Since 2020, orcas off the coast of Spain and Portugal have been ramming boats, biting rudders and, in a few cases, sinking entire vessels. Now it has been reported that a similar encounter has happened off Shetland. Madeleine Finlay speaks to marine biologist and orca expert Hanne Strager about what might be behind these incidents and where our fascination with orcas comes from. Help support our independent journalism at theguardian.com/sciencepod