Ah, summer in Israel. The beaches throng with sun-kissed skin on show, ice-cream executives rub their sweaty palms in glee and swarming giant jellyfish clog the seawater-intake cooling pipes at power plants up and down the coast. By the ton.
Bathers have been reporting the mild stings of Rhopilema nomadica, the nomad jellyfish, from Ashkelon in the south to Haifa in the north. The beautiful light-bluish cnidarian, indigenous to the tropical areas of the Indian and Pacific Oceans, swam through the Suez Canal and invaded the Mediterranean in the 1970s. Since then the beasts, which can easily get bigger than your head, have been frightening swimmers, though they're pretty harmless.
But they are a particular bane to the Israel Electric Corp., which has five seawater-cooled power stations along the Mediterranean coast. The stations installed filters over their seawater intake systems, but when the jellyfish swarm, they can overwhelm the systems, the company told Haaretz.
First in the world
Nomadica normally swarms in June and July, so at least the IEC was braced and ready to get rid of the pests as they poured in.
In fact, because they were such a plague, one of its own employees, Avi Algazi, collected data and wound up doing a Masters' degree at Haifa University on nomadica. Last year, Algazi became the first in the world to realize that their swarming correlates with water temperature between 28.2 and 30 degrees Celsius, exactly, and the full moon.