More than 800 volunteers, many of them teenagers, broke coastal cleanup records in Shimada Park Saturday by turning out to pick up trash along the park’s shoreline as part of California’s 28^th annual Coastal Cleanup event.

The volunteers spent three hours wading through marshland and searching among boulders, filling dozens of buckets and plastic bags with trash in an effort to beautify an otherwise beautiful shoreline that offers sweeping views of San Francisco, the Bay Bridge, the Berkeley Hills and Brooks Island.

Juliana Gonzalez, the Healthy Watersheds Program manager for the Richmond-based Watershed Project, said the volunteers who showed up at Shimada Park unearthed 2,165 pounds of trash.

That’s enough to fill three dumpsters with trash.

Gonzalez’ preliminary results for coastal cleanup efforts across Contra Costa County and the Albany Bulb showed that almost 3,000 volunteers collected nearly 25,000 pounds of trash.

That’s enough to fill 36 dumpsters with trash.

But most of what was collected along these beaches was small and made of plastic.

At Shimada Park, the most common items (in descending order) were plastic food wrappers and containers, plastic caps and lids, plastic bags, plastic straws, tobacco packaging, plastic cups, plates, forks and knives, cigarettes and filters, plastic bottles, glass bottles and paper bags.

Among the “weirdest” category? One magic eight ball.

Eventually, the ocean grinds all this plastic into tiny pieces that cause big problems when fish, birds and other marine animals swallow them.

Oakland resident Beth Terry, author of “Plastic Free” which documents her struggle to live without plastic since 2007, was on hand at Shimada Park, touting her entire plastic use for 2011—a single orange plastic bag weighing two pounds and mostly containing empty pharmaceutical containers and packaging that can’t be recycled.

“Each year, I was reducing more and more,” Terry said, describing how her lifestyle shift involved giving up microwaveable meals, finding stores that let her fill her own glass jars and cloth bags with bulk produce, and restaurants that let her pack leftovers into her own reusable containers.

County Supervisor John Gioia said 823 people volunteered at Shimada Friendship Park—a record for the park since it began participating 22 years ago.

“We started with 40 to 50 people, then it went up to 100, 150, then down to 75 people,” Gioia said. “Over the last few years, we picked up to 200 people, then 300 because we started getting youth groups. Here’s what I’m hoping: that we get more volunteers than Berkeley, one of these years.”