Ship-boring mussel threatens German North Sea ports

The wood-boring mussel Teredo navalis is causing extensive damage to wooden harbour structures along Germany's North Sea coast. In Bremerhaven, sections of the new harbour and the Weser ferry terminal have been closed after the mussel gnawed through pilings, halting ferry services temporarily. The tiny organism, often no larger than a finger, can grow up to 45 cm and erodes wood from the inside, making damage hard to detect until structural integrity is compromised. Researchers warn that rising salinity and other environmental changes are allowing the species to spread more rapidly, endangering historic and modern port facilities from Wilhelmshaven to Emden.

The infestation poses significant economic risks for maritime trade and local tourism, as repairs to submerged wooden infrastructure are costly and time‑consuming. Authorities are investigating mitigation measures, including the use of alternative construction materials and targeted biological controls, to protect the vital harbour network.