Staff Reporter

First-ever scientific census conducted in the lake

  • Global positioning system used for census
  • Researchers, NGO workers, academicians take part in survey

    BHUBANESWAR: Chilika lake, Asia's largest brackish water lake, now houses more number of endangered Irrawaddy dolphins than any other lagoon of the world. Authorities of Chilika Development Authorities (CDA) on Thursday made this announcement after conducting the first-ever scientific census of dolphins in the lake on Tuesday.

    While total population of this highly-endangered species is estimated to be around 1,000 in the world, the CDA claimed to have found 135 Irrawaddy dolphins in the Chilika alone. Of total population, 115 are adults, 15 sub-adults and five calves.

    Irrawaddy dolphins primarily inhabit the waters of Southeast Asia (including India and Bangladesh) - extending down to northern Australia. Irrawaddy dolphins are found in Songkhla lake, southern Thailand and Chilika lake of Orissa.

    "Till this census, the dolphins were counted on basis of sightings. However, for the first time we conducted the census using global positioning system (GPS) sets, thermometer, water sample bottle and binoculars. The method of line transect survey was adopted," CDA chief executive officer Sudarshan Panda told reporters.

    He said the lagoon was divided into 18 zones and 83 persons, comprising researchers, officials, NGO workers and academicians, took part in the survey, which continued for over eight hours at a stretch.


    As per the break-up provided by CDA, about 73 dolphins were found in the outer channel of the lake while southern sector housed 32 dolphins. The latest survey pointed out that all four sectors of the lake had some population of the species. Experts were excited to find six dolphins in northern sector of the lake where there was no sightings last year.

    The dolphin population stood at 131 last year and eight casualties were also reported. "This is a good sign that dolphin population is scattered now," Mr. Panda said. The CDA was now in the process of dredging Magarmukh mouth connecting Bay of Bengal for facilitating movement of Irrawady dolphins.

    Socio-economic study

    Moreover, the nodal agency for the lake development was conducting a comprehensive socio-economic study to prepare an action plan for conservation of these dolphins.

    "Once the study, which is expected to be completed by July, gives us a clear picture on demographic profile of the villages situated in and around the lake, the CDA will try to introduce new programmes for reducing pressure on the water body," he said.

    "The marginal increase in dolphin population has been possible due to close cooperation of the local fishermen community and tourist boat operators," Mr. Panda said.