Are jellyfish taking over our oceans?

Jellyfish are in danger of taking over the world’s oceans, a leading expert has warned, putting a growing number of tourists at risk 

 

Dr Lisa-Ann Gershwin, a US scientist and author of the book On Jellyfish Blooms and the Future of the Ocean’, told CNN that overfishing and changing water temperatures were responsible for huge increases in “bloom” activity.

"The French and Spanish Rivieras, Chesapeake Bay, the Great Barrier Reef, Hawaii... some of the numbers are staggering," said Dr Gershwin, who's now based in Australia.

"Jellyfish and tourism are not happy bedfellows. In Hawaii there have been times that 800 or 1,000 people have been stung in a day. In Spain or Florida, it's not uncommon in recent years for a half a million people to be stung during an outbreak. These numbers are simply astonishing," she added.

Two incidents have highlighted the problem in recent weeks. On October 13, operators at the Oskarshamn nuclear plant in Sweden had to shut down a reactor as jellyfish clogged the pipes that move cool water to the plant’s turbines. A week later up to 20,000 farmed salmon were killed by a jellyfish bloom off the coast of County Mayo in Ireland.

This summer has seen a jellyfish infestation in southern Europe so severe that the Foreign Office issued a travel warning, while in July the Marine Conservation Society reported “huge numbers” of several species in British seas, including the Lion’s Mane, which has a powerful sting.