SEATTLE — A toxic algae bloom off the coast of Washington state has grown to about 30 miles wide, the largest and most potentially lethal algae yet found by scientists in the region.

The algae, about 15 miles from the coast, can release potentially deadly domoic acid, which accumulates in the tissue of clams and other shellfish and, if ingested by humans, attacks areas in the brain responsible for learning and memory.

The algae should not pose any danger if it remains afloat away from the shore, but researchers said this week they are concerned the bloom could eventually wash onto land.

"Within the next week, if there's a major storm, it's possible it might hit the beach," said Barbara Hickey, a University of Washington oceanographer. Fair weather could reduce the bloom and help prevent the algae from approaching land, Hickey added.

State officials test coastal waters twice a week for domoic acid, and satellites are being used to track the algae for any movement toward the coast, scientists said.

"We'll have enough early warning to know for sure that the (shellfish) resource is safe to dig," said Vera Trainer, of the Northwest Fisheries Science Center.

This is the second year that scientists have tested the algae bloom. Concentrations of the poisonous algae are as high as 11 million cells per liter, compared with about 200,000 cells per liter last year, scientists said.

For centuries, occasional "red tides" have occurred along the Pacific coast, but for unknown reasons, the colorful blooms of poisonous algae became a significant problem starting in the late 1980s.

Source: Associated Press