MELBOURNE BEACH, Fla. -- And then there was the day last year when the Barbie butts started washing ashore.

Cathie Katz got calls and e-mails, dozens of them, from fellow beachcombers along America's coastlines. They were finding dozens of peach-colored plastic derrieres, legs, torsos that appeared to be pieces of Barbie dolls.

"There were just too many for it to be a coincidence," Katz recalled. "Too many for children to be leaving them behind on the beach."

The Barbie parts remain a mystery. But they are important to Seattle oceanographer Curt Ebbesmeyer, who's been studying drifting objects for 30 years. He uses the beachcombers' reports around the world to track cargo spills that loose millions of items from ships into the ocean each year.

Thanks to an international network of beachcombers -- a group becoming more connected, organized and efficient -- environmentalists and scientists can now follow things swept from one place to another in the ocean's roiling currents. That's important for tracking everything from weather systems to the movement of oil spills.

Thousands of beachcombers, once considered a solitary lot, now correspond on the Internet and meet several times a year to show off their finds: There are the Beachcombers Fun Fair in March in Ocean Shores, Wash., the Conchologists (shell collectors) of America Convention in Florida in July, and the International Sea-Bean (drift seeds) Symposium in October in Florida, which Katz organizes.

Everything washes up on beaches everywhere. Shoes and shells. Computers and crabs. Rocket parts and body parts. Money. Toys. Cocaine. Toothbrushes. Even candy.

"If humans use it, it's out there," said Ebbesmeyer, 57, who publishes the 600-circulation Beachcombers' Alert!, a quarterly newsletter reporting the stuff both natural and man-made that spotters find worldwide.

At his Web site (www.beachcombers.org), visitors may print out a checklist to help Ebbesmeyer keep track of found items. Categories include "Military ordnance (dangerous)," "Stranded marine creatures," "Glass fishing floats," and "Unmentionables," such as toilet seats and condoms.

Perhaps the most publicized cargo spill was of nearly 5 million LEGO toys that washed overboard from the container ship Tokio Express off Land's End, England, in 1997. Beachcombers are still gathering the little plastic pieces, even some with sea-themes -- rafts, flippers and octopuses.

Between 100 and 200 massive ocean shipping containers are lost to the seas annually, said Michael McDaniel, an attorney with Countryman & McDaniel, a Los Angeles customs broker law firm. The losses run into the hundreds of millions of dollars each year.

Shipping firms often avoid admitting the mishaps, fearing they may be billed for cleanup costs, experts say. And so, anything that crashes overboard in rough seas is simply carried away and forgotten.

That is, unless it makes its way to a beach, along with other flotsam and bits of nature, where someone like Bill Pope eagerly waits.

Pope, 76, displays his finds in his small guesthouse on the Louisiana shoreline. "We refer to it as our museum," he said.

There's a World War II machine gun round. A dolphin skull. Three bottles with notes inside. An oil exploration device with an offer of $250 for its return.

"Actually, I found that one, but he claimed it," said Pope's wife, Bess, 73. "There was money involved."

The retirees divide their time between Alexander, Ark., and their beach house 20 miles inside Louisiana from Port Arthur, Texas, Bill Pope said.

"Last time we were down there, I found something really unusual," he added. "It looks like maybe a petrified cow's tooth."

David Williams, a 35-year-old graphic artist from Charlotte, N.C., has come across more ominous items: Blood bags and hypodermic needles.

"There's a lot of hospital waste out there," he said. He prefers collecting the toys that wash up: Action figures, soldiers, Disney characters.

What first got Williams interested in beachcombing 10 years ago were the dozens of varieties of drift seeds, also called sea beans, that he found while living in Florida. "Some are beautiful, some are very strange," he said.

Katz, 53, is known as the Sea-Bean Lady, author of six nature books including "The Little Book of Sea-Beans and Other Beach Treasures."

Sea beans drop from trees and vines into rivers in South and Central America and the Caribbean. From there, they meander out to sea. The seeds are especially buoyant, with a hard shell that discourages hungry fish. Some are small as a grape, others large as a watermelon. They seem to be made to float thousands of miles on ocean currents for many years. Why, no one knows.

"I call them little messengers from other lands," Katz said.

Formerly a senior editor at Johns Hopkins University's Applied Physics Laboratory at Cape Canaveral Air Station, Katz now publishes a newsletter, The Drifting Seed, for 600 enthusiasts in 20 countries -- including a woman in Chicago who is so nuts about the beans she has them tattooed on her shoulder.

As the Sea-Bean Lady, Katz speaks at schools and organizes the symposium, which last year lured beachcombers from as far away as England and Africa. She also oversees the Web site www.seabean.com.

Although sea beans are her passion, Katz considers anything she finds beachcombing a treasure. Many favorites land in her beach box, a well-worn wooden chemist's cabinet that she totes to schools. Other items are used to create elaborate collages that hang in her sunny home.

She's most at home on the beach. "Here, this is a pelican feather," she said on a breezy morning, bending down to pluck a long quill from the Florida sand. "They're used to make harpsichords."

A few more feet, another find: "Look, a hamburger bean! That's good luck." That's a brown sea bean with a dark stripe around its middle -- and it does indeed look like a hamburger.

A dried chunk of honeycomb-like material is part of an egg case from a lightning whelk snail; it contains teensy shells holding more whelk snails. "Beachcombers collect all the stuff that other people just pass by," said Katz, picking it up.

Katz favors clothes with big pockets for her finds. She prowls the "wrack line," a strip of debris a good ways in from the water. That's where the sea beans are. Shells and heavier items generally lodge in the "swash zone" near the surf's edge.

It's a misconception that the best beachcombing is early in the morning. "Any time after the tide goes out is a good time," she said.

And for a beachcomber, time spent on the shore is never time wasted.

As Williams said, "It's a good day walking on the beach. If you find something, that's even better."

(Dru Sefton can be contacted at dru.sefton@newhouse.com.)