Biology and meso-scale distribution patterns of North Sea cephalopods

摘要

Between 2007 and 2009, 132,178 cephalopods were sampled in the North Sea during ICES International Bottom Trawl Surveys. Most abundant were the long-finned squids Alloteuthis subulata (124,751 animals) and Loligo forbesii (3415 animals). Short-finned squids such as Todaropsis eblanae, Todarodes sagittatus and Illex coindetii were rare (195 animals). During winter, A. subulata individuals, mostly immature and maturing, were concentrated in the central and northern parts of the North Sea. In summer, the abundance of A. subulata, mostly maturing and mature, increased in the southeastern part suggesting a southward migration to spawning grounds. L. forbesii individuals, some fully mature, were abundant in the northwestern part of the North Sea during winter indicating spawning areas in this region. In summer, L. forbesii individuals, mostly immature, occurred in lower numbers throughout the North Sea. Our data provide new information on abundance, distribution, migration, and possible recruitment areas of North Sea cephalopods.