SLO County residents should avoid locally harvested shellfish after the state reported dangerous levels of toxins
By Libbey Hanson[
{
"name": "Newsletter Promo",
"id": "NewsletterPromo",
"class": "inlineCenter",
"insertPoint": "4",
"component": "15264767",
"requiredCountToDisplay": "0"
},
{
"name": "Ad - Medium Rectangle CC01 - 300x250 - Inline Content",
"class": "inlineCenter",
"insertPoint": "8",
"component": "15582119",
"requiredCountToDisplay": "12"
},{
"name": "Ad - Medium Rectangle LC01 - 300x250 - Inline Content",
"class": "inlineCenter",
"insertPoint": "18",
"component": "15582122",
"requiredCountToDisplay": "22"
},{
"name": "Ad - Medium Rectangle 9 - 300x250 - Inline Content",
"class": "inlineCenter",
"insertPoint": "28",
"component": "15582121",
"requiredCountToDisplay": "32"
}]
Harvesters of local clams, oysters, and scallops were told to beware of consuming the shellfish after the California Department of Public Health found high levels of toxins throughout San Luis Obispo County.
Issued on Aug. 29, SLO County Environmental Health Services notified residents not to consume any shellfish harvested in the region due to dangerous levels of paralytic shellfish poisoning, or PSP, based on recent biotoxin screening results.
Environmental Health Services Director Peter Hague told New Times that summer is the prime time for toxins to increase, and typically every summer the California Department of Public Health issues what's called a "mussel quarantine" that ranges from May to October as a precautionary step to test what's in the water—whether heavy metals in harbors or algae blooms in warmer months.
"During the summer is when we get our warmest weather and longest days. That's why you can grow things in your garden," Hague said. "Well, the ocean is a giant garden, essentially, and there's lots of things growing out there, and some of those plants are microscopic phytoplankton, and they can produce toxins that get concentrated in the mussels."
This type of shellfish is the specimen for testing because of its ability to absorb, he said.
"Mussels are a bivalve—you have two shells—and they are attached to rocks and pier pilings throughout California and the West Coast, and they are filter feeders, so whatever's in the water ends up inside the mussel," Hague said.
Now that SLO County has surpassed the quarantine stage and is in official advisory, Hague said the warning extends to other bivalve creatures like clams, oysters, and scallops, which are assumed to also be contaminated by PSP.
According to California Health Department Information Officer Beth Deines, commercial shellfish are still safe to eat in SLO County restaurants, though.
"Shellfish sold by certified harvesters and dealers are subject to frequent mandatory testing to monitor for toxins, including those that cause paralytic shellfish poisoning," Deines said via email. "Certified harvesters or dealers must meet rigorous safety standards before their products can be sold to the public."
Deines specified that in contrast, sport-harvested shellfish are not subject to the same level of oversight, therefore they're only issued an advisory for recreational harvesting areas.
A common spot for sport-harvesting is in the Pismo Beach and Oceano Dunes areas, where in 2023 New Times reported that the California Department of Fish and Wildlife discovered an increase in illegal harvesting of the Pismo clam, especially during summer months. Harvesting is considered illegal when the bivalve shellfish are smaller than the 4.5-inch threshold that makes them ripe for recreational picking.
In the summer months of 2022, Fish and Wildlife was issuing more than 200 citations to people for illegally poaching the clams, but this summer, those numbers are down, according to Fish and Wildlife Information Officer Krysten Kellum.
"Through the end of July, 112 citations have been issued for Pismo clam violations in San Luis Obispo County. A total of 2,466 undersized clams have been seized through July," Kellum told New Times via email. "These numbers are historically lower than previous years, but August and September continue to be busy months where clamming activity continues."
According to the California Department of Public Health's website, the advisory is expected to remain in place until Oct. 31. Δ
Latest in News
-
Stuck in storage: Loss of funding for the county's History Center means decades' worth of artifacts won't see the light of day
Sep 4, 2025 -
Planning Commission wants Cal Poly to publish frat addresses to curb illegal parties
Sep 4, 2025 -
Cal Poly Campus Health and Wellbeing providers are working overtime to lessen student wait times
Sep 4, 2025 - More »
Readers also liked…
More by Libbey Hanson
