Algal blooms, fueled by warmer waters in the Northwest, create a toxic recipe for coastal mussels

In the deep, blue waters that lap along the coast of Washington State and into Puget Sound, algal blooms burst in colorful explosions as the sun shines on the surface, giving life to these aquatic plants.

But sometimes these brightly colored flowers have a lot to them.

It has been a year of many toxic algal blooms in Washington waters. The Washington State Department of Health has discovered paralytic mussel toxin in many marine areas of the state. This is a naturally occurring marine biotoxin produced by some algae. The toxin enters the shellfish when they consume the algae. When humans consume these shellfish, they can become sick from this powerful toxin, which can be fatal.

Many counties recently closed recreational fishing at the direction of the health department. More counties may close soon, said Jerry Borchert, the health department’s marine biotoxins officer.

“What I’m seeing right now is concerning because it’s starting to move south. From what I’m seeing, Kitsap County and King County are probably next,” Borchert said.

The Ministry of Health’s Public Health Lab said that not so many shellfish samples had been tested for biotoxins in the first half of 2016.

The department receives numerous alerts from partner organizations that test phytoplankton in marine waters, Borchert said, prompting them to conduct more frequent testing of shellfish and notify potentially affected groups.

This map from the Department of Health shows where scallop fishing is allowed and where it is not. There are many closures from Whatcom County, San Juan County, Clallam County, Island County, Skagit County, Snohomish County to Jefferson County.

“We are in the best environmental conditions for such events to occur. We have warm water and calm weather,” Borchert said. “The conditions are more favorable for the rapid growth of toxic algae, if they are present, and that is exactly what is happening in several areas right now.”

Borchert, who has been with the department for decades, said this year has been more active than previous years.

A particularly unusual event occurred in May when a type of algae called Alexandrium bloomed. This algae spread from the Oregon coast to Washington, bringing commercial mussel farming to a halt.

“We sent in the samples that morning and by the afternoon we were getting calls saying everything had to be shut down,” said Kathleen Nisbet Moncy, operations manager at Goose Point Oysters in Willapa Bay. “This (paralytic mussel poisoning) bloom started very quickly.”

The algal bloom has had a significant impact on coastal shellfish farmers like Nisbet Moncy, who is also president of the Willapa-Grays Harbor Oyster Growers’ Association and said growers in the area estimated about $1 million worth of product was lost to recalls or on-site destruction due to the toxic outbreak.

“Mind you, this happened on Memorial Day weekend and also the weekend before our local schools’ graduations. The farmers and processors here had no idea when their operations would reopen,” Nisbet Moncy said.

Such incidents are becoming more common. Borchert said there have been closures due to biotoxins every month of the year recently. Closures in the winter were previously unthinkable. That leads to higher costs for the department. Borchert said the agency is looking for cost-saving methods to continue testing the products and ensure their safety.

“How can we do this and save some money while still maintaining the same level of safety that we’ve always offered to the people of Washington and everyone who comes here and eats shellfish?” Borchert asked. “Anything is possible.”

One way the health department keeps testing under control is by maintaining more than 100 clam stations along the coast, in coastal bays and in Puget Sound for testing during the summer.

Mussels ingest toxic algae faster than other species, Borchert said. The department tests these mussel sites every two weeks, increasing the frequency if toxins are detected. There are also organizations that conduct phytoplankton testing in water samples to look for toxic algae.

If the values ​​during testing approach the limit of 80 micrograms of poison per 100 grams of meat, the producers must send samples of their harvest for testing before it can be sold.

When an algal bloom broke out along the coast in May, it was the health department and the Washington Department of Fish and Wildlife that notified the breeders.

Fortunately, thanks to careful coordination and testing by growers, health departments and fisheries and wildlife officials, the late spring outbreak in Washington resulted in no illnesses from commercial products.

There have been Alexandrium blooms in the region in the past, Nisbet Moncy said, but there has not been an incident like this one, in which shellfish have been debilitatingly absorbing mussel toxins, since 1997.

Algal blooms certainly occur, and government agencies detect toxins in mussels, but these rarely end up in popular food items like oysters and Manila clams.

“In most cases, we cannot detect any poison in commercially available shellfish,” said Borchert.

While the spring event was unexpected, with climate change the conditions that caused it are becoming more common.

The state is not prepared for coastal farmers to face these problems, said Nisbet Moncy.

“One of our key learnings as growers is that, first of all, our labs are not designed to handle estuarine water levels dropping or causing any other problems,” said Nisbet Moncy.

Given the large number of affected farmers on the coast, the laboratories that test shellfish for the poison are overwhelmed, said Nisbet Moncy. The same problem also exists in Oregon. There are not enough supplies to test this volume of samples.

Borchert said the department had to focus on testing commercial samples first because of the supply shortage. While it continued to test all samples, the department had to prioritize testing in the areas it knew were most affected.

Commercial fishing resumed along the coast in July. Washington’s coasts are closed to sport fishing during the summer due to the high probability of a toxic incident.

“Right now we’re in the middle of a really dangerous algal bloom,” Borchert said. “We’re already seeing a lot of toxins all over Puget Sound.”

While recreational fishing is banned in many marine waters, purchasing shellfish from commercial operations is still safe.

Commercial fishing is subject to stricter regulations than recreational fishing to ensure companies can continue operating and provide safe products to consumers. These farmers are certified by the state health department to continually test mussel beds for paralytic mussel poisoning and other toxins, said Bill Dewey, director of public affairs at Taylor Shellfish Farms.

For example, this week Dewey received a call from the health department that some oysters in Samish Bay had been found to contain the lowest levels of toxins. In response, all commercial species from all beds harvested in Samish Bay are being tested before being placed on the market.

As climate change makes harmful algal blooms more likely, larger companies that have mussel beds in numerous bodies of water are better positioned to stay afloat. Taylor Shellfish Farms, for example, has mussel beds across the state. That’s helpful because if one body of water closes because of toxic outbreaks, the company can harvest its other beds, Dewey said.

To respond in the coming years, the region needs more resources to monitor harmful algal blooms, according to Nisbet Moncy.

The state Department of Fish and Wildlife, the Department of Health and the National Oceanic and Atmospheric Administration are working with coastal fisheries to obtain more forecast information and emergency plans.