On a steamy July morning in 2006, I accompany three men and a woman to the gate of a Cleveland ship dock. A guard checks our passes, waves us on, and we pull ahead to the waterfront. Parking our cars and pickup truck, we stand and chat on the pockmarked and cracked asphalt as another morning in a Great Lakes port unfolds on a grand industrial scale.

Tied to the dock behind us, rising 10 stories above the parking lot, is a 656-foot, Polish-owned ocean freighter that powered into the Lake Erie port at 6 a.m. By 9, when our group arrives, stevedores are off-loading at a brisk pace. A towering crane reaches time and again into the cargo hold, grabbing two rolls of imported steel at a time, each weighing many tons. The crane engine strains with the enormous weight, then surges and blows black diesel exhaust out its stack.

Waiting on the asphalt is a fleet of forklifts the size of UPS vans. They race with steel from ship to warehouse like insects hurrying from a food source to a nest. The motors roar. The beep, beep, beep never stops. The smell of exhaust, fuel and sweet-sour chemicals from nearby factories mingles with the algae-fish vapor of a great lake. Seagulls spiral above it all.

The four people I’m with, now pulling on navy blue jumpsuits and white hardhats, are here to examine an unwanted byproduct of this hustling nexus of global commerce and lake: aquatic invasive species. The research team – with members from the United States and Canada – will descend into the cavernous ballast water tanks of the ship looking for organisms that might have begun their lives in, say, a bay in Morocco or an estuary in the Baltic Sea or a river in Rio de Janeiro, or wherever else the ship has recently stopped. If the foreign organisms escape from the ship and flourish in this harbor, they could wreak additional havoc on a Great Lakes ecosystem already besieged by foreign invaders.

In the years since Europeans settled in the Great Lakes, at least 180 foreign species – from microscopic viruses to carp the size of kindergartners – have established populations in these waters, changing forever and in dramatic ways a food web that evolved during the 11,000 years since the last glaciers receded. Scientists discover a new invader, on average, every eight months, or about 15 per decade – about double the rate of 1890. The rising number is especially troubling because research suggests that aquatic environments can become more vulnerable to invasions as the number of invaders increases.

The biologists’ work today is about figuring how to seal off a pathway – introductions through ship ballast water – that has accounted for an estimated 67 percent of invasive species since 1994. Eventually their findings could influence the design of ships, ballast treatment technology and maritime laws around the world, and ultimately help stop the slide of the Great Lakes toward biological chaos.

The researchers grab a mud-stained blue canvas bag filled with testing equipment and head up the bouncy stairway to the ship deck. There they show their driver’s licenses and sign a register. Dr. David Reid, director of the National Center for Research on Aquatic Invasive Species (within the National Oceanic and Atmospheric Administration); Dr. Thomas Johengen, scientist from the University of Michigan; Colin Van Overdijk, senior researcher from the University of Windsor; and his associate, Ewa Szanlinska, who is here to translate Polish.

In a brief display of diplomacy, the team then climbs five more stories to a spacious suite, where they present the captain a plaque expressing appreciation for allowing them to conduct research on the ship. In Polish-accented English, the captain says, "You can put instruments into the tanks anytime. Pollution is very important, especially the Great Lakes, the most freshwater in the world." He holds the plaque and smiles for the camera.

The team then gathers on the deck around the tank hatch, and Captain Phil Jenkins, a marine consultant who specializes in safety and environmental management, joins us to run through a safety checklist. Ballast tank entry can be risky – slip off a ladder, knock your head on a low beam. Jenkins was once in a tank when the crew began to fill it with water, a thousand gallons per minute gushing in. But the greatest risk is suffocation. In a poorly maintained ship the rusting of a tank can happen on such an expansive scale that it consumes the oxygen inside. As a check, Reid breathes on a pager-sized monitor clipped to his shirt; the absence of oxygen makes it beep and flash.

