Giant Toxic Algae Bloom Hits West Coast Shellfish
The West Coast is experiencing the largest bloom of toxic algae in more than a decade, prompting wide-ranging closures of commercial crab and shellfish harvesting.
It’s also causing some very weird behavior in marine wildlife.
Wildlife managers spotted a sea lion on the southern Washington coast that was arching its back and having seizures. They had to euthanize it.
The animal had eaten some sort of marine life that was contaminated with a type of neurotoxin produced by the algae, Pseudo-nitzchia. If people eat shellfish or crab meat contaminated with it, they can also suffer seizures, short term memory loss and even death.
The Washington Department of Health tests commercial shellfish, but warns that recreational harvesters should check the agency’s website for maps of toxic algae hotspots.
“The biggest thing this year is that it started really early,” said Jerry Borchert with the Washington Department of Health. “We don’t typically see closures like this until June and we got closures in early April.”
Borchert also noted that this year marks the first time that all three types of harmful algae found in the Northwest are blooming at the same time - a perfect toxic cocktail that has closed down recreational shellfishing in Grays Harbor, Willapa Bay and other areas along the Washington coast.
Toxic algae expert Vera Trainer called the toxic algae bloom unprecedented in its scale. Trainer is a scientist with the National Oceanic And Atmospheric Administration.
Trainer sat down for a conversation with Ashley Ahearn of KUOW/EarthFix. Here are some excerpts from their conversation, which were edited for brevity:
Ashley Ahearn: What’s going on off the West Coast right now?
Vera Trainer: We’ve had an unprecedentedly large bloom all the way from at least Monterey Bay, probably even farther south, all the way to Homer, Alaska. We’ve had reports of this toxic cell called pseudo-nitzchia that in our state, Washington state, can make razor clams and dungeness crab toxic.
Ahearn: How does it do that?
Trainer: These are small microorganisms, phytoplankton, that are floating freely in the ocean and they’re food for shellfish and plankton-feeding fish. So when these shellfish or fish eat the plankton they can retain the toxins, which are then poisonous to us.
Ahearn: What are the conditions that make them thrive?
Trainer: Well we know we need upwellings - so it’s a process that brings water from depth that is full of nutrients and rather cold to the surface of the ocean. We need sunlight. We need all the conditions that are ideal for your land plants, we need them to also happen in the ocean.
Ahearn: And tell me how has the ocean looked for these guys so far this season.
Trainer: We have this warm blob offshore and we suspect that it’s playing a role in the blooms but one of the reasons for sending scientists out on a National Marine Fisheries Service research cruise is to … better understand the environmental conditions.
Ahearn: How common are these blooms?
Trainer: We haven’t seen a razor clam closure off our coast for 10 years so things have been really quiet and then all of a sudden: Bang! Early May we had a sea lion with seizures off our coast and now we’ve closed the razor clam fishery and also the dungeness crab fishery, which is very unusual.
In California, scientists are telling us that the concentrations of toxins in anchovies are unprecedented.
Ahearn: When we last spoke about harmful algal blooms, I was asking you in the context of climate change. What do you make of this now?
Trainer: We’re told that this warm blob offshore is potentially a window of things to come so that’s part of what we’re trying to find out. We’re trying to find out if this is a scenario this year that’s going to give us a taste of what’s to come. What’s particularly worrisome is that we’re not just seeing this one type of algal bloom but two others that call paralytic shellfish poisoning in people.
Ahearn: Can you give me some more images of what domoic acid does to animals?
Trainer: What it does is it affects a region of the brain that’s important in memory and learning.
In extreme cases it can causes seizures, it can cause in people permanent short term memory loss or even death. So the sea lion that was found off the coast it had its back arched, head back, and it’s just bobbing back and forth.
Ahearn: What’s your takeaway for people?
Trainer: Your commercial shellfish are absolutely safe. You can buy shellfish in stores with confidence, but when you go out to dig on your own you should be really careful. Look at the Washington Department of Health website to make sure that the shellfish you are collecting are from an area that is free from this toxic algae.
If beachgoers spot marine mammals that are acting oddly they should call the West Coast Marine Mammal Stranding Network hotline: 1-866-767-6114.