Pseudo-nitzchia is a form of diatom that produces the toxin domoic acid that can accumulate in shellfish. This sample was collected off the coast of Oregon in May 2015.
NOAA Fisheries/NWFSC
Scientists at Oregon State University have figured out a way to predict outbreaks of a dangerous neurotoxin called domoic acid in the Pacific Ocean. The toxin is produced during algae blooms and can make crab and shellfish unsafe to eat.
A few years back, Oregon State University researcher Morgaine McKibben noticed that the ocean off Oregon had warmed considerably. It was part of a natural climate cycle called the Pacific Decadal Oscillation.
“I couldn’t help but think, 'Wow, is there going to be domoic acid event?' And there was,” McKibben said.
Domoic acid can accumulate in some seafood and be harmful to humans if consumed. High levels of the neurotoxin caused the temporary closure of West Coast Dungeness crab fisheries in 2015, costing the industry around $100 million dollars.
The toxin has also been linked to the deaths of marine mammals.
McKibben looked at historic data and realized what she saw was part of a larger pattern. She used the information to create a mathematical model to predict the toxic blooms.
“The stronger these warm phases are, it’s more likely we will see higher levels of the domoic acid over a much larger range,” she says.
The research published Monday in the Proceedings of the National Academy of Sciences.
McKibben says the model should be able to provide a seasonal or even yearly indication of probable toxic algae blooms.
But Matt Hunter with the Oregon Department of Fish and Wildlife’s shellfish program says they will likely apply the new tool to look at the more immediate future. This is because knowing whether the neurotoxin is present is only part of the equation. Shellfish don't automatically absorb the toxin every time there's a bloom.
“If the shellfish aren’t feeding at the time, then sometimes you can have these big [algae] blooms that produce toxin that we never see in our shellfish,” he says.
Still, Hunter says the tool will let ODFW know when to start testing to ensure shellfish and crab are safe for human consumption.
“Being able to have a proactive response when we see these risk factors," Hunter says, "gives us the ability to almost do a warning if there’s going to be an issue.”