Van Overdijk lowers a more advanced air monitor on a rope down into the tank. When it reports safe levels for carbon monoxide, hydrogen sulfide, combustibles and oxygen, he and Johengen click on their headlamps and descend into the dark hole – five stories of metal ladder, no safety cage. Reid and I soon follow.

The lamps illuminate the rich brown of the rusted tank and create a warm, brown light. The tanks are high enough to walk upright down the outer side, but are low toward the middle of the ship. Sticking to the tank walls, ceiling and floor are thousands of husks from dead marine worms – white confetti reminders of why the scientists are here. Setting to work, Van Overdijk hunkers in a tank section with a 4-foot ceiling, scooping mud into a bucket that will later be analyzed in the lab. Occasionally something enormous bangs in the cargo hold above, and a thunderous shudder runs through the tank. Van Overdijk’s team has sampled ships for four years, covering about 70 ballast tanks. Today’s trip is the final excursion for the study, which was published in June 2007.

Johengen and Reid walk farther into the tank, going slowly on the mud-slick floor and silhouetted by their flashlights. Now and then Johengen’s camera flashes as he snaps a photo of mud to record the flow pattern on the floor. The point: study how sediment, which provides habitat for microscopic animals, gets trapped in ballast tanks. Such information could help naval architects design ballast tanks so they flush cleaner. As the two men talk, their voices echo softly down the length of the metal walls.

They also gather up test equipment that was placed in the tanks four months ago. Every 15 minutes it recorded the temperature of the water, the saltwater concentrations and other parameters. The results will tell researchers about conditions for life in the tanks. For things that lived: what were they able to withstand? For things that died: what killed them?

An hour and a half later, the crew climbs back on deck, sweating from the near 100-degree heat of the tank and squinting in the haze and midday sun. They carry the bucket of mud, bag of gear and the testing unit back to the guest log to sign out. While there, three sailors pull Szanlinska aside and speak in Polish, pointing to a Kohl’s flyer from the newspaper. They want to buy some jeans.

Back in the parking lot, Johengen, Reid and Van Overdijk sit on coolers and their truck’s tailgate, pouring mud into sample jars that will be sent to specialty laboratories: University of Michigan to search for phytoplankton, University of Windsor to see if, among other things, microscopic eggs of zooplankton will hatch in freshwater. Old Dominion University will look for bacteria, microbes and virus markers.

If you set out to design a system for moving aquatic organisms from their home waters to places around the globe, you might invent something precisely like ballast water tanks. But of course, distributing sea animals is not a ballast tank’s purpose.

Ballast is what ships use to keep stable when they are not loaded with cargo – if a ship is too light, rough seas can destroy it in any number of violent ways, including cracking the ship in half. Prior to the 1850’s, sailors often piled pig iron or cobblestones in the lowest cargo holds. But in 1857, a ship-builder installed metal tanks for water in the bottom of a ship, and the modern practice of ballasting was born.

From a ship operations standpoint, ballast water tanks were a great idea. To maintain an ideal weight, ships simply filled tanks while unloading cargo (reduce cargo weight, increase water weight by an equal amount) and emptied tanks while loading cargo (increase cargo weight, reduce water weight by an equal amount) – no messing around with pig iron.

But it’s easy to see how a ship taking in millions of gallons of water at one port and discharging the water in another port would also be sucking in and spitting out all sorts of critters along the way. A large oceangoing tanker can carry more than 25 million gallons of water, but ships squeezing into the Great Lakes through the St. Lawrence Seaway – the only route in for freighters – top out at about 6 million gallons, and many carry half that when fully ballasted.

It wasn’t until the discovery of the zebra mussel in Lake St. Clair, near Detroit, in 1988 that the United States became serious about trying to stop the spread of species through ballast water. We’ve all become numb to news of the zebra mussel’s stunning advance through our nation’s waters, but it’s worth reflecting upon the biological carnage.

The bivalve spread through all of Lake Erie within two years of discovery, setting up colonies on virtually every hard surface. It rapidly spread to other Great Lakes, then the Mississippi River – quickly reaching New Orleans. Along the way the zebra mussel killed tens of millions of native clams.

