Project

Project on Gangetic Dolphins in West Bengal

by Partha Pratim Kundu

Project Report on Gangetic Dolphins in West Bengal

by Partha Pratim Kundu
The Gangetic Dolphin is not only critically endangered under IUCN red list but also among the world's most threatened mammals which lives in one of the most densely populated regions of the world. One of the main threats to the species is loss of habitat due in large part to the creation of dams and irrigation projects. But lives still exist even after these loss and fragmentation. This article is based upon those remaining living creatures in Ganges after the fragmentation in West Bengal region between Farakka and Ganga Sagar. There are 50 to 70 dolphins between Farakka and Ganga Sagar. Numbers are going down fast. We know that in locations where pollution levels and man-made disturbances are high, dolphins are usually not found. However, there are some highly-polluted points such as Kolaghat and Gadiara, these mammals were sighted. The dolphins were sighted very close to human intrusions in Katwa and Nabadwip. Most dolphins were seen at Sabujdwip and Khamargachi in the Hooghly district, Bakshi near Bagnan in Howrah district, from Katwa to Nabadwip in Nadia district, and near Nayachar. Sabujdwip is at the confluence of the Hooghly and the Behula rivers, Nabadwip at the confluence of the Jalangi and the Hooghly rivers and Bakshi is where Rupnarayan, Damodar and Mundeshwari meet. The Farakka Barrage on the Ganga is one major impediment in the movement of dolphins since its commissioning in 1975. Currently, there are five connecting bridges over the river Rupnarayan at Kolaghat and a series of sluice gates over river Damodar near Garchumukh obstructing the movement of the dolphins. In Sundarbans region it was found that raising water salinity level is threatening the habitat of Gangetic dolphins which caused change of habitats and most of dolphins migrated to upper streams. Why they are decreasing? Pollution: The contamination of the Ganges River comes from chemicals, garbage, and industry spills. Industrial waste is causing dangerous for Gangetic Dolphins. Hazardous toxins, such as chromium, arsenic, mercury come from industrial wastes. Compounds such as organochlorine and butyltin were found in the tissues of Gangetic Dolphin which are cause for concern about their potential effects on this species. Dumping of corpse and carcasses are another major threat as they pollute the water. Usage of plastics has caused significant damage to this stretch. Receding water level: Due to global warming and waters diversion for hydroelectricity and irrigation, water level has been decreasing and flow slowing down in river Ganges which causing struggle to aquatic lives in Ganges to survive. Dolphin - fisherman competition: Riverine areas of high productivity sustain a rich and diversified fish community, which attracts dolphins as well as fishermen. Dolphins face strong competition with the fishermen and are brought into close proximity with them. Accidental killing in fishing nets, as well as directed killing by the fishermen to reduce competition, affects dolphin populations. Siltation and Sedimentation: Siltation level is increasing in the river. The Farakka barrage has changed the salinity regime, water transparency, suspended sediments and altered freshwater fish assemblage. The increasing rates of sedimentation have direct impact on the physical and biological characteristics of the river basin. It affects the other river biota including fish which is reducing the prey base of Dolphin. Poaching: Poachers kill dolphins for their flesh, fat and oil, which are used as a prey to catch fish, as an ointment and as a supposed aphrodisiac. Vessel Traffic: Increasing amount of vessel traffic caused immense risk to the endangered riverine wildlife, including Gangetic Dolphin. Often they are being struck by vessels and of being displaced from critical habitat by vessel-induced disturbance. The propeller blades of the vessels are a life hazard to the dolphins and other aquatic life. Riverine resource extraction: Illegal sand mining have altered its nature and eliminates counter currents, one of the most preferred habitats of the dolphin. It threatens the ecological integrity of the riverine environment, especially in small tributaries where suitable habitat is more confined and therefore more vulnerable to local sources of degradation. What measures we should take to save Gangetic Dolphin: - Pollution control: West Bengal discharges over 50% waste water untreated into Ganga. Restriction of usage of plastics in Ganges riverbank may have worthy effect to control the pollution. Preventing and curtailing all waste water, starting with sewage and industrial waste, from mixing with the river needs to be prevented. Promoting massive water conservation and water resource management, inclusive of rain water harvesting schemes, at both centralized and decentralized levels within the Ganga River Basin will play essential role. Maintaining levels of water flow: Survival of the Gangetic Dolphin is dependent on riverine ecology in general and the maintenance of an optimum water flow. Based on methodical research and monitoring with the association of hydrologists, critical water flow and minimum depths for Gangetic Dolphin habitats should be maintained. Control and minimise Dolphin – fisherman conflict: It is very important to minimise fisheries interface and incidental capture and killing of Gangetic Dolphins. Fishing has to be restricted during their breeding period. Few fishing lures like ‘hazari’ is already banned but still being used. These kinds of activities have to be stopped through regular monitoring and investigation. Appointment of area wise civic dolphin trackers to stop poaching: It is necessary to appoint trackers and area monitors for tracking the dolphins and communicating with other area monitors and government officials. Because dolphins move frequently. Prime motto should be protecting them from incidental or intentional killings and quick rescue and release. Community Involvement: Involving fishermen communities and others stakeholders along the river flood plains is the only way. The active participation of local stakeholders like traditional fishing community and other riverbank communities is essential for dolphin conservation. There have been some initiatives such as ‘Dolphin Mitra’ module in Bihar should be followed in West Bengal. Implementing dolphin-oriented tourism: Dolphin watching is a potential sustainable income source for fishermen and locals. If fishermen start earning from it they will learn to love and protect dolphins. Simultaneously poaching for oil will be minimised. It is important to ensure that dolphin watching on the Ganga is conducted in a manner that is respectful to the animals, local people and fellow tourists. Guidelines and codes of conduct should be developed, adopted and promoted by both the tourism industry as well as by government agencies to ensure that unregulated dolphin watch tourism does not become a menace for the Gangetic Dolphin. Education &Awareness: It has to make people aware how to use and not to abuse the river. Their traditional uses should be respected and which cannot alienate them from that, but still Gangetic Dolphin has to be protected within this ecosystem. So social awareness and education is required. The communication materials such as films, poster and social media campaigns should also be given a high importance. Stop illegal sand mining: Illegal sand mining has to be stopped to maintain the counter currents of river, which are most preferred habitats of the dolphin. Rescue & Rehabilitation: A special team is to be recruited and trained for rescue and rehabilitation of dolphins. Incidental mortality has to be reduced through quick rescue and release efforts. The more we pollute the earth, the less we deserve to live on earth. This is the high time to conserve our national aquatic animal from extinction