KOLKATA: Are alternative livelihood sources, such as bee-keeping, interfering with the ongoing natural processes in the world’s largest continuous mangrove forests — the fragile Sunderbans?

Scientists of the Zoological Survey of India (ZSI) have discovered something unusual in the activity of insects that flit around the mangrove plants collecting pollen grains and nectar from flowers and unknowingly spread the pollen around, helping these plant species reproduce.

“In the Bali Island of Indian Sunderbans in West Bengal, domestic bees from bee boxes are not allowing wild insect pollinators to sit on the flowers of some species because of aggression and large numbers. In other islands, in the same species, we can see wild pollinators visiting,” Bulganin Mitra, an entomologist with ZSI, told IANS.

This could indicate that means of local livelihoods, like bee-keeping, may be “restricting” the natural work of these pollinators that have a role in the proliferation of the mangrove species in the Sunderbans, Mitra added.

Sunderbans, a UNESCO World Heritage Site, is known for its exceptional biodiversity in flora and fauna with a staggering 334 plant species and 693 species of wildlife, which include 49 mammals, 59 reptiles, eight amphibians, 210 white fish, 24 shrimps, 14 crabs and 43 mollusks. It is also home to the majestic Royal Bengal Tiger. The livelihood issues in Sunderbans are also linked to climate change with increasing sea-levels and salinity depriving locals of means of sustaining themselves.

At the core of sustainability are the declining mangrove species, crucial to support livelihoods, provide carbon sinks and act as a buffer against climate change. To shed light on protection strategies, Mitra and a team of ZSI scientists are investigating the role of insect pollinators on the conservation of the major mangrove species of the Sunderbans.

Through observations carried out during the day as well as night on eight mangrove species across five islands in the Indian Sunderbans, experts “unexpectedly” found that overall, more species of flies were visiting the plants instead of bees, known to be one of the most common insect pollinators. “In Bali Island, where bee boxes are placed as a source of alternative livelihood, the wild insect pollinators are kept at bay. But one can’t simply ask the locals to remove the bee boxes because that would put them in harm’s way (tiger attacks and the like) as they would have to resort to other means of livelihood in another part of the island,” Mitra explained.

This relationship between man and animal in Sunderbans calls for discussions with all stakeholders, as per ZSI director K Venkataraman.