Rare Great White Sighting Highlights the Mediterranean's Vanishing Shark Population

A rare video of a large adult great white shark in the Mediterranean made headlines worldwide after divers filming ghost-net removal from a wreck between Tunisia and Sicily captured the predator on camera. The sighting, in the Strait of Sicily, surprised many observers and renewed interest in a species that is still present in the region but seldom seen.

The great white shark, Carcharodon carcharias, has been part of the Mediterranean ecosystem for more than 150 years, with historical records from Spain, France, Italy, Malta and Greece. But fishing, prey depletion and accidental capture have driven numbers so low that the animals are now often described as a “ghost population,” meaning they are not extinct but appear only rarely. Many reports remain hard to verify, which has added to the mystery.

A genetic study led by researchers at the University of Bologna and published in the Journal of Biogeography found that Mediterranean great whites are a distinct population that has lived in the sea for 3.2 million years. The study also found they are genetically closer to sharks in the Pacific Ocean than to those in the Atlantic, while showing extremely low genetic diversity, a sign of a small and vulnerable population at high risk of extinction.

Researchers said major gaps remain in understanding where these sharks feed, migrate and breed in the Mediterranean, which makes conservation difficult. The latest sighting, along with an accidental capture of a young great white about 40 kilometers off Alicante, Spain, in April 2023, suggests the species never left the sea, but survives at very low density. Scientists say more sightings may partly reflect better cameras, satellite tracking and citizen reporting, while warming seas and shifting prey may also be changing where and when sharks appear. The sighting has prompted calls to expand marine protected areas, but because the sharks move across national borders, conservation will require identifying key habitats across several countries.