JOIN USSundarbans is the largest deltaic region of the world, encompassing hundreds of islands in India and Bangladesh, which are formed by the Ganga and Brahmaputra rivers. The islands are separated by smaller rivers branching out from these two major rivers. The Indian portion of Sundarbans has 102 islands. It occupies an area of 4,263 sq km, and is situated in South 24 Parganas and North 24 Parganas district of West Bengal. As part of the Man and Biosphere Programme, the Union Ministry of Environment, Forest and Climate Change declared Sundarbans as the Sundarbans Biosphere Reserve in 1989.
Rich biodiversity
It is also a National Park and Tiger Reserve. As a Tiger Reserve, it constitutes of the Sajnekhali Wildlife sanctuary (362 sq km), Sundarbans National Park (1,330 sq km) and some parts of the Reserve Forests of Basirhat Range, totalling up to 2,585 sq km. It is one of the original nine Project Tiger areas of India declared in 1973. Furthermore, it is the only mangrove tiger habitat in the world that is spread over two countries. While 40% of the Sundarbans is in India, the remaining 60% is in Bangladesh.
It is named after Sundari trees (Heritiera fomes) which were once found throughout the area. Over the years, they have become confined to the eastern and southern sectors. The shift in distribution is attributed to gradual reduction of sweet water, as rivers are cut off from the origin due to siltation, and remain connected to the sea. Among the mangroves species, the fruits and leaves of Sonneratia, mangrove date palm (Phoenix paludosa), genwa (Excoecaria agallocha) and baen (Avicennia species) are eaten by chital and rhesus macaque.
Apart from the tiger, Sundarbans is also home to a large number of endangered fauna such as fishing cat, Gangetic and Irrawaddy dolphins, king cobra and the northern river terrapin (Batagur baska). Several species of sea turtle, including the olive ridley, nest in the Sundarbans. One can also spot estuarine crocodiles, water monitor lizards and nine species of kingfisher here.
More than 200 years ago, human settlements started in some of these islands by clearing the forests. Earthen embankments were also constructed to prevent ingression of tidal water. The population grew despite shortage of drinking water and irrigation facilities. Presently, 54 of the 102 islands are inhabited, while rest are Reserved Forest with mangrove vegetation. Much of this cover is, however, threatened by various factors like population pressure, excessive resource extraction, sea level rise, and climate change.
Over the past few decades, cyclones have become more frequent and more intense. This may be due to climate change. As a result, fertile agricultural lands are increasingly becoming saline, which is affecting the socioeconomic conditions of the communities residing here. Many of these islands are facing the threat of submersion. It would also impact the biodiversity and status of many threatened species taking refuge in these islands.
Islands without human habitations, especially in the southern portion, have been constituted as Sundarbans Tiger Reserve. On the eastern border of the Reserve, River Raimangal separates India and Bangladesh and the border is porous. This makes it easier for people to enter the Reserve in boats for activities such as fishing, collecting honey and removing trees for firewood. They also poach tigers to trade the body parts. This is a challenge that the Tiger Reserve management faces everyday and the officials are looking at possible preventive measures.
Water is the only mode of transportation to these islands. Patrolling parties also move in rivers and creeks on boat. The Forest Department has 23 anti-poaching camps located on some of the islands within the Tiger Reserve. In addition, there are seven floating camps, where all members of the camp stay in a boat and use another boat for patrolling through narrow creeks within the islands. It is not easy to patrol the jungle within these islands as regular high and low tides keep the islands slushy. This makes walking through the islands difficult. Furthermore, there is always threat from tigers hiding in the bushes. Unlike tigers in other reserves, the tigers in Sundarbans are known to hunt humans. Even if the tiger is at a distance, one is unsafe as the boat can only be approached through slushy soil.
Reducing conflict
Many southern islands have no anti-poaching camps as establishing one is difficult. To do so, one has to select a spot, construct a jetty, and then build an earthen embankment to prevent tidal water entering the proposed area. Additionally, the location will need to have a chain-link fence to prevent the straying of tigers in the area. Once basic facilities are ready, a sweet water pond and buildings have to be constructed.
Sweet water ponds for wild animals were constructed near the camps and many other areas away from the camp. However, poachers used these for hunting. So, to prevent this, a conscious decision was made by the management to close the water holes which were away from the camps.
Human-tiger conflicts in the northern islands are quite alarming. At times, these conflicts have resulted in human deaths. Now, the management has evolved a cost effective and practical technology of nylon fencing. Around 94 km between human and tiger interface is covered. Nylon ropes have been purchased and some families stitch nets with a height of around eight to 10 feet. This is fixed along the periphery using bamboo. This is the most effective method of keeping tigers away from human areas. This method has brought down the number of tigers straying into human areas considerably. For instance, in 2003-2004, around 22 tigers had strayed, while in 2016-2017, no tigers had strayed.
The number of human deaths caused by tigers, however, has not reduced. This is because people visit southern islands, where there are no nylon fencing, by engaging in activities that act as a way for them to earn a living. Human deaths during the period 2010-2011 to 2016-2017 in the Indian Sundarbans were around 47.
The data collection from trails and transects in every beat is in progress in all the tiger states. In Sundarbans, the data is collected by moving in boats in creeks through islands as well as in water along the shore. Camera traps are also laid in 2 sq km grids by moving in rivers and creeks. No camera is laid in grids in the interior of islands as it is unsafe for staff to move on foot. Around 63 tigers have been captured on camera in the last camera trap exercise in 2016-2017.
Though it is a UNSECO's World Heritage Site, the Sundarbans is witnessing several challenges. Which is why we should minimise our interference, so that we can prevent further irreversible damage to a unique landscape.
(The author is retired principal chief conservator of forests, Karnataka)