Swarms of jellyfish could make landfall along Israel’s Mediterranean coast within a week, as Israelis increasingly hit the beaches during the beginning of the summer season.
Dori Edelist, a marine biologist at the University of Haifa, told Channel 12 news on Monday that jellyfish have been spotted several kilometers off the coast, estimating it would take a week or two before they begin appearing on beaches.
The jellyfish usually stick around for about a month to a month and a half, according to Edelist. He predicted the swarms would be smaller and be around for less time than last year, but nevertheless intense.
“We see there are long-term cycles of maybe twenty years in the rise and decline in the number of jellyfish,” the marine biologist told the network.
He added: “Even within the cycle there are big changes. In 2016, there were almost no jellyfish, a short swarm of two weeks. However, in 2015, 2017 and last year, we saw developed swarms of 2-3 months in the summer and another 3-4 months in the winter.”
A Hebrew-language app exists for Israeli bathers seeking to avoid jellyfish.
Jellyfish tentacles can sting and inject venom into humans, which usually results in mild to serious discomfort and, in rare cases, lead to extreme pain, or even death.
Most of the jellyfish that visit Israel are migratory, invasive species that originated in the Indian Ocean and are thought to reach the eastern Mediterranean via the Suez Canal.
While jellyfish have swarmed to Israel’s Mediterranean coast for decades, scientists understand little about the rules according to which they live and move and find it difficult to predict when the swarms will appear, which specific species they will consist of, and how long they will stay.
In 2016, University of Haifa researchers looked at when a power station was most badly affected by the jellyfish and correlated it with the moon and water temperatures, concluding there was a link between the annual arrival of the sea creatures and the phase of the moon.