By Theresa-Marie Wilson

Digging for clams was once a thriving tourist attraction as well as a business opportunity in Pismo Beach but declining populations led to an end to the popular activity. According to Cal Poly professor Dr. Lisa Needles, the last legal-sized clam, in the area was taken in 1993.
The Pismo Beach City Council voted to dole out $15,000 clams to help bring back the mollusk population. The money will support a University of Southern California (USC) Sea Grant proposal to study the impact of pollutants on the development and health of Pismo clams.
The grant total is $90,000, with a two-to-one, $45,000, fund matching requirement. Cal Poly committed to approximately $30,000.
“They actually very rarely come in and cash match,” Dr. Ben Ruttenberg of Cal Poly said of the grant. “This is a fantastic thing for us, and it is going to make this proposal much more competitive.”
Should the grant not be awarded to Cap Poly, the council asked that they return to discuss other possibilities to continue with the study.
“I think we are all committed to bringing that clam back,” said Mayor Shelly Higginbotham. “Especially in honor of Ted Erhing.”
The late Erhing, who served on the city council from 2006 to 2012, was an advocate of research that would support bringing the clam population back to Pismo.
Last year at the request of the Central Coast Aquarium Society Needles and her team looked into the decline of the local clam population and the possibility of restoring it.
The team first looked at common culprits; ocean acidification, pollution and harmful algal bloom as possible factors as to why the population diminished, but determined there was also something else going on.
Contributing factors appeared to be a result of the numbers taken by people and predators as well as a change in the larval supply or young clams.
Small female clams, 1.2 inches, produce about 400,000 eggs while a 5-inch female produces 15 million eggs.
Clams typically take two years to mature and release their eggs and sperm into the ocean. A limited number of eggs decreases the probability of fertilization. The greater the density of the clams the more likelihood of fertilization.
Then there is the larval stage where they are floating in the ocean at the whim of the currents and exposed to predators.
This isn’t the first time clams have been missing from the shore. The beach was closed to clamming from 1929 to 1949. After the ban was lifted, over a two-and-a-half month period more than 2 million clams were taken on a single stretch of beach.  An additional million sub-legal size clams were left stranded there.
Between 1987 and 2000, the California Department of Fish and Wildlife (CDFW) surveyed the size and the number of Pismo clams locally as well as at other beaches throughout the state.
There was resurgence in clam numbers until about 1990 when they started declining again. The most obvious reason for the decline was the return of otters that had moved offshore two years prior.
In 2014, Cal Poly conducted a similar survey from the pier to Lesage Drive— they found a total of six Pismo clams.