A University biology professor is working with satellite technology to make seafood safer.
Michelle Wood is part of an effort to develop detection methods for toxic algal blooms, which are ocean growths that can turn ordinary seafood poisonous.
She and Oregon State University assistant professor of biological oceanography Peter Strutton are studying growths of Pseudonitzschia, a type of one-celled algae that produces a substance called domoic acid.
When birds and mammals eat fish, especially shellfish, that have consumed Pseudonitzschia, the side effects range from an upset stomach to permanent short-term memory loss to death because the domoic acid from the fish’s tissues crosses into the bird or mammal’s brain and interferes with nerve-signal transmission.
Most of the adverse events involving domoic acid on the West Coast involve birds and non-human mammals, Wood said, adding that people swimming in water with Pseudonitzschia in it or people swallowing mouthfuls of such water are not in immediate danger.
“You pretty much have to eat a very concentrated amount,” Wood said. “It kind of takes concentration by something else eating them.”
Wood said biologists at the University of California at Santa Cruz suspect the aggressive behavior by a flock of sea birds in Santa Cruz that inspired Alfred Hitchcock’s movie “The Birds” may have been the result of Pseudonitzschia-induced brain damage.
Oregon Department of Agriculture officials monitor the water along the Oregon coast for domoic acid concentration and, based on the findings, prohibit or allow the harvesting of shellfish.
Currently, razor clam beaches from Newport to Waldport and Reedsport to Coos Bay are closed because of their high levels of domoic acid. Anything exceeding 20 parts per million is considered unsafe.
A Sept. 28 statement on the Oregon Department of Agriculture Web site said: “These levels are still declining from 200 ppm seen at the peak of this summer’s toxic algae bloom. Razor clams accumulate the toxin in edible tissue. It can take several months for the clams to purge the toxin.”
“That’s good, but it’s sort of a retroactive way of looking for this,” Strutton said, reacting to the department’s reports. He explained that the goal of his and Wood’s research is
to be able to predict harmful algal blooms with satellites and give health officials advance warnings.
The research, funded by the National Oceanic & Atmospheric Administration, uses data from satellites maintained by the National Aeronautics and Space Administration. The satellites determine the color pigments present in the ocean by measuring light wavelengths from the surface of the ocean.
The satellites provide a “bird’s-eye view of the topography of the ocean,” including various streams and rivulets within the water, Wood said.
Sensors on the satellites also collect data regarding the temperature of the ocean.
“It’s a whole new revolutionary way to see the ocean,” Wood said.
There are various types of harmful algae blooms and some of these, such as the dinoflagellates that cause “red tides” in Florida, are obvious to the naked eye. However, Wood said that Pseudonitzschia blooms may not be visible to a person walking on the beach because they are often below the ocean surface and often similar in color and density to other non-toxic algal blooms.
The main way that Pseudo-nitzschia are detected by the satellites is through their production of chlorophyll, a byproduct of plants that is green in color. The green pigment is most visible when Pseudonitzschia populations are large, during blooms.
Strutton said that while Pseudo-nitzschia can reproduce either sexually or asexually, they most commonly reproduce asexually by splitting into two cells. Depending on amounts of nutrients and light available, this happens every day or so.
During the spring and summer, winds from the north bring high-nutrient water closer to the surface. Combined with increased sunlight, this leads to rapid increase of Pseudonitzschia populations.
It is at this point that domoic acid is most frequently produced. When Pseudonitzschia run out of nutrients toward the end of their bloom, they switch to producing the toxin as part of their natural metabolism, Wood said.
Finding a way to stop Pseudo-nitzschia from producing domoic acid is not likely at this point, Wood said, although she said the more controlled setting of Pseudonitzschia blooms near Prince Edward Island on the east coast of Canada may be a better place to look for such information in the future.

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