Ichthyoplankton in the plankton community of the Crimean Peninsula shelf zone (Black Sea) in July 2010

Abstract

Data on the species composition and quantitative distribution of ichthyoplankton, zooplankton, and jelly fish macroplankton from different areas of the Crimean Peninsula shelf zone in July 2010 are presented. It has been shown that the structure of species composition and the maximum abundance of ichthyoplankton are comparable to those in July 1988, i.e., until negative changes in the ecosystem of the Black Sea shelf, which took place in the 1990s. The average abundance of ichthyoplankton in July 2010 corresponds to the lowest long-term data obtained in July 1950s and 1960s. The effect produced by organochlorine contaminants and by the abundance of jelly fish macroplankton on the survival of pelagic fish eggs and fish larvae is studied. The prevalence of juvenile copepods in the guts of fish larvae, as well as the low proportion of fish larvae with empty stomachs (<10%), if compared to the data obtained in the 1990s (50–90%), point to the favorable trophical conditions for fish larvae in the area of investigation.