Journal of Coastal Conservation

, Volume 18, Issue 2, pp 121–130 | Cite as

The infection of the European eel with the parasitic nematode Anguillicoloides crassus in inland and coastal waters of northern Germany

  • K. Wysujack
  • M. Dorow
  • C. Ubl


Recruitment of the European eel is in decline since three decades. So far, the reasons of the decline have not been fully understood. Beside other factors, infection with the exotic swimbladder parasite Anguillicoloides crassus has been discussed as a threat to the species. In the present study monitoring results for A. crassus in eels from North German waters are presented. Between 1996 and 2011, the swimbladders of 17,219 eels from eight freshwater and coastal water areas were analyzed. Prevalence, abundance of parasites, infection intensity and severity of the damage to the swimbladder were recorded by visual inspection. In the freshwaters the prevalence was in the range of 65–83 %, whereas significantly lower values were found in the brackish waters. The differences were less clear for infection intensity but significantly lower values were found in the outermost location in the Baltic Sea. Mean damage to the swimbladders was highest in eels from the Rivers Weser and Elbe and lowest in the Baltic coastal waters. Prevalence and damage degree were stable in all waters except for two rivers, where a decreasing trend in infection intensity was found.


European eel Anguilla anguilla Anguillicoloides crassus 



The authors wish to thank C. Köthke, L. Dobberschütz and R. Endjer for providing the samples from the rivers Elbe, Weser and Ems, respectively. We are grateful to colleagues of the association “Fisch und Umwelt Mecklenburg-Vorpommern e.V.” for providing samples from the remaining waters and to A. Beiermeister, C. Wiege-Pfeiffer and S. Jennerich for their laboratory work. We also like to thank two anonymous referees for their helpful comments. Since 2009, the study was partly conducted in the project “Living North Sea” and financed in the frame of the Interreg IVb North Sea program of the European Union (European Regional Development Fund).


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Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  1. 1.Thünen‐Institute for Fisheries EcologyAhrensburgGermany
  2. 2.State Research Center for Agriculture and Fisheries Mecklenburg-VorpommernInstitute for FisheriesRostockGermany

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