The oil spill may spell bad news for migratory birds such as flamingos that will make their way to the city by the month-end. Experts said the concentration of oil in their habitats — creeks and mangroves — would affect the birds.
“It’s a blessing that the birds haven’t reached Mumbai yet,” said Sunjoy Monga, naturalist, Bombay Natural History Society (BNHS). But with the oil having accumulated in the mangroves at Navi Mumbai, Uran and Alibaug, contaminated smaller organisms, clams and mussels will enter the birds’ food chain.
Besides, the oil film over leaves and plants will hamper the oxygen-water exchange.
The birds could get trapped and choke on the oil. “Trapped birds get weighed down by the oil. When oil comes in contact with their water-resistant coated feathers, it could either strip or weaken the coating,” said Monga.
On Thursday, BNHS scientists got back to collecting water samples of the on-shore oil. Marine biologist Deepak Apte said the oil had reached Sasvane in a big way and that it could be smelt 300 metres from the shore. Tar balls were found in Uran, Vashi and Raigad as well as Colaba. However, there was no impact beyond Dadar towards Bandra and Gorai.
“Adult mangroves may be less affected than young plants and seeds,” said Apte.
Old seeds that have germinated into 6- to 8-inch plants will surely die. Seeds that are yet to fall on the sea floor and germinate may also be affected. “After falling on the seabed, it will take a month for them to mature. So the impact will be seen only in mid-September,” Apte said.
Tests are also being conducted by the National Environmental Engineering Research Institute (NEERI), which has collected samples of water and sediments, to check for pesticide content.
“Since there was some apprehension of pesticides having leaked from the containers aboard the marooned MSC Chitra, we decided to analyse the samples,” said Rakesh Kumar, director, NEERI, Mumbai. “Except Dadar, we found oil in the sand at Colaba, Priyadarshani Park, Breach Candy, Alibaug and Uran. The reports will be out in a couple of days.”