|The ctenophore Mnemiopsis leidyi A. Agassiz 1865 in coastal waters of the Netherlands: an unrecognized invasion?|
|Faasse, M.A.; Bayha, K.M. (2006). The ctenophore Mnemiopsis leidyi A. Agassiz 1865 in coastal waters of the Netherlands: an unrecognized invasion? Aquat. Invasions 1(4): 270-277. dx.doi.org/10.3391/ai.2006.1.4.10|
|In: Aquatic Invasions. European Research Network on Aquatic and Invasive Species: St. Petersburg. ISSN 1818-5487, more|
Introduced species; Mnemiopsis leidyi A. Agassiz, 1865 [WoRMS]; ANE, Netherlands [gazetteer]; Marine
The introduction of the American ctenophore Mnemiopsis leidyi to the Black Sea was one of the most dramatic of all marine bioinvasions and, in combination with eutrophication and overfishing, resulted in a total reorganization of the pelagic food web and significant economic losses. Given the impacts this animal has exhibited in its invaded habitats, the spread of this ctenophore to additional regions has been a topic of much consternation. Here, we show the presence of this invader in estuaries along the Netherlands coast, based both on morphological observation and molecular evidence (nuclear internal transcribed spacer region 1 [ITS-1] sequence). Furthermore, we suggest the possibility that this ctenophore may have been present in Dutch waters for several years, having been misidentified as the morphologically similar Bolinopsis infundibulum. Given the level of shipping activity in nearby ports (e.g. Antwerp and Rotterdam), we find it likely that M. leidyi found its way to the Dutch coast in the ballast water of cargo ships, as is thought for Mnemiopsis in the Black and Caspian Seas. Given the magnitudes of the impacts this ctenophore has shown in its native and introduced ranges, the animal’s potential effects on the North Sea pelagic ecosystem and fisheries warrant close observation in the coming years. The development of large ctenophore aggregations during recent years was probably driven by the higher than average sea surface temperatures in the North Sea, and we hypothesize that populations from the southern North Sea may have been the source of the invaders reported in the Baltic Sea and the Skagerrak. If these northern populations (Baltic, etc.) are not able to overwinter, it is possible that established populations in southern North Sea estuaries may serve as a yearly supply of invaders to the colder waters to the north.