|Mnemiopsis leidyi in the Baltic Sea: distribution and overwintering between autumn 2006 and spring 2007|
|Kube, S.; Postel, L.; Honnef, C.; Augustin, C.B (2007). Mnemiopsis leidyi in the Baltic Sea: distribution and overwintering between autumn 2006 and spring 2007. Aquat. Invasions 2(2): 137-145. dx.doi.org/10.3391/ai.2007.2.2.9|
|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, Baltic [gazetteer]; Marine
In autumn 2006 the first observations of the West Atlantic comb jelly Mnemiopsis leidyi in Northern Europe were reported from the North Sea, the Skagerrak and the south-western Baltic Sea. Here we report on the further spread of this invasive ctenophore from the south-western towards the central Baltic Sea up to the south eastern Gotland Basin during autumn/winter 2006 and spring 2007. The abundances were generally low (max. 4 ind. m-3). While M. leidyi was located in the entire water column in Kiel Bight, it was found exceptionally below the halocline in the deep stratified central Baltic basins. Data of a weekly sampling program at a near shore sampling location in Mecklenburg Bight between January and May 2007 showed that up to 80 % of the individuals were juveniles, smaller than 1 mm total body length and that M. leidyi survived the winter in the Southern Baltic Sea, even if abundances dropped down to <1 ind. m-3 in February. A first assessment of the physiological demands of this species versus the environmental conditions of the Baltic Sea showed that the successful establishment of this ctenophore is probable in the south-western and central Baltic Sea.