‘They have schedules to follow’: how fast ferries can threaten endangered whales in the Mediterranean

A Guardian investigation has found that despite a recommendation to slow down, leading shipping companies continue to travel above advised speeds in a key habitat for cetaceans

Marine biologist Alice Barbarioli waits with her camera trained on the horizon. A few minutes earlier, the hydrophone beneath the Pelagos research vessel detected codas - the sequence of clicks sperm whales use to communicate.

The sperm whale reveals its head and dorsal fin as those onboard the vessel in the Pelagos sanctuary, a conservation area established to protect marine mammals in the north-western Mediterranean, rush to take photos and note the rhythm of its breathing. After a few minutes, the animal arches its back, and begins to head back into the depths of the sea. They wait to catch a glimpse of its tail.