Yamuna Biodiversity Park goes down the drain

NEW DELHI: Officials at Yamuna Biodiversity Park (YBP) last week were stunned to find 47 dead fish species floating in the artificial wetland they created to attract bird species. Panicked, scientists of the Delhi University's Centre for Environmental Management of Degraded Ecosystems (CEMDE) went for manhunt for culprits who they thought had poisoned the water in the nascent wetland.
What they found was even more surprising. The submerged vegetation they planted had overgrown faster than they could realise, the deep in the mid-region wetland was sucked up, killing the trapped fishes which feed on the vegetation. Water had nothing abnormal for the dead fishes, which had grown up too big, about four kg each, for cormorants and other birds to feed on.
The wetland apart, the saline-soiled YBP plantation is growing slow, giving sleepless night to CEMDE chief CR Babu. Water availability down at 20 feet is not enough, deeper lies saline water unfit for use. Monsoon didn't fill enough of the wetlands.
Babu's deputy, former MoEF official and now a consultant for CEMDE's biodiversity park projects, Vilas Gogte said, "It strikes us often, we should have taken up the Aravalli park before the YBP, which is a bigger challenge. The Aravalli soil is highly fertile and is giving us the expected results, despite sprawling jungles of prosopis juliflora. At YBP we are tackling two natural hardles, salinity of soil and water crisis."
The meandering wetland has huge submerged vegetation now, ready for lakhs of fishes and birds. If the wetland does not get water, the vegetation would dry up, said Gogte. Fingerlin fishes released a year back have grown fast, despite heavy picks by the migratory birds and cormorants. "The ones escaped the birds' eyes, have grown into over four kg in size, which the birds can't lift now", said Gogte.
With growing bushes and bamboo thickets here and there there are already swirms of mosquitoes and insects. The CEMDE has hired seven young scientists from all over the country specialising in various lifeforms.
A bat specialist among them, C Srinivasulu will soon start a few bat boxes to roost a few insectivorous bats (pipistrelles), popularly known as black-bearded tomb bats.
"It's difficult to roost bats until specially designed boxes are constructed. They need to be acclimatised in boxes for sometime. Once used to live there, the bats will start feeding on mosquitoes and pests, which too are night-active. Bats are traditionally roosting mammals, known to live at fixed places even for over 100 years. Bats roost between old tiles, tree-holes, old palace-cracks or ducts, ancient building roofs or minerets, remain there for generations. These mammals need very small holes to enter and aren't disturbed by birds, which can't enter their holes," explained Srinivasulu.
Bats will wonderfully keep the natural balance in the park, the scientists feel. "They eat insects and mosquitoes weighing about 50% of their body weight. A 4-gm bat feeds on over 600 mosquitoes per hour, besides eating beetles, moths, pests. Friends to agriculturists, bats catch preys like a Gangetic dolphins, through eco-location. "According to the evolution of extinction, aquatic dolphins and airy bats have much things in common at preying," explained Srinivasulu.
The YBP has got a few new inhabitants haunting its skyline. A bird of prey, black-shouldered kite was found "hovering" at about 200 feet height. Gogte, who is also a seasoned ornithologist, said, "It's stalling now, as it has located a rodent releasing ultra-violate emission in its urine, and is just waiting for the right time to swoop down on it."