Hydrography and mackerel distribution on the shelf edge west of the Norwegian deeps

A combined acoustic, fishing and hydrographic survey was carried out in the Viking Bank area of the North Sea in December 1995. The aim of the survey was to locate and map the distribution of the western mackerel in the area prior to the start of their spawning migration and to determine the hydrogr aphic background. Large numbers of mackerel were found in greater than 200 m of water on the western edge of the Norwegian Trench. The area was define d by cool waters to the east, south and west, suggesting that the distribut ion was modulated by water temperature. Data from CTD sections, sea surface temperatures and current meter moorings are presented and the implications for the distribution and migration of the western mackerel are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.