The Great Lakes have far less food available to other species these days because billions of zebra mussels filter so much from the water. Scientists have linked the breathtaking decline of one of the lake’s most important and abundant food sources, the Diporeia, a 1/4-inch shrimp, to the zebra mussel. In Lake Michigan, for example, the Diporeia historically accounted for about 65 percent of the animal biomass on the lake bottom, but it has vanished in all but a few small pockets. An outbreak of Type E botulism that has killed thousands of loons and other waterbirds in the Great Lakes has been linked to zebra mussels. There are many more impacts, and some have yet to play out, but you get the idea: a single species introduction can cause disaster.

And not to be too alarmist, but scientists fear the quagga mussel, a Great Lakes invader that looks almost exactly like the zebra mussel, could have an even greater impact because it can colonize on soft soils – all over the lake bottom – and can live at greater depths. The quagga recently vaulted the continental divide; it was found in Nevada’s Lake Mead in 2007 – "our nightmare come true," said one biologist.

Congress passed the The Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 and the National Invasive Species Act of 1996 to prevent species introductions. A central piece of the laws required ships coming into the Great Lakes to replace the ballast they took on in port with mid-ocean water while out at sea. In theory, the port organisms would be purged at sea where they couldn’t do any harm to the Great Lakes. Any freshwater or brackish water organisms (the type found in many ports) that somehow remained in the tanks would be killed by the high salinity – 3 percent salt – of mid-ocean water.

The law, however, had a giant loophole. Only 10 percent of the ships entering the Great Lakes come loaded with ballast water. The remaining 90 percent are filled with cargo and are classified as "no ballast on board" or NOBOBs, and are exempt. But the term NOBOB is misleading. "No ballast" doesn’t truly mean "no ballast." It means "not much ballast." And in the case of such large vessels, not much ballast can still mean thousands of gallons. The average NOBOB carries 10,000 to 15,000 gallons of water. But amounts vary, and Reid knows of one ship that carries 100,000 gallons. By comparison, a swimming pool measuring 25 feet by 50 feet and 5 feet deep contains 46,000 gallons of water.

Ships retain such water because their ballast pumping systems can’t reach it all. The tanks create a honeycomb, with some ships having 30 separate tanks. Water and sediment become trapped, sloshing around in intricate places. With about 500 foreign-owned oceangoing ships a year coming into Great Lakes ports, critics of the law complained that NOBOBs were still spewing invading species into the waters.

Despite the unabated rate of invasive species discoveries, Canada and the United States waited nearly 20 years after the discovery of the zebra mussel to address the NOBOB problem. Last year Canada passed legislation that required (with a few exemptions) NOBOBs to do what in industry parlance is called a "swish-and-spit": while crossing the ocean, at some point the ship must take in enough saltwater to cover the bottom of the tank, hold it for a while and then purge it. The U.S. Coast Guard established a similar policy in 2005, but critics complain that it remains voluntary. As with full ballast water exchange, the idea behind swish-and-spit is that the salinity of the water will kill whatever would otherwise escape to the Great Lakes. Jenkins says that at this point, nearly all ships are implementing the practice.

Critics of the shipping industry say that nothing is being done to stop invasives, but in fact the ballast water exchange, the swish-and-spit requirements and other operational changes are very meaningful, says Hugh MacIsaac, one of North America’s most highly regarded aquatic invasive species researchers and the man who oversees the lab where Van Overdijk works at the University of Windsor.For one, simply putting 1-centimeter mesh screens over ballast water intakes has thus far prevented new fish invaders. The last fish invader was recorded prior to 1993, when the rules went into effect.

The largest animal MacIsaac’s team has found in inspecting about 70 ships is one crab about the size of a penny. As for life still getting into the tanks, MacIsaac’s research (some of the data came from the Polish ship in Cleveland) shows kill rates exceeding 90 percent with the saltwater flushing. Would the zebra mussel make it through today? "The zebra mussel does not survive salinity well," MacIsaac says. If such measures had been in place during the 70’s and 80’s, and if every ship had complied, the odds of a zebra mussel surviving the trip from Europe to the Great Lakes would have been "infinitesimally small."

