The Sunderbans: A fragile ecosystem with vulnerable avifauna

January 7, 2015 by  
Filed under Features

The Sunderbans, represents a sensitive ecological region that is split across the international boundary of India and Bangladesh in South Asia and represents an unique ecosystem unparallel to anywhere else in the world due to its spectacular mangrove forest and amazing biodiversity. Home to a wide variety of highly endangered flora and fauna the region deserves special conservation status. However, the mangrove vegetation has been negatively impacted as a result of unrestricted growth of local human population well beyond the carrying capacity of this fragile ecosystem. The majority of the population being impacted due to lack of economic opportunities is heavily dependent on the easily accessible forest resources for their daily sustenance. As a consequence, the highly endangered mangrove vegetation and the local wildlife have been seriously impacted due to anthropogenic activities such as encroachments in the restricted forest belts, non-judicious harvest of forest and riverine products, poaching and capturing wildlife, deforestation, pollution and diseases. Due to severe anthropogenic pressures, the mangrove vegetation is rapidly disappearing making this region extremely vulnerable to cyclonic disturbances from the Bay of Bengal.

Figure 1. The map of the Sunderbans.

The mangrove vegetation serves as an important natural barrier to the regular micro-climatic turbulence and fluctuations in weather pattern of the adjoining Bay of Bengal with enhanced frequency of powerful cyclones (Fig 1). The local mangrove vegetation (Fig 2) is a nature’s safeguard in the form of a protective shelter belt to the devastating cyclones impacting this region from geological past. The rapid and unrestricted destruction of this natural shelter belt is soon or later going to have serious environmental impacts in South Bengal and adjoining region including the city of Kolkata, India (Fig 3).

Figure 2. The spectacular mangrove vegetation of the Sunderbans.

Similar situation is also prevalent in adjoining Bangladesh with similar impacts. It is therefore important for all of us to realize the ecological significance of the mangrove forest and take every necessary measure to protect it from further degradation. Unless suitable monitoring and stringent laws are not applied very soon the ecosystem that has been stretched beyond its carrying capacity may be irreparably damaged. Since anthropogenic impacts are the significant factors impacting the stability of this ecosystem; as long as the economic condition of the local human populations of the region remains impoverished, very little is expected in terms of successful conservation of the fragile mangrove ecosystem.

Figure 3. Progressive deterioration of coastal mangrove vegetation due to severe anthropogenic pressure, environmental pollution and natural disasters is severely impacting the local ecosystem and its unique wildlife.

This unique global ecosystem is home to a wide diversity of avifauna such as fishing eagles or ospreys, Pallas’s sea-eagle, white-bellied sea eagles, peregrine falcons, brahminy kite, pariah kites, northern eagle owl, brown fish owl, common crow, jungle crow, white-breasted kingfisher, pied kingfishers, white collared kingfisher, black-capped kingfisher, pied kingfisher, brown-winged kingfisher, woodpeckers, drongo, common snipes, crow pheasant, magpie robin, wood sandpipers, marsh harriers, paradise flycatchers, jungle babbler, green pigeon, spotted dove, cotton teal, munia, common mynah, black-tailed godwit, sparrow, red jungle fowl, swamp partridge, Indian cuckoo, rose ringed parakeet, Rufous treepie, water hen, coot, pheasant tailed jacana, cormorant, grey heron, purple heron, green-backed heron, night heron, golden plover, pintail, egret, white ibis, white-eyed pochard, greater adjutant, Asian open billed stork, black-necked stork, herring gull, spotted-billed pelicans to name only a handful. However, the rapid and illegal encroachments and severe anthropogenic pressure has been negatively impacting the habitat of the helpless avifauna as they are proving detrimental to all forms of wildlife inhabiting this unique ecosystem.

Figure 4. Avifauna of the Sunderbans. Photo credit: Rahul Ray

Heavy rates of poaching, illegal capture of birds for both local and international, underground pet markets, pollution of the local stream and tidal creeks through toxic wastes directly released into the river without treatment and detoxification from industrial workhouses and agricultural run offs rich in toxic agro-chemicals (synthetic fertilizers, pesticides, insecticides fungicides, weedicides etc) are deteriorating the local environment and negatively impacting the fish and other estuarine and aquatic food sources which in turn is having their subsequent secondary impact on the avian population. Several of the bird species inhabiting this ecosystem are top predators and as such are severely impacted through the process of biomagnifications as a consequence of consistent and unrestricted environmental pollution. Recently ecological disasters in this region in the form of oil spillage from oil tankers travelling across the sensitive ecozone and from accidents are further deteriorating this ecosystem making the life of the local wildlife including the avifauna at the turn of a dangerous peril; Unless strict measures of conservation are adopted and the anthropogenic pressure on this ecosystem is not considerably curbed the future of this unique ecosystem and environment and its majestic wildlife and avifauna stands the chance of being slowly wiped out in the not so distant future.

Figure 5. Avifauna diversity of the Sunderbans. Photo credits: Saikat Kumar Basu, Rahul Ray, Peiman Zandi, Srimoyi Mazumder and Pallav Mukhopadhyay

Figure 6. Avifauna of the Sunderbans. Photo credits: Saikat Kumar Basu, Manorma Sharma, Rahul Ray and Srimoyi Mazumder.

Fig 7. Anthropogenic pressure on Sunderbands include growing human population, extensive and unrestricted developments in horticulture, agriculture, fisheries, small industries, tourism and increased transportation severely impacting this fragile ecosystem. Photo credits: Saikat Kumar Basu, Ratnabali Sengupta, Srimoyi Mazumder, and Pallav Mukhopadhyay.

Article contributed by Saikat Kumar Basu

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