Quadrillions of invasive mussels are damaging the Great Lakes, documentary shows

Yvonne Drebert and Zach Melnick love the Great Lakes. The married documentarians live on the Bruce Peninsula, which is on Lake Huron in Ontario and has similar terrain to Wisconsin’s Door Peninsula: limestone cliffs, cedar trees and lake vistas.  

So, when the two learned about the massive drop in lake whitefish populations, they knew they wanted to make a film about it. Whitefish are one of the most important commercial Great Lakes fish, and they hold significance for Indigenous people of Canada and the U.S.

They wanted to go deep — literally.  

The resulting three-part series, “All Too Clear: Beneath the Surface of the Great Lakes,” uses cutting-edge underwater drone technology to capture life hundreds of feet below the surface of the world’s largest freshwater ecosystem, resulting in what the filmmakers believe to be the first shots of whitefish spawning in the wild. 

“We wanted to bring whitefish to life,” Melnick told WPR’s “Wisconsin Today.” 

Even though whitefish are an important species, people have a hard time picturing them, he added.

“If we sort of close our eyes and imagine it, we’re much more likely to imagine … tuna in the ocean than we are whitefish in the Great Lakes, even if we’re Great Lakes people,” he said. “So, we really wanted to use the underwater drone technology to take us into the world of the lake whitefish and film as much of their life cycle as we could.”

Since the late 1990s, the lake whitefish population has declined as much as 80 percent in parts of the Great Lakes. The culprit is a tiny invasive species called the quagga mussel, a close relative of the infamous zebra mussel. Both species are native to eastern Europe and traveled to the U.S. on ballast water in the 1980s.

The quagga mussel has infiltrated the lowest level of the Great Lakes’ food chain, eating tiny phytoplankton that algae need to grow — and the reverberations are felt throughout lake ecosystems. Microscopic creatures called zooplankton don’t have enough algae to eat. Small prey fish and baby fish don’t have enough zooplankton to eat. In turn, the large fish who do manage to make it to adulthood often lack adequate food. 

The scale of the invasion is enormous. Not millions, not billions, but quadrillions of quagga mussels now populate all of the lower Great Lakes. 

“All Too Clear” features many shots of lakeshore bottoms carpeted with quagga mussels, with nothing else around as far as the eye can see.

There are so many mussels and they are such efficient filter feeders that fewer than every two weeks the entire volume of Lake Michigan is filtered by them, resulting in clear, blue water that’s beautiful but inhospitable for many lake species.

The Great Lakes have tripled in clarity in the last three decades, Drebert said. UV rays penetrate depths they never did before, killing delicate embryonic and baby fish.

One of the scientists featured in the documentary is the University of Wisconsin-Milwaukee’s Harvey Bootsma, who has experimented with innovative, and at times scrappy, ways of killing quagga. That includes laying a large tarp over them and dragging what is essentially a handmade underwater bulldozer over the lake bottom.  

Scientists and environmentalists across North America are working to reverse the damage done in innovative ways. The scientists featured in “All Too Clear” breed baby whitefish and let them grow strong in a pond before releasing them into the lakes, attempt to engineer a contagious blood cancer to transmit to quaggas, rebuild reefs where trout and whitefish spawn, and more. 

Bootsma is “one of the people that is out there every day doing everything he can to try to figure out how we can manage these mussels to help our native species make it through this really tough time,” Drebert said.

“Africa has the Sahara, we’ve got the ice in the Arctic. We here in North America, we’ve got the Great Lakes. And it’s something that we really do need to treasure and protect the best we can,” she added.

The documentary is only available in Canada for now, with the exception of some U.S. film festivals.