Destructive Red Tide Halts Shellfishing

An unusually late, unusually potent red-tide bloom has laced some shellfish with high levels of toxins, prompting the state to prohibit recreational shellfishing in areas of south Puget Sound that aren't normally affected by the malady.

While a red-tide bloom off Washington's coast is diminishing in power, the one in south Puget Sound is building up steam, according to the Department of Health. Blue mussels the agency sampled in Case Inlet, near the Mason County town of Allyn, contained 6,799 micrograms of paralytic shellfish poison (PSP) per 100 grams of tissue, a level that could prove fatal if eaten. It takes only 80 micrograms of PSP per 100 grams for the state to close an area to shellfish harvest.

Oyster farmers, who reap a large chunk of their $30 million to $35 million in annual sales during the holiday season - say they expect to lose millions of dollars.

It's not unusual for red tide to close some areas in the state - but that normally happens in warmer months. Hot spots like Case Inlet, in Pierce and Mason counties, have extremely high levels of toxicity. Plus, some recently closed areas in Western Washington, such as Willapa Bay, haven't had a red-tide problem in the past decade.

"Some people in that area become complacent not having toxicity in the winter," said Maryanne Guichard, the Health Department's shellfish program director. "We want to urge people to pay attention to those closures. So far, we have no illnesses and we want to keep it that way."

The micro-organisms responsible for red-tide photosynthesize and multiply as they process light and nutrients into food. When their concentrations are high, they tint the water tomato-soup red, chocolate brown or a winelike maroon. Some of the algae are benign; others are harmful.

And not all shellfish are affected equally. Willapa Bay, for example, is closed for mussels, oysters and other shellfish, but razor clams are safe to eat.

One organism, Alexandrium catenella, produces PSP. These neurotoxins act like stalled cars in the body's expressway. Impulses no longer travel between nerves and the brain, leading to a rapid-fire set of ailments: nausea, dizziness, listlessness and sometimes death.

No one's exactly certain why the harmful Alexandrium catenella bloom is growing this late in the season. Some speculate last week's rains followed by this week's warm, dry and calm conditions have given the harmful algae optimal growing conditions. The single-celled organism is believed to link up in chains when it's free from stress. A grower whose samples were tested yesterday at the University of Washington counted 14-cell chains.

"I hope nobody is making any guesses - that's really all they would be - as to why it is here now," said Rita Horner, UW principal oceanographer who is analyzing some of the tainted tissue.

Regardless, the red tide has some of Washington's oyster farmers singing the blues. Unlike clam farmers, who have roughly nine months of high demand for their product, oyster growers faced closed operations in the two months when they make 40 percent of their sales. During November and December shoppers want shucked Pacific oysters for Thanksgiving stuffing, stews, chowders and other holiday menu items.

"You're probably talking several millions of dollars" in losses, said Bill Taylor, president of Taylor Shellfish, based in Shelton, Mason County. "A lot of times, it's difficult to make up those sales. . . . It's like missing Christmas if you're a toy maker."

Taylor is lucky. The company farms nearly 8,000 acres of tidelands throughout Puget Sound and on the coast. If one area is closed, Taylor makes up for it in a different region. Still, it suffered losses when Willapa Bay harvests were closed before Thanksgiving - the first shellfish-harvest closure there since 1984.

The state routinely samples shellfish for toxins, a program that catches tainted shellfish before they hit store shelves. The larger question is the safety of people who shellfish on the weekends for fun.

"It's important that people understand it's a very serious thing," Taylor said. "If you're in an area that's not being tested, you definitely need to ask before you start eating."