PORT TOWNSEND — The shellfish biotoxin advisory along the North Olympic Peninsula is continuing longer than normal, with beaches all along the Strait of Juan de Fuca closed in both counties to recreational shellfish harvesting.

The marine biotoxin that causes Paralytic Shellfish Poisoning (PSP) has persisted in both counties and much of Puget Sound, keeping all shellfish harvesting such as clams, oysters and mussels closed until further notice, according to the state Department of Health.

Still under a biotoxin advisory in Jefferson County are Discovery Bay, Port Townsend Bay, Admiralty Inlet, Kilisut Harbor, Mystery Bay, Oak Bay, Mats Mats Bay, Port Ludlow, Bywater Bay, Northern Hood Canal, Squamish Harbor, Dabob Bay and Quilcene Bay.

In Clallam County, Sequim Bay also is closed to recreational shellfish harvesting.

Public access points are posted with warning signs.

All ocean beaches remain closed to harvesting.

Shellfish harvested commercially are tested for toxin prior to distribution and should be safe to eat.

Crabmeat is not known to contain the biotoxin, but the guts can contain unsafe levels. To be safe, clean crab thoroughly and discard the guts (sometimes called the “crab butter”).

Marine biotoxins are not destroyed by cooking or freezing. People can become ill from eating shellfish contaminated with the naturally occurring marine algae containing toxins harmful to humans.

Symptoms of PSP can appear within minutes or hours and usually begin with tingling lips and tongue, moving to the hands and feet, followed by difficulty breathing, and potentially death. Anyone experiencing these symptoms should contact a health care provider immediately. For extreme reactions call 9-1-1.

In most cases the toxic algae cannot be seen and must be detected by a laboratory. Recreational shellfish harvesters are urged to call the Shellfish Safety Hotline at 800-562-5632, or visit the Department of Health’s Shellfish Safety website at www.doh.wa.gov/shellfishsafety before harvesting anywhere in the state.