Influx could block plant’s cooling water filters and halt operations, amid concern the creatures could be significantly harming local fish life
Zafrir Rinat | Jul. 4, 2019

A power station in southern Israel has been dealing with a wave of thousands of jellyfish that could affect its output, the Israel Electric Company said Thursday.

The jellyfish have been piling up at the Ashkelon station’s filters, which are designed to prevent them from reaching operating systems and to divert them to dedicated tanks.

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The IEC’s coastal plants use seawater to cool its systems. Jellyfish have also caused problems for desalination plants in Israel as well. In 2011, jellyfish obstructing filters forced a nuclear reactor in Scotland to shut down temporarily.

The seasonal wave of nomad jellyfish reached the Ashkelon and Ashdod areas this week, and is expected to move on to the beaches of central and northern Israel. It appears that it is having a negative effect on local marine life.

According to Bella Galil of the Steinhardt Museum of Natural History at Tel Aviv University, the jellyfish swarms subsist on fish eggs, young fish, and the components of fishes’ diets. The jellyfish thus threaten fish not only by direct predation, but also by competing for their food. Galil adds that while there has been no study into the matter in the region, the scientific literature suggests a drastic effect on fish life.

Galil believes it is possible that a decrease in Mediterranean fish life and its replacement with invasive marine fish species could partly be the result of jellyfish swarms, which could be hurting local species’ reproduction. Juvenile fish from local species, she says, are usually present in the sea’s upper column when the swarms arrive. In contrast, invasive fish species arriving from the Red Sea spawn later in the season, meaning their juveniles are not consumed by the jellyfish.