From a small boat, Gero and colleagues are planning to fit an acoustic measurement kit on the backs of the whales when they are near the surface. This will be done using a 10-metre long pole.
The acoustic measurement kit uses accelerometers, magnetometers and pressure sensors to measure movements, speeds and depths, and it measures the whales’ positions as well as the sounds they emit.
”The whales do not feel the 200-gram instruments that we stick onto their backs and which come off after 48 hours. When the kit has come loose, it emits a radio signal, which enables us to locate it. We extract the data and then we can reuse these so-called DTAGs on other whales,” says Gero.