The objectives of the research are: i) To utilize extensive collections of hydrothermal vent faunas made by russian research vessels, and now conserved in Russia; ii) To examine this material and data from other sources according to vicariant and dispersal models and critically relate the influence on hydrothermal faunas of depth gradients and other environmental factors; iii) To compare cold seep and hydrothermal vent fauna, analysing similarities and differences in their community structure and habitat relationships; and especially to analyse the influence of depth gradients on the faunas and their evolution; iv) Based on the results of the foregoing, to plan new investigations of the fauna and habitat characteristics at the hydrothermal vent sites on the Mid-Atlantic Ridge south-west of the Azores.
