Why in news?
Operations at France’s Gravelines nuclear power station were temporarily halted after a swarm of jellyfish clogged the plant’s seawater intake system. The incident drew attention to how biological phenomena can affect critical infrastructure.
About jellyfish
Jellyfish are free‑swimming marine animals belonging to the phylum Cnidaria. They have a bell‑shaped, gelatinous body and trailing tentacles that contain stinging cells to stun prey. Jellyfish lack bones, a heart or a brain and are made up of more than 90 per cent water. They have existed for over 500 million years and drift through oceans by pulsating their bodies and riding currents.
Why do they cause problems?
- Mass blooms: Under favourable conditions jellyfish can multiply rapidly, forming huge swarms. Warm water, pollution and overfishing of predators contribute to such blooms.
- Clogging intake systems: Coastal power plants and desalination facilities draw in seawater for cooling. Large numbers of jellyfish can clog the pipes and filters, forcing shutdowns to prevent damage.
- Wider impacts: Jellyfish blooms can disrupt fisheries by competing with fish for plankton and by feeding on fish eggs. Their stings also pose a nuisance to swimmers.
About the Gravelines plant
Located on the North Sea coast of France, Gravelines is one of Europe’s largest nuclear power stations. It uses pressurised water reactors and supplies electricity to millions of homes. Following the jellyfish invasion the plant temporarily shut down three reactors to clean the filters and resumed operations after a few days. The event underscores the need for ecological monitoring and resilient designs in coastal infrastructure.