Saturday September 02, 2017

Whales are learning to dodge deafening military sonar

Satellite tag deployment on a Cuvier's beaked whale

Satellite tag deployment on a Cuvier's beaked whale (Erin Falcone)

Listen 7:10

There are many factors that could explain why whales strand themselves, sometimes en masse.  One species of whale - Cuvier's beaked whale - is known to experience strandings in association with the use of military sonar.  But like all other strandings, the exact mechanism for why this happens remains a mystery.  

A new study by Erin Falcone, a researcher with the Foundation for Marine Ecology and Telemetry in Seabeck, Washington found that military sonar changes specific behaviours in the whales.  Using satellite tags, the researchers determined that these whales are diving for longer periods of time, and foraging less.  Even though Cuvier's are deep water specialists, one whale remained underwater for over two and a half hours; more than twice the average dive duration for this species.  Although the whales seem to be adapting to the presence of sonar by changing their diving behaviour, more research is required to establish long term health risks.