Tattered nylon nets bordering forests in Kultali in the Sunderbans will soon be replaced, forest officials said.

Tigers from the forests strayed near villages on the other side more than 15 times between September last year and April this year. Breaches in the nets, caused naturally and by humans, were one of the main reasons for the intrusions, foresters said.

The forest department will replace old nylon nets with new ones and repair them where the damage is relatively less.

“We will soon replace and repair nylon nets along 56km of the existing nylon fence. The tender has been awarded, and the work will begin soon. We want to finish the job by September,” said Nisha Goswami, divisional forest officer of South 24-Parganas forest division.

Nylon nets border around 85km of forests in the entire division.

A bulk of the project — around 45km — will cover forest compartments of Ajmalmari 1 and 11 and Herobhanga 9. They fall under the Raidighi range, one of three tiger ranges in the South 24-Parganas forest division.

On the other side of the forests are villages — part of the Kultali block and under the jurisdiction of Maipith coastal police station — like Nagenabad, Deulbari and Kishorimohanpur.

A creek, locally called Makri, separates the villages and the forests.

“There is a thick mangrove cover on the other side of the creek, too, leading to the villages. In most cases, the tigers that come out of the forests take shelter in this mangrove cover,” said a forest official.

But not always.

In February this year, a tiger that had sneaked out of the Ajmalmari 11 forest compartment and hid in the mangrove cover near Nagenanabad village. But it then came out and hid in a patch of agricultural land.

The tiger attacked a member of a quick response team who was trying to rescue a villager who had climbed a tree to escape the claws. It eluded a large team of foresters for a long time before being caught in a trap cage.

There were no casualties in tiger intrusions. Every time, the tiger was either caught or returned to the forest on its own.

“The lifespan of nylon nets is less than five years, even with rigorous upkeep. The tidal ebb and flow of the saline water and anthropogenic interference in the form of fishing in the creeks put the usual longevity under stress in the mangrove delta. Not to mention cyclones every year,” said a forest official.

The nets were placed in phases, the last time in 2021.

Sources said the proposal for an exhaustive “repair-and-replacement project” had been in limbo for a long time. It was cleared recently. The project cost is around ₹50 lakh.

“We are waiting for May to end. May is the time for cyclones that often cause a lot of damage in the Sunderbans,” said a source in the forest department.

Pradeep Vyas, former chief conservator of forests in Bengal who has served in the Sunderbans for years, told Metro in January that though nets were more of a psychological barrier, effective upkeep was vital. “Damaged nets can be a major cause of tigers sneaking out. The tiger does not always want to come to the village side. Often, they come towards the embankment and spot prey. Lack of proper maintenance and humans breaching the nets are the main damaging factors. But the nets are more of a psychological barrier. If a tiger wants, it can find a way to sneak out,” he had said.

Foresters believe the increase in the tiger population in the mangrove delta is also behind the rise in straying incidents.