Every five years, Lake Michigan is the focus of intense research and monitoring when scientists come together to answer critical questions and fill information gaps. A report summarizing the results of the 2015 data collection on the lake is now available.

Each year since 2002, through the Cooperative Science Monitoring Initiative (CSMI), multiple federal, state, and university scientists gather on one of the Great Lakes to take part in coordinated research. CSMI is a binational program organized through the U.S. Environmental Protection Agency Great Lakes National Program Office and Environment and Climate Change Canada.

“CSMI provides an ideal opportunity for scientists to work collaboratively to tackle complex questions in the Great Lakes,” said David “Bo” Bunnell, a researcher with U.S. Geological Survey. “For example, to understand whether changes in plankton are affecting larval fish, given the size of Lake Michigan and the frequency of sampling required, collaboration among agencies offers the best opportunity to enhance our knowledge and inform managers.”

In recent years, Paris Collingsworth, Illinois-Indiana Sea Grant Great Lakes ecosystem specialist and Purdue University researcher, has provided leadership in collaboration with EPA scientists, defining critical questions and coordinating research efforts of various agencies for large-scale studies. He works with the lake partnerships for each lake as they define research priorities, and with scientists as they set up studies and analyze data. He is also helping coordinate Great Lakes Sea Grant programs to develop CSMI outreach products to share research results.

The 2015 Lake Michigan field-year priorities included learning more about the nearshore conditions and the movement of nutrients and organisms offshore, the effect of nutrient loading on water quality, the health and status of the lake’s lower food web, and the movement of contaminants through the food web.

Quagga mussels featured prominently in the key findings of the compiled research results. The researchers found that in mid-depth regions of the lake, where most of these invasive mussels are, their numbers have declined, but their biomass has increased—the mussels are getting bigger. Meanwhile, in deeper parts of the lake, quagga mussel populations continue to expand.

“As quagga mussels filter water, they remove nutrients, bacteria and phytoplankton from the lake, which means that resources at the base of the food web that would have been available under pre-invasion conditions are now bound up in the quagga mussel,” said Collingsworth. “Quantifying the effects of these mussels on energy flow throughout the lake is an important concern for the management community of Lake Michigan.”

In the open waters of the lake, studies revealed that larval fish are growing about half as fast as they did before quagga mussels were established in the early 2000s. In fact, fish data suggest that nearshore areas, and potentially the entire Lake Michigan ecosystem, may not have a sustainable food supply.

The news is better from studies on contaminant levels. The results suggest that efforts to reduce contaminants in Lake Michigan are meeting or exceeding their goals. For example, scientists looked at concentrations of atrazine, a herbicide commonly used in agriculture, and PCBs, a group of industrial chemical banned since 1979, but still present in the lake. In monitored locations, they both are declining faster than predicted.

The CSMI monitoring on Lake Michigan also provided an opportunity to use advances in technology to answer complicated questions. For many decades, devices known as Ponar dredges have been lowered to the lake bottom at a series of single points to capture and bring up bottom-dwelling animals. In 2015, this work was supplemented with a camera attached to a benthic sled that recorded video of the lake bottom.

“The traditional method is still necessary to examine individual animals to learn how they are growing, or the makeup of their DNA,” said Carolyn Foley, IISG research coordinator. “However, the sled sampling gives a much broader picture of exactly where animals are, and in what numbers. Using both sampling techniques can help scientists get a much better picture of exactly what is happening 60 to 900 feet below the surface of Lake Michigan.”

As the CSMI cycle continues, planning has begun for the 2020 Lake Michigan field season. To begin this process, in October, about 60 Lake Michigan federal, state, university and tribal scientists as well as managers met in Milwaukee, Wisconsin to reflect on past research outcomes, explore scientific gaps, and suggest future research areas. The workshop was facilitated by IISG and sponsored by the International Joint Commission.

You can find the CSMI 2015 Lake Michigan Report, including the executive summary and the compendium of research project results, on the IISG website. IISG specialists are also creating an Esri Story Map, which will use an interactive approach to describe the research results.

