Mass numbers of alien comb-bearing jelly-fishes Mnemiopsis leidyi and Beroe ovata in the Sea of Azov, Black Sea, and the Caspian Sea is a focal point of current research. To monitor the jelly plankton, the IKS-80 net is used with the opening diameter of 80 cm and mesh size of 500 µm, similar by construction to the Bogorov-Rass (BR) net for horizontal catch. Sampling occurs in summer by vertical towing from the bottom to the surface (the Sea of Azov) and in the layer of 0 – 50 m (the Black and Caspian Seas). The net does not have a meter of filtrated water. The determination of volume filtrated by the net is by the length and slope angle of a loosened rope. Measuring of jelly plankton wet biomass by species with the use of a graduated cylinder (volume method) once organisms are separated from the water. Hydroid and scyphozoan jelly-fishes, as well as comb-bearing jelly-fishes, are considered in the samples.
The database contains data from 12 expeditions that sampled jelly plankton in the Taganrog Bay of the Sea of Azov and in the Russian sector of the Caspian Sea for the summer period (Figure 1 è Table 1).
|Sea of Azov|
|Total by seas||0||0||0||12||0||0||45||128||192||84||0||0||461|