Bangladesh Sundarbans won't have Bengal Tigers in 50 yrs over habitat loss

The Sundarbans in south-coastal Bangladesh is the world's largest surviving mangrove ecosystem, spanning over 6,000 sq km.

Bengal tigers could vanish from the Bangladesh Sundarbans in the next 50 years--by 2070--as a combination of climate change and rising sea levels threatens their last remaining habitats, says a new study by a team of researchers from Bangladesh and Australia, published in the journal Science of the Total Environment.

The Sundarbans in south-coastal Bangladesh is the world’s largest surviving mangrove ecosystem, spanning over 6,000 sq km, and “the last stronghold” of the Bengal tiger, a species that is particularly adapted to living in this environment. Situated on the lower Ganges-Brahmaputra delta, up to 70% of the Sundarbans area is less than one metre above sea level, meaning rising water levels pose a significant threat to the low-lying tiger habitats. Meanwhile, climate change effects such as changing weather patterns, heatwaves and extreme weather events are likely to have an even greater impact, the study says.

Using computer simulation models based on two climatic scenarios developed by the Intergovernmental Panel on Climate Change (IPCC), coupled with projected sea level rise in the area, the researchers have assessed the future suitability of the Sundarbans region for tigers.

“While this is preliminary analysis, we can conclude that the largest population of Bengal tigers is in an area where a combination of actors including climate change and human encroachment could both contribute to the decimation of habitats,” William Laurence, distinguished research professor at James Cook University and co-author of the study, told IndiaSpend.

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The global tiger population is currently estimated at just under 4,000, with an illegal trade in tiger parts, hunting and habitat loss having culled the population by 96% from 100,000 in 1990, the study says. Three of the eight sub-species of tiger have already become extinct, with the remaining five species currently either ‘endangered’ or ‘critically endangered’.

As global temperatures rise and melting polar ice raises sea levels, the influx of salinated sea water can make it harder for certain plants to grow, subsequently decreasing the availability of certain food types. The Sundarbans’ spotted-deer population, a key food source for the Bengal tiger, is likely to be affected as the tree leaves on which it feeds begin to disappear. As resources become scarce, tigers are more likely to stray into human settlements in search of food, increasing the chance of tiger-human conflict.

The loss of the world’s largest mangrove ecosystem also raises concerns for human populations and other animal species. Mangroves are an effective water regulation system, preventing shoreline erosion that also act as a shelter belt against cyclones and tsunamis. Villages surrounded by mangroves experienced less loss of life and capital during the 2004 tsunami, than those that were not, according to this 2005 Annamalai University study.