The invasive “shipworm” Teredo navalis at the Mecklenburg-western Pomeranian coast – Distribution and infestation risk

Since ancient time shipworms are commonly known due to their destructive activity. These bivalves bore into, and consume, all types of wood in marine coastal habitats. At the Southwestern Baltic Sea coast, wooden coastal protection measures become regularly infested and destroyed by the shipworm species Teredo navalis. At the island of Hiddensee, for example, 22 groins had to be replaced between 2010 and 2012 leading to maintenance costs in the order of three Million Euro.
While for the North Sea Teredo navalis already is known since its mass occurrence in 1730, this species is mentioned in the Baltic Sea not earlier than the second half of the 19th century and thereby is considered an invasive species to the Baltic Sea. The distribution border of Teredo navalis at the Mecklenburg-western Pomeranian coast has shifted east in the beginning of the 1990th and today is located at the west coast of the island of Hiddensee. Mass occurrences of the species are temporal and spatial restricted and it is yet unknown by which factors they are indicated.
To verify the actual infestation density, the reproduction success and to monitor further expansion to the eastern parts of the Baltic Sea, a detailed ecological study on behalf of the Federal Environmental Agency for Coastal Protection is conducted by the Chair of Applied Ecology and Phycology since 2012. The fieldwork is complemented by laboratory experiments concerning the physiology of the species. Furthermore the impact of climate change on the distribution of Teredo navalis at the Baltic Sea coast is one of the major questions being essential for a sustainable planning of coastal protection activities.

Funding
Federal Environmental Agency for Coastal Protection (StALU MM Rostock)

Responsible persons
Dr. Heike Lippert, Prof. Dr. Ulf Karsten, Michael Bugenhagen (StALU)

Applicant
Prof. Dr. Ulf Karsten

Funding Period
2012 - 2018

Cooperation partners
Prof. Dr. Thomas Schweder, Ernst-Moritz-Arndt University, Greifswald
Prof. Dr. Inna Sokolova, University of Rostock
 

Field work at the Mecklenburg-western Pomeranian coast (© Frank Bernhardt, TU Dresden)
Wooden panel infested by Teredo navalis
Wooden panel destroyed by shipworm (© Frank Bernhardt, TU Dresden)