LELAND — Sleeping Bear Dunes National Lakeshore is playing host to an underwater research laboratory.
The scientific goal is to find a way to better manage invasive zebra and quagga mussels that have infested Great Lakes waters, particularly in natural rocky reef habitats. The project involves divers who build underwater containment areas with poles and plastic tarps, so they can treat mussels collected on an offshore reef in Good Harbor Bay.
The hope is the invasive mussels will die and the area won’t recolonize.
Several treatments took place in recent weeks and researchers will begin to check results of the effort in coming days.
“It’s sort of wait and see on the effects and how much mussel mortality we were able to achieve,” said Erika Jensen, program manager with the Great Lakes Commission.
North America’s freshwater inland seas have experienced a pervasive invasive mussel problem for the last three decades, introduced through the ballast waters of ocean-faring ships. First zebra mussels had a population surge in the Great Lakes, then the quagga mussels took over when the zebra mussels diminished.
Aquatic ecologist Matt Herbert, with nonprofit The Nature Conservancy, recently said during a talk on Old Mission Peninsula that quagga mussels are the bigger threat at this point. That’s because they can live in soft sand and don’t need a hard surface to which they must attach, like zebra mussels require.
Herbert said the overall big impact is how invasive mussels change the entire water column, concentrating nutrients on the lake bed. That effects the fishery food chain, he said.
Meanwhile, the research happening in Good Harbor Bay is one of several projects in the Great Lakes to find the best ways to manage the invasive species.
Julie Christian, chief of natural resources at the national park in Benzie and Leelanau counties, said the work started in 2016 when divers hand-removed invasive mussels from a 430-square-foot zone on the same reef.
It was “very heartening” that the area has not recolonized with mussels, but that removal process was far too laborious, she said.
“It was a positive sign that if we can get rid of the mussels, there’s hope we can restore the reef,” Christian said.
There were other notable outcomes on the reef when the invasive mussels disappeared after hand-removal, including a shift in the water content from abundant claudophora to diatom algae instead.
Claudophora is the algae connected to avian botulism outbreaks that kill fish, shorebirds and also mammals that eat carrion on the beach. Diatom is a type of micro-algae with a natural place in the Great Lakes food chain.
“It’s shifting it away from claudophora and toward a better food source for fish,” Christian said.
Mark Breederland, educator at Michigan Sea Grant Extension in Traverse City, said the work offshore at the dunes is a key part of ongoing food-web research for Lake Michigan.
“This Good Harbor geographic area has been impacted with avian botulism, when the native bacteria germinates and produces one of nature’s most potent toxins and passes on up the food web killing waterfowl that are migrating through the region — loons and lots of species of diving ducks,” Breederland said.
The study underway builds off the success of that prior project, Jensen said.
It involves the application of an inert, or dead, bacteria in a compound called Zequanox, a molluscicide designed to target zebra and quagga mussels without affecting native mussel species. The compound disrupts the invasive mussels’ ability to consume nutrients and they eventually die.
Christian said treatment requires areas on the reef kept beneath plastic tarps up to about 8 hours so the concentration of the molluscicide injected into a containment area’s water is maintained until the material eventually degrades.
Early observations show some success, she said.
Jensen said this project is the first time the method has been applied on a coastal reef.
In 2017, officials with the Tip of the Mitt Watershed Council also conducted an invasive mussel research project. It involved Zequanox, too, but not within a contained underwater zone.
“Our study was the first open water application, so not including some kind of barrier under the water,” said David Edwards, monitoring and research director for the Petoskey-based nonprofit organization.
That project took place at Round Lake, found between Petoskey and Harbor Springs along the Inland Waterway which connects to Lake Huron in Cheboygan.
“We didn’t see any significant decrease in the mussels’ population numbers,” Edwards said.
Officials said they hope the new underwater cocktail being used this summer in Lake Michigan finds more success.
The research effort falls under the umbrella of the Invasive Mussel Collaborative, a joint project of the Great Lakes Commission, Great Lakes Fishery Commission, National Oceanic and Atmospheric Administration and the U.S. Geological Survey.
More information is available at invasivemusselcollaborative.net online.