A young whale's journey across the Mediterranean highlights the many threats facing ocean animals, researchers say.
Scientists from Greenpeace and the universities of Exeter and Haifa studied whales and dolphins in the Eastern Mediterranean, off the coast of Israel.
They found Cuvier's beaked whales, bottlenose dolphins and sperm whales - including a young adult male previously seen off southern France.
The distance between sighting locations makes this the furthest recorded movement of a sperm whale in the Mediterranean - and means the whale made a hazardous journey.
Audio analysis provides further evidence that whales off the Israeli coast are part of the wider regional population, as their vocalisations matched the "Mediterranean dialect".
The researchers say their findings demonstrate the need for targeted protection at key locations.
"Marine life in the Mediterranean faces numerous threats - from fishing and pollution to noise and boat strikes," said Dr Kirsten Thompson, from the Greenpeace Research Laboratories at the University of Exeter.
"The journey of this particular whale must have gone through narrow straits - either the Sicily Channel or the Strait of Messina, both of which are extremely busy, noisy and potentially dangerous for a deep-diving sperm whale."
The whale - known variously as Kim, Elia and Onda by researchers in different regions - was probably travelling with other young males, which typically leave their birth group at this stage of their lives.
"The fact that these whales pass through narrow, shallow seas means that listening devices could be installed at those points to protect them," Dr Thompson said.
"This could create an alert system to prevent ship strikes."
Dr Thompson added: "The Mediterranean is the busiest sea in the world, with rich wildlife and a high human population.
"Unfortunately, some species like these threatened whales are facing further industrial development, with oil and gas exploration and the construction of a new gas pipeline between the eastern basin and Italy.
"Some state that further hydrocarbon extraction is a violation of EU environmental protection legislation - this expansion is not just bad for our future climate targets but for the wildlife that is already struggling in this busy sea."
Relatively little research has been done on whales and dolphins in the Eastern Mediterranean.
In this study, visual-acoustic surveys were conducted during April and May 2022.
Acoustic detections found: sperm whales (three encounters), Cuvier's beaked whales (one encounter), bottlenose dolphins (one encounter) and unidentified dolphins (17 encounters).
The study was funded by Greenpeace International.
