DOLPHINS IN GANGA

(C) 2020 Ramaswami Ashok Kumar

DOLPHINS IN GANGA

Summary

Dams have destroyed the habitat and ecology of animals in rivers and in particular in Ganga River. The discharge of chemicals and sewage is causing the rapid decline of animals in the rivers and the dolphin is now endangered. The bioconcentration factors of the chemicals are totally unacceptable and presents a suicidal situation for all life and abiota(Tables 1 and 2). The ecology of the habitat having been destroyed we see no future for the dolphins. Also the dams are causing the proliferation of dangerous bacteria. By applying set theory of Goedel to the sets of animals and plants after the advent of dams, we can, by applying the precautionary principle, suggest that all the flu pandemics and the bird flu and caronavirus proliferation is the result of dams destroying nature completely. 

The status history from the 1980s

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See MARINE MAMMAL SCIENCE, 10(3):368-375(July 1994)

© 1994 by the Society for Marine Mammalogy

STATUS OF GANGES RIVER DOLPHINS(PLATANISTA GANGETICA) IN THE KARNALI, MAHAKALI,NARAYANI AND SAPTA KOSI RIVERS OF NEPAL AND INDIA IN 1993

Brian D. Smith et al

The Ganges river dolphin, Platanista gangetica, or susu, is a freshwaterdolphin distributed thrpoughout the Ganges/Brahmaputra/Meghna river systemsin India, Bangladesh and Nepal(Jones 1982).The World Conservation Unionregards the species as vulnerable (Klinowska 1991). The total world population has been crudely estimated to be 4000-5000 animals, with very small numbers in Nepal(Jones 1982).

Details of commission of barrages: Mahakali 1929,Sapta Kosi 1965, Narayani 1970, Karnali 1976.

Susus are found normally downstream of shallow areas or tributary junctions alone or less frequently in groups of 2-3(Jones 1982).Smith(1993) observed groups of 1-3 susus(mean 1.38,sd 0.04, n=72) in the Karnali river most often in “primary habitats” where convergent streams create an eddy counter-current system in the mainstream flow. Less often the dolphins are found in “marginal habitats” where a sharp upstream bend creates a similar eddy counter-current system but of smaller dimensions. Census surveys of susus on the four largest river basins in Nepal(See data on barrages above) in low water seasons 19-25 Feb,1-3 Mar,12-18 Mar and 26Mar-3 Apr 1993 respcly. The rivers are located downstream of the Siwalik foothills of the Nepal Himalayas, and represent the extreme upstream limits of Ganges river dolphin distribution as well as the upstream limits of gharial crocs(Gavialis gangeticus),smooth Indian otters(Lutra perspicillata),Asian small clawed otters(Aonyx cinerea), soft shell turtles(Aspiredetes gangeticus, Chitra indica),and hard-shell turtles(Kachuga spp.).

All four river systems have the following characteristics:

1.Alluvial braided channels, 2. Relatively high velocity flows compared with downstream waters,3. Large seasonal and year to year variations in stream-flows and sediment transport,4. Mixed use riparian areas, with small settlements and subsistence farmers and fishermen frequently on one bank and forested jungle and grassland contained within national parks or ‘wild’life refuges on the other bank. At one time all four rivers were open to the Ganga river system but now are affected by barrages(dates of commissioning above). Barrages are low dams used to divert water for irrigation and ‘flood-control’. The Narayani and Sapta Kosi rivers are contained behind barrages at the Nepal-India border and the Karnali river behind a barrage located approx. 20 km downstream  of the border in Kailashpuri, India. These barrages have isolated living species populations from any possible GENERIC INTERCHANGE with animals inhabiting downstream waters.Dolphins upstream of the barrage may move downstream through the barrages during flood periods, RESULTING IN A PERMANENT LOSS OF ANIMALS to an already fragmented population.The barrages also block the movement of migratory fish to spawning streams of the Himalayan foothills. The Mahakali river in Nepal is located below a barrage that severely reduces downstream flow. No dolphins were observed in the section of the Mahakali river that flows through Nepal. During the low water season there is not enough water released by the upstream barrage to support river dolphins(a max depth of 20 cm in some crosssections). Local villagers report that dolphins are sometimes seen in the Mahakalijust below the Nepal/India border during the monsoon season.

POPULATIONS DOOMED TO EXTINCTION BECAUSE OF THE BARRAGES

Dolphins inhabiting the Narayani and Sapta Kosi rivers do not represent viable populations at all. Since new immigrants are blocked by barrages at the Nepal/India border, we consider these populations doomed to extinction.  

International Journal of Ecology and Environmental Sciences 23:343-355,1997.

© International Scientific Publications,New Delhi.

Status and Conservation of Ganges River Dolphin in Bhagirathi-Hooghly River Systems in India.

R.K. Sinha, Environmental Biology Laboratory,Zoology Department,Patna Univ.,Patna-800005,India.

Abstract:

The Ganges river dolphin, Platinista gangetica,is a freshwater dolphin, commonly known as susu and is distributed in Ganga-Brahmaputra-Megna and Karnaphuli river systems in India,Nepal and Bangladesh.It is found in freshwater and estuarine zones but never enters sea.It is one of the four freshwater cetacean species found in the world.

Overexploitation and habitat destruction are the major factors for rapid decline in dolphin population.Construction of Farraka barrage in the mid 1970s has genetically isolated the susu population.

The case of dams on  the Yangtse and the dolphin habitat.

Reference:

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APPLIED ORGANOMETALLIC CHEMISTRY. VOL. 11.223-230(1997).

Sources and Accumulation of Butyltin Compounds in Ganges River Dolphin,Platanista gangetica.

