CHARLESTON - People trickled into the Boathouse auditorium slowly at first. They scattered around the room finding seats. Oregon Institute of Marine Biology students. Professors, a fisherman, port commissioners and everday folks.

They came to hear a marine biology expert's explanation of a global invasion. As the seats slowly filled, the murmurs centered on science.

“Isn't that evolution?”

“... just because it comes in on a ship.”

“But the zebra mussel? ...”

At 7:29 p.m., a large wave of people swept into the remaining chairs, and squeezed sitting side-by-side along the walls. Soon, Dr. James Carlton hopped down steps to stand in the dimly lighted room before his audience. Carlton taught at OIMB for three and a half years in the late 1980s. Now, he's famed among marine biology and shipping industry types as the guy who pioneered research into ship ballast water and the resulting biological invasions.

Carlton, who is visiting from Williams College in Connecticut, didn't appear to be the scholarly type. Sure, he wore wire-framed glasses. But he was a small man comfortably snug in a dark gray sweater vest and he talked in simple language.

One or two streaks of lightning flashed off the dark waters of Coos Bay and through the windows behind Carlton throughout his talk, which easily could have been the fuel for bad dreams. Many came to hear his take on the possibility of non-native plants, animals and other organisms sneaking into Coos Bay aboard ships. In particular, they wanted to know about the possibilities clinging to mothballed ships one company wants to tow to Coos Bay for dismantling and recycling.

But he made them wait.

First, Carlton's lecture sailed over history, peaking at times with wry comments that brought his audience to smiles or outright laughter.

Invitation to clingons

Humans have been changing life on land and in the oceans for centuries, by accident and intention, he said. And we're getting better at it all the time. With the spread of cultures and global exploration starting about 500 years ago, humans cast a deep and broad biological cloud across the ocean.

Think about oysters, really the whole seafood industry. Big, huge container ships serve essentially as biological islands that can carry literally hundreds of species. And, as he chuckled over a more modern twist to the problem, he jabbed fishermen for “releasing it because you feel sorry for the little worm.”

Carlton speculated that between 1800 and 1900, there was a doubling of introduced species here. From 1900 to 2000, it was a doubling again. With the thousands of ships that came to the West Coast in the 19th century's Gold Rush came the first clear invasions of exotic species.

For biologists in 1890, Coos Bay would have been a fun place to be with all the species that started pouring in at one time, he said.

Post Gold Rush, mariners worked furiously to keep things from attaching to the hulls of their ships to slow wooden hull rot. Wood-masted vessels gathered critters during longer stays in port. Those ships were slow-moving, so there was less tendency for organisms to get ripped off while the vessels were in transit.

The economics of the shipping industry these days have helped lessen the hull-sticking problem. Hull encrustations slow down cargo ships and waste fuel, so ships don't stay long in port to deter colonization. These ships move fast in the open sea, so it's harder for critters to hang on.

And, “they have wonderful anti-fouling paints that kick butt,” Carlton said.

While those paints were highly damaging to estuaries up until a few years ago (remember the tributyltin days where paint chips devastated the oyster industry), the U.S. Navy is working on new paints that aren't as bad on the environment but kill the sticky invaders.

Offloading hitchhikers

In about 1990, the world with the lead of the United Nations became interested in ballast water. That's not the “sluzolla bilge water” that seeps into a ship, Carlton said, but the water sucked into strategically engineered tanks to help balance a vessel. Cargo and container ships these days are like floating lakes, with millions of gallons of plankton-enriched water aboard, and even their own schools of fish.

“These ships radiate out like spokes of a wheel as they set out across the Pacific,” he said.

Sure there are ballast water dumping rules, requiring vessels to exchange water at sea.

“Just how much water is exchanged, we don't know yet,” he said, adding that kind of research will take years.

But shipping doesn't deserve nearly all the marine-invader blame. Carlton talked about a study he and some of his college students did. They cruised the Internet and paid for four items mail order, as is the trend these days. They ordered live crab, a marsh plant, a type of sea squirt and one type of bait worm. They ended up with 18 species that came along in the same box with the bait worms, 12 with the crab, 10 with the plant and 104 with the sea squirts.

Sure, many of the hitchhikers were microscopic. But, Carlton said, the lack of control of species spread was staggering.

So for Coos Bay, scientists' best guess is that there are about 100 species that likely are not native here. For sure, they know 65 organisms are basically newcomers. Then again, he said, it's hard to analyze history, especially microscopically.

Here, Carlton swung around his talk to the present.

Mothballed ships

“Can more species come?” Carlton asked rhetorically.

It's hard to imagine anyone in the audience didn't know the answer. For scientific sake, Carlton explained that it's logical to assume new organisms might have a tough time getting established due to climate, water quality and habitat barriers. But there's always a lucky one and the water's getting warmer.

And as to preventing newcomers to Coos Bay from the species clinging aboard the decommissioned military ships at California's Suisin Bay near San Francisco, that's something that will require study, Carlton said. He has characterized the ships as floating reefs, since most have been anchored there for decades.

The fuzzy hulls could be scraped, but as the costs go up, the less likely it is to happen. Some people have speculated that the ships could be anchored in fresh water , as captains of the 18th and 19th centuries did to rid their hulls of ship worms. That too, presents unknowns.

He gave a recent example. It happened when the USS Missouri was sailed from Bremerton, Wash., to Hawaii about seven years ago. The vessel was anchored in the Columbia River's freshwater near Astoria for a time to kill the hull inhabitants, but upon its arrival in Hawaii, researchers found the water hadn't been quite fresh enough. Hawaii soon had a new species.

As Carlton's talk came to a close, he addressed those early murmurings on evolution.

“Humans are part of the grand scheme of things,” he said.

Invasions are natural and occurring on a globalized scale, considering that an entire mix of species can be moved from one place to another within a day.