At the Paluel nuclear plant in France, a nuclear power plant saw a 2.4 gigawatt reduction in output. The reason? Jellyfish.
This is the second time this year that France’s nuclear reactors have been affected by large swarms of jellyfish. In August, four reactors at France’s Gravelines nuclear power plant had to shut down due to jellyfish in the plant’s cooling systems.
The Gravelines plant is located between Dunkirk and Calais and is cooled via a canal connecting it to the North Sea. To produce 5.4 gigawatts of energy, the plant has six units, each producing 900 megawatts, and 4 of which were shut down due to the jellyfish invasion. Fortunately, no physical harm was done to the reactors or the employees who service them.
The Paluel nuclear plant typically produces 5.2 gigawatts of electricity, yet that production was cut in half on Wednesday. The plant, located on the English Channel, also had swarms of jellyfish flooding its cooling systems.
Nuclear shutdowns like this have happened in the past. Scotland’s Torness plant shut down in 2011, and Sweden’s Oskarshamn shut down two years later in 2013. France’s Gravelines facility was also affected by jellyfish in 1993.
Rapid increases in jellyfish populations are called jellyfish blooms. During a bloom, hundreds to thousands of jellyfish can take over the seas, and scientists say that these blooms are occurring more frequently.
The Cause of Jellyfish Blooms
Jellyfish thrive in warm waters. As oceans warm due to climate change, jellyfish populations inevitably grow. Derek Wright, marine biology consultant with the U.S. National Oceanic and Atmospheric Administration, said, “Jellyfish breed faster when water is warmer, and because areas like the North Sea are becoming warmer, the reproductive window is getting wider and wider.”
Polluted waters created by sewage runoff or agricultural waste are a haven for these marine animals. The nutrients from this pollution, such as potassium, nitrogen, and phosphorus, start a process called eutrophication, where algae grow and die, removing oxygen from the water. Jellyfish can survive in low-oxygen zones where fish often suffocate. With abundant food, jellyfish tend to multiply in these “dead zone” environments.
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Another reason for population growth is overfishing. Tuna is one of the biggest predators of jellyfish, next to sea turtles. Overfishing tuna effectively removes these predators from the sea, allowing the jellyfish to flourish.
Some jellyfish species are considered biologically immortal. One species, Turritopsis dohrnii, has earned the label of the “immortal jellyfish.” Dr. Lisa-ann Gershwin, director of the Marine Stinger Advisory Service in Tasmania, explained, “When the Turritopsis dies, its body begins to decay, as it would, but then the cells reaggregate into polyps. These little polyps keep cloning, and they can cover an entire dock in a matter of a few days! Some types can form whole ‘shrubs’ and when the conditions are right, they bloom in vast numbers like flowers and ‘bud off’ baby jellyfish.”
Fortunately for France’s nuclear plants, the lives of many jellyfish are short, often only living through a single summer. Nevertheless, as waters get warmer and species adapt, the problem could persist.
Editor’s Note: The opinions expressed here by the authors are their own, not those of Impakter.com — In the Cover Photo: Jellyfish at the Monterey Bay Aquarium, Monterey, United States Cover Photo Credit: Francis Taylor
