For more than a month, much of the state's shellfish industry has weathered a one-two punch of harmful algae blooms, which can cause paralytic shellfish poisoning in humans, and Vibrio parahaemolyticus, a naturally occurring bacteria that can sicken those who eat raw oysters.

Record-setting levels of toxins and bacteria in sun-warmed waters have prompted the state to close lengthy stretches of shoreline to harvests. Some restaurants will only serve oysters from cooler climes.

Shellfish growers, particularly those in areas unaffected by the outbreaks, fear consumer confidence in Washington shellfish could take a dive, with a national advisory against eating raw shellfish from the region and the ever-changing lists of which beaches, inlets, bays and coves have been closed for either or both outbreaks and which shellfish are affected in a given area.

As much as Washingtonians savor summer, the state Health Department and shellfish farmers say they're looking forward to fall, when cooler, stormy weather should arrive to break up massive algae blooms and low tide shifts back from day to night, reducing bacteria growth.

Both changes should help affected shellfish beds get the all-clear for harvesting, though that could take until October, officials say.

"This has been a very warm summer here for Puget Sound, and that has played a role in what we're seeing in the water in terms of what's happening with our shellfish," said Jeff Smith, state Health Department spokesman.

Scientists have found toxic levels of Alexandrium — toxic organisms that grow within algae blooms, also commonly called red tide — in shellfish beds at more than 30 sites, said Frank Cox, marine biotoxin coordinator with the state Health Department.

The state closes beaches when levels reach 80 micrograms of toxin per 100 grams of shellfish tissue. This summer, tissue tested from clams, mussels and other bivalves at some sites has topped 12,000 micrograms.

"We're talking huge amounts. At that level, 100 grams of shellfish tissue would be several lethal doses," Cox said. Cooking does not eliminate the toxins from affected shellfish.

Washington has not recorded a death from paralytic shellfish poisoning since three people were killed in 1942. But Cox recalled the ordeal of two men who were paralyzed in 2000 after eating contaminated shellfish.

"These guys were paralyzed for five days before their bodies threw off the effect of the toxin," Cox said. So far, the state has not recorded any illnesses related to the marine biotoxins, which began prompting shellfish bed closures in early August.

However, since July, more than 100 people who ate raw oysters have been sickened with the bacterial infection vibriosis, the largest outbreak in the state to date. Health officials began closing affected beds, and the federal Food and Drug Administration issued a national advisory against eating raw oysters harvested from the Pacific Northwest, as is its custom during health hazards, said spokesman Michael Herndon.

The warning came to the chagrin of farmers in unaffected Willapa Bay, one of the West Coast's largest oyster producing regions.

Unlike shellfish affected by red tide, Vibrio bacteria can be neutralized by cooking oysters to an internal temperature of 145 degrees. Health officials say the best way to avoid getting sick is to avoid raw oysters.

The outbreaks have endured long enough to pinch the bottom lines of local shellfish growers. Shelton-based Taylor Shellfish Farms, the state's largest farmed-shellfish producer, has lost at least $150,000 a week in live-oyster sales due to the Vibrio outbreak, said Bill Dewey, a company spokesman.

The company was thrilled when the state declared Eld Inlet near Olympia safe and reopened it to commercial harvesting in mid-August.

"The growers have been very responsible. This has been a challenge for them, but I think one of the things that works to their advantage is by being this responsible it means people will continue to trust the shellfish that comes from Puget Sound," Smith said.

The state Health Department encourages anyone planning to harvest shellfish to first check its Web site, www.doh.wa.gov/ehp/sf/biotoxin/htm or call 800-562-5632 for closures. The state has ramped up testing and posts frequent updates.

Karen Gaudette: 206-515-5618 or kgaudette@seattletimes.com

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