Hundreds of thousands of volunteers gathered on local shorelines in mid-September to take part in the Ocean Conservancy's International Coastal Cleanup (ICC), the world's largest single-day volunteer effort to remove trash frombeaches and waterways.

This year, the Ocean Conservancy says, people in more than 100 countries participated in more than 6,000 events where they not only removed trash (much of it plastic) but they also logged the debris they collected into a database, which researchers, industry leaders and policymakers use "to inform policy and determine solutions to the growingmarine debris crisis," according to the conservancy.

International Coastal Cleanup volunteers in Lagos, Nigeria. (Photo: Ocean Conservancy/Shine Gabienu)

"Marine debris, specifically plastics in the ocean, is a pervasive and proliferating problem that threatens every corner of our global ocean, from sea surface to sea floor and from beach sand to Arctic sea ice," said Nicholas Mallos, director for Ocean Conservancy’s Trash Free Seas Program. "The International Coastal Cleanup not only mitigates the threat of debris, but it raises global public awareness of the issue."

Some of the bags of debris removed from shorelines in Santa Cruz, California, during the 2017 International Coastal Cleanup. (Photo: Kimberly Saxton-Heinrichs/Save Our Shores and Ocean Conservancy)

Since the first ICC in 1986, nearly 12 million volunteers have removed more than 220 million pounds of trash from oceans, rivers and lakes, the Ocean Conservancy says.

Millions of tons of trash flow into oceans each year, and that garbage gets tangled up with wildlife. "Plastics — which never fully biodegrade but rather break up into smaller and smaller pieces called microplastics — are of particular concern," according to the conservancy. About 8 million tons of plastic alone pollutes oceans each year, and turtles and fish mistake bits of that plastic trash for food and eat it.

Some of the items pulled from waterways in Washington, D.C. (Photo: Ocean Conservancy/Joy Asico)

Cigarette butts, plastic bags, plastic bottles, food containers, bottle caps and straws are some of the most-commonly collected items. But the Ocean Conservancy runs a contest to see which volunteer can collect the weirdest trash. The 1980s-era keyboard below might be a candidate. Other surprising finds included an Incredible Hulk action figure, a Polaroid camera, suitcases and a toy Godzilla. (You can see some of them here.)

John Rible, a 25-year site captain at Natural Bridges for Save Our Shores Annual Coastal Cleanup, shares an interesting find during an ICC event in Lagos, Nigeria. (Photo: Kimberly Saxton-Heinrichs/Save Our Shores and Ocean Conservancy)

"Year after year, I meet volunteers all around the world who remark on how transformative the International Coastal Cleanup has been for them in understanding the marine debris issue and the impact that they can have as an individual," said Allison Schutes, senior manager for Ocean Conservancy’s Trash Free Seas Program. "The ICC illustrates how individual choices matter to ocean health."

This volunteer in Washington, D.C., collected armloads of trash during an ICC event. (Photo: Ocean Conservancy/Joy Asico)

As the Ocean Conservancy points out, removing pollution from our waterways is just one way to chip away at the problem. More effective waste management is another, and that's the one that will lead to cleaner oceans in the long term.