A swarm of jellyfish forced a shutdown of nuclear reactors at western Europe’s largest nuclear power station after clogging the pumps.

The Gravelines plant in northern France was left with only one of its six reactors operating at full capacity after the marine life disrupting cooling units on Monday, EDF said.

Images from the scene show groups of bright blue jellyfish in the waters around the plant, which then appear to have been sucked in to the pumps.

EDF said that around 100kg of jellyfish arrived on Saturday increasing to an influx of “several tens of tons” by Monday.

(see article for the images)

Fishing vessels are now taking part in “preventive fishing operations” on a 24 hour basis with three fishing boats “constantly patrolling off the coast of the plant”.

The operations involve the jellyfish being caught by trawlers and then released offshore. Teams have also increased the frequency of cleaning the equipment at the pumping stations, according to EDF.