A surprising swarm of jellyfish has reached the Haifa shores in winter

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A huge swarm of jellyfish is seen as far as the eye can see in the Haifa Bay off the coast of Israel, on July 20, 2022. (photo credit: Rotem Sadeh/Nature and Parks Authority)

By: Judy Siegel-Itzkovich  Published On: December 20, 2023

Jellyfish have been thought only to be a summer phenomenon, however, a surprising appearance of jellyfish in December has raised new questions.

After an unusually jellyfish-free summer, a swarm of the wandering filamentous kind has been seen off the coast of Haifa.

“This swarm, unlike the ones that usually arrive in the summer, is different because most of it is below sea level at depths of a few meters. It appeared a few days ago and is found in small groups,” said Dr. Gur Mizrahi and Dr. Eli Shemesh from the Charny School of Marine Sciences at the University of Haifa.

Jellyfish in the winter may not be unusual

According to the researchers, the arrival of swarms of jellyfish in the winter is not unusual, and their non-arrival in the current summer season did not prevent them from arriving close to Israel’s shores in recent days.

“The swarm looks young, the creatures are not large, and their density differs from those in the summer.

Jellyfish off the coast of Haifa (CREDIT: UNIVERSITY OF HAIFA).

Even though we do not always notice them in winter, when there are almost no bathers in the sea, the jellyfish have not left us yet.

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Jellyfish 370 (credit: Jonathan Miller)

“We, from the lab of Dr. Yoav Lehan and Prof. Dani Tchernov, are trying to cope with the annual phenomenon of jellyfish,” Mizrahi said, concluding that they “are simple creatures—but they surprise us every time!”