Hundreds of dead fish and other marine life found floating in the river Halda in Bangladesh

Hundreds of dead fish of different species, and other aquatic animals have been found floating in the river Halda for the last couple of days.

The dead fish are posing a serious threat to the aquatic biodiversity of Bangladesh’s largest natural breeding ground for carp.

According to the Department of Fisheries lab, the level of dissolved oxygen (DO) went below 1mg per litre on an average against the required level of at least 5mg per litre.

According to the District Fisheries Office, the level of dissolved oxygen was found low in the two feeder canals of the river. In some points, the level of ammonia was found to be 0.5-1.5ppm against the tolerable limit of 0.01ppm.

The high concentration of ammonia in water makes it difficult for aquatic organisms to sufficiently excrete the toxicant, leading to toxic build-up in internal tissues and blood, which leads to their death.

Humans need air to breathe, and the aquatic organisms need dissolved oxygen to respire. It is necessary for the survival of fish, invertebrates, bacteria, and underwater plants. Dissolved oxygen is also needed for the decomposition of organic matter.

Locals said the water of Halda River turned pitch-black on June 20, spreading the rotten stench of dead fish.

Following the matter, the locals formed a human chain at Madunaghat area on June 23, demanding that the river be saved from industrial pollution.

Courtesy of dhakatribune.com

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