How dolphins survived killer spill
HARIKE: World Wildlife Fund experts are still trying to find out how the dolphins remained unscathed from the acidic water after the deadly spill from a Gurdaspur sugar mill on May 16.
Dolphins do not breathe using gills but oxygen in the atmosphere from the blowhole located on top of their heads. The loss of dissolved oxygen in the water didn’t cut off the dolphin’s oxygen supply, so they survived, say experts. However, factors like a diminished prey base, which includes catfish, could affect them in the longer run.
HARIKE: Villagers living downstream along the Beas river from Kiri Afgana village in Punjab’s Gurdaspur district woke up on May 17 to a sight they had never seen before.
Thousands of fish of all sizes were turning dead up along the river banks. The villagers immediately took the fish and put them in buckets and tubs of water, local forest department official Karm Singh said.
A chemical reaction inside the molasses storage tank of a sugar mill owned by Chadha Sugar Industries Private Limited at Kiri Afgana released thousands of litres of molasses into the main stem of the Beas late on May 16.
Among the creatures that were affected were the Indus river dolphin, one of the India’s rarest mammals. This dolphin (Platanista gangetica ssp minor) is a subspecies of the South Asian River Dolphin, which includes the Gangetic river dolphin. Both the subspecies are threatened and protected under Schedule I of Wildlife Protection Act, 1972.
A WWF team and forest department officials had been tracking the precarious return of the Indus River dolphins to the Beas about a decade ago after they were believed to have become locally extinct. Their return to the Beas was reported and confirmed in 2007 but their population was less than a dozen.
The WWF had announced earlier in May that a healthy population of five to 11 dolphins inhabited the stretch of the river between Pong dam in Himachal Pradesh and Harike barrage in Punjab. In the survey between May 3 and 6, presence of a calf suggesting a breeding population was big news. But the ugly disaster threatened to wipe the Indus river dolphins off the face of India.
A small isolated population like this is at greater risk of local extinction, according to experts.
“It felt like losing a close family member,” said Gitanjali Kanwar, a WWF India field researcher who has studied this riverine system for close to a decade, about her first reaction.
SURVEY FOUND 511 OF THE INDUS RIVER DOLPHINS, WHICH WAS BIG NEWS; UGLY SPILL THREATENED TO WIPE THEM OFF FACE OF INDIA
THE GILLS MATTER
Apart from turning the stretch of water acidic, the molasses also ate up the dissolved oxygen. Like humans, fish require oxygen to live, which they absorb directly from water using their gills. When the oxygen dries up, a fish usually comes to the surface to breathe in the air from its mouth. This works for only for a short time as it is not what fish are made for and so they suffocate and die.
The only glimmer of hope for the conservationists was that dolphins do not breathe using gills but oxygen in the atmosphere from the blowhole located on top of their heads. The loss of dissolved oxygen in the water didn’t cut off the dolphin’s oxygen supply but whether they survived the acidic polluted water remained a torturous mystery.
A survey team of WWF and forest personnel searched in vain for two days after the leak for any signs of the dolphins and during that period they thought the endangered species was lost again.
Forest official Singh glimpsed a dolphin near Karmuwala village on the third day after a disappointing morning of spotting nothing and then mistaking a floating dead cow for a dolphin.
What Singh spotted was an adult female and a few heartstopping moments later a calf emerged in a graceful arc from the waters.
On Sunday, they found a group of three. “All of us heaved a sigh of relief,” he recalled.
Experts are still trying to find out how the dolphins remained unscathed from the acidic water.
WWF’s Kanwar believes that when faced with the torrent of foul polluted water the dolphins scurried to find cleaner side channels of the river. Since the pollutants followed the path of the river flow the side channels were not contaminated.
AFTERMATH
The dolphins may have survived the initial death blow but factors like a diminished prey base, which includes catfish, could affect them and the long-term impact on the ecosystem will have to be studied.
“We are still investigating the impact on the river and species,” GS Majithia, chief engineer at the Punjab Pollution Control Board, said.
The Rs 25 lakh security posted by the sugar mill was seized and it was shut down on May 18.
Kanwar said the board waited for a disaster to take action ignoring red flags along the way.
“They were fined, they were shut down, but the fish are dead,” Atman Singh, a local forest official who guards the Harike bird sanctuary, said.
The elderly men in his group, who also guard the bird sanctuary, nodded sagely. They seemed to have grasped something that slipped from the consideration of officials: No amount of fines and shut factories could manufacture a lost species.
“The fish are gone,” one said quietly shaking his head.