The new species has been drawn to the waters because the temperature of the Black Sea is becoming more like the Mediterranean, which, in turn, is becoming more like a tropical sea, said Snezhana Momcheva, a SESAME project coordinator in Bulgaria. SESAME is a European Union-funded study of ecosystems in the Mediterranean and Black Seas.
SESAME scientists are watching to see if the new jellyfish species spreads to Bulgaria's Black Sea coast, the Sofia news agency reported Friday.
Momcheva and her team also are watching a new tropical fish species that has migrated to the Mediterranean. That species of fish becomes toxic when it reaches a length of 3 inches, she said.
Notable deaths of 2014 [PHOTOS]