Fight to protect Lake Michigan and the Great Lakes from invasive species pays off

Asian carp, startled by an electric current from a research boat, jump out of the Illinois River near Havana, Illinois.
Associated Press archive photo

Lake Michigan is one of the state’s most significant recreational resources, one of its largest economic contributors, and the state’s largest source of public drinking water – benefits that suburban residents enjoy.

That’s why local governments, environmentalists and conservationists keep a constant eye on invasive species that could destroy the ecosystem and invade Lake Michigan, despite all efforts over the past decades to contain potential invaders.

Since 2006, the number of new invasive species entering the Great Lakes has declined by 85%.

While these statistics suggest a global success story, they also reflect the endless efforts to keep new invaders at bay. And as climate change warms the lakes, the number of freshwater species that can ultimately survive in the interconnected waters is only increasing.

“Fighting invasive species is very similar to dealing with a pandemic like COVID,” said Scott Sowa, Great Lakes program director at The Nature Conservancy. “It’s almost identical, so prevention is key.”

Since the 1990s – “when people really became aware of the impacts of invasive species,” says Sowa – the focus has been on combating the various vectors through which invasive species are introduced.

These include recreational boating, the live pet trade, and connected channels such as the Chicago metropolitan area waterway system. One area where significant progress has been made is the monitoring and regular treatment of ballast water, or the water stored in the hull of a ship for added weight and stability.

But some invasive species – similar to COVID-19 – survive these preventive measures without exception.

“We want to flatten the curve, but we also need to focus on early detection and rapid response and then ultimately control where we can,” Sowa said. “Because if you can detect a species early, and just like you can detect the virus early, you’re more likely to be able to contain it and potentially eradicate it.”

Given the size of the Great Lakes, discovering an invasive species is “like looking for a needle in a haystack,” Sowa added.

Groups like The Nature Conservancy are using tools like environmental DNA and optimized monitoring systems to help find the needle. They are also testing new ideas like selective passage, which would prevent the spread of invasive species while allowing native species.

“It’s funny that in the past we created connecting channels that removed natural barriers between the Great Lakes basin and other basins. Now we’re trying to build barriers to restore those blockages,” Sowa said. “But in some cases that also prevents the movement of native species, and that’s why we need to focus on selective passages.”

Selective passage would be particularly beneficial in the Mississippi and Illinois rivers, where barriers prevent invasive carp from entering the Great Lakes. For example, the last line of defense between the Mississippi and Lake Michigan is an electric barrier in Romeoville.

Invasive carp entered the Mississippi River basin during floods in the 1970s and 1990s after being imported from Southeast Asia to help with wastewater treatment and aquaculture. Since then, the voracious eaters and breeders have migrated into the Illinois River, causing severe damage to native fish populations.

Strategies like Romeoville’s electric barrier designed to keep fish from entering the Great Lakes offer protection, “but they’re not foolproof,” says Molly Flanagan, an invasive species expert and vice president of programs at the Alliance for the Great Lakes.

To better protect the carp from the current, Flanagan said, a project is currently underway at the Brandon Road Lock and Dam in Joliet. The $1.14 billion project would be what Flanagan calls a “fish challenge,” complete with a bubble barrier, an electrical barrier and underwater acoustics.

If approved, the project would be funded by the federal government and the governments of Illinois and Michigan, with the federal government covering 90 percent of the cost.

“When you think about the Great Lakes economy, the jobs and businesses that support it, the damage that invasive carp could do if they get into the Great Lakes is in the billions of dollars,” Flanagan said. “They say prevention is better than cure, and that really is true in this case and with all invasive species. It’s much easier and cheaper to keep them out than to try to control them once they’re here.”

• Jenny Whidden, [email protected], is a climate change and environment writer who works with the Daily Herald as part of a partnership with Report For America, supported by The Nature Conservation Authority. To Support their work with a tax-deductible donation, see dailyherald.com/rfa.

A scientist at the Hammond Bay Biological Station near Huron Beach, Michigan, holds a female sea lamprey. The Great Lakes have endured a lot over the past century, from oversized clumps of algae to invasive mussels and bloodsucking sea lampreys that have nearly wiped out fish populations.
Associated Press archive photo