INVASIVE SPECIES EDITION—Where we take a moment to explore the species that threaten the Great Lakes region.
What was originally seen as a decorative and easy-to-maintain aquarium plant is now one of the most noxious weeds in the U.S. Sold under the name “Indian star-vine” in the late 1950s, Hydrilla verticillata was first introduced after live samples were shipped from Sri Lanka to a Florida aquarium dealer. More than half a century after careless disposal into Florida’s waterways, hydrilla can now be found throughout the south and along the east coast, with populations extending inland to the Great Lakes region. Isolated communities have also been found in Idaho and Washington.
This spread is not surprising since hydrilla is unusually hardy and versatile. It can grow in as little as a few inches of water or as much as 20 feet. It requires very little light to thrive and is just as happy in a nutrient-rich environment as one deprived of nutrients almost all together. It can even grow in slightly salty conditions or in water as hot as 81°F. And while it can spread through seeds, hydrilla is also able to grow from stem fragments as well as tubers that can lie dormant for up to four years. Taken together, it’s little wonder that this perennial is found on every continent except Antarctica.
Hydrilla’s unique biological characteristics give it a leg up over many native plants in the Great Lakes region. For example, its early sprouting season and ability to grow rapidly leaves less light for natives later in the spring, making it harder for them to grow once they begin to sprout.
These same characteristics also make it a nuisance to other aquatic wildlife and humans. Growing as long as 30 feet, hydrilla vines form dense mats that alter the water’s pH and oxygen levels, which in turn makes it difficult for some fish species to reproduce and grow. These mats can also impede irrigation, hinder recreation, and clog water intakes to power plants.
Efforts to contain hydrilla have been historically cautious out of fear that the robust plant may mutate or develop a resistance to chemical herbicides—a fear that was realized when fluridine-resistant hydrilla was found in Florida. Today the Asian hydrilla leaf mining fly, weevils, and even the invasive grass carp are used to manage hydrilla invasions. These and other methods cost states millions of dollars a year.
In recent years, Illinois and Indiana have banned the sale, barter, and transport of hydrilla. Water gardeners, aquarium hobbyists, and others can learn how to recognize the plant—and distinguish it from the invasive Brazilian elodea—with our species WATCH card.
We’ll have more species spotlights on aquatic invaders throughout May in honor of Illinois Invasive Species Awareness Week.
Last month, the U.S. EPA awarded University of Illinois at Chicago and University of Illinois at Urbana-Champaign first and second prizes in their Campus RainWorks Challenge. The national competition recognizes student-led green infrastructure plans and projects to manage stormwater on campus. Eliana Brown, has been following the UIUC plan from the beginning. The first time I heard that landscapes could be designed to improve water quality, it was a revelation. I knew about the highly-effective bioremediation treatment cells at industrial facilities. But, the fact that the landscapes we walk through in our daily lives could have that power was exciting. What came to be known as “green infrastructure” is an elegant blend of landscape architecture and civil engineering that places of higher learning should embrace.
The EPA Office of Water seems to agree. Since 2012, it has invited students to design innovative green infrastructure projects to show how managing rainfall in a more natural way can benefit their community and the environment.
Because I’m fond of the small creek running through the University of Illinois’ engineering college—known as Boneyard Creek—I have always wanted to see an entry from my campus. This year, I got my wish and then some. U.S. EPA announced on Earth Day that “Reverse Engineering: The Engineering Campus as Catalyst,” a master plan designed by a multi-disciplinary team of UIUC students under the direction of landscape architecture instructor Tawab Hlimi earned 2nd place. According to the EPA, 64 teams from 23 states submitted entries.
The plan focuses on improving water quality in Boneyard Creek by installing green streets, roof catchments, bioswales, and rain gardens in the surrounding area. Native plants and pollinator habitats are also proposed to boost the creeks’ ecological role and create more recreational opportunities. Building off this success, Hlimi and teaching assistant Faezeh Ashtiani showed the plan along with the work of their spring semester students in an exhibit called “Reverse Engineering: Reconfiguring the Urban-Riparian Interface” at [CO] [LAB] in downtown Urbana. Students expanded on the Campus RainWorks plan upstream and in other parts of campus, including three visions of Dorner Driver Retention Pond that add water quality filtration to the existing water storage function.
Looking to the future, Hlimi has applied for a Student Sustainability Committee grant to build a multi-purpose demonstration rain garden.
Over 200 bags of trash, some shopping carts, mattresses, and a port-o-let were removed from Milwaukee’s Lincoln Park earlier this month during an annual river cleanup led by Milwaukee Riverkeeper. The event drew nearly 3,500 residents and local officials to rivers across the city. Almost 100 of these volunteers were members of the Friends of Lincoln Park. Formed last October, this cleanup was the group’s first outreach project, with many more slated for 2015.
Members of the Lincoln Park community first came together in response to ongoing efforts to rid the Milwaukee River bottom of legacy contaminants like PCBs and PAHs. Phase two of the Great Lakes Legacy Act project was underway, and with the river making up such a large portion of the park, the community was taking notice. With support from focus groups conducted by Caitie McCoy and UW-Extension’s Gail Epping Overholt, residents were inspired to create a way to voice their thoughts and concerns on the direction of the park.
The result was the Lincoln Park Friends Group, who, in association with Milwaