Over 1 million pieces of trash collected along Monterey Bay shoreline over 4 years

Food wrappers. Plastic bottle caps. Cigarette butts – 231,735 cigarette butts, to be precise. These are just a few of the more than 1 million items collected by over 37,000 volunteers along the shores of the Monterey Bay National Marine Sanctuary between 2017 and 2021, according to a National Oceanic and Atmospheric Association report released in October.

The report from NOAA’s Marine Debris Program combined five citizen science datasets to analyze the trash collected in cleanups throughout the marine sanctuary over four years. Organizations that run local cleanups, such as Save Our Shores, the Surfrider Foundation and Downtown Streets Team, supplied the data.

Marine debris washes up on beaches from the ocean, is left by beachgoers or migrates downstream when it rains. Some debris makes its way to Monterey Bay from distant locations through tides and ocean upwelling.

All marine debris can potentially harm ocean life, causing intestinal blockages, malnutrition and even poisonings when consumed. Fishing gear in particular can pose a threat to marine life that becomes entangled in stray nets or fishing lines. In July, an employee from the Santa Cruz Wharf alerted the Long Marine Lab’s Marine Mammal Stranding Network to a dead California sea lion on Cowell Beach, which died when a fishing line wrapped around its neck and prevented it from eating.

Plastics of various kinds made up 73% of the debris, and included food containers, bags, bottles, food wrappers and many other miscellaneous items. Plastic breaks apart, but doesn’t break down – the pieces just get smaller and smaller. Much of the plastic collected was in small pieces, and could not be attributed to any specific waste category.

Beaches in urban areas such as Santa Cruz tended to have the highest amount of debris collected, but also the highest number of cleanups. Some parts of the coastline, especially in Big Sur, were completely inaccessible to beach cleanup participants.

“Cleanups are still needed, and we would love for that to not be the case,” said Erica Donnelly-Greenan, the executive director of Save our Shores, an organization that has been running beach cleanups in the Santa Cruz area since the early 1980s.

Donnelly-Greenan noted that while beach cleanups do not address the source of the problem, they do make people aware of the problem. And perhaps just as importantly, they provide valuable data for large-scale reports.

Cigarette butts made up 23% of the debris, despite only 10% of Californians identifying as cigarette smokers. Cigarette butts contain harmful pollutants such as arsenic and lead, which can be ingested by marine birds and mammals.

“There’s just this misconception that (cigarette butts) are only a little bit of tobacco and some paper, so there’s this thought that they’re actually biodegradable and not that harmful,” said Donnelly-Green. The number of cigarette butts collected did decrease after 2019, when California State Parks banned smoking on state beaches.

While cigarette butt pollution decreased, e-cigarette waste and dog waste bags increased over the past two years of the study. Face mask pollution showed a steady increase over the entire study period, most likely because of their use during the coronavirus pandemic.