Apr 1, 2016 - During these studies, researchers observed the deaths of several Ganges River ... near Basilla site in the Buriganga River in October 2013.
© 2016 The Authors. The Bulletin of the Ecological Society of America, published by Wiley Periodicals, Inc., on behalf of the Ecological Society of America. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
P HOTO G ALLERY Photos 1–4 by Md. Muzammel Hossain. Photos 5–7 by Shayer Mahmood Ibney Alam.
GANGES RIVER DOLPHIN Md.Muzammel Hossain, Shayer Mahmood Ibney Alam, Mohammad Abdul Baki, and Naser Ahmed Bhouiyan Department of Zoology, Jagannath University, Dhaka, Bangladesh
Ganges River dolphins live in different river systems of Bangladesh—both inland and estuaries. A case study was carried out in the Buriganga River from December 2012 to November 2013. The river is under intense anthropogenic pressures caused by urban occupation of the surrounding areas and by the use of the water body. Also, water pollution, human intervention, and water traffic were observed to be the major threats for dolphins. In the meantime, a total of 34 sightings of dolphins were recorded both in individuals and in groups. The mean density was 0.38 (SD ± 0.37) dolphins/km² with the highest density of dolphin observed also in the month of November, which was 1.14 dolphins/km². We encountered the dolphins at the rate of 0.48 dolphins/km in the river. So we need to conserve Buriganga river ecology which can save the river dolphin. But day by day dolphin mortality increases in Bangladesh. Here, habitat loss due to river and floodplain encroachment and lack of fish fauna during December to May, coupled with pollution, urges our attention to immediate conservation. Dolphins are listed as endangered in Bangladesh by the International Union for Conservation of Nature due to human intervention, illegal development, and water pollution. Without an immediate and concerted conservation effort, river dolphins will almost certainly become extinct locally and perhaps nationally in the near future. Additionally, Sonadia Island is known for its importance as a habitat of globally threatened shorebirds such as critically endangered spoon-billed sandpipers and endangered Nordmann’s greenshanks and great knots. The Department of Zoology at Jagannath University in Dhaka, Bangladesh, has been working on Sonadia to save these species since 2014. Sonadia Island is a part of the Moheskhali upazila (district) located between 21°28′26.92″N; 91°55′53.74″E and 21°32′49.47″N 91°50′38.45″E. During these studies, researchers observed the deaths of several Ganges River dolphins. This has not yet been studied but deserves special attention.
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Photos 1–2. View of the Platanista gangetica gangetica (Roxburgh, 1801) sightings near Amin Bazar Bridge site in the Buriganga River, Dhaka, Bangladesh in November 2013.
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Photos 3–4. View of the river dolphin sighting with caudal fin near Basilla site in the Buriganga River in October 2013.
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Photos 5–6. View of a river dolphin sighting with dorsal fin near Kholamora site in the B uriganga River in December 2012.
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Photo 7. Death of a Ganges River dolphin on Sonadia Island, Cox’s Bazar, in December 2015
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