Every five years, the WWF-Pakistan along with the Sindh, Punjab and KPK Wildlife Departments and other NGOs, conduct an Indus Dolphin population survey on the river. According to the findings of the latest survey, conducted in 2011 after the massive floods of 2010 (with one section covered in 2012 due to security concerns), an increase in dolphin population was observed in some of the river sections, showing that its distribution had increased (previously it was concentrated in the river section between the Sukkur and Guddu barrages).
According to Uzma Noureen, who is the Project Coordinator of the Indus River Dolphin Conservation Project, “In the river section between the Taunsa and Guddu barrages, we recorded 465 dolphins. This section previously has a record of 259 dolphins according to the 2001 survey. In the river section between the Sukkur and Kotri barrages, we recorded 34 dolphins whereas in 2006 only four dolphins were seen”. This is a direct count (one boat goes out on the river and surveys the dolphins, spotting them when they come up for air). “Sometimes we can’t survey all the side channels and canals due to security concerns. On the computer, we do a further analysis and the areas that we missed, we extrapolate. This is done on a scientific basis using the standard methods and techniques. This gives us the estimated population,” explains Uzma Noureen.
During the last survey completed in 2006, the estimated population of Indus Dolphins was found to be around 1,600 and this year it is around 1,452, which Uzma Noureen says is “a slight decrease”. This decrease in dolphin population, however, could be due to the increased water level in the Indus after the floods, providing the dolphin population an opportunity to disperse. She further explains that after the floods of 2010, many channels have become active again and they could have been missed during the survey.
“We survey during low flow season, when the possibility to spot dolphins is high due to a concentration of the dolphin population in the main river stream, but after the floods of 2010, there is more water in the river and the river’s extent has increased, dispersing the dolphin population and increasing its distribution. If after the floods, we found slightly fewer dolphins, we can’t really say that the population has decreased”.
Uzma Khan agrees: “What we are saying is that if you look at the numbers there is a slight decrease but this needs careful interpretation; because of the massive 2010 floods there was so much water in the river, its span was wider and there were more side channels and therefore, detection was much harder. The study also found that while the dolphin population decreased in Sindh, it almost doubled in the Punjab, so clearly its distribution has spread”.
In a previous news report based on the same study it had been claimed that the Indus Dolphin’s population had decreased. However, various other reports contradicted it. The conservationists involved say it is a matter of interpretation.
The movement of the Indus Dolphin is not restricted to the main stretch of the Indus River. During high flow season, the Indus Dolphin routinely swims into the many connecting irrigation canals of the Indus when the gates are usually opened. It frequently moves back and forth in the irrigation canals and tributaries of the river. When water levels go down and the canals are closed, the dolphins get stranded in small water pools – in the past, they often died of starvation or inadvertently drowned in the nets of the local fishermen who fish heavily in the closed canals. WWF-Pakistan, in collaboration with the Sindh Wildlife Department set up an Indus Dolphin Rescue Unit several years ago to rescue trapped dolphins and physically transport them back to the Indus River. According to Uzma Khan, while rescues had been taking place in an ad-hoc manner for years, “the organised rescue programme was launched in 2000”. Since 1992, around 112 dolphins have been successfully rescued. The rescue unit is based in Sukkur and is equipped with a special dolphin rescue ambulance. There have been a number of rescues since the floods of 2010 because many dolphins spread into irrigation canals and active channels and had to be rescued from there.
It is not just the blind dolphin but also the local fishermen, who benefit from the floods. And that also brings bad news to this ancient creature. The biggest threat the Indus Dolphin currently faces is from unsustainable fishing practices. “The local fishermen sometimes throw pesticides into water to get fish or use nets whose sizes are too small – I don’t know the exact mortalities because they know it is illegal to kill Indus Dolphins so they tend to hide the carcasses. We really don’t know how many die each year because of fishing – the Indus River is so huge and difficult to monitor”. Unfortunately, there are no laws against the use of thinner nets, which are not detected by the Indus Dolphin’s sophisticated sonar. These thin nets are so light they float under the water with the currents, and they are deadly since they can easily entangle the dolphins and drown them (the Indus Dolphin is a mammal and needs to come up to the surface of the river to breathe).
Before the construction of the barrages, both the fishermen and the Indus Dolphin enjoyed the free range of the mighty River Indus. A cousin of the sea dolphin, the Indus Dolphin is thought to have come into existence millions of years ago, when the Indus Valley was cut off from the large Tethy’s Sea by the collision of the Central Asian and Indian subcontinent tectonic plates. The sea dwelling dolphin was trapped in a river system that flowed out onto a new landmass. The marine dolphin was thus forced to become an entirely freshwater species and centuries of living in the turbid waters of the Indus made its eyes redundant (hence it is also called the “Blind Dolphin”). This is the theory of how the Indus River Dolphin, one of the world’s four remaining freshwater Cetacean species, came to inhabit the Indus River (the others are found in the Amazon, Ganges and Yangtze Rivers). According to new genetic research, the Indus Dolphin is essentially a “living fossil” that has not shared a common ancestor with any other living creature for around 25 million years! The Indus Dolphin is hence the most unique Cetacean lineage in existence.
In the 19th century British India, the ecology of the Indus River started to change with the building of barrages and dams. Today, there are seven barrages on the river and several dams, constituting one of the most significant irrigation systems in the world. The barrages have carved up the Indus Dolphin’s home range. The largest school of the Indus Dolphin is found in the area of Sindh between the Guddu and Sukkur Barrages. This approximately 170 kilometre stretch of the Indus River was declared an “Indus Dolphin Reserve” by the Government of Sindh in 1974. According to Uzma Khan, however, “we radio tagged an Indus Dolphin around five years ago and discovered that he was able to move upstream and downstream through the barrage. It was the first scientific evidence that we had that dolphins can pass through barrages both upstream and downstream”.
The Indus Dolphin Reserve stretches for miles in either direction. Uzma Khan feels that it is very difficult to manage and monitor such a large area and proposes that: “under the Fisheries law, you can declare an area as a fish sanctuary which has many benefits – you can increase both fish productivity and protect the Indus Dolphin (the Fisheries law does not care for dolphins as such). What we need is to have smaller areas declared as sanctuaries with strict monitoring – this is much more manageable but no one is doing it!”
The writer is an award-winning environmental journalist based in Islamabad, who also covers climate change and health issues.
She can be reached at firstname.lastname@example.org
The views expressed by this blogger and in the following reader comments do not necessarily reflect the views and policies of the Dawn Media Group.