The resighting of Atlante, the scarred sperm whale

The sperm whale sighted on July 20th was unmistakable. Both biologists and citizen science participants aboard the research vessel “Pelagos,” engaged in the Cetacean Sanctuary Research (CSR) expeditions in the Ligurian Sea, were impressed. The whale’s tail had a strikingly jagged edge, almost like a comb. This individual, named “Atlante,” is missing about a third of its tail.

The flukes are a cetacean’s propulsion organ; in sperm whales, it typically surfaces before a dive, allowing researchers to distinguish individuals. Atlante’s flukes immediately bring to mind a propeller as the cause of the deep scars. Collisions between cetaceans and boats can kill the animals or leave them with severe injuries, which can impair essential functions like feeding, ultimately threatening the population’s survival. Beyond collisions with large ships, ferries or cargos, often cited as responsible for injuring and killing large cetaceans, recreational motorboats in the Mediterranean are also a growing concern.

Sperm whales (Physeter macrocephalus) are regularly living in the Mediterranean and are an iconic species of the Pelagos Sanctuary, the large transnational marine protected area established for whales’ and dolphins’ conservation. In the Mediterranean, there are likely fewer than 2,500 mature individuals, and the declining population is classified as endangered on the International Union for the Conservation of Nature (IUCN) Red List.

Luckily, Atlante seems relatively healthy. Through the hydrophone, an underwater microphone used for research, Tethys biologists learned more about him: his vocalizations indicated he was feeding, and in acoustic contact with other sperm whales in the area. Atlante was first sighted in October 2021, named by researchers from Menkab – Il Respiro del Mare, who estimated his length at about 8 meters at the time. He has been regularly seen since, both in the Pelagos Sanctuary and in the waters around Ischia.