Restoring Great Lakes reefs brings back spawning grounds

February 29th, 2016 by

There are reefs in the Great Lakes?

That was my first thought when I sat down to interview for a field technician position in the fall of 2014. I had been working at a tech job at Purdue University, but I felt that it was time for a change–to something that was a bit more interesting to me. When I had the chance to interview to be a field tech on a fish ecology project, I knew that the time for change had arrived. But working on reefs? Coral, colorful, vibrant reefs teeming with a spectacular array of exotic fish species? I asked the post-doctoral fellow conducting my interview, Dr. Mitchell Zischke, if those were the kind of reefs he was talking about.

“Not quite,” said Mitch. “Reefs in the Great Lakes are rocky, made of cobble, gravel, and other stony fragments.” Ah. That’s very different than the vision most people get when they think of underwater reefs. A lot of publicity is directed towards oceanic coral reefs and their current plight worldwide, and rightly so. But I think sometimes that comes at the expense of exposure to unique and threatened environments much closer to home. The reef systems of the Great Lakes are a prime example.

I say this based on my own experiences as a native of the Great Lakes region. I grew up in a small town in western Michigan, right on the shores of Lake Michigan. My family often traveled around the state, spending time at all of the Great Lakes. Yet I never heard mention of any rocky reefs. I’d wager that outside of die-hard fishermen, most citizens of the region haven’t been exposed to our local reefs, either. Going forward, I’m hopeful that a lot of exciting research on the Great Lakes is about to change that fact.

That’s how my current project fits into all of this. It turns out that I liked being a fisheries ecology technician enough that it led directly into graduate school at Purdue University. I am now a Master’s student under the guidance of Dr. Tomas Höök, associate professor at Purdue and associate director of research for Illinois-Indiana Sea Grant. Along with many other organizational partners (including Michigan Sea Grant, Michigan Department of Natural Resources, Michigan Department of Environmental Quality, U.S. Fish and Wildlife Service, and the United States Geological Survey, to name a few) we are in the beginning stages of potential rocky reef restoration in Saginaw Bay in Lake Huron.

DuckReef cropped

To understand why reef restoration in Saginaw Bay is a good idea, a little historical background is important. Years ago, Saginaw Bay was the second largest walleye fishery in all the Great Lakes, and had a healthy population of fish spawning on rocky reefs in the bay. These reefs provided many benefits to incubating eggs, including excellent protection from predators. Long-term sedimentation and poor land use led to most of those reefs being lost. This had profound negative impacts on walleye, as well as on other recreationally- and commercially-important fish species. Today, the walleye population has recovered, but the fish spawns almost completely in tributary rivers that feed into Saginaw Bay, rather than the bay itself. Reef restoration would allow walleye to have prime spawning habitat in the bay once more, and hopefully encourage these fish to resume using some of their historic spawning grounds. Beyond the obvious benefits to an increased amount of spawning area, this would also pave the way for a more geographically- and genetically-diverse walleye population. Such diversity could prove very important during times of stress. Of course, many other fish species, such as lake whitefish, would also be able to use restored reefs.

Nick Kalejs 2

However, before rocky reef habitat could be restored in Saginaw Bay, we needed to make sure that restoration would have a good chance of being successful. Restoration projects are never cheap, and we wanted to be sure that funding was being wisely spent. That’s where my specific project comes in. A small field crew, comprising members of Purdue University (including me, Dr. Zischke, and Jay Beugly, who also serves as an aquatic ecology specialist for Illinois-Indiana Sea Grant) and the USGS, was tasked with assessing current spawning patterns within Saginaw Bay. Essentially, we wanted to see what currently degraded reef sites looked like, whether key species like walleye and lake whitefish were spawning near those degraded sites, whether they were depositing eggs, and whether predators were around to eat those eggs. If we could say that water quality was decent, target species were spawning in the area and depositing eggs, and that egg predators weren’t too abundant, we might have a reasonable shot at successful reef restoration.

NorthIsland cropped

We’ve been at it since late 2014, and though results are still preliminary, there are some positive signs. Water quality is good, and some sites look receptive to adding additional reef structure. Spawning walleye and lake whitefish are being found across the bay, and they’re depositing eggs, too. Numbers of fish and eggs are low, but the fact that fish exist to take advantage of potentially restored reefs is hugely important. We’ve also found that egg predators are present, but that the biggest predation risk is probably from large-bodied fish like common carp and catfish. Given these findings, we are optimistic that rocky reef restoration can be successful in Saginaw Bay. Hopefully, restored reefs will attract higher numbers of fish to spawn, while simultaneously providing cracks and crevices to help eggs avoid large egg predators.