So why is it then that 15 new invasive species a decade continue to be discovered in the Great Lakes? A key word in that question is "discovered." Biologists don’t really know how long an organism survives in a waterway before its population is large enough to be noticed. The zebra mussel was highly visible, and biologists suspect it was introduced two years before it was discovered. Smaller organisms, like a microscopic copepod, might swim in the Great Lakes for decades before being discovered. "Scientists are looking harder now than ever, so perhaps they are just discovering more," Reid says. Also, the NOBOB swish-and-spit requirement hasn’t had time to reveal its effectiveness. And of course, there are the non-ballast vectors – bait buckets, escaped pets, the hulls of ships, the anchors, and others – that account for the remaining 30 percent of invasions.

But another problem is that scientists still don’t know a lot about invasion ecology, a relatively new science. How do policymakers stop something nobody fully understands? "You get into the question of how clean is clean," Reid says. "How low do you have to get the number of organisms in ballast water so they won’t be likely to create a sustaining population?"

And that question takes scientists into the wondrous and diverse ways that species have evolved to reproduce. Consider the tiny arthropod called an opossum shrimp. It holds its microscopic babies in a pouch. "If you kill the mother, it releases its young alive – does that mother count as one or as several?" Reid says.

Or consider that many invertebrates don’t need two to tango. A non-scientist might think, If there are only a few individuals of a species roaming the vast Great Lakes, the odds are very remote that a male will find a female to fertilize an egg. But many invertebrates have only a female form – they make more of themselves all on their own.

Or consider organisms that produce resting eggs. The microscopic eggs are very durable and can wait in sediments for long periods until favorable conditions for hatching arrive. A researcher hatched resting eggs from Scotland that were 300 years old. A researcher on Michigan’s Keweenaw Peninsula hatched resting eggs found there that were 90 years old. "We’ve submerged resting eggs in saltwater for days, and the organisms hatch out in freshwater, waving at you and looking fine," Reid says. Invaders over the past decade tend to have resting eggs – often produced after the parent is dead.

Legislators in both Canada and the United States are working to close off remaining exemptions to the swish-and-spit rules, pushing for 100-percent compliance. Proposed bills also require the use of technology that would ensure higher kill rates of organisms in ballast water. "They’re talking about nearly distilled water," Reid says. "We know how to distill water, but we don’t know how to do it at a rate that meets the operating needs of a ship. Some ships discharge 3,000 gallons a minute." A ballast water technology development center is planned to open this year in Duluth to help speed viable treatments to market.

On the U.S. side, legislators have introduced bills in every recent Congressional session, but Republican leadership has refused to allow them to the floor. Supporters have renewed hope with the Democrats now in charge of the House and Senate, and the Great Lakes delegation has taken lead roles. As of mid-June, representatives had introduced five House bills, and two Senate bills dealing with various aspects of ballast water.

Beyond a change in Congressional leadership, other issues are putting pressure on federal lawmakers to act. One, a court ordered the Environmental Protection Agency to come up with discharge standards for ballast water. The EPA would prefer that Congress pass legislation stipulating that this authority resides with the Coast Guard – they have greater ship expertise and regulate ships as part of their daily work. Two, Michigan passed a law that became effective January 2007. It requires ships to have a permit to discharge ballast water. Shippers are suing the state, claiming in part that they cannot abide state-by-state standards for ballast water. A federal law could solve that problem too.

But perhaps the biggest push for new standards is coming from Mother Nature herself through an outbreak of viral hemorrhagic septicemia (VHS), a deadly fish disease that has killed thousands of fish in Lake Erie and has now been discovered in Lake Michigan and some Wisconsin inland lakes and one Michigan inland lake. The virus can infect at least 25 species of fish, and is especially lethal to some of our most important game fish, including yellow perch and muskellunge.

