1990 Status and conservation of the Ganges River dolphin Platanista gangetica in the Karnali River, Nepal

https://doi.org/10.1016/0006-3207(93)90002-IGet rights and content

Abstract

Information is given on the population status, distribution and ecology of the Ganges river dolphin, Platanista gangetica, in the Karnali River, Nepal. Seven animals were counted. Sightings were highly habitat-specific. Six habitats were identified and classified as primary or marginal, according to differences in physical characteristics and sighting frequencies within them (χ2, p < 0·05, d.f. = 5). Mean sighting frequencies were 0·57 and 0·13 sightings/visit for primary and marginal habitats, respectively. Primary habitats were characterized by an eddy counter-current system in the main river flow caused by a fine sand/silt point bar formed from sediment deposits of a convergent stream branch or tributary. Marginal habitats were characterized by a smaller eddy counter-current system caused by an upstream meander. Mean group size was 1·38 animals. Dolphin movements within primary habitats were found to be nonrandom and aggregate for 25 theodolite tracking sessions (χ2, p < 0·05, d.f. = 1–7), concentrated in locations of high prey availability and reduced flow. Human disturbance effects are summarized. Recommendations are given for preservation.

References (46)

  • N. Atkins

    Summary of national laws and international agreements affecting river dolphins

  • G.M. Bernacsek

    Dam design and operation to optimize fish production in impounded river basins

  • G.E.P. Box et al.

    Statistics for Experimenters, An Introduction to Design, Data Analysis, and Model Building

    (1978)
  • K.W. Cummings et al.

    Stream ecosystem theory

    Verh. Int. Verein. Limnol.

    (1984)
  • J.W. Elwood et al.

    Resource spiraling: An operational paradigm for analyzing lotic ecosystems

  • M.E. Gilpin et al.

    Minimum viable populations: Processes of species extinction

  • D. Gyawali

    Water in Nepal, an interdisciplinary look at resource uncertainties, evolving problems and future prospects

    Occ. Pap. East-West Center, Honolulu, Hawaii

    (1989)
  • A.K.M. Haque et al.

    Comments on the abundance and distribution of the Ganges susu Platanista gangetica and the effects of the Farakka barrage on its population

    (1976)
  • E.S. Herald et al.

    Blind river dolphins: First side-swimming cetaceans

    Science, N.Y.

    (1969)
  • W.E. Hearns

    Interspecific competition and habitat segregation among stream-dwelling trout and salmon; A review

    Fisheries

    (1987)
  • Y. Hua et al.

    The habitat and behavior of Lipotes vexillifer

  • S. Jones

    The present status of the Gangetic susu, Platanista gangetica (Roxburgh), with comments on the Indus susu, P. minor (Owen)

    FAO Advisory Committee on Marine Resources Research, Working Party on Marine Mammals. FAO Fish. Ser.

    (1982)
  • C.B. Joshi

    Procurement of stocking material of mahseer, Tor putitora, material from the hill-streams in UP and Himachal Pradesh with special reference to collection techniques

    Int. J. Acad. Ichthyol.

    (1980)
  • T. Kasuya et al.

    Some information on the distribution and seasonal movement of the Ganges dolphin

    Sci. Rep. Whales Res. Inst.

    (1972)
  • M. Klinowska

    Dolphins, Porpoises and Whales of the World: The IUCN Red Data Book

    (1991)
  • P. Nautiyal

    Mahseer conservation problems and prospects

    J. Bombay Nat. Hist. Soc.

    (1989)
  • P. Nautiyal et al.

    Recent records of Garhwal mahseer Tor putitora, Ham. with a note on its present status

    J. Bombay Nat. Hist. Soc.

    (1982)
  • P. Nautiyal et al.

    Preliminary observations on the migratory behavior of the Garhwal Himalayan mahseer

    J. Bombay Nat. Hist. Soc.

    (1984)
  • P. Nautiyal et al.

    Destruction of the spawning grounds of mahseer and other fish in Garwhal Himalayas

    J. Bombay Nat. Hist. Soc.

    (1988)
  • V.R. Pantulu

    Fish of the lower Mekong Basin

  • W.F. Perrin et al.

    Report of the workshop

  • G. Pilleri

    Observations on the behaviour of Platanista gangetica in the Indus and Brahmaputra Rivers

    Invest. Cetacea

    (1970)
  • Cited by (62)

    • Prioritising river stretches using multi-modelling habitat suitability of Gangetic dolphin (Platanista gangetica) as a flagship species for aquatic biodiversity conservation in the Ganga River Basin, India

      2022, Ecological Indicators
      Citation Excerpt :

      Its extirpation from river systems serves as a tool to measure the extent of human footprints exploiting riverine resources (Sinha et al., 2010; Sinha and Kannan, 2014; Behera et al., 2014). Once commonly distributed in major river systems between longitudes 77° E and 89° E in India, Nepal and Bangladesh (Anderson 1879, Smith, 1993; Mohan et al., 1997), the species is now restricted to disjunct stretches of the Ganga-Brahmaputra-Barak river system in India (Wakid, 2009; Behera et al., 2014; Sinha and Kannan, 2014; Choudhury et al., 2019), Karnali, Sapta Koshi and Narayani river systems in Nepal (Shrestha, 1989; Paudel et al., 2015) and Meghna, Karnaphuli and Sangu river systems in Bangladesh (Reeves et al. 2000; Smith et al. 2006). The GD is now isolated into small groups and is under severe threat due to a wide array of factors such as flow modification, habitat degradation, prey depletion, noise pollution, poaching and net entanglement (Dey et al., 2019; Paudel and Koprowski, 2020: Kolipakam et al., 2022).

    • River Dolphins

      2017, Encyclopedia of Marine Mammals, Third Edition
    • Irrigation demands aggravate fishing threats to river dolphins in Nepal

      2016, Biological Conservation
      Citation Excerpt :

      Prior to 2010, the park authorities had provided fishing licenses to traditional fishermen, which allowed them to fish both within and outside the protected river stretch of the Geruwa, with strict restrictions on use of gillnet mesh size enforced by the Department of National Parks and Wildlife Conservation (DNPWC) of Nepal. This kept fishing activity in reasonable check until 2009 at much lower intensities than in 1990, as reported by Smith (1993). However, in 2010 (independent of the flood event), fishing licenses were terminated by DNPWC because a few fishermen were found to be involved in poaching of rhinoceros in the park, and hence fishing restricted to near-complete levels.

    • Territory and status of dolphins in Nepalese rivers: A review

      2023, Aquatic Ecosystem Health and Management
    View all citing articles on Scopus

    Present address: PO Box 283 Arcata, California 95521, USA.

    View full text