Jellyfish density in the Black Sea

Environmental factors can directly affect the population size and timing of gelatinous organisms, Bat said.

Pointing out that rhizostoma pulmon, also called “sea liver”, which is the largest jellyfish species of the Black Sea, has recently increased in abundance, Bat said, “Jellyfish are known as creatures that live in water with temperature, salinity and move depending on the current. Due to the increase in water temperature, rhizostoma “Pulmo species frequently form clumps. Sometimes these clumps become large and dense. One of the factors that enable jellyfish to multiply is that they are carnivorous and feed on plankton.” he said.

Explaining that the Rhizostoma pulmo jellyfish species has high biomass in the Black Sea, Bat said that its abundance and distribution increases with the increase in water temperature, depending on the seas where it is found.

Stating that jellyfish are observed frequently in the late summer and autumn months, Bat said:

“It is thrown onto the shores by storms in autumn and winter. Rhizostoma pulmo may not be seen until the end of June of the following year, probably because it retreats to the open sea depths during the winter months. For example, in our study on the coast of Samsun, its population, which started to increase in the summer months when the water temperature was high, was observed to be at a high rate in the autumn months, and in the winter “It started to become rare starting from the second half of 2017 and disappeared in the spring months. These data also support the assumption that water temperature affects the distribution of the rhizostoma pulmo species.”

Stating that the distribution of the species on the world is in the northern and southern Atlantic Ocean, Black Sea, Mediterranean and Red Sea, Bat said: “Rhizostoma pulmo is seen on all coasts of the Mediterranean and the Black Sea, and is abundant in the months of June and August.” he concluded.