Sad news, seafood lovers: Scientists have found what might be the largest toxic algae bloom off the West Coast, causing concerns for marine life and humans.
Ocean scientist Raphael Kudela and his researchers at UC Santa Cruz noticed the bloom in Monterey Bay in May, now spreading from California to Alaska. Toxic algae known as Pseudo-nitzschia make up the bloom, producing a neurotoxin called domoic acid.
“It’s definitely the largest bloom of this particular algae seen on the West Coast, possibly anywhere, ever,” Kudela told CBS News.
Algal blooms occur at this time of year because winds cause upwelling, but the size and widespread toxic algae make this bloom unique, says Duncan Berry, CEO and co-founder of Fishpeople Seafood.
“Once the winds die down and the sun has a chance to do its job, the ever-present algae begin to multiply and consume the nutrients,” Berry says.
Scientists think that a patch of warm water in the Pacific might have contributed to the algae bloom, but they don’t know for sure.
“Blooms are normal and in this case the conditions in the ocean favored the specific species to reproduce to numbers that pose a threat. The water temperatures are higher than usual, which plays a part in the size and scope of this bloom,” Berry says.
The toxin has led to fishery closures along the West Coast in Washington, Oregon and California.
Shellfish and small fish feed on the algae, causing them to be infected with domoic acid. Sea lions and other marine mammals that consume ocean life with domoic acid are at risk for amnesic shellfish poisoning, an illness that causes permanent short-term memory loss, brain damage or death.
In June, the National Oceanic and Atmospheric Administration sent scientists to study the bloom for further research.
So far, scientists have found that bloom activity has decreased in California near the coast, although the toxin is still present in Monterey Bay, according to Kudela in a recent interview with Well.org. The NOAA also reported high concentrations of cells on the Oregon coast.
In light of the bloom, we’ve compiled some tips to help keep you safe from shellfish poisoning in Washington, California and Oregon.
- For shellfish gatherers, refrigerate or put on ice immediately after gathering, harvest shellfish as the tide dies down and avoid shellfish exposed by the receding tide for more than an hour. Cook thoroughly to kill bacteria (Vibrio parahaemolyticus) in the fish.
- If you suspect having consumed infected fish, watch for signs of Vibrio poisoning, including diarrhea, stomach cramps, nausea, vomiting, headache, fever and chills. Unfortunately, not all toxins – including paralytic shellfish toxin (PST) – are killed by cooking. Fish infected with PST, which can also result from an algae bloom, can cause paralytic shellfish poisoning, with possible symptoms including tingling of the mouth and tongue, dizziness and numbness, arm and leg paralysis, or even death.
- When buying seafood, buy fish that has been refrigerated or placed on fresh ice, lacks a fishy and sour odor and has maintained its color. In addition, do not buy clams, oysters or mussels if their shells are broken.
- When buying frozen seafood, watch out for packages that are broken or torn, on top of the freezer case or with frost or ice crystals.
- After buying the seafood, refrigerate or freeze immediately. When storing cooked seafood, separate it from raw seafood.