Humpback whale “Hartwin” spotted in Denmark’s Little Belt heading toward the Baltic Sea

A humpback whale was seen on June 20‑23 2026 swimming through the Little Belt, the narrow strait between Denmark’s Jutland peninsula and the island of Funen. The animal was filmed by tourist guide Linda Frølund Hansen from a bridge 55 metres above the water and identified as a humpback by marine experts Peter Teglberg Madsen and Carl Kinze. The whale, estimated at about 15 metres long, displayed an unusually pale skin tone and visible lesions, which Kinze suggested could be a fungal infection or a natural growth anomaly.

The whale has been dubbed “Hartwin” and has already been sighted earlier this year off the coasts of the United Kingdom and the Netherlands before entering Danish waters. Experts warn that the Baltic Sea’s low salinity and shallow coastal areas make it an unsuitable habitat for humpbacks and that Hartwin could face the same fate as the previously stranded whale “Timmy”, which died after a rescue attempt near the Danish island of Anholt. Conservation groups are calling for immediate assistance, including possible medical treatment and guidance to steer the animal away from the German coasts of Schleswig‑Holstein and Mecklenburg‑Vorpommern.

Authorities in Denmark and Germany are monitoring the situation, urging vessels to keep distance and preparing contingency plans should the whale require rescue to prevent another high‑profile marine incident.