Distribution and Abundance of the Macrozooplankton Comunity in the Black Sea in 2021

Abstract

This paper focuses on the dynamics of four jellyfish species, Aurelia aurita, Beroe ovata, Mnemiopsis leidyi and Pleurobrachia pileus, from the Black Sea. The samples were taken in time of two expeditions in 2021 (May-June and August-September). Aurelia aurita species was dominant in terms of biomass due to its large size, The density of the species Pleurobrachia pileus recorded high values, in the north, but also between the isobaths of 40-80 m. The density of the species Mnemiopsis leidyi was higher in the southern and central area of the Romanian Black Sea. Because jellyfish feed on zooplankton organisms, the eggs and larvae of commercially important fish, high densities of jellyfish can produce direct decreases in the trophic chain by reducing the biomass of zooplankton, and fish eggs and larvae.

Summer Biomass Variability and Spatial Interactions between European Sprat (Sprattus sprattus) and Moon Jellyfish (Aurelia aurita) in the Western Part of the Black Sea

“…Small pelagic fish stocks have shown signs of recovery; in particular, during the late 1990s and the 2000s, catches and biomass began to increase [39]. The proportion of moon jellyfish has increased and currently has the highest biomass among gelatinous species [40][41][42][43].…”