An unusual phenomenon is damaging mangroves in Airoli

Alarmed by the mysterious decaying of mangroves in Airoli and Mahul areas, environmentalists have appealed to the authorities for a high-level scientific probe into the unusual phenomenon.

“Pests, projects, and now unusual phenomena have been causing a lot of harm to our precious mangroves,” said B N Kumar, director of NatConnect Foundation.

Initially, it was believed that the seasonal moths and caterpillars have been drying up the mangroves, said Nandakumar Pawar of Shri Ekvira Aai Pratishtan. “But the current phenomenon has been on since February and it is a cause of grave concern,” he said.

The environmental groups have written to the Bombay High Court-appointed Mangrove Protection and Conservation Committee and the State Mangrove Cell calling for a thorough study. “We can even rope in the services of organisations such as UNEP and WWF,” said Kumar.

NatConnect has already drawn the attention of UNEP asking to share study reports of similar instances, if any, from other parts of the world.

In the Maldives, too, a mysterious mangrove decay has been noticed in Neykurendhoo where studies have begun in June. “We have requested for these reports if available,” said Kumar. The wetlands of H A Kelaa and N Kendhihulhudhoo too appear to be facing mangrove decaying, he said.

In the Mumbai region, the Institute Of Wood Science and Technology under the Indian Council of Forestry Research & Education has studied the pest attacks and suggested some measures such as spraying insecticides.

The State Mangrove Cell is, however, wary of using any insecticide treatment as it could have a detrimental effect on the other moths required for the mangrove ecosystem, said Nenu Somraj, deputy conservator of forests.

Large stretches of mangroves in MMR, including Navi Mumbai, have been affected and one can hardly find a green tree amid bunches of plants which have turned brown, said Pawar. “The situation is alarming and we have to find a solution before pests devour the sea forest,” Kumar said.

The much talked about Ahmedabad-Mumbai Bullet train project is set to destroy mangroves equivalent to the size of five and a half Azad Maidans.

In view of the need to conserve mangroves, it is important to save the sea forest that the Mumbai region is left with, the environmentalists said.

The study by the Institute Of Wood Science and Technology was conducted to record the defoliating and sapsucking pest problems in this region.

Surveys conducted to assess the pest problems of mangrove species in Airoli and Vashi creek, and in Gorai mangrove areas revealed the infestation of about 20 defoliating pests and two sapsucking pests. The details of these pests and their management practices are described in this technical bulletin.

The study report said, for instance, a number of sapsucking insects are associated with the mangrove ecosystem and they are usually causing considerable damage to the mangrove plants. Among the sapsucking pests, Dysmicoccus brevipes is observed as a major pest in the mangroves of Maharashtra.

On certain snail species destroying the mangroves, the report says Melampus pulchellus are air breathers and small in size. These are gregarious and occur under the bark and crevices in the roots of mangrove plants. It is a major and serious pest causing damage to the mangroves, particularly in the rainy season. The snails are distributed in Maharashtra and West Bengal in India and also in the Philippines, the report said.