Gelatinous Zooplankton along the Romanian Shelf - Qualitative and Quantitative Distribution during 2010-2013

Abstract

Gelatinous zooplankton plays a key role in the marine area, abundance and biomass fluctuations leading to understanding the ecosystem functions and pressures. In 2010-2013, a number of 111 samples were collected from the Southern to the Northern part of the Black Sea in order to determine the qualitative and quantitative structure and spatial distribution patterns of gelatinous zooplankton. The identified species were represented by the scyphozoan Aurelia aurita and the ctenophor Pleurobrachia pileus and non-indigenous ctenophores Mnemiopsis leidyi and Beroe ovata. The species that recorded the highest value of density was represented by Pleurobrachia pileus, with a maximum value in 2012, the minimal value being recorded by Mnemiopsis leidyi in 2010. Maximum value for biomass was recorded in 2013 by Aurelia aurita, Beroe ovata presenting the smallest values. The scyphozoan Aurelia aurita is a large species, therefore it reaches high values of biomass. Spatial distribution was influenced by the environmental factors like temperature and salinity.