Scientists say Marina sand-mining plant is quickening coastal erosion.

When Ed Thornton recently completed a study examining coastal erosion rates for the Monterey County coastline, he noted something strange. The data just didn’t line up as he’d expected. At least, not until Thornton, an oceanography professor at Naval Postgraduate School (NPS), began to focus his sights on a little-known sand-mining operation in Marina that may in fact be one of the largest sources of present-day coastal erosion on the Central Coast.

“[Especially] from the Marina to Sand City area, coastal erosion rates are not decreasing as they are in the southern part of the bay,” Thornton says. “One of the biggest reasons why is that mining operation.”

Situated between Marina State Beach and the Salinas River, the sand mining plant was purchased by the giant Mexican cement company CEMEX in March of 2005. When asked about Thornton’s assertion, CEMEX spokeswoman Jennifer Borgen says CEMEX “doesn’t comment on theories. We do know that we run a safe and environmentally-conscientious operation.”