It’s a cool, wet morning in late April 2008. Somewhere in the islands near Put-in-Bay, Ohio, Jeff Reutter, director of the Stone Lab, has just hauled in the net from a five-minute trawl.

The good news is that there are plenty of fish. “More than I’d expected at this time of year,” says Reutter, pointing out the yellow perch and various other species. But a lot of the fish he pulls out—and puts into a bucket to take back to the lab—aren’t native to Lake Erie. It seems most of the smaller fish are round gobies, one of the fastest-growing populations of fish to invade the Great Lakes.

The round goby, like the zebra mussel that became the poster child for the aquatic invasive species threat, likely entered the lake when a ship discharged its ballast water. Ships pump water into and out of special tanks when they load and unload cargo. The water helps balance the load and keeps the ship floating just right. More than 180 non-native species have been introduced to the Great Lakes. Ballast water is responsible for more than half of them, according to the Department of Fisheries and Oceans. Ballast water from the Caspian Sea is responsible for the zebra mussels in the Great Lakes.

As recently as two years ago, the salt and freshwater fleets were locked in a nasty dispute with regulators on both sides of the border, including Canada’s fisheries ministry, the U.S. EPA, the U.S. Coast Guard, and activist groups calling for expensive ballast water filtration systems to be installed on ships.

At an industry and government roundtable overlooking the port in Cleveland, Ohio, you could cut the tension with a knife. Great Lakes United, a conservation group, went so far as to suggest banning the saltwater fleet from the Great Lakes altogether. But a lot changed in the ensuing two years.

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“It’s been a rapidly changing regulatory playing field and that’s not stopping,” says Jennifer Nalbone, director of navigation and invasive species for Great Lakes United, a conservation group pushing for better protection of the Great Lakes. There have been “real improvements in environmental protection,” she says.

Tackling the salties

The first and biggest change was that ships entering the Great Lakes are now required to flush their ballast tanks with salt water while at sea.

The rate at which species were entering the lakes was fastest between 1984 and 1999. The saltwater fleet began a voluntary ballast water exchange program to help in the 1990s, but by the time it became mandatory in 2006, almost one-third of ships still weren’t flushing their tanks while at sea. Most freshwater species cannot survive in salt water.

Today, ships are required to exchange ballast water. When they enter the St. Lawrence Seaway, they’re tested. If the water salinity is below 30 parts per thousand, they’re turned away.

The other big change is that, this April, Canada ratified the International Convention for the Control and Management of Ships’ Ballast Water and Sediment. The convention largely governs ballast water exchange and sets out minimum standards, in effect entrenching what Canada has already begun to do. In the United States, responsibility for ballast water is shared by the EPA and the Coast Guard, which are still sorting out how to unify their regulations and enforcement responsibilities.

The good news is that the flushing system seems to be working. Since it became mandatory, there have been no proven introductions of new invasive aquatic species from ballast water. Still, it’s not a 100 per cent guarantee.

“It was a significant improvement, but it’s not good enough. Everyone across the board is researching new technologies,” says Nalbone. “Even though we say there’s a reduction in risk, it’s not okay to stop.”

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As a result, there will be an increasing need for systems to filter or treat ballast water. Since flushing at sea doesn’t get rid of every organism and egg, particularly those that hide in sediments, treatment may be required to fully protect the lakes.

“Despite the fact that we’ve seen quite a reduction in invasives, the regulations are becoming more stringent,” Dr. Euan Reavie told a gathering of invasive species researchers at the International Association of Great Lakes Research conference, held at the University of Toronto this May. He oversees a special facility to test ballast water treatment systems at the University of Minnesota, in Duluth.

A couple of systems exist with approvals under the Convention, including the PureBallast System from Alfa Laval/Wallenius Water AB in Norway, the SEDNA Ballast Water Management System from Degussa Gmbh (which uses Peraclean Ocean) in Germany, the Electro-Cleen System from Techcross Ltd. and Korea Ocean Research and Development Institute, the OceanSaver Ballast Water Management System (OS BWMS) from MetaFil AS in Norway, and the NK-O3 BlueBallast System (ozone) in Korea. But, as Nalbone points out, they have not yet been tested in freshwater or approved for use in Canada and the United States.

Systems must be tested on land before they can be considered for on-ship use. Reavie’s facility is providing that testing in North America.

There are basically three options, chemical (chlorine, lye, ozone or menadione for instance), physical (filtration, UV, sonic), and biological products such as BallaClean, a yeast that removes oxygen.

“We’ll probably see something that’s a combination of these,” Reavie says. His facility is testing each system’s ability to kill the organisms that naturally occur in the harbour—species that can survive in fresh water.

Not surprisingly, ship owners are reluctant to shell out for treatment systems, which could cost anywhere from $600,000 to $36 million per ship, until the regulations and approvals are finalized.

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Inside the lakes

Saltwater ships have been the focus because they introduce species to the watershed. Lake carriers that travel within the great lakes may also help spread invasive species once they’re in the waterway, but have been a lower priority.

Zebra mussels and their heartier cousins, the quagga mussels, have been the subject of a great deal of study since their introduction. A new study from the Great Lakes Genetics Laboratory at the University of Toledo, shows that the mussel populations in North America didn’t all come from the same place. The zebra mussels came from northern Europe and the Baltic Sea, while quagga mussels came primarily from the Southern Bug and Dnieper rivers.

What’s interesting about the study, other than that it confirms that each mussel species came from multiple introductions, is that it suggests transportation between the lakes may have been less significant than previously thought. Populations in the upper and lower Great Lakes are genetically distinct, for example. And those in the west are related to those in the eastern Great Lakes, suggesting that boater education programs need to be more widespread.

Requirements for ballast water flushing were an important first step, says Nalbone. And evidence that the flow of species into the Great Lakes has slowed is “exciting.” Technology regulations and treatment research are also steps in the right direction, she says. Today, the emphasis is on standardizing regulations and overcoming hurdles in the certification process for treatment technology.

Despite all these positive steps, “we can’t let our guard down,” she says. And there’s only one guarantee: the regulatory landscape will likely be as different a year from now as it was two years ago when we pulled round gobies out of the Lake Erie catch.  WC

Craig Saunders is a writer and editor based in Toronto.

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