Kurunthachalam Kannan(1), Kurunthachalam Senthilkumar(2) and Ravindra K. Sinha(3).

1.Skidaway Institute of Oceanography,10 Ocean Science Circle, Savannah, Georgia 31411, USA.

2.Department of Environment Conservation,Ehime University,Tarumi 3-5-7,Matsuyama 790,Japan.

3. Environmental Biology Laboratory, Department of Zoology, Patna University, Patna, 800005,India.

Concentrations of butyltin compounds(mono-,di-, and tri-butyltin) were determined in dolphin(Platanista gangetica), fish,invertebrates and sediment collected from the River Ganges, India, in order to understand the contamination levels, sources and potential for biomagnification in freshwater food chains. Total butyltin concentration in dolphin tissues was up to 2000 ng g-1 wet wt, which was about 5-10 times higher than butyltinin their diet. The concentrations in fish and benthic invertebrates, including polychaetes, were 3-10 times greater than in sediment. The biomagnification factor for butyltins in river dolphin from its food was in the range 0.2-7.5. Butyltin concentrations in Ganges river organisms were higher than those reported for several persistent organochloride compounds. Discharge of untreated domestic sewage was one of the major sources of butyltin residues in the Ganges river delta. High concentrations of  butyltin   compounds in fresh water food chains suggest the need to assess their toxic effects in aquatic organisms and to regulate their  use.

Dolphins are rapidly declining and as of 2020 they are under the endangered list of the World Conservation Union. The species is threatened by the rapid deterioration of habitat due to pollution, construction of dams, mining,and directed and incidental catch(4,5).

The River Ganges is heavily polluted by the annual usage and discharge of about 2500 tons of pesticides, 1.2 million tons of fertilizers in its catchment area. Tanneries, textiles, wood and jute mills, sugar mills,distilleries, pulp and paper factories, the synthetic rubber industry, fly ash from coal washeries, and DDT factories are the major sources of chemical pollution in the River Ganges and its tributaries(6).

Earlier studies showed the accumulation of heavy metals,organochloride pesticides and polychlorinated biphenyls(PCBs) in Ganges River dolphins(7). The isomer/cogener profile of PCBs,DDTs and HCHs(hexachlorocyclohexanes),BHC:hexachlorocyclohexanes in river dolphin tissues suggested that this species has been vulnerable because of its reduced capacity to dgrade xenobiotics(8). A xenobiotic is a chemical substance found within an organism that is not naturally produced or expected to be present within the organism. It can also cover substances that are present in much higher concentrations than are usual. Wikipedia.

Tributyltin(TBT) at low concentrations is highly toxic. Hence TBT and its degradation products have received considerable attention.

 Butyltin compounds  are used as PVC stabilizers, industrial catalysts,industrial and agricultural biocides and wood preserving and antifouling agents.See

https://en.wikipedia.org/wiki/Biofouling

Studies on marine bivalves(9) and gastropods(10,11) have demonstrated that TBT exerts chronic toxic effects on susceptible species at water concentrations of a few nanograms per litre. Growth of susceptible algae(12,13) and some zooplankton species(14,15) were inhibited at a few hundred nanograms per litre or even at lower concentrations. The acute toxicity of tBT in fish lies at a few micrograms per litre(16,17). An important effect of TBT on mammals is on the immune system(18). Thus the accumulation of high concentrations of butyltin   compounds in higher trophic aquatic vertebrates , including cetaceans(19,20) is of great concern.

 Search Results

Web results

Organotin definition and meaning | Collins English Dictionarywww.collinsdictionary.com › dictionary › english › organotin

organotin in British English (ɔːˌɡænəʊˈtɪn) adjective. of, concerned with, or being an organic compound with one or more tin atoms in its molecules: used as a pesticide, hitherto considered to decompose safely, now found to be toxic in the food chain.

Organotin chemistry - Wikipediaen.wikipedia.org › wiki › Organotin_chemistry

Organotin compounds or stannanes are chemical compounds based on tin with hydrocarbon substituents. Organotin chemistry is part of the wider field of ...

‎Structure of organotin ... · ‎Preparation of organotin ... · ‎Reactions of organotin ...

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Other articles which are worthy of study regarding dolphins in the Ganga are

3.1

Investigations on Cetacea-1992-1998.Ed by G. Pilleri, Museum of Natural History,Paciano(Umbria,Italy).Vol.XXIV.

1993.pp  317-321. R. K. Sinha et al. Gut-content of the Gangetic Dolphin, Platanista gangetica.

The food of susu : fish and crustacean.one dolphin’s stomach was filled with prawns. Others had mud frequenting fish and freshwater shrimp.susu eats only oninjured live fishes and  dead fish are untouched.Also molluscs are eaten.the Amazon river dolphin, Inia geoffrensis eats 50 species of fish in Central Amazon including including turtles and crabs.

3.2 K. Kannan et al Heavy Metals and Organochloride residues in Ganges River Dolphins in India.in Baseline.DGH Phillips. Ed.Vol 26,No 3, Mar 1993.

Highly unacceptable contaminants widespread in Gangetic River Dolphins and their food(Fish): See Tables 1 and  2 below.

Some references.

1. Modern Civilisation: The 1918-1919 Pandemic Flu: Dams the cause by

R.Ashok Kumar,dated 2009, at the link

https://stopflowcatchflu.blogspot.com/2009/05/modern-civilisation-1918-1919-pandemic.html

2.See the present status of gangetic river dolphins at

https://currentaffairs.gktoday.in/tags/gangetic-dolphin

3. R. Ashok Kumar.2012.

https://livingnormally.blogspot.com/2012/03/nuclear-parks-energy-audit-goedel-and.html