A collaborative research project about the impacts of quagga mussels in Lake Michigan has led to more funding for the issue from the National Science Foundation (NSF). The original project, jointly supported by the Illinois-Indiana and Wisconsin Sea Grant programs, looked at the effects of this invasive mussel in the deep parts of Lake Michigan on plankton abundance, the phosphorus cycle, and water movement.

Harvey Bootsma

The new project is funded by the Biological Oceanography and Physical Oceanography divisions of NSF for more than $1 million with the expectation that the results will be useful in understanding conditions in other large lakes as well coastal areas.

The principal investigators are Harvey Bootsma and Qian Liao with the University of Wisconsin-Milwaukee,

and Cary Troy with Purdue University. David Cannon is a Ph.D. student working on the project at Purdue.

In the original project, the team discovered that quagga mussels in Lake Michigan are eating more plankton than what is reaching them by sinking from above. They’ll be looking at how and why this could happen with the new project.

“We think that food delivery to the bottom of the lake is not just determined by the passive settling of phytoplankton as it’s sinking through the water, but that

Cary Troy

plankton is always being circulated in the lake,” said Bootsma. “It’s like the plankton are on a kind of conveyor belt where they’re going up and down.”

The researchers now will be studying turbulence in the entire water column.

Troy studied the impact mussels have on water movement as they filter it—sucking in water and spitting it

out. “Although this filtering has a dramatic effect on water quality, we found that quaggas do not strongly influence movement throughout the entire water column,” explained Cannon.

But the movement they cause in the thin layer immediately above the lake bed—a

Qian Liao

phenomenon consistent throughout the year thanks to stable temperatures at the bottom of Lake Michigan—is an element missing from most mussel filtration models.

The researchers also found that the mussels are changing the phosphorus cycle in the lake. “The nutrient-loading models used to set limits for phosphorus aren’t accurate anymore because of these new components to the ecosystem – bottom-dwelling filter feeders,” Bootsma said. “They have changed the rules for how Lake Michigan works.

David Cannon

“Lake managers have a conundrum right now. They’ve got too much algae in the nearshore zone and they want to reduce phosphorus to solve that problem. But there’s not enough phytoplankton in the offshore zone because of the mussels. So if they reduce phosphorus loading in the lake, they could make that offshore problem even worse so that there’s virtually no food left out there for the rest of the food web,” Bootsma said.

With the new project, Bootsma said his team hopes to determine what the “sweet spot” is for phosphorus loading. “There may not be one perfect phosphorus load that solves both the nearshore and offshore problem, but we’d like to try and find one that minimizes the nuisance algae while at the same time keeps the offshore animals alive with enough plankton production.”

The NSF project will start this spring. “Although we’re focusing on Lake Michigan, the work has implications for most of the other Great Lakes as well as other lakes in general that are being invaded by mussels,” Bootsma said. “We’re looking at a fundamental change in the way lakes work, and that’s the kind of thing the NSF is interested in.”

“It’s generally accepted that the ecosystems of smaller, shallower lakes—Lake Erie, for example—are at the greatest risk of quagga mussel invasion,” Cannon added. “Our results could help show other researchers that the effects of mussels on large, deep lakes cannot be ignored and, more importantly, how they can be accounted for.”

Irene Miles, IISG coordinator of strategic communication, contributed to this post.

Illinois-Indiana Sea Grant is a part of University of Illinois Extension and Purdue University Extension.

“Some good and long-awaited stormwater news quietly dropped the other day—a federal judge approved the Metropolitan Water Reclamation District of Greater Chicago’s (MWRD) Consent Decree, which is a binding agreement detailing very specific steps MWRD will take to move toward full compliance with the Clean Water Act and other federal guidelines on an equally specific timeline. There has been and will continue to be debate about whether the Consent Decree is strong enough, fast enough or green enough. But the reality is that it is now in place, and I’m excited that we can finally get to work on something, rather than sitting around waiting. I don’t read too many court rulings, but I found this one quite scannable.  

