January is the height of grey whale migration season off the coast of California. But are the whales being threatened by the Navy’s sonar? On today’s Terra Verde co-hosts Adam Greenfield and Karolo Aparicio speak with Stan Medasian with the Oceanic Society on grey whale migration and with Cara Horowitz with the NRDC on the legal battles to get the US Navy to curb its use of midrange sonar because of the effects on whales.