The state Department of Health announced Thursday the closure of beaches along the western Strait of Juan de Fuca to harvesting all species of shellfish.

Beaches from Cape Flattery to Pillar Point are affected because tests detected unsafe levels of a toxin that causes paralytic shellfish poisoning.

Ocean beaches in Jefferson County had been closed earlier to harvesting of all species, as are those at Port Ludlow, Mats Mats Bay, Discovery Bay, Port Townsend and Kilisut Harbor, including Mystery Bay.

Oak Bay is closed only to butter clams.

Paralytic shellfish poisoning — sometimes called red tide — is caused by poison-producing plankton that shellfish ingest.

It cannot be detected by color or taste.

Neither cooking nor freezing renders such shellfish safe to eat.

Early symptoms of poisoning include tingling lips and tongue followed by tingling fingers and toes.

The disease may progress to loss of control of arms and legs, difficulty breathing and death.

Crabmeat is not known to contain the toxin, but crab guts — sometimes called butter — can concentrate the poison.

In Clallam County, ocean beaches and Discovery Bay also are closed to all species.

Sequim Bay is closed only for butter clams that can contain the poison for more than a year.

For updates on shellfishing in western Washington, visit www4.doh.wa.gov/gis/mogifs/biotoxin.htm.

The Department of Fish and Wildlife has pictures and descriptions of butter and other types of clams posted on its Web site: www.wdfw.wa.gov/fish/shelfish/beachreg/1clam.htm.