 

MWRD, of course, is responsible for wastewater and stormwater management throughout Cook County; on a daily basis it discharges treated effluent to area waterways, and that water must meet Clean Water Act standards. The same requirements hold true in storms, and that’s where most of the impetus for the Consent Decree lies: If there is more rain more quickly than MWRD’s infrastructure system can handle, the result is overflows of untreated wastewater and stormwater into those same waterways…resulting it MWRD being out of compliance with aspects of its Clean Water Act (and associated regulation) requirements. To be fair, many other metropolitan areas have the same problems, and as a result have their own Consent Decree in place. Several years ago MWRD, the U.S. Environmental Protection Agency and the Ill. Environmental Protection Agency began working out the requirements—finish the Tunnel and Reservoir Plan (TARP) by X, improve collection of ‘floatables’ in our waterways by Y, etc. When the draft Consent Decree was released for public comment, two separate coalitions of environmental organizations opined that the whole thing should be faster and greener. A federal judge was asked to determine if the requirements were reasonable, that went on for a bit, he decided they were, and now it’s what we have to work with, so let’s get to work.”

“Over the last decade or so, a huge range of interests — from environmental groups to fishermen to shipping experts to politicians — have raised the alarm over just how much this artificial connection has created an opening for invasive species such as the Asian carp to make their way through North America’s waterways. And the costs associated with the damage caused by these species have been high enough to prompt serious consideration of closing off the link between the Mississippi and the Great Lakes.

 

How high? First, consider the figure $18 billion. That’s the estimate the U.S. Army Corps of Engineers released last week to re-insert a physical separation between the Great Lakes and the Mississippi system. The full report, the Great Lakes and Interbasin Mississippi River Study, was commissioned by Congress to address the growing threat of invasive species in the area known as the Chicago Area Waterway System. The final report details a wide spectrum of actions — ranging from essentially maintaining the status quo to engineering a complete separation over a 25-year period — but doesn’t offer recommendations on which course to take.”

Towards the beginning of the school year, my class spent about a month on our “Aquatic Habitats and Biodiversity” unit. After exploring the general nature of aquatic systems (both marine and freshwater), we took a closer look at our local water systems, specifically Lake Michigan. During this time, we discussed the history of the Great Lakes, identified the various ways in which humans have used and altered the makeup of the Great Lakes, spent two days conducting water-quality testing and macro-invertebrate sampling (using both biotic and abiotic indicators to compare water quality in various tributaries to that of the mouths in which they fed into Lake Michigan), and debated plausible methods to prevent invasive species such as the Asian Carp from entering the Great Lakes. 

 

Throughout this entire unit, I found myself regularly referencing experiences I had during the Lake Guardian summer workshop. The experiences not only allowed me to better explain the complexity of some of these issues, but it also opened my students’ eyes to hands-on opportunities available in the world of science. It taught me a great deal about the Great Lakes, but, more importantly, it improved my ability to teach students about the Lakes’ significance. I hope this program continues to be funded for years to come as it is a wonderful way of spreading both knowledge and passion regarding the importance of preserving the gift that is the Great Lakes.

“To help combat the invasive, eel-like fish, Gov. Scott Walker signed legislation on Thursday for the state to spend up to $564,500 in the next two fiscal years on lamprey control efforts on Lake Michigan and Lake Superior.

 

The controls include chemical treatments and barriers that block the movement of swimming lamprey, which according to the Wisconsin DNR ‘have no jaws, no true teeth, no paired fins and a skeleton made of cartilage, not true bone.’

 

The state funds are expected to be matched with federal dollars for control efforts that are taking place across the Great Lakes basin.

 

In Lake Michigan, 126 of 511 tributaries have historic records of sea lamprey production. Of those 83 tributaries have been treated with chemicals, according to the Fish and Wildlife Commission. A major focus of treatment took place on the Oconto River in northeastern Wisconsin, where about 60 miles of the river were treated.”