Separation AnxietyBy Chris Landers
Published: June/July 2013
The Chicago waterways are a path for invasive species, but for the Mississippi and Great Lakes watersheds, breaking up is hard to do.
On a cold day in January 1900, a group of prominent Chicagoans gathered quietly at an earthen dam. The crowd, which started out as a few friends and trusted newspapermen, grew to about 100 as the men, trustees of the Chicago Sanitary and Ship Canal, broke through the ice and dirt separating the Mississippi and Great Lakes watersheds. They labored with dynamite, shovels, and a large dredge, keeping an eye out for the arrival of a threatened injunction from the Supreme Court. In the end, the water arrived before the litigation. They had reversed the flow of the Chicago River.
Half a century later, the Chicago Area Waterway System was named one of the seven wonders of the modern world by the American Society of Civil Engineers. "It was a tremendous feat of engineering, and it was the right thing to do 100 years ago. It has served the city of Chicago well," says Tim Eder, executive director of the Great Lakes Commission. Eder is one of a new group of civic leaders who are trying to solve a different problem — how to make the water stop. The solution to that problem could have a huge effect on the environment and on vessel traffic, both commercial and recreational. But, in the face of the environmental challenges of separating the watersheds, the effect on boaters gets little attention. "We knew there would be a need to lift boats over a barrier," Eder says. "We also know that such lifts and machinery exist. But we didn't spec out any particular apparatus. Frankly, while recreational boats are a very significant and important user of the waterway, it's not nearly as challenging to get recreational boats up and over a divide or through a lock as it is for commercial transportation [barges] and commercial goods."
Michael Ahart is news editor for Dozier's Waterway Guides, where he's been following the barrier story for the Great Lakes edition. Ahart says the plans he's seen are light on detail, but have the potential to affect a lot of boaters. "Not only do cruisers use the waterways for the Great Loop, or just for going south for the winter," he says, "but Lake Michigan boaters also take their boats inland through the Ship Canal to dry-dock them and get them out of the way."
The problem is one of unintended consequences. The canal that gave cargo barges access via the Illinois and Mississippi rivers to the Southern states, and Gulf of Mexico from the Great Lakes, also provided a path for invasive species to make the same trip in reverse. In 2002, an electrical barrier was installed downstream from Chicago to stop the round goby, an invasive fish, from spreading downstream from the Great Lakes. The goby had different ideas, though. It had established a home in the Mississippi watershed three years earlier. The goby, it turns out, have good and bad points. While they can spread botulism, they also eat zebra and quagga mussels, fellow invasive species.
But it's difficult to find as much of a silver lining in the invader currently making its way back up the pipeline. The electrical barrier, which arrived too late to stop the goby, has been repurposed to stop Asian carp from entering the Great Lakes. The fish have been dive-bombing boaters on the Illinois and Mississippi rivers, and destroying aquatic ecosystems on a march toward Lake Michigan for about 10 years now. The Army Corps of Engineers has undertaken a massive study of the problem, but with the specter of the damage carp could do to Lake Michigan, public patience in the Great Lakes region has worn thin. Last year, the Great Lakes Legislative Caucus, composed of lawmakers from the States and Canadian provinces bordering the lakes, sent a letter to the Corps urging them to hurry it along. The current deadline for the Great Lakes Mississippi River Interbasin Study is the end of 2013, but the Corps has already predicted that it won't be done in time.
The legislative caucus, in their letter, urges the Corps to take a good look at another study by Eder's Great Lakes Commission, which recommends what many see as a definitive solution for the carp problem, as well as any other invaders that may try to jump watersheds in the future: Cut the link once and for all. The plan has the advantage of finality, but it comes with its own unintended consequences. In fact, it could put a crimp in America's Great Loop.
"There's a real sense of urgency," says Eder. "We have a crisis on our hands. If the Asian carp get into the Great Lakes, it's going to put a real dent in boating, fishing, and recreation." Eder says his group looked at three schemes for separating the watersheds, ranging from a single barrier some 30 miles downstream to five barriers next to Lake Michigan. "The solution that turned out to be just right is in the middle, with four barriers."
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Asian Carp Kryptonite
As anglers grapple with the specter of Asian carp knocking on Lake Michigan's doors, it's worth revisiting the story of another Great Lakes invader, now kept in check for more than 60 years, the sea lamprey. In the 1950s Great Lakes fishermen looked at the sea lamprey with about the same disdain current anglers have for Asian carp. The difference is, the sea lamprey got into the Great Lakes when no one was watching and devastated native fish as it spread. With its suction-cup mouth and barbaric ring of teeth, the eel-like creature can leech the life out of an average-size lake trout or whitefish in about seven days, and kill about 40 pounds of fish in its lifetime.
According to Dr. Marc Gaden, with the Great Lakes Fishery Commission, although the lamprey had always been present in Lake Ontario and the St. Lawrence River, it entered the rest of the lakes around 1920 with the expansion of the Welland Canal that connects Lake Ontario and Lake Erie. By the 1940s its population had exploded in all of the upper Great Lakes. "One lesson we've learned with the sea lamprey is that just one species or one invader can have a serious impact on both the ecosystem and the economy," said Gaden.
Over the next 20 years, fish specialists and biologists worked tirelessly to find a way to stop this invader. Their hard work paid off with the discovery of TFM, a chemical that selectively kills sea lamprey larvae while in spawning streams. Although lamprey may one day develop an immunity to the lampricide, or opt to spawn in the deeper lake waters where treating the larvae would be difficult, this method has reduced the population by 90 percent and kept it in check for more than 40 years. So as Great Lakes anglers and fishery managers contemplate the prospect of another potential invader, the past may provide hope. If the malevolent lamprey could be tamed by the dogged work of biologists, then maybe they'll find the Asian carp's kryptonite as well.