The endangered Ganges river dolphin is one of two distinct dolphins living in the rivers of South Asia. It lives in the Ganges and related rivers of South Asia, namely in the countries of India, Nepal, and Bangladesh.
The Ganges river dolphin’s range lies within some of the Earth’s most densely populated areas. Typically, both fishermen and dolphins congregate in the same spots where nutrients are rich, currents slower, and fish concentrated.
Because of this intersection, Ganges river dolphins are mainly threatened by human activities such as pollution, bycatch, and infrastructure, but also suffer similar consequences of climate change as other marine mammals.
Although the Halda River in Chattogram was declared as Bangabandhu Fisheries Heritage in 2020, it has gradually become more dangerous for these freshwater mammals.
The Ganges dolphins locally known as Utom or Shushuk like to live in clean water. But Halda's aquatic environment is becoming increasingly unsafe for dolphins due to water pollution, which experts say is a gloomy sign for the environment and Halda as well.
The Ganges dolphin was red-listed by the International Union for Conservation of Nature (IUCN) as an endangered species in the country.
Read more: Another dead dolphin recovered from Halda River
According to experts, there are only 1,100 of these dolphins in the rivers across the world. Among them, there are 170 in Halda alone.
Unfortunately, 39 dolphins are documented to have died in the Halda in the last four years, including 6 in 2022. Of these, three dead dolphins were recovered within a span of just one week in July.
The last dolphin carcass (39th) was recovered from the Halda River in Hathazari upazila of Chattogram district on November 3, 2022. The cause of the dolphin's death could not be known as the carcass was found decomposed. These aquatic animals are dying one after another but no one cares.
Dr. Md Shafiqul Islam, a researcher on the Halda River, said fishing is being done illegally in various parts of the river using different types of nets, spears and poison.
Besides, food scarcity, pollution, poor water quality and climate change are behind the deaths of dolphins. Lack of awareness about the existing laws among the people, indifference on the part of authorities concerned have made water pollution a negligible crime - even though its effects on the environment can be severe.
The authorities concerned as well as everyone involved in Halda must work together to make the Halda a safe habitat for dolphins, added Dr. Shafiqul.
According to Halda River Research Laboratory, the local administration has recovered 39 carcasses of dolphins from the Halda River since September 2017 and most of the carcasses bore several injury marks.
Read more: Halda fish egg collectors brood on misfortune
A research report on the biodiversity and pollution of the two banks of the Karnaphuli River, led by Omar Faruq Russell, associate professor of the Botany Department of Chittagong University, was published in October 2022.
According to the report, Shikalbaha and Boalkhali are the two points of the Karnaphuli River where dolphins are usually sighted due to the fewer water vessels. It also mentioned that dolphins are under constant threat due to pollution.
Manjurul Kibria, river researcher and chairman of the zoology department of Chittagong University, told UNB that the rate at which dolphins are dying in the Halda River is alarming. Effective steps should be taken now to protect the Halda dolphins immediately. Otherwise, it won't take long for the number of dolphins in Halda to drop to zero.
“In 2018, we found the presence of 167 dolphins in Halda. In 2020, that number decreased to 127. In 2022, the number again rose to 147, which is the highest in the rivers of Bangladesh,” he added.
Nets are the main cause of death of these dolphins as most of them died after being caught in the nets of poachers, the researcher observed.
When asked about this, Hathazari Upazila Executive Officer (UNO) Muhammad Shahidul Alam told UNB that they are working regularly to protect the dolphins and biodiversity of Halda River.
New action plans are being taken to protect the dolphins, he added. In 2019, the High Court formed a committee to protect Halda river dolphins comprising Chattogram District Commissioner and Chittagong Divisional Forest Officer (Wildlife and Nature Conservation Department) as Member Secretary.
Read more: Miscreants kill dolphin in Halda River
According to the instructions of the High Court, the responsibility of protecting these dolphins goes to the Forest Department. But they have no headache in this regard.
Locals complained that they did not get any rescue support from the Forest Department upon the death of any dolphin.
In this regard, Chittagong Divisional Forest Officer (Wildlife and Nature Conservation Department) Md. Rafiq said dolphins are dying due to geographical changes. "We are taking necessary measures upon the news of any dolphin's death," he said.
Mohammad Mominur Rahman, district commissioner of Chattogram said, "We have stopped all sources that pollute Halda, and 17 industrial plants along the Halda river have already been shut. And the waste from the remaining industries is not allowed into the river.”
He also said that the district administration is doing everything necessary to protect the Halda River.
“We have brought the important part of Halda River under CCTV camera. Not only that, we have closed 9 brick kilns adjacent to the river. Motorboats have been completely banned. But we are yet to identify the reason behind the death of dolphins in Halda,” he sighed.