Gelatinus macrozooplankton of the north-eastern shelf of the Black Sea: interannual changes in abundance

Noticeable changes in the abundance of the invasive species occur 5-15 years after its introduction; this time interval also allows one to assess its long-term impact on the biota, especially on the species included in the food spectrum and competitor species. Therefore, long-term monitoring studies are of great scientific and practical interest. The paper examines the dynamics of the abundance of gelatinous macrozooplankton in the Black Sea 8-10 years and 12-15 years after the appearance of the invasive comb jelly Beroe ovata. Year-round ship monitoring was carried out on a standard 5-mile section from the shore on the shelf in the area of the South Branch of the Shirshov Institute of Oceanology of the Russian Academy of Sciences (Gelendzhik). The paper compares two research periods in 2005-2007, the second period - in 2010-2012.