"Almost 500 people were stung by the jellyfish-like creatures on beaches in Fort Lauderdale on Friday and Saturday, while another 320 were stung 45 miles up the coast in Palm Beach during the weekend.

Officials said the US invasion, which numbered several thousand, had ridden in on steady 5-10mph south-easterly winds, which could continue for several more days."

"Stings from microscopic jellyfish are plaguing swimmers at popular beaches on Auckland's North Shore. A health warning has been issued for Takapuna, Cheltenham, Narrow Neck and Red Beach after reports of people developing itchy and painful red rashes after swimming. The rashes were very likely caused by microscopic jellyfish, a statement from Auckland Regional Public Health Service said."

"It's decimated the fishing industry in Japan. I watched a documentary last week on the Documentary channel about these mammoth jellys... up to 250-300 lbs and 6 feet across and there are millions of them"

I've been reading that jellyfish blooms around the world might be connected to over fishing.

As near shore areas lose their fish populations, jellyfish come in to feed on the remaining smaller animals in the ecosystem. If its ruining the fishing industry in Japan, it could very well be a case of circular causality. i.e., the Japanese fished out most of their coastal waters. The small, remaining fishing communities are now faced with the consequences of their state's non-sustainable fishery management policies.