Publication Abstract

The snake pipefish a coastal and a truly oceanic species

Beginning 2004 a massive invasion of snake pipefish , Entelurus aequoreus, into waters of the northeast European shelf was observed. This invasion peaked in 2007 and 2008 reaching far up North into the Barents Sea and up to Spitsbergen. The most puzzling observation was that almost all of these occurrences were pelagic, often far offshore while this species was at the time primarily considered as being coastal. This study presents the full extent of the appearance of the snake pipefish on the northeast European shelf. Starting with the appearance from the open ocean and outburst along the full northern European shelf and North Sea. Re-examination of plankton and bottom trawl survey data west of the British Isles revealed that first offshore findings occurred in the western areas with subsequent spreading of the species to the North and East. These findings suggest, that snake pipefish were advected from the West, thus from the open ocean. Since snake pipefish is not known from the Western Atlantic margin, we conclude that there might exist a population above the Mid Atlantic Ridge. We will discuss possible explanations on why this sudden invasion occurred.