KARACHI - The 2010 super floods of the Indus River is speculated to be one of the reasons for recording an increase in dolphin distribution and may have even helped in increasing the population in certain river sections in the province, said 2011 and 2012 report recently published by WWF-Pakistan.

Though the floods did result in a number of mortalities of dolphins due to stranding, an increased water extent in the main survey channel may have allowed the dolphins to move along the Indus River and establish sub-populations, thereby adding to the overall population.

The report also suggests that a number of active channels after a high flood might have provided the dolphin population an opportunity to disperse. 

With less food competition and new habitats created, this could have been a blessing for the species which is unique to Pakistan. 

Opened barrage gates during high floods also facilitate dolphin movement both up and downstream directions which resulted in the increase in population of in some areas such as Taunsa Guddu river section and Sukkur Kotri section and decrease in Guddu Sukkur river section could be attributed to the movement.

Previous research conducted by WWF–Pakistan that involved radio tagging dolphins reveals that the river cetacean can pass through the barrage in both upstream and downstream directions.

This also shows that the suitable habitat for the Indus River Dolphin has increased because of floods.

The study area for Indus River Dolphin population assessment includes a stretch of the Indus River between Jinnah and Kotri Barrages representing species core habitat.  It is divided into five river sections marked by constructed barrages where each river section holds a specific dolphin sub-population.

These include Jinnah – Chashma (River Section I); Chashma – Taunsa (River Section II); Taunsa – Guddu (River Section III); Guddu – Sukkur (River Section IV); and Sukkur – Kotri (River Section V).

In 2001, the first comprehensive study was conducted by WWF–Pakistan and led by Gillian T Braulik covering the entire distribution range of Indus River Dolphins between Jinnah and Kotri Barrages.

 The results of this study revealed that an estimated population of 1,100 dolphins exist in the Indus River.  Another study was conducted by WWF–Pakistan in 2006 which showed a total abundance of 1,600 – 1,750 dolphins.  According to Uzma Noureen, Coordinator Indus River Dolphin Project, ‘In the 2011 dolphin population survey, total abundance of 1,452 dolphins was estimated in the Indus River.’

 The 2011 and 2012 survey was conducted in collaboration with World Wide Fund for Nature-Pakistan (WWF-Pakistan), International Union for Conservation of Nature (IUCN) Cetacean Specialist Group, Wildlife Departments of Punjab, Sindh and Khyber-Pakhtunkhwa, Zoological Survey Department of Karachi, with the Adventure Foundation Pakistan, Nature Conservation Pakistan and the Conservation and Hunting Association of Pakistan.