Men jump into a canal to cool themselves in Lahore, capital of Pakistan's Punjab province, on May 30, 2021. The temperature reached 38 degrees Celsius in Lahore on Sunday, according to the Pakistan Meteorological Department.(Photo: Xinhua)

Freshwater dolphins are flourishing in a stretch of Pakistan's main river after a helping hand from fishermen mobilized to defend a rare species driven to near-extinction.

Identifiable by their saw-like beaks, Indus River dolphins once swam from the Himalayas to the Arabian sea, but now mostly cluster in a 180-kilometer length of the waterway in southern Sindh Province. 

A glimpse of a dolphin cutting through muddy water to gasp for air is a regular sight along the mighty river, but most villagers nearby were unaware that their neighbors were on the brink of extinction.

"We had to explain that it was a unique species only found in the Indus and nowhere else," Abdul Jabbar, who gave up fishing for a job on the dolphin rescue team, told AFP on the banks of the Dadu Canal, which he patrols by motorbike.

Decades of uncontrolled fishing and habitat loss caused by pollution and man-made dams saw the dolphin population plummet to around 1,200 at the turn of the century.

They are classed as an endangered species by the International Union for Conservation of Nature, which says their numbers have fallen by more than 50 percent since the 1940s.

In a bid to turn around the fortunes of the mammals, Pakistani wildlife officials began a painstaking door-to-door awareness campaign with the local fishing community on the riverbanks and arterial canals.

They offered advice on dolphin-friendly nets and warned against harmful and illegal poison-fishing, the practice of using chemicals to kill small fish used for poultry feed.

The World Wide Fund for Nature also offered up 1 million rupees ($6,300) worth of loans, encouraging fishermen to set up alternative businesses.

With the help of the provincial wildlife department, they established a dolphin monitoring network of 100 volunteers and a handful of paid staff, and a 24-hour phone helpline for villagers to call if they see a dolphin in distress.

The latest survey, from 2017, showed numbers had rebounded to about 1,800 and wildlife officials expect the population has increased further since.  

Harmful fishing practices are not the only hazards facing dolphins.

Every January, when water levels are at their lowest, the floodgates to canals are shut for cleaning, creating pools and lagoons that become death traps for stranded marine life.

Wildlife Department official Adnan Hamid Khan told AFP that the recent steady rise in those kind of dolphins had been a "success story." 

AFP