Genetic testing reveals the virus derives from the Maritime provinces of Canada, but researchers are not certain how the disease made its way to the Great Lakes. "The virus can survive in water for a couple of weeks, so ballast water is a possibility," says Dr. James Winton of the Western Fisheries Research Center in Seattle, a branch of the U.S. Geological Survey. But viruses travel better when in a host, so some speculate it arrived in a fisherman’s bait bucket. Either way, "VHS is a critical issue in the ballast water debate because now the question is, How do we keep VHS from spreading to other ports?" Winton says. It’s possible that soon, "countries won’t want to accept ships from the Great Lakes."

But even if legislation passes and new technologies are required, insiders say that optimistically, meaningful change is five years away, given the state of technology, likely implementation deadlines and the time it would take companies to install equipment on ships. In the meantime, scientists hope that swish-and-spit will prove effective and wonder if we’ll begin to see a fall-off in new invaders.

On the last day of April 2007 I’m standing in a 22-foot boat that floats just a few yards from the ship dock of one of the largest cement plants in the nation, the LaFarge plant in Alpena. A bank of 28 cement silos rise stoic and gray on shore, and another bank of 16 silos stands nearby. A bulldozer plows along the top of a ridge of coal three stories high that runs hundreds of feet – there to feed the tremendous flames within the kilns. And over and around and through it all, a constant rumble, the sound of giant rotating kilns – cylinders more than 100 feet long and 20 feet in diameter that turn limestone into clinker that’s ground into cement.

With me are three researchers. Two were on the expedition into the Polish ship in Cleveland – Dr. David Reid and Dr. Tom Johengen. In two days, Johengen will fly to Washington, D.C., to report to a Congressional subcommittee about gaps in the ballast water laws. Onboard, too, is Dr. Scott Santagata, a researcher from the Smithsonian Institution’s marine research lab in Maryland. As large as the Great Lakes invasive problem is, it is just a portion of Santagata’s research. He also studies invasions in two of America’s marquee marine bays – Chesapeake Bay and San Francisco Bay.

The researchers are here for a couple of reasons. First, they are looking for the most recently discovered Great Lakes invader, called the bloody red shrimp. The 1/2-inch crustacean came from the same part of the world, the Pronto-Caspian region of Eastern Europe, that gave us the zebra mussel and several other invaders. Researchers still only can speculate on its long-term effect on the food web, but near-term, they want to determine how widely it has spread throughout the lakes.

The red shrimp can rise in the water en masse, like a swarming red cloud, which is how it was discovered near Muskegon in November 2006. The researchers are dragging sampling nets here in Lake Huron to see if a freighter might have discharged some of the shrimp.

The researchers are also trapping microscopic organisms that they will take to a lab at the Thunder Bay Marine Sanctuary, in Alpena, to see how long they can survive in various concentrations of saltwater. The answers will provide more evidence about the effectiveness of such practices as swish-and-spit and ballast water replacement.

As I watch the men work, I recall a line from the movie Jurassic Park that I often think about when I consider invasive species. It’s delivered when the park developer asks his risk assessor what he thinks of the idea of a theme park populated with live dinosaurs. The consultant pauses for a moment and says, "I don’t like it." He contemplates again and adds, "Life … it’ll find a way."

He means, of course, that life will find a way to do all the things that living things do – expand territory, eat, defend, attack, and most troubling, multiply. The line encapsulates and launches the central drama of the film.

Making conversation, I say to Santagata. "Your work reminds me of this line from Jurassic Park …" He looks up from the organism-filled sample jar in his hands, a brilliant 10 a.m. sun reflecting large in his sunglasses, and without a moment’s hesitation completes the idea: "Life, it’ll find a way."

Jeff Smith is editor at Traverse, Northern Michigan’s Magazine. smith@traversemagazine.com

Seen some bloody red shrimp? Scientists would like to know when and where. Check glerl.noaa.gov/hemimysis/index.html to see photos of the shrimp and get details on how to report your sighting of the latest Great Lakes invader.

Note: This article was first published in August 2007, and was updated for the web February 2008.