Snails entering new territory

PATHANAMTHITTA: The Giant African snails are spreading fast in the district, after being confined to a few wards in the Konni grama panchayat limits since their first sighting in 2008.

People fear that the snails will pose a health hazard and will have an impact on the ecosystem. They complain that effective steps have not been taken to contain the mollusc menace, despite repeated warnings from experts and environmentalists.

After the monsoon set in, the snails have been spreading to the nearby panchayats of Pramadom, Chenneerkara, and Thumpamon and in certain parts of the Adoor and the Pathanamthitta municipal areas, especially the Kumbazha market.

These nocturnal creatures have been causing much harm to the tapioca, papaya, and rubber crops and other vegetation in Konni. They feed on tender leaves of coconut palms.

The Kerala Forest Research Institute (KFRI), after a study on the snail menace in Konni eight months ago, had stressed the need to eradicate them before summer by the time they go into hibernation. The study report was submitted to the Ombudsman for Local Self-Government Institutions.

People are now pinning their hopes on Health Minister Adoor Prakash, who represents the Konni constituency, says Ratheesh Babu, a social activist who has been actively involved in the snail-eradication campaign.

After the first sighting in June 2008, the snails have multiplied fast. Experts say that a snail lays as many as 400 eggs at a time and at least 380 of them are hatched. The snails come out of their daytime hideouts, such as wet burrows on trees and rocks, during night and move in clusters.

Aby Abraham and K.M. Koshy, members of an Agriculture Department team that had visited the snail-infested areas of Konni in October 2010, were of the opinion that cleanliness and sanitation should be given top priority in keeping creatures such as snails from the courtyards and surroundings of houses. The snails they found in Konni weighed 700-800 grams. The team was awestruck witnessing the snails feeding on the walls of a building. The snails feed on vegetation and walls as their shells require a good amount of calcium.

The expert team opined that steps should be taken to launch cultivation on all lands lying fallow in the affected area as wet fallow lands were the best breeding grounds of such creatures. The team felt the need to adopt chemical control methods to combat such a large-scale menace.

The KFRI study report said the practice of using metaldehyde and common salt to kill the snails would have an adverse impact on terrestrial and aquatic fauna and excessive use of common salt would alter the soil chemistry, making it unfit for agriculture.

Snails should not be consumed as it was an intermediate vector of the rat lungworm which caused eosinophilic meningitis in humans, besides playing host to Aeromonas hydrophila, a pathogen found in hosts with weak immune systems, the report said.

It suggested thorough checking of vehicles moving out from the infested area to make sure that snails were not accidentally transported to new locations.

The report said the snail menace had been reported from the districts of Thiruvananthapuram, Pathanamthitta, Kollam, Idukki, Ernakulam, Palakkad, Kozhikode, Kannur, and Kasaragod. However, the infestation in Konni was high, requiring urgent efforts to reduce its numbers as the wells in the area were contaminated by snail excreta.

Source: The Hindu 29-06-2011