California issues urgent shellfish warning due to algae bloom

The Star

02-05-2025

LOS ANGELES, May 2 (Xinhua) -- California health officials have urged residents to avoid eating shellfish harvested recreationally from the coast due to the toxic algae bloom that killed a large amount of sea life this year.
The California Department of Public Health (CDPH) has issued a quarantine for all recreationally harvested mussels for the entire coastline from May 1 through Oct. 31, citing the move was caused by elevated levels of PSP toxins and domoic acid in shellfish in the region.
Paralytic Shellfish Poisoning (PSP) toxins are a group of potent neurotoxins, primarily known as saxitoxins, that accumulate in shellfish like clams, mussels, oysters, and scallops.
Meanwhile, a separate advisory was issued for eating clams, scallops and oysters in Santa Barbara, Los Angeles, Orange and San Diego counties.
The warnings do not affect commercially sold shellfish from certified sources, which health officials said are safe.
The algae bloom sickened and killed thousands of sea lions, dolphins, whales and birds in Southern California in recent months. Dead dolphins and even whales washed ashore along the coast.
The algae produces domoic acid, a neurotoxin, that concentrated in small fish such as anchovies and sardines and then was consumed by marine mammals and birds. The poison affects the heart and nervous system, causing the animals to become disoriented.
There have been no reported human cases of domoic acid poisoning in California to date, health officials said. However, they warned that consuming recreationally harvested shellfish had the potential to cause serious illness.
Early symptoms of shellfish poisoning include tingling of the lips and tongue, which may begin within minutes to a few hours after eating toxic shellfish, the CDPH said in its warning issue don Apr. 23.
"These symptoms are typically followed by a loss of balance, lack of muscular coordination, slurred speech, and difficulty swallowing," the CDPH said.
Milder symptoms of shellfish poisoning include vomiting, diarrhea and headaches. In severe cases, people can become paralyzed and die from asphyxiation.