Venice is facing an extraordinary invasion of a bizarre, cannibalistic jellyfish that scientists warn is threatening fish stocks and wreaking havoc across the city’s fragile lagoon ecosystem.
The strange marine creature – known as the warty comb jelly, or sea walnut – has exploded in number throughout the Venetian lagoon, clogging fishing nets and devouring the building blocks of marine life.
Originally native to the western Atlantic, the gelatinous animal is believed to have reached the Adriatic after hitching a ride in the ballast water of cargo ships, before rapidly colonising large swathes of the lagoon.
Scientists say its success has been fuelled by climate change, with warmer waters and ideal salinity levels creating perfect conditions for the species to thrive.
The jellyfish, whose Latin name is Mnemiopsis leidyi, is infamous for its unsettling biology.
Its anus appears only temporarily during defecation before vanishing again – and it is also known to eat its own offspring.
Researchers say there has been a sharp surge in the number of the creatures in Venice’s lagoon, creating ‘serious issues’ for fishermen who are already struggling to protect their livelihoods.
Not only do the squishy jellyfish clog up nets, but they are also voracious predators that feast on fish eggs, fish larvae and plankton – essential elements of the lagoon’s ecosystem.
Venice is facing an extraordinary invasion of a bizarre, cannibalistic jellyfish that scientists warn is threatening fish stocks and wreaking havoc across the city’s fragile lagoon ecosystem (stock image)
The strange marine creature – known as the warty comb jelly, or sea walnut – has exploded in number throughout the Venetian lagoon, clogging fishing nets and devouring the very building blocks of marine life. Pictured: Stock image of the Grand canal in Venice
The species is listed among the 100 most harmful invasive species in the world and is now widespread throughout Venice’s lagoon, according to a two-year study by scientists from the University of Padua and Italy’s National Institute of Oceanography and Applied Geophysics.
Their findings were published in the journal Estuarine, Coastal and Shelf Science.
The invasion poses a growing threat to the Adriatic fishing industry, which is worth billions of euros and is particularly renowned for its production of clams and mussels.
‘Ongoing climate change could create increasingly favourable environmental conditions for this ctenophore, potentially boosting its presence in large aggregations and, consequently, increasing the risk of impacts on the entire lagoon ecosystem,’ the scientists warned.
The warty comb jelly is not the only invasive species causing chaos in the Adriatic. The region is also battling an explosion in blue crabs – another Atlantic interloper believed to have arrived via ballast water.
Named for their vivid blue claws, the crabs tear into clams, mussels, prawns and other seafood, ripping apart fishing nets and causing millions of euros worth of damage.
Italy is now attempting to eat its way out of the problem, with blue crabs increasingly appearing on supermarket shelves and restaurant menus as officials scramble to curb their numbers.
