slow down the aging of brain cells. In addition, fish scales are rich in many trace elements, especially high levels of calcium and phosphorus, which can prevent rickets in children and osteoporosis in the elderly...