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Scientists say dangers from marine toxins getting worse - and nobody is sure why
Fighting a growing problem
09/12/2000
Sandi Doughton; The News Tribune
Rita Horner wasn't surprised to hear that nine people in Pierce County were sickened by shellfish poisoning two weeks ago - several so severely they had to be kept alive on mechanical respirators.
The University of Washington oceanographer has been warning for years that the dangers from red tide and other marine toxins are increasing in the state, while little is being done to figure out why.
"We've been seeing a lot more toxic blooms in the last few years, including some horrendous problems throughout Puget Sound and out on the coast," she said.
Once restricted to northern Puget Sound, red tides are now popping up regularly south of the Tacoma Narrows. Once limited to warm summer months, beach closures now frequently extend through the winter. And almost every year, records are being set for the concentration of toxins found in shellfish, say Horner and other experts.
Alarmed that similar trends may be occurring across the country, the federal government has launched a $40-million, multiyear initiative to study the single-celled plants, called algae, responsible for killing fish in Chesapeake Bay, poisoning manatees in Florida and devastating shellfish beds in Maine.
"There is no doubt that harmful algal blooms are increasing," said Don Anderson, a Woods Hole Oceanographic Institution researcher, who's helping spearhead the new effort.
But despite the fact that some of the country's worst red tides occur in Washington, only a few hundred thousand of the federal dollars are being spent here.
"You have fish dying in the Gulf of Mexico, but you have people on respirators out here right now," said Vera Trainer, who studies toxic algae at the Northwest Fisheries Science Center in Seattle.
With enough research, Trainer and Horner believe it would be possible to forecast red tides and other population explosions of toxic algae - which scientists call blooms.
"We're hoping to be able to predict these blooms much like the weather service can predict a hurricane," said Trainer, who's leading the state's single research project funded by the national initiative.
For example, based on preliminary studies, she suspects this fall and winter may be bad for razor clams on Washington's outer coastline. California's Monterey Bay is in the midst of one of the worst blooms ever recorded of the algae that produces domoic acid, a potentially lethal toxin that causes nausea, seizures and memory loss.
In 1991, when the toxin was first detected in razor clams on Washington's coast, it was preceded by a similar episode in California. In 1998, when sea lions began dying in California from domoic acid poisoning, Trainer and her colleagues started taking measurements in Washington.
Within a few months, the toxin started showing up in record levels in razor clams, wiping out the popular clam-digging season. If the pattern holds true, the same thing could happen this year.
"It's incredibly devastating to our coastal economy," Trainer said.
Eventually, if scientists can predict when toxic algae blooms are about to sprout, it may be possible to open shellfish seasons earlier, so people can gather clams before they become poisonous, Trainer said.
Shellfish growers also could be warned in advance, allowing them to harvest before the damage is done. And while advance warnings wouldn't guarantee against future tragedies, like this summer's, they might make them less likely, Horner said.
But prediction will first require long-term studies - and the money to pay for them.
An old problem
Shellfish poisoning is nothing new in the Pacific Northwest. In 1793, four of explorer George Vancouver's crew got sick and one died from eating shellfish from the British Columbia coast.
What does appear to have changed in recent years, though, is how widespread the problems are how, how long they last and how intense they've become.
This year, mussels from Carr Inlet in Pierce County contained more than 170 times the federal safety limit. In 1999, beaches across the entire state flared simultaneously, and in 1996, some areas remained toxic all summer, winter and well into the following spring.
In addition to imperiling people's health, the blooms harm the region's economy. When shellfish beds in Willapa Bay and Grays Harbor were closed during the winter of 1997, growers lost $8 million.
The 1991 appearance of domoic acid cost coastal communities in Washington and Oregon $7.6 million in lost revenue. The resulting panic when the toxin also was discovered in crabs took an $18 million toll on the fishing industry, said Terry Nosho of the Washington Sea Grant program.
Nationwide, Anderson and his colleagues estimate average annual economic losses because of toxic algae at nearly $50 million.
Since many different types of algae are involved, there are no universal explanations for why the problems seem to be growing.
