El Niño could bring a lot of rain this winter. Coastal Cleanup Day aims to pick up trash before it washes to the ocean. Here’s how to join in Saturday.

You might have done spring cleaning at your house. Every year, California gets a fall cleaning. A really big one. And it’s that time again.

Litter at the beach? Trash on the banks of the local creek? Plastic pollution threatening wildlife? Those are the targets.

From 9 a.m. to noon this Saturday, the California Coastal Commission is hosting the 42nd annual California Coastal Cleanup Day — the state’s largest yearly volunteer event. And with sunny skies forecast, organizers say more volunteers are still needed.

More than 40,000 people are expected this year at more than 750 sites in all 58 of California’s counties, said Eben Schwartz, marine debris program manager at the California Coastal Commission, which oversees the event.

To sign up, go to Coastalcleanupday.org.

“It’s the one opportunity we have each year to clean our entire state to protect the coast,” he said, “and make sure trash in our environment doesn’t become trash in the ocean where it can cause incredible damage to marine wildlife, our economy and our own health.”

The cleanup isn’t just limited to beaches along the ocean.

Volunteers for years have cleaned up creeks, rivers, lakes and other inland areas, including along the shores of San Francisco Bay, Lake Tahoe and other waterways. For the second time since the event began in 1985, all 58 of California’s counties will participate this year.

Volunteers will be especially important this year, organizers say, as the strongest El Niño conditions in recorded history build up in the Pacific Ocean near the equator. The increased rainfall expected from El Niño this winter can wash plastic, bottles, cans, tires and other debris from creeks and streams into the ocean.

“Everything flows eventually to the ocean,” Schwartz said. “If we can capture that trash before the rains come, we prevent an incredible amount of harm by keeping it off the beaches and out of the marine environment.”

Since its first year, more than 1.8 million volunteers have picked up more than 27 million pounds of debris across California.

As in past years, agencies, including the East Bay Regional Park District and the Santa Clara Valley Water District, are cleaning up multiple sites.

Volunteers are asked to bring gloves and a bucket to the site they choose. If they aren’t able to bring either, the site coordinator, often part of a parks department or non-profit group, provides them. Everyone tallies up what is picked up. After four decades, the data has shown numerous trends.

In general, California’s beaches and waterways have gotten cleaner over the past 40 years.

In 2014, volunteers picked up an average of 17.8 pounds of litter per person. Last year, it was 8.2 pounds. Some of that is due to monthly cleanups that non-profit groups do on their own throughout the year.

“It has been a steady drop,” Schwartz said. “It’s very good progress.”

The event is still bouncing back from the COVID-19 pandemic. In 2019, the year before the virus hit, 74,410 people volunteered. In 2020, only 19,730 people did, without organized group events. Last year, 41,867 people turned out statewide, with Los Angeles, Orange, San Mateo, San Diego and Alameda counties generating the most volunteers.

Statewide, volunteers collected 342,528 pounds of debris, of which 54,221 pounds was recycled.

Over time, changes in California laws have affected the type of trash found during Coastal Cleanup Day. After voters passed a statewide ballot measure in 2016 to phase out single-use grocery bags, the number found on beaches, streams, rivers and lakes fell significantly. After Gov. Gavin Newsom signed a law in 2019 to ban smoking at all state beaches, the number of cigarette butts found plummeted.

Every year, volunteers — who come from community groups, scout troops, corporate volunteer programs and families — find some odd things among the trash. Last year, volunteers in Santa Rosa found a crocheted “emotional support pickle” holding a sign that said “you are a big dill.”

In Alameda County, volunteers last year found a cannonball, poetry from a wedding ceremony, a NOAA weather balloon, a boombox and a 1970s soda can, said Jessica Sloan, volunteer supervisor for the East Bay Regional Park District.

“We’ve found doll parts, a Social Security card, all sorts of oddities,” she said. “And we find a lot of single shoes. We should put them all together like socks in your house to try to find a match.”

East Bay Regional Parks is working to clean up about a dozen of its parks this year, she said, including Martin Luther King Jr. Shoreline, Lake Del Valle, Crown Beach and Point Pinole. Last year, 1,778 people collected more than 14,000 pounds of debris on Coastal Cleanup Day at East Bay parks, she noted.

“The best thing is getting outside,” she said. “It’s such a joy to give back. When you pick up trash, you are making the landscape better for plants and animals and people. We get to see people from all walks of life. It’s a wonderful way to feel like you have made an impact.”