Environmental DNA reveals the presence of the pygmy sperm whale
Environmental DNA reveals the presence of the pygmy sperm whale
The species was long believed to be absent from the Mediterranean Sea, but a study published in Mammal Review in late March 2026 has revealed, for the first time, the presence of the pygmy sperm whale (Kogia breviceps) in these waters. The discovery was made by a research group from the University of Milano-Bicocca, led by Elena Valsecchi, within the framework of the LIFE Conceptu Maris project.
The finding does not come from direct sightings, but from the analysis of environmental DNA (eDNA): genetic traces released by animals into the water through skin, secretions, and excretions. Samples were collected aboard commercial ferries used as monitoring platforms in the central-western Mediterranean. Overall, pygmy sperm whale DNA was identified in 10 samples, corresponding to at least 5 independent presence events, across a wide area extending from the Tyrrhenian Sea to the Strait of Gibraltar.
The result is particularly robust: the genetic sequences match Kogia breviceps unambiguously and clearly differ from those of the dwarf sperm whale (Kogia sima). In the same areas and periods, onboard observers also recorded sightings of unidentified small cetaceans, a finding that may provide indirect support for the species’ presence in the Mediterranean. Detections were also more frequent in samples collected at night. One possible explanation relates to the species’ behaviour or to its remarkable defence mechanism: when threatened, Kogia whales release a cloud of dark fluid, similar to “ink”, which is extremely rich in DNA.
The discovery suggests that the pygmy sperm whale is not an occasional visitor, but may have a stable presence in the western Mediterranean.
This result, of significant scientific interest, opens new perspectives and strengthens the call to formally include the species among those protected under international Mediterranean agreements such as ACCOBAMS.
In the picture pigmy sperm whale, by Vidal Martin
