Three dives of the Mir manned submersibles with plankton counts and two vertical plankton hauls with a BR net were carried out above the Lost City (Atlantis underwater massif) and the Broken Spur hydrothermal fields during cruise 50 of R/V Akademik Mstislav Keldysh. Above the Atlantis seamount no significant increase in plankton concentration was found. Above the Lost City field horizontal heterogeneity of plankton distribution in the near-bottom layer and in overlying water layers was shown. Near-bottom aggregations of euphausiids and amphipods previously reported by other scientists seem to be related to attraction of these animals by the submersible's headlights rather than represent a natural phenomenon.

Supplement to: Vinogradov, Georgy M; Vereshchaka, Alexander L (2006): Zooplankton distribution above the Lost City (Atlantis massif) and Broken Spur hydrothermal fields in the North Atlantic according to the data of visual observations. Translated from Okeanologiya, 2006, 46(2), 238-248, Oceanology, 46(2), 217-227