Humans & conservation
R. nomadica can cause very painful injuries to humans, since it has vermicular filaments, which are covered in venomous stinging cells, in the mouth arms. The R. nomadica had caused the largest numbers of envenomisations along the southern Levant coast. These jellyfishes are notorious for the large swarms they form in the summertime. The R. nomadica have caused a socioeconomic problem in Israel because of such outbreaks, during which they can release their venomous stinging cells. The outbreak has caused seaside visits to be reduced from 3-10.5%, causing a monetary loss of $6 million for recreational beaches.
Their presence can clog up seawater intake systems, such as those used by seawater-cooled power plants.

