The Pismo Clam (Tivela stultorum) is one of the largest clams found along California’s coastline, capable of growing up to seven inches in diameter. Due to natural predators like sea otters and human harvesting, most do not reach this size.
In fact, the largest one ever found was here in Pismo Beach, measuring in at 7.37 inches across. It was estimated to be 26 years old and is displayed at Pismo Beach City Hall.
These clams filter thousands of gallons of water each year and provide food for marine life, keeping our coastal waters clean and balanced. They use their siphons to filter food particles from seawater.
The History of the Pismo Clam
The Pismo Clam supported a booming commercial and recreational fishery in the early 20th century. Clammers harvested bucket loads every day that are beyond comprehension nowadays.
Unfortunately, the abundance could not not last and overharvesting led to the commercial fishery closing in 1947. Recreational clamming persisted but declined as legal-sized clams became harder to find. By 1993, they had virtually disappeared from the shore.
For decades, the once-thriving population seemed lost—until an astonishing revival began in 2020.
Why are there so many clams on the surface of the sand?
If you’re asking this question, you’ve likely witnessed the semi-rare Pismo clam surfacing event. A few times throughout the year, the clams will surface in large numbers and sit on top of the sand for a few hours or days. In 2023, 2024, and 2025, this number has been especially high and drawn concerns from onlookers. However, there’s no need to be worried, as far as we know.
The Cal Poly researchers, along with environmental scientists, are working to better understand this behavior. At the moment, there are theories but no strong evidence or a conclusion on why the clams do this.
What they do know is that most clams will rebury themselves. This has been observed repeatedly. It’s a natural behavior for the species.
Onlookers are often curious if they should rebury the clams themselves to help their survival rate. While the thought is considerate, it’s best not to touch them. They are wild animals, and this is their natural behavior. Less human interference is almost always the best route to take.
However, clam reburying is extremely important in the context of fishing. Educate yourself and others around you on the best way to rebury clams that they dig up themselves. This action lowers the human impacts of fishing on the populations.
Understanding the Comeback of the Clam
The return of the Pismo Clam sparked excitement, and scientists at Cal Poly San Luis Obispo’s Ruttenberg Lab are leading the charge in understanding this remarkable resurgence. Their research investigates the historical decline, the environmental factors contributing to the clams’ comeback, and the best management practices to ensure their long-term survival.
Through hands-on fieldwork and the City of Pismo Beach funding, researchers and volunteers track clam populations, measure growth rates, and monitor environmental conditions. This collaborative effort highlights the importance of conservation, education, and responsible harvesting, ensuring that Pismo Beach’s beloved clams remain for future generations.
Learn more about the Clam Comeback in our Stewardship Blog Series
A Future for the Pismo Clam
The resurgence of the Pismo Clam is a testament to nature’s resilience and the power of conservation efforts. Thanks to the dedication of scientists, community members, and responsible clammers, Pismo Beach is witnessing the return of one of its most cherished natural icons.
Whether you’re an experienced clammer or a curious first-timer, embracing sustainable practices ensures that this coastal tradition thrives for years to come. So grab your clam fork, hit the beach, and be a part of Pismo Beach’s living history!
A Guide to Clamming in Pismo Beach
For years, Pismo Beach was known as the Clam Capital of the World. Much of the town was built on its connection to clams, as both the fishing industry and tourism for clamming thrived in the 1940s and 1950s.
Families gathered for decades along the Pismo Beach shores with buckets and clam forks, searching for both Pismo and Pacific Razor Clams. This generational tradition is back again for visitors and the community to enjoy!
Before going out clamming, take a moment to appreciate the story of the Pismo Clam’s shocking comeback after a 30 year disappearance.
Going Clamming: Regulations and Best Practices
These rules apply specifically to the Pismo Clam, Tivela stultorum. Reference California Code of Regulations, Title 14, Sections 29.20 and 29.40.
- California Ocean Sport Fishing License required for clammers over the age of 16. (Apply for a license from the state online.)
- A measuring device is required.
- Keep only clams 4½ inches or larger.
- Rebury all undersized clams. (View state guidelines.)
- Limit: 10 clams per person at any time.
- Every clammer must use their own container.
- Clamming only permitted from 1/2 hour before sunrise to 1/2 hour after sunset.
- Hydraulic pumps may not be used to take clams
Rebury Undersized Clams
- Bury at least 2” deep with the hinge towards the ocean and ligament pointing upwards. (View state guidelines.)
Report Violations
- To report a violation, call 1-888-334-CALTIP, visit wildlife.ca.gov/enforcement/caltip or download the free CALTIP app.
The Pacific Razor Clam, on the other hand, can be taken at all times during the year with a valid fishing license. There is a limit of 20 Pacific Razor Clams per person.
To go clamming you need:
- Saltwater fishing license – acquire online HERE.
- Clam fork
- Caliper
- Bucket of seawater
You can purchase clam forks and calibers at Pismo Hardware or they are available to rent by the pier.
If you do not use a clam fork, you can use a modified rake, or any utensil that has prongs a foot or so long.
Where to Go Clamming
The best place to dig for Pismo Clams is south of Grand Avenue in Pismo Beach. There are large parking lots where you park for free, or drive on the beach for $10 a day.
How to Go Clamming
During low tide, use a clam fork to gently dig near the water line. When you find a clam, measure it with a caliper to ensure it is legal size. Be sure to bring a bucket of seawater to allow clams to purge any impurities before cooking.
Important Considerations:
- Beware of Red Tide: Red tide events produce harmful toxins that accumulate in shellfish. Always check local advisories before consuming clams.
- Properly Rebury Undersized Clams: To give them a chance to grow, dig at least two inches deep and place the clam hinge-up, pointing toward the ocean.
- Fees and penalties for illegal clamming: Those caught not adhering to any of the California Department of Fish and Wildlife guidelines will be subject to heavy fines (ranging from $100 to $1,000).
