Israeli jellyfish experts predict jellyfish-free on Israel’s shores


Researchers at the University of Haifa have “cautiously” predicted that there will be very few jellyfish on Israeli beaches this summer. However, they are not willing to bet big money on that because the reality could still change, but “if we look at past cases, there is no doubt that this is a reasonable estimate at this point.” said.

In contrast to previous years, at this time of year, large swarms of water-soaked wandering invertebrates had already reached the coasts of Israel, but these shores are now almost completely free of them. Does not exist. Therefore, this situation is likely to persist throughout the summer.

“Given the situation last year, when jellyfish arrived late and small swarms of jellyfish occurred, it is possible that we will see this phenomenon again this year,” said marine ecologist Dr. Dor Ederist, a lecturer in the university’s Department of Marine Civilization. said. . In recent years, swarms of jellyfish filled the beaches in early July, clogging power plant filters and causing beachgoers to fear stings.

Dr. Edelist and his faculty colleague, Professor Dror Angell, founded the website “Jellyfish Among People” (Meduzot Ba’am) (www.meduzot.co.il) to report encounters with this creature. , said most people are now reporting encounters with the creature. Participants are happy that there are no jellyfish. “Previously, we would receive reports from yachtsmen and trawlers in the middle of the ocean that jellyfish were approaching.”

Dr. Gur Mizrahi, laboratory manager at the university’s Charney School of Marine Sciences, also reported a similar photo, this time from a bird’s-eye view. He regularly sees swarms of jellyfish flying by in a light aircraft, then sails towards them in a boat to examine them closely. He took a flight earlier in the week and didn’t see any jellyfish. “The area surveyed from the air was very wide. We flew along all the beaches 10 kilometers from the coastline and no swarms of jellyfish were observed. “We saw a few jellyfish that may have remained,” he continued. He also predicted with a high probability that there would be relatively few jellyfish this summer.

On July 20, 2022, a large swarm of jellyfish can be seen as far as the eye can see in Haifa Bay off the coast of Israel. (Created by: Rotem Sadeh/Nature and Parks Authority)

What could be the reason for their absence?

One possibility, the researchers suggested, was a change in ocean currents that may have pushed the jellyfish to other areas, but other locations the jellyfish could have reached due to changes in ocean currents. No herds were observed. In addition, this year the northerly currents that push jellyfish to Israel’s coast and further afield were weak.

Researchers agree that climate change has slowed ocean warming this year, delaying the ideal temperature for jellyfish polyps to “ripe” by about two weeks. Based on this, it was initially assumed that the jellyfish would also be delayed for a similar amount of time, but as time passed, the jellyfish stopped coming. “Other factors may have become a problem as the jellyfish grew, such as animals that preyed on the jellyfish when they were still small. Of course, the ocean is a complex and complex system, so other things may have happened. “That’s a possibility,” Angel added.

“There is no doubt that a jellyfish-free summer is good news for beachgoers, but if anyone thinks this is the end of jellyfish, they are wrong. It doesn’t say anything about the population of jellyfish sitting on the ocean floor. Perhaps colonies of polyps still exist, waiting for suitable conditions for mature jellyfish to hatch and be released into the ocean. “This year is just a slight blow for them,” Angel concluded.







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