Last November, a 10-mile-wide and 42-foot-thick swarm of baby mauve stingers (Pelagia noctiluca) decimated Northern Ireland’s farmed-salmon population. Overnight,120,000 fish were reduced to a floating mass of carcasses by billions of the small jellies native to warmer waters thousands of miles to the south. The salmon, which were killed by stings and oxygen deprivation, had a market value of $2 million.
Since 1996, massive “blooms” of mauve stingers have also plagued Mediterranean beachgoers. In previous decades, the jellies showed up along the French Riviera every 10 to 12 years and remained for about four years before retreating. But that pattern changed in the 1990s as the time span between the infestations shortened and jelly numbers shot up. In 1996, the Mediterranean coast experienced its largest blooms ever. The jellies retreated in 1998 but returned in even greater numbers just five years later. In August 2006, 60 million jellyfish reportedly swept up on Spanish beaches and stung more than 70,000 people, causing swollen limbs and allergic reactions. Beaches were closed throughout the entire region.
Europe’s mauve stingers aren’t the only jellies wreaking havoc. From the U.S. to Japan to Australia and beyond, several species of jellyfish—and their gelatinous cousins that are often mistaken for jellies—are expanding their numbers at a rapid pace and moving into foreign waters. Far from a simple nuisance, the creatures are dramatically changing marine ecosystems, costing commercial fisheries millions of dollars, and invading tourist destinations. Notoriously understudied, jellyfish are now attracting growing scientific attention.single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.