With an aim to build a 'whale atlas', two Indian Institute of Technology (IIT) engineers tracing migratory patterns of baleen whales. These whales are considered among the largest animals on earth.
With an aim to build a ‘whale atlas’, two Indian Institute of Technology (IIT) engineers tracing migratory patterns of baleen whales. These whales are considered among the largest animals on earth. Two engineers from IIT-Madras Nikita Pinto and Tarun K Chandrayadula have been listening in “a very strong call” for the past 15 years. “Every year, it turns up at the same month. We don’t really know which whale is making this sound. We can’t find it in previous published literature but it is a distinct sound,” Pinto was quoted as saying by IE.
Pinto is an MS student at IIT’s department of ocean engineering and Chandrayadula is an assistant professor. Interestingly, Pinto and Chandrayadula have been borrowing acoustic signals recorded by CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization). CTBTO generally monitors nuclear testing across the world. “We use the vast recordings from the CTBTO network to get the acoustic data. These hydrophones are deployed in groups of three, and are referred to as triads. These triads are currently in place at Diego Garcia (central Indian Ocean), Cape Leuwin (Western Australia), and Crozet Islands (close to Antarctica),” Chandrayadula told IE.
Though the hydrophones that record low frequency sounds from less than 10Hz to up to 100 Hz are only a few in number, low frequency sounds travel far in the deep ocean. “They propagate up to thousands of kilometres, because of a special waveguide property of the ocean,” he says. “A big contributor to the background spectrum are sounds made by fin whales, and blue whales. These animals make these sounds while scouring long distances across the ocean basins, looking for mates and food,” Chandrayadula was quoted as saying by IE.
According to report, the blue whale, and fin whale populations are currently endangered. “Acoustics is thus a vital part of their life cycle. We are currently using these acoustic recordings to track the whales, their migratory patterns, and their potential relationship to changing oceanic conditions,” he says. The two engineers are working with recordings since the early 2000s.
Two engineers underlined that mapping the whales is important for conservation. “If we know the position of the whales at different times of the year, we know where their habitats are, which conservationists can use. Population estimation is a key part of conservation efforts,” says Chandrayadula. “By tracking these animals we should be able to separate the sounds in location, so that we know if it is the same animal making sounds at a higher level, or actually different animals.”