SAN FRANCISCO (KPIX) — An effort to beautify a popular beach on Sunday turned the focus away from those who toss garbage to those who manufacture it.

One day each month an army of volunteers shows up to do a little cleanup of Baker Beach in San Francisco.

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Surfrider, an ocean protection group, staged Sunday’s event. More than two hundred people fanned out over the mile-long beach, searching high and low for even the tiniest pieces of trash — especially plastic, which experts say poses the biggest threat to marine wildlife.

Some of the volunteers wondered why anyone would throw trash on a beach.

“You never know how many people are just, like, terrible people,” said Jacob Carter.

Environmental groups are now examining and recording the debris to hold responsible those companies that manufacture it in the first place.

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Surfrider says soft drink companies produce a lot of the garbage but the granddaddy of all litter worldwide is the cigarette. Many smokers feel it’s OK to discard them, assuming they’ll just dissolve but the filters, which are toxic to fish, are actually made of fine-spun plastic filament.

“People think that they’re cotton or something biodegradable so our goal is to end cigarette litter as the last socially-acceptable form of littering. It’s a behavior change,” Surfrider program leader Shelly Ericksen said.

Sunday’s cleanup was sponsored by New Day, a socially-conscious investment app popular with millennials. New Day directs funding away from companies which produce materials that pollute.

“We’re continuing to gather data on those major producers, as well as others that are not as well known, so we can go back to these companies and say … ‘what can we do to help you find solution,'” said Eva Holman, beach cleanup leader for Surfrider.

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Organizers say the data they collect is helpful in applying pressure to companies — either economically or legislatively — to produce less plastic that will end up in the sea.