A group of Cal Poly researchers is beginning a study to track Pismo Beach clams, with the hope of restoring the species’ population.
The research team will start the new ‘mark and recapture’ study May 29 on Pismo Beach. This kind of study involves tagging individual animals so researchers can track them over time.
In this case, the purpose of tagging the clams is to help their population recover by learning about their growth rates, mortality rates and how much they move on the beach.
After the initial clam tagging, researchers like Cal Poly biology graduate student Marissa Bills will return monthly to try to find them and collect data.
Bills said the research team is asking community members to participate in the study. The clams will be tagged with QR codes so if somebody finds one, they can scan the code and send information about it to the research team.
Bills said community involvement is critical for the success of the study because more people can send in data about the clams’ growth and movement.
“It’s just going to allow us to hopefully get this information that would be really hard for us to obtain otherwise,” Bills said.
Ben Ruttenberg is a Cal Poly biology professor and lead scientist for the project. He said Pismo clams used to exist in abundance along the Central Coast and recreational catching of them used to be a large part of local culture.
Pismo clams can be harvested with a valid fishing license. But Ruttenberg said a clam large enough to be legally harvested hasn’t been found on Pismo Beach since 1993.
“That is the question. What is limiting them from getting to this size? And honestly we do not know at this point,” Ruttenberg said. “Part of this is trying to figure out what’s happening with the populations so that we can answer that question about why there aren’t any big ones.”
The legal limit for harvest is 10 Pismo clams per day if the clams meet a minimum diameter of 4.5 inches in San Luis Obispo County. All undersized clams must be immediately reburied in the area they were found.
Bills said restoring the Pismo clam population is important for people, the local economy and the natural ecosystem. She said this study could open the door for seeing these benefits in the future.