Since its inception, nuclear energy has faced a host of opposition, from oil conglomerates to well-intentioned anti-nuclear-weapons activists to environmental groups. As it turns out, even ocean critters are getting in on the movement.

Four reactors at France’s Gravelines nuclear power plant, located along the English Channel, were temporarily shut down over the weekend after a swarm of jellyfish threatened to clog critical water intake systems.

The ongoing war between the natural world and humanity has entered its squishiest battle yet. On Monday, France’s Gravelines nuclear power plant went from humming along nicely to locked up like a French waiter being asked for ketchup thanks to a “massive and unpredictable presence of jellyfish.”