If everything goes right, reef restoration in Saginaw Bay could be going on long after I’ve left Purdue. Really, I think that’s one of the coolest things about this project: It has so much potential. With many groups involved, like Sea Grant, and tons of habitat to restore, reef restoration could be the definition of a long-term undertaking. Who knows, maybe I’ll find myself back on the familiar shores of Saginaw Bay one day, working once more on a project that helped launch what I hope will be a long career in fisheries science. For now, I’m just focused on the upcoming field season. It’s the last chunk of field work in our spawning assessment. If we keep finding some of the same patterns, I’m very excited for the future of reef restoration in Saginaw Bay and across the Great Lakes.

Cure to TB may be living at the bottom of Lake Michigan

March 24th, 2015 by
Scientists at the University of Illinois at Chicago have unearthed a species of Lake Michigan bacteria that may become a powerful weapon in the fight against tuberculosis. Found in the sediment off the coast of Milwaukee, the microbe’s medicinal power lies in the small compounds it makes to defend itself. 

UIC researcher Brian Murphy and colleagues at the College of Pharmacy are still trying to pin down how the molecules attack the M. tuberculosis bacterium, but they know that the compounds display drug-like potency against a range of antimicrobial-resistant strains that rivals existing clinical treatments.
This study is part of a larger effort by Murphy and others to determine the disease-fighting potential of aquatic actinomycete bacteria. Current treatments for many diseases are built around the chemical defenses used by land-based bacteria, but a growing number of pathogens are now resistant to standard drugs. Results like these in Lake Michigan suggest that freshwater bacteria may create molecules that dangerous pathogens have yet to evolve defenses against, making the Great Lakes a potentially untapped reservoir of treatments for some of the world’s deadliest diseases.  
To understand the potential of the lakes, Murphy has collected more than 600 strains of freshwater actinomycete bacteria with support from an IISG Discovery Grant. The size and diversity of the library will help reveal both whether these bacteria are significantly different than their land-based cousins and if strains found in different lakes produce unique chemical defenses.


This analysis is still underway, but Murphy and his team have already discovered that the makeup of actinomycete communities in Lake Huron varies both by location and depth, a diversity that makes the lake a potentially important site in the hunt for new cures. 

In the news: Lake levels look to get back on track

April 17th, 2014 by
With the big spring thaw underway (mostly) and warmer weather on the way, Lakes Michigan and Huron are on track to get closer to their long-term water levels than they were last summer. 
“Water levels on Lake Michigan- Huron typically rise from March through July. Lake Michigan- Huron has risen one inch since early March, but is 13 inches higher than this same time last year. Although the above two lakes are higher, they are still 16 inches below the long term average for this date.
The rise in the lakes in the past month was the result of melting snow. Precipitation didn’t help much to the rise in lake levels, as March was fairly dry. The dry pattern in March was good for helping Michigan avoid major flooding. However, heavy rain would have really boosted lake water levels. March precipitation over the Lake Michigan-Huron drainage basin was only 1.49 inches, which was 69 percent of normal.”
Read more about the projected lake levels for this summer at the link above.

In the news: Lakes Michigan, Huron on the rise

March 11th, 2014 by
Water levels in the Great Lakes, especially the Lake Michigan and Huron combo, have been a concern in recent years. But with this winter’s heavy snow and ice coverage, the water levels of both lakes may rise as much as 14 inches this spring and summer. 
“This winter, the abundance of snow and near-record ice cover are the reasons for the rebound in water levels, according to Keith W. Kompoltowicz, a meteorologist with the Corps’ office in Detroit.
Snowfall around Lake Michigan is 30% higher than any time in the last decade, and ice cover on the lake is flirting with a record.
On Tuesday, ice on Lake Michigan reached 92.45%, according to the Great Lakes Environmental Research Laboratory in Ann Arbor, Mich. That’s the second highest level since the record of 93.1% in 1977…
But the winter of 2013-’14 can only have so much effect on the lakes. Water levels are cyclical and rise and fall due to a series of events over many months and years, Kompoltowicz said.
Even if the next six months mirrors the rainy spring of 2013, Kompoltowicz said, Lake Michigan and Lake Huron might reach within a few inches of the lakes’ long-term average. The Corps doesn’t make predictions beyond six months.”
Read more about the lake levels and the potential effects at the link above.

Great Lakes hold great potential for curing diseases

January 22nd, 2014 by
The cure for some of the world’s deadliest diseases may be living at the bottom of the Great Lakes. This is the theory Brian Murphy, a medicinal chemist at the University of Illinois at Chicago (UIC), set out to test in 2012 when he scoured Lake Huron in search of a largely unexplored type of bacteria that may hold the key to new treatments. 

The IISG-funded study unearthed more than 600 strains of freshwater actinomycete bacteria, making it one of the largest “libraries” of its kind in the world. Murphy—with help from UIC researchers Scott Franzblau, Joanna Burdette, and Lijun Rong—is still testing whether these strains can be used to create new treatments for tuberculosis and other life-threatening diseases. But their initial results suggest that at least a handful of freshwater bacteria could lead to new cures. 

