Venice Battles an Invasive Sea Walnut Threatening Lagoon and Fisheries

Venice’s lagoon is being invaded by Mnemiopsis leidyi, the warty comb jelly known as the sea walnut, originally from the western Atlantic and now spreading through the Adriatic likely via ballast water and warmer waters linked to climate change. Scientists warn the invasive jellyfish are proliferating, clogging nets and preying on fish eggs, larvae and plankton, which harms the lagoon ecosystem and threatens the region’s multi‑billion‑euro fishing industry as conditions become increasingly favorable for its spread.