New Delhi, April 13 (IANS) The Sundarbans, the world's largest contiguous mangrove forest, has 182 tigers -- 106 in Bangladesh and around 76 in India, according to the first ever modern survey jointly conducted by the two countries across a 6,724 sq km area.
According to the report, Status of Tigers in the Sundarban Landscape, the tiger habitat is threatened by pollution from cargo like oil, cement, fertiliser ferried along the rivers in the region as well as from poaching.
Using the SECR (Spatially explicit capture-recapture) technology in the difficult Sundarbans landscape for the first time, the survey says: "Tiger number, estimated using camera trapping using SECR was 182 (145 to 226) in the total tiger occupied areas of 6,724 square km, with 106 (83 to 130) tigers on the Bangladesh side and the Indian Sundarban had estimated abundance at 76 tigers (63 to 96)."
SECR technique uses software for analysis of the data based on each animal's activity centre. The survey was conducted by Wildlife Institute of India, Bangladesh Forest Department, and World Wide Fund for Nature - India, in eight regions with three in Bangladesh and five in Indian Sundarbans. They used 528 camera locations over 422 days of sampling and "captured" 105 common tigers.
The reports, released at the Third Asia Ministerial Conference on Tiger Conservation here, claimed highest tiger density in India's Sajnekhali block, while the lowest density was in Khulna of Bangladesh.
"Data from radio collared tigers suggested that tigers in general show avoidance in crossing channels wider than 600 metres and also they are most active from 5 a.m. to 10 a.m.," the report claimed.
The report attributes the low density of tigers to the hostile mangrove habitat that supports low tiger prey density.
It also points out other threats such as pollution caused by the usage of water channels by commercial boat traffic, poaching of tigers and their prey, as a challenge to the commitment to the Global Tiger Recovery Program.
"over 200 vessels ply everyday through the Sela and Passur river located in Bangladesh Sundarbans. The constant movement of boats can be potential barriers to dispersal between islands leading to fragmented and isolated tiger populations within Sundarbans."
"The vessels plying inside Sundarban often carry cargo like oil, cement, fertiliser etc. These vessels are veritable 'mobile bombs' as attested by the massive oil spillage in December 2014, when the ship Star-7 dumped 358,000 liters of Heavy Fuel oil in the Sela river."
"This unfortunately is not an isolated event."
The report also calls for appropriate measures to reduce the negative impact of developmental projects on the ecology of the area.
"A 1,320 MW coal-based thermal power plant at Rampal and exclusive economic zone in Mongla, a collaborative efforts between India and Bangladesh alongwith already established busy Mongla Port would only further exacerbate this problem," it said.
The Sundarbans is one of the top five global concentrations of the tigers in the wild. It is the only exclusive mangrove habitat where the tiger exists. These tigers differ morphologically from the mainland tigers.
One of the globally important wetlands, the Sundarbans is recognised as a world heritage site.
The Bangladesh Sundarbans' three wildlife sanctuaries cover 1,397 km sq area. The Indian Sundarbans, which has been declared as 'Sundarban Biosphere Reserve' by Unesco, has 2,585 km sq of area, further divided into Sundarban National Park, Sajnekhali wildlife sanctuary and the Basirhat buffer zone.
Concerns over the man-animal conflicts were also cited in the report, with an estimated 36 people in Indian Sundarbans and 22 in Bangladesh killed every year due to this conflict.
The mangrove forest covers an area of approximately 10,000 sq km of which 62 percent lies in Bangladesh.
Beside tiger, spotted deer, wild pig, rhesus macaque -- which is one of the best-known species of old world monkeys -- monitor lizard, dolphin, otter and crocodile are also seen there.
The tiger, wild pig, rhesus macaque and crocodile are seen more on the Indian side, while spotted deer, dolphins and otter are seen more on the Bangladesh side.
The monitor lizard, due to its large size and high abundance, form an important component of the tiger's diet in the Sundarban.
"This study provides the first authentic baseline from which we need to work towards addressing commitments to the Global Tiger Recovery Program. It is possible to double the tiger numbers in Sundarban by investing in resources that promotes tiger conservation," the report underlined.
It stressed on delineating corridors for tiger movement across the Sundarbans by controlling ship traffic and human disturbance.
The report is the first ever effort to quantify tiger abundance in the entire Sundarbans based on a scientific protocol using camera traps.
