Beach-Goers Bothered by Blood-Sucking Pests : Nature: The saw-toothed crustaceans, about a quarter-inch long, have arrived earlier than usual--and in greater numbers--at Newport Beach.

An unusually large number of small blood-sucking, flesh-nibbling creatures have invaded the waters around Balboa Island and the Balboa Peninsula.

“They can be pretty nasty when they get going,” said Richard Brusca, curator of crustaceans at the San Diego Natural History Museum. “They’re somewhere between a wolf pack and a pack of mosquitoes. They’re like mini-sharks.”

Although beach-goers over the past decade or longer have occasionally reported painful attacks, this is the first year that Excirolani chiltoni-- also called marine pill bugs for their similarity to the common garden insect--have arrived so early and in such numbers.

Their favorite food is fish, but the pests are not picky about what they eat, as 2-year old Crystal Johnston recently found out.

The little girl was splashing in the water near the Balboa Peninsula Pavilion when her father heard her crying.

The tiny crustaceans “were climbing up in her diapers,” said Craig Johnston, 36, who has spent summers at Newport Beach all his life. “They drew some blood. It happened so fast.”

Living in sand near the water’s edge, the tiny flesh-eaters are about a quarter-inch long and have a pair of saw-toothed mandibles designed to cut quickly and cleanly into skin. After making an incision, they suck their victim’s blood for about 30 seconds before dropping off.

The water-borne vampires pose no serious danger to humans, but people who have suffered the bites say they sting.

“I was trolling for them and they swarmed around me,” said Monica Mazur, who is investigating recent complaints about the creatures for Orange County’s environmental health department. “They felt like little pinpricks all over my ankles and feet.”

Health officials say they have had five reports of attacks by the pests in the past 10 years, including one last August, but never this early in the summer season.

“This is pretty unusual,” said Larry Honeybourne, who oversees beach water quality for the county.

Marine biology experts say evidence suggests there may be an unusually large population this year of the crustaceans, which move up and down the coast of California in packs of tens of thousands that cover several square miles.

“From the evidence at hand, they seem to be more abundant at this time than previously,” said Bill Newman, a professor of biological oceanography at the Scripps Institution of Oceanography at UC San Diego.

Brusca said it is difficult to explain the population boom, although it could be caused by a glut of food in Newport Bay or a normal surge in the life cycle of the creature.

In any case, those using bay beaches should prepare for a summer of painful bites, Brusca said.

“They have a propensity for finding the thin skin parts of your body, between your toes and fingers, the backs of you knees, on your crotch,” said Brusca, who discovered a related species on a Mexican beach gnawing on his 2-year-old daughter’s bottom. He named it after her.

Veterans of the beach, though, say the creatures are more an annoyance than anything else.

Scott Durre, who was going windsurfing in the bay Thursday, said he had little fear of the pests, whose bites he says he has often endured during his 15 years in the area.

“It’s like little tiny pinches all over you,” said Durre, 43, an independent contractor. “It doesn’t hurt, it’s just irritating.”

Brusca gives the pests somewhat more credit, noting their ability to clean a minnow of its flesh in two to three hours.