Target practice. This is Freja, the world’s oldest-known and most-studied harbour porpoise (Phocoena phocoena). She has lived at Fjord & Bælt, a research facility in Kerteminde, Denmark, since 1997, after being caught in a fishing net and is deemed unreleasable. Freja is involved in non-invasive experiments that help researchers to understand how porpoises use echolocation to hunt and how underwater noise influences their ability to forage. Here, her eyes are gently covered with suction cups while she is asked to distinguish between two underwater targets using echolocation. A device on her back records her acoustic responses. This photograph, part of a series by nature photographer Lana Tannir, was a highly commended entry at the Nature Photographer of the Year competition — see below for a selection of other winning and commended entries.
Lana Tannir/NPOTY 2025
