A dead dolphin, weighing around 37kg with a length of 4ft 7 inches, was found floating near Ajimer Ghat of the Halda River at 11am on Wednesday.
SM Mujib, a resident of the area, said: "We recovered the dolphin after we spotted it floating in the river. It seemed that the dolphin died a few days ago."
Prof Dr Manzoorul Kibria of the zoology department at Chittagong University, who has conducted significant research on the Halda River, confirmed that the dolphin sustained injuries in its mouth and died a couple days ago.
"It is a matter of grave concern for the Halda fisheries and livestock. The dolphin may have died after being hit by the propeller of an engine-run boat or sand-extracting dredger," Prof Kibria added.
From September 17 last year to February 1 of this year, as many as 18 dolphins were found dead in the Halda River. Among them, 17 dolphins were adults, while the rest were yet to reach maturity.
On February 22, the Ministry of Fisheries and Livestock formed a probe committee following the deaths of 18 dolphins in the Halda River, and the committee subsequently submitted a list of recommendations to prevent the deaths of the marine mammals.
The six-point recommendations include stopping all types of dredgers used for extracting sand and the plying of engine-run boats in the Halda River, prohibiting all types of nets and gears which hinder the free movement of fish and dolphins in the river, ensuring stern legal action so that industrial pollutants and polluted water do not get mixed with the river, forming a co-management committee involving the locals to conserve the biodiversity of all aquatic fauna including dolphins, as well as amending the existing fisheries law and conducting research to ensure safe reproduction and habitat for the dolphins in the river.
According to the researchers, rampant pollution, the use of dredgers for extracting sand from the river, shallow water, and the plying of mechanized boats are sharply reducing the dolphin population in the Halda River, which is Bangladesh’s largest natural breeding ground for carp.
Two types of dolphins are found in Bangladesh- the irrawaddy dolphin (Orcaella brevirostris) and gangetic dolphin (Platanista gangetica).
The official status of the river dolphins, locally known as Shushuk [Platanista gangetica] is “critically endangered,” as per the International Union for Conservation of Nature (IUCN) Red List.
The IUCN Red List of Threatened Species is a universally recognized index of the world’s endangered animals.
According to Halda River Research Laboratory, the number of river dolphins around the world does not exceed 1,200. Of the total number, some 250 dolphins are found in the Halda River.