A microbe’s medicinal power lies in the small compounds they make to defend themselves, which can destroy cell walls, prevent DNA from replicating like it should, and more. Current treatments for many diseases are built around the chemical defenses used by land-based cousins of the bacteria Murphy has collected. But some treatments, like the ones for tuberculosis, require patients to be on a complex cocktail of antibiotics for months at a time. Worse still, a growing number of diseases are now resistant to standard drugs. The hope is that some of the freshwater bacteria in Murphy’s library might create molecules that dangerous pathogens have yet to evolve defenses against.  


“Researchers have been operating on the assumption that bacteria in the lake are nearly identical to what are found on the land,” said Murphy. “But we think these freshwater strains are likely to produce new molecules that target diseases in different ways.”

Murphy and his team will spend the next few months scrutinizing chemical compounds from 10 actinomycete strains already showing disease-fighting potential and comparing them against known antibiotics, anti-virals, and anti-cancer agents. At the same time, they will keep working through their bacterial library hoping to find even more molecules with drug-like potency. 

Just as important as finding new molecules is learning more about the relationship between a microbe’s chemical properties and where it lives. This is where Murphy’s library of strains really comes in. Its size and diversity will help reveal both whether aquatic actinomycete bacteria are significantly different than their land-based counterparts and if strains found in different lakes use unique chemical defenses.


“One of the biggest barriers in the discovery of new drugs is knowing where to look,” said Murphy. “Knowing where bacteria populations are similar and where they are different helps us figure out exactly where to sample when looking for new drugs.”


Because of his collection, Murphy has already discovered that the makeup of actinomycete communities in Lake Huron varies both by location and depth, a diversity that makes the lake a potentially important site in the hunt for new cures.

In the news: October rains raise water levels in Lakes Michigan, Huron

November 7th, 2013 by

Following last year’s record low water levels in the Great Lakes, and in Lake Michigan and Lake Huron specifically, this year’s rains have helped push those levels back towards the historical average. 


“Heavy October rain could help Lake Michigan and Lake Huron continue to rise toward the long term average water level. Lake Michigan – Huron is still 15 inches below the long term average, but is 11 inches higher than this time last year. Slowly the lake level is increasing. The lake levels will likely fall over the next four months. This is a normal cycle. If the lakes don’t fall as much as normal this winter, the lakes are set up to be higher next summer than this summer…
All of this rain can help Lake Michigan – Huron not fall as much as usual in November.”
Read the complete article at the link above. 

Climate change on the Great Lakes touches all areas

August 22nd, 2012 by
Changes in weather patterns, such as warmer winters and lower rainfall averages, can have large effects on water availability, lake levels, plant and fish life, and more. Because so many people and industries rely on the Great Lakes, those changes can have a significant impact beyond the obvious, as is the case for the shipping industry. 
“For decades, the mathematics of waterborne transport here were simple. For every 10 to 11 metric tons of cargo that moved into and out of the Toledo port, about one metric ton of sediment left the channel. (Last year, 10.4 million metric tons of cargo were handled at the port.)
But with climate change, the equation is almost certain to get more complex and more expensive, say scientists and port managers. More mid-winter snow melts and rainstorms — and more frequent heavy rainfalls, especially in spring — may lead to higher soil-erosion rates, meaning that Great Lakes rivers are likely to carry more soil into harbors. Higher air temperatures already are warming the Great Lakes, blocking ice from forming, and increasing rates of evaporation that may lead to lower lake levels.”
Follow the link above to read the complete article on these potential consequences for the Great Lakes, the shipping and transportation industry, and the communities that rely on these resources.

Sea Grant staff take to the sea for research

August 10th, 2012 by
Community outreach specialist Kristin TePas rinses a
PONAR dredge used to collect sediment containing
benthic organisms.
IISG staff members Paris Collingsworth and Kristin TePas are sailing on the research vessel Lake Guardian this week on both Lake Michigan and Lake Huron, assisting the U.S. Environmental Protection Agency with its annual monitoring program. The USEPA’s Great Lakes National Program Office is responsible for monitoring the offshore water quality for all five of the Great Lakes in order to assess their health. The water quality surveys take place every spring and summer and include, among other things, assessments for phosphorus and dissolved oxygen in the open waters, as well as phytoplankton, zooplankton, and benthic (bottom-dwelling) organisms.
IISG Great Lakes ecosystem specialist
Paris Collingsworth deploys a net to
collect zooplankton.
From the U.S. EPA:

“The Great Lakes National Program Office (GLNPO) of the U.S. Environmental Protection Agency (USEPA) is responsible for monitoring the offshore water quality of the Great Lakes to evaluate water quality over time and identify any emerging water quality problems. Comprehensive water quality surveys are conducted in all five Great Lakes in both the spring, when the water is cold and well mixed, and in the summer, when the lakes are biologically active. The R/V Lake Guardian is currently being used to conduct the summer water quality survey.”

More information about the EPA’s Great Lakes monitoring program is available at their site.

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