Jellyfish bloom in ’05 bugged paddlers

Answer: In June 2005, Hawaiian outrigger canoe paddlers complained to the state Department of Health about painful, itchy stings or bites they received while in the water of Keehi Lagoon.

Most paddlers who reported stings said their itchy welts went away after a few days or a week. But a few were treated by doctors for infected sting wounds.

Within a month of the outbreak, local and international scientists concluded that the cause of the paddlers' discomfort were tiny jellyfish -- no bigger than the head of a pin -- of the genus Proboscidactyla.

The same genus has been implicated in outbreaks of "bathers' eruption" periodically at New Zealand swimming beaches.

But no one might ever be sure if the culprits are the same, because you need both the adult and juvenile stages to determine a species, said Waikiki Aquarium curator Jerry Crow. Only the juveniles were ever detected in Keehi water samples, he said.

The "bloom" of jellyfish subsided, allowing paddlers to resume normal use of the lagoon for canoe regattas. Paddlers have not reported any trouble with the creatures since.

Health officials continued taking periodic water samples at Keehi to look for the jellyfish about a year. "But they always got low numbers," Crow said. "The levels never went back to that level" when the tiny jellyfish were canceling regattas.

Hannie Anderson, president of the Oahu Hawaiian Canoe Racing Association, praised the Health Department for continued sampling that year. "The state kept their word and kept testing. They did a good job with that," she said.