In an unusual turn of events, four reactors at France’s Gravelines nuclear power plant were forced to shut down after massive swarms of jellyfish clogged its cooling systems. Located on the northern coast between Dunkirk and Calais, Gravelines is one of France’s largest nuclear facilities, producing up to 5.4 gigawatts of power. With two other units already offline for maintenance, the entire plant temporarily halted production.
According to operator EDF, there was no lasting damage to the plant. The jellyfish had packed the filter drums at the pumping stations, automatically triggering shutdowns. Once cleaned, the systems are expected to restart safely. While the reactors and staff were never at risk, the incident reveals a growing vulnerability for coastal power plants: marine life disruptions amplified by climate change.
Marine biologists point to warming waters as a key factor. Jellyfish reproduce faster in higher temperatures, extending their breeding seasons in regions like the North Sea. Invasive species, such as the Asian Moon jellyfish introduced in 2020, thrive in ports and canals, making them especially problematic for infrastructure that relies on steady water intake. Similar shutdowns have already been recorded in China, Japan, and India.
The issue goes beyond local ecosystems. Rising ocean temperatures, overfishing, and nutrient-rich pollution have all contributed to global jellyfish blooms. These factors not only disrupt biodiversity but also highlight the unintended consequences of human activity and energy production. While nuclear power is often labeled “clean,” events like this remind us that energy systems are deeply interconnected with the environment — sometimes in unpredictable ways.
The Gravelines shutdown may be temporary, but the broader question remains: how resilient are our energy systems in the face of climate-driven ecological change?
