Küstenbiologie - Coastal Biology

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Shipworm Baltic Shipworms in the Baltic Sea

Shipworms in the Baltic Sea

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In Germany Teredo navalis is usually more numerous in the North Sea, presumably due to salinity conditions. Before 1993 its appearance seemed to be rather erratic, lasting each time for only about two or three years. A theory stated, that only larvae from the North Sea could reach the Baltic with appropriate currents at the right time in the summer. They would establish a short-lived population, not being able to multiply. However, even then this theory was subject to doubt, because there actually were little known damage events between the infamous "mass attacks". Also, a study in 1989 revealed a small population, too small to cause a lot of damages and attention. Now the theory is completely invalidated by experiments in Rostock in the mid-90s.

It seems more likely, that it just takes a combination of clean water, a good food supply for the larvae (eutrophication) and especially a warm summer to trigger another mass reproduction. However, why exactly this is happening in a large way since 1993 and why it started in the Eastern regions is not known.

Our longterm study since 1997 in Kiel shows, that almost every year larval settlement can be observed. Damages were recorded from the Danish border in the North West to the island of Rügen, where in suitable years the salinity is just high enough for shipworm larvae.

You can help!

Please let us know, where you have seen shipworms or its tell-tale traces. Also, a negative information like "our 20 year old Bongossi pilings are still teredo-free" could be very usefull for our research. Please send any information to:


Last Updated on Thursday, 22 February 2018 09:45