By Marta SerafinkoMay 1 (Reuters) – Deep beneath the ocean surface, sperm whales swim through the dark waters, clicking to each other in bursts of sound that can travel for kilometres (miles). Now, scientists say they are beginning to follow those exchanges in real time using an autonomous underwater robot that can track whales by listening to their voices. Sperm whales use clicks to navigate and hunt, and also produce patterned sequences of clicks, known as “codas,” that are thought to play a role in communication. Scientists first identified that sperm whales vocalize in 1957. But understanding how they communicate has remained difficult because these marine mammals dive to depths of more than 1.6 km (one mile) for around 50 minutes each hour, making continuous observation challenging. “The underwater glider is listening for whales via four hydrophones and then steering itself toward them using a feature called backseat driver,” said David Gruber, founder and CEO of Project CETI, professor of biology and environmental sciences at Baruch College at the City University of New York and a co-author of the study published this week in the journal Scientific Reports.”When the glider detects the distinctive vocalizations of sperm whales, the software on board identifies where that sound is coming from and automatically communicates with the glider’s navigation system to change directions and follow the whale,” Gruber added. A glider is a small robot that slowly changes its buoyancy, becoming slightly heavier to sink and lighter …
