One of the biggest toxic algae blooms in recent history can be seen off the West Coast of the US right now, stretching from central California to Alaska.



NOAA has been mobilizing scientists and experts to take control of the situation, and publicly says marine algae blooms are common in the spring. Although this is true, algae blooms are substantially worse and larger when fed by excess nitrogen run-off from farms, this could explain why this one has grown so large.

Not only does the algae block light and oxygen from reaching deeper into the ocean, it contains some of the highest concentrations of the natural toxin known as domoic acid (which can be lethal and has led to several deaths after people consumed contaminated seafood).

“This is unprecedented in terms of the extent and magnitude of this harmful algal bloom and the warm water conditions we’re seeing offshore,” said Vera Trainer from the Northwest Fisheries Science Center in Seattle. “Whether they’re related we can’t really say yet, but this survey gives us the opportunity to put these pieces together.”

​In response, Washington state and Oregon have started to closed their coasts to shellfish harvesting.

Literally all coastal beaches in Washington have been closed to razor clamming. NOAA estimates that has cost coastal communities more than $9 million in revenue.

Officials in Oregon have stopped shellfish harvesting from between the Columbia River south to Tillamook Head, and closed the entire state coastline to razor clamming. The state has also closed mollusk harvesting along the Oregon Coast north of Gold Beach.

So if you live between California and Washington, it might not be the best time for a swim. And if you are a fish or a crab living in the ocean, this might be a season with a low survival rate. This might be an important time to mention that farms are excluded from the EPA’s clean-water regulations.