VERTICAL STRUCTURE OF THE ZOOPLANKTON COM MUNITIES IN THE OLIGOTROPHIC AREAS OF THE NORTHERN ATLANTIC, AND INFLUENCE OF THE HYDROTHERMAL VENT

Patterns of the vertical distribution of the zooplankton above the hyd rothermal vents TAG (26 degrees N) and Broken Spur (29 degrees N), Mid dle Atlantic Ridge, are presented. Material was collected with 150-1 w ater bottles. BR nets, the data of the direct observation from DSRV '' Mir'', are also used. Local enrichment of the plankton at a distance o f several tens and hundreds of meter above the bottom is shown to be a bsent. The water layer adjacent to the bottom, is dominated by the ben thopelagic shrimps of the family Alvinocarididae; net plankton is almo st lacking, bottle plankton is rare, the share of dead specimens being high. A supposition that hydrothermal ecosystens are sufficiently clo sed energetically, is done.