This book represents the Proceedings of the 37th European Marine Biology Symposium, held in Reykjavik, Iceland, 5-9 August 2002. The main themes of the symposium were Migrations and Dispersal of Marine Organisms. These themes are highly relevant today. There is widespread man-aided dispersal (e.g. by ballast water) of marine plants and animals, which may have substantial effects on the regions receiving new species. The new introductions may result in reduced diversity of plants and animals and may affect natural resources in the countries receiving toxic algae and other foreign elements. Studies of changes in distribution and dispersal of marine animals and plants are also highly relevant with reference to the changing climate taking place. The study of dispersal has recently gained new impetus with the discovery of the remarkable communities found on isolated hydrothermal vents and cold water seeps in the world’s oceans.