Fish surface on Karnaphuli after burnt sugar waste flows in

Various species of fish and aquatic animals have started floating to the surface of the Karnaphuli River under the influence of waste stemming from melted raw sugar burnt in a fire at the S Alam Group warehouse in Chattogram.

Big fish are rare in the pollution-hit river. Hundreds of people gathered to fish on both sides of the river on Wednesday after witnessing the unusual sight.

Experts said the level of oxygen in the water dropped due to the waste from the burnt sugar, and so fish and other aquatic species are floating to the surface due to the lack of sufficient oxygen.

The river has been largely devoid of large fish for the past decade due to pollution over the years. The few species of small fish that survive in the river are also at risk of extinction because of chemical pollution from the burning of sugar.

S Alam Refined Sugar Industries Limited is situated in Karnafuli Upazila’s Charpatharghata Union on the south bank of the river. A warehouse of the company is used to store refined sugar, while the four others are used for crude sugar, a compound of carbon, hydrogen, and oxygen.

Around 400,000 tonnes of raw sugar were stored in four warehouses owned by the company, including 100,000 tonnes in the one that burnt, an S Alam Group official said.

The fire could not be fully extinguished despite efforts made since it started on Monday. The warehouse was seen burning even on Wednesday afternoon.

Speculation by experts on the impact of the fire on the river and the surrounding environment came true when the melted crude sugar from the burning warehouse began flowing into the river. Since Tuesday, fish have been seen floating on both sides of the river.

The water has turned brown in parts near the river’s south bank due to the pollution.

“The authorities collected samples of water and sent them to a laboratory for a test on Tuesday. Initial test showed the oxygen level in water fell from 5 ppm to 1 ppm. The sugar burnt into carbon dioxide and fell into the water in liquid form," said Kamrul Alam, chief chemist at the Environment Department’s Chattogram office.

“The S Alam Group is trying to stop the liquid from flowing into the river alongside the sand. A team from the environment office also launched efforts to identify the quality of water.”

District Fisheries Officer Shrivas Chandra Chand said he hoped the tide would restore the normal water quality.

The amount of chemicals in the river bed is expected to reduce when the tide comes in, and the situation will return to normal then, he said.