Acoustic Observation of Gangetic Dolphin
Acoustic observation system composed of 6- hydrophone array and a GPRS modem based data transmission system which can distribute real-time 3D location of dolphins through internet world over.
INCASTS (Indo- Nippon Collaboration on Acoustic Surveillance Technology for Susu) has been running successfully in the Ganges River system at Narora, Uttar Pradesh since November 2008. The first ever real time long term monitoring of the endangered freshwater dolphin Platanista gangetica for 5 years has successively completed its first phase of monitoring (Nov 2008 – Feb 2009) and now is running in the next 4 month -phase (March 09 – June 09). The project is meant to continuously operate the newly developed acoustic observation system composed of 6- hydrophone array and a GPRS modem based data transmission system which can distribute real-time 3D location of dolphins through internet world over.
These blind mammals fear extinction in absence of a focused conservation program. WWF-India, University of Tokyo and IIT-Delhi have joined hands to study the details of dolphin life. In November’08, the deployment of the array system in the Ganga facilitated 24 hour monitoring of Dolphin behavior. Sound frequencies produced by dolphins are picked up by the sensitive hydrophones and observers on land can view the real time location displayed by Graphical User Interface on a PC over a wireless LAN connection.
The umbrella array deployed in Ganges at Karnabas has yielded some useful data. The findings have opened a window to the Gangetic Dolphin behavior which until now was an underwater mystery. The data has given clues to parental behavior of these blind dolphins. Dolphins maintain a nursery where they leave their calves in secure pools of water and visit regularly. A paper titled “Long-term Real-time monitoring of the Ganges River Dolphins using Integrated Observation System using Multiple acoustic arrays” has been recently presented at Sixth International symposium on Underwater Technology ’09 held at Wuxi, China. Various important points regarding the inter-click interval and the acoustic processing time in the dolphin brain have been discovered using the array system. As an extension of data analysis, we have confirmed that a dolphin can view on an average 20 m distance using its sonar system by sending clicks and gathering information by reflected clicks.
Being passive, the system doesn’t alter the usual behavior pattern. The thrust now is to elucidate more about the parental behavior and maintenance of nursery. At the same time we hope to get more information on behavior patterns. The Feb’09 trials also included use of J-arrays and A-tags for a period of one week to get more streamlined information. Information regarding the exact time of visit to a particular area and related behavioral activities have also been an interesting achievement. Visual observations have never been sufficient to understand their underwater activities. Corroboration with the visual data and successful accumulation of information which is getting recorded in HDD, not only will enable us to understand the dolphin behavior but will also assist in moving a step further in the direction of sustainable conservation .We hope to use the information for further long term monitoring at other locations. Making this underwater cryptic information available to people all over the world will deepen the awareness of individuals other than scientists and conservationists.
These blind mammals fear extinction in absence of a focused conservation program. WWF-India, University of Tokyo and IIT-Delhi have joined hands to study the details of dolphin life. In November’08, the deployment of the array system in the Ganga facilitated 24 hour monitoring of Dolphin behavior. Sound frequencies produced by dolphins are picked up by the sensitive hydrophones and observers on land can view the real time location displayed by Graphical User Interface on a PC over a wireless LAN connection.
The umbrella array deployed in Ganges at Karnabas has yielded some useful data. The findings have opened a window to the Gangetic Dolphin behavior which until now was an underwater mystery. The data has given clues to parental behavior of these blind dolphins. Dolphins maintain a nursery where they leave their calves in secure pools of water and visit regularly. A paper titled “Long-term Real-time monitoring of the Ganges River Dolphins using Integrated Observation System using Multiple acoustic arrays” has been recently presented at Sixth International symposium on Underwater Technology ’09 held at Wuxi, China. Various important points regarding the inter-click interval and the acoustic processing time in the dolphin brain have been discovered using the array system. As an extension of data analysis, we have confirmed that a dolphin can view on an average 20 m distance using its sonar system by sending clicks and gathering information by reflected clicks.
Being passive, the system doesn’t alter the usual behavior pattern. The thrust now is to elucidate more about the parental behavior and maintenance of nursery. At the same time we hope to get more information on behavior patterns. The Feb’09 trials also included use of J-arrays and A-tags for a period of one week to get more streamlined information. Information regarding the exact time of visit to a particular area and related behavioral activities have also been an interesting achievement. Visual observations have never been sufficient to understand their underwater activities. Corroboration with the visual data and successful accumulation of information which is getting recorded in HDD, not only will enable us to understand the dolphin behavior but will also assist in moving a step further in the direction of sustainable conservation .We hope to use the information for further long term monitoring at other locations. Making this underwater cryptic information available to people all over the world will deepen the awareness of individuals other than scientists and conservationists.