A Pacific sea nettle (Chrysaora fuscescens) jellyfish at the Monterey Bay Aquarium in California. Photo: Dan Parsons via Wikimedia Commons.

A massive swarm of jellyfish hundreds of miles long is closing in on Israeli waters along the Mediterranean coast.

Stray jellyfish have already been seen on the shores of Israel’s south and a few on the central coast as far north as Herzliya, and there have also been reports of swimmers being burned by jellyfish venom.

It is believed that the swarm may include tens of millions of individual organisms, and is expected to stay in Israeli waters for at least a month.

Dr. Dor Edelist, a marine ecologist at the University of Haifa, told the Hebrew news site Walla that he was “excited” about the arrival of the swarm, commenting, “There is no need or reason to panic.”

He pointed out that there has never been a report of a single death from jellyfish venom in the Mediterranean Sea.

Nonetheless, a web page and phone app have been set up that allow Israelis to track jellyfish and avoid any waters where they are concentrated.

Edelist has a broadly positive outlook on the jellyfish, saying, “They’re part of nature and they’ve been here for hundreds of millions of years.”

“They have a role,” he explained. “They clean the sea. They serve as food for a great variety of marine creatures like sea turtles and fish.”

“Human beings can also produce healthy food, cosmetics, and pharmaceuticals from them,” Edelist notes. “In Israel, we are already working on the innovative development of the use of their mucus to clean micro-plastic waste, for example in wastewater treatment plants.”

He says that the swarm was likely to dissipate by next month and “we will be able to return to the sea without fear.”