Small worm - big danger

This worm is actually a mollusc, calledteredo navalis. Its shells have developed into an effective boring head with which the mussel bores into wood. The rasped wood serves as a food source, and the resulting tunnel as a living cavity.

The shipworm, which has an affinity for saltwater, is highly adaptable and has been making inroads into the Baltic Sea since the early 1990s. Since then, it not only infests wooden hydraulic structures of all kinds, but also poses a major threat to historic shipwrecks. Larger populations are capable of destroying the monuments within a few years.

On the 12 barrels recovered so far, hardly any wood has been preserved. One of the reasons lies in the shipworm, as the photo shows.