The simple fact that more people are looking for toxic algae may account for some of it, Horner said. Climate shifts may play a role, but scientists aren't sure exactly how. Some experts suspect that increased ocean traffic may be spreading algae around the globe.
Certain species, such as the East Coast fish-killer Pfiesteria, thrive as water pollution increases. This year, researchers in California discovered that urban and agricultural run-off boosts the growth of one common red tide algae. In other cases, algae that spread naturally via ocean currents may be more likely to explode into bloom if they wind up in polluted waters, Anderson said.
Natural causes?
In the Northwest, though, there's no evidence that red tides and other toxic blooms are linked to pollution, Horner said. Alaska, which boasts some of the world's most pristine coastlines, also has some of the nastiest red tides. Some of Washington's most intense blooms occur along the Strait of Juan de Fuca, where human development is sparse.
The spread of red tide into South Puget Sound apparently began naturally, when heavy rains in 1978 washed unusually high amounts of sediment and nutrients into Skagit Bay, Horner said. The red tide algae population mushroomed, with cells and seed-like pods called cysts dispersing widely.
Likewise, the recent appearance of the domoic acid algae on the coast doesn't appear to be linked to pollution. Trainer suspects that weather and ocean conditions trigger the blooms, with California's coast simply experiencing the conditions a few months before they develop off Washington.
With $300,000 from the federal initiative, she and her team are making the first coordinated measurements of algae concentrations, domoic acid levels in shellfish and ocean conditions, hoping to uncover the specific triggers.
She and Horner would like to launch a similar program in Puget Sound to figure out how blooms begin and blossom and what causes some areas to become intensely toxic. It's clear that warm, sunny weather plays a role, but beyond that, very little is known.
The state Health Department regularly measures toxin levels in shellfish, but that data doesn't reveal much about what led up to the crisis.
"Once the toxins are already in the shellfish, it's like hitting the scene of the crime too late," Trainer said.
Of the 33 projects funded by the national initiative, one is in Washington, four are in California, and the rest are focused on the East Coast and Gulf of Mexico, said Kevin Sellner, who oversees the program from the National Oceanic and Atmospheric Administration headquarters in Maryland.
Horner, Trainer and other local experts chafe at what they perceive to be an East Coast bias, but Sellner said many of the studies conducted elsewhere may apply here as well.
For example, some scientists are looking at ways to interrupt toxic algae blooms, either by using fine clay particles to sweep the tiny plants out of the water column or by attacking them with bacteria or viruses. A small pilot project next year will test the clay method in Puget Sound, where salmon farmers lost $2 million worth of fish in 1997 to toxic algae.
Other researchers are studying the toxin that causes paralytic shellfish poisoning - the type that sent so many people to Tacoma hospitals this year. A thousand times deadlier than cyanide, the toxin has no known antidote, but the studies might lead to one.
The first national conference on toxic algal blooms is set for December, and Horner and Trainer plan to argue that more of the federal money should come to the Northwest.
"This is real human health issue," Trainer said. "If, indeed, toxin levels are getting higher, more areas are being affected and we're seeing toxins during extended periods of the year, I think we're going to see more and more people getting sick."
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* Staff writer Sandi Doughton covers medicine, health and science. Reach her at 253 597-8516 or sandi.doughton@mail.tribnet.com.
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SIDEBAR: Washington's Toxic Marine Algae
* Alexandrium: The so-called red tide algae usually isn't red at all. It produces the toxin that causes paralytic shellfish poisoning. Found throughout Puget Sound and on the Pacific Coast.
* Pseudo-nitzschia: Found on the Pacific Coast. It produces domoic acid, which causes amnesiac shellfish poisoning. It can kill or cause memory loss.
* Heterosigma: Not harmful to humans, it can be deadly to fish - particularly in salmon farms. Found in Puget Sound.
* Check for biotoxin closures by calling the state Department of Health's biotoxin hot line at 1-800-562-5632 or check the Web site at www.doh.wa.gov/ehp/sf/biotoxin.htm.