These days, there are a lot of butts in the ocean.

The kind you smoke, that is.

New numbers out today from environmental advocates at the Ocean Conservancy show that cigarette butts are at the top of the global trash heap, outnumbering plastic bottles, bags and cans littering the world's shorelines and waterways. The group estimates that if all the butts that have been picked up by volunteers over the last 26 years were stacked up, they would be as tall as 3,613 Empire State Buildings.

"The ocean is downstream from all of us," says Nicholas Mallos, a conservation biologist and marine debris specialist with the Ocean Conservancy. "All of our actions regarding trash have the potential to impact the oceans."

The Ocean Conservancy numbers come from an annual effort called International Coastal Cleanup. It began in Texas in 1986 and by last year had grown to include 600,000 volunteers in 96 countries. The cleanup is sponsored by government agencies including the National Oceanic and Atmospheric Administration and private companies like Coca Cola and The Walt Disney Company, the parent of ABC News.

In 2011, the Ocean Conservancy says volunteers picked up:

-266,997 pieces of clothing, enough to dress every member of the audience at the opening ceremony of the London 2012 Summer Olympics.

-Enough cans and bottles to fetch $45,489.15 if recycled.

-940,277 food containers, enough to get takeout for breakfast, lunch and dinner for the next 858 years.

Among the more unusual finds: 195 cell phones, 155 toilet seats, and nearly 10,000 fireworks.  The top ten trash items can be found here.

All that refuse, Mallos says, has an impact on ecosystems around the world."We know that trash is entering the ocean.  We know wildlife is ingesting it and becoming entangled in it," Mallos said. "There's a whole host of potential impacts and problems, including the toxicological impacts of the chemicals that are in the plastic."

Experts say the trash problem could get worse if debris swept offshore by last year's tsunamis in Japan starts turning up on North American shores.

An estimated one to two million tons of lumber, boats and other debris are still floating around the ocean, according to researchers at the University of Hawaii.  Just a few days ago, a large fishing vessel from  Hokkaido, Japan was spotted off the coast of British Columbia in western Canada.

"Debris will make its way to the west coast, but there's still a great deal of uncertainty over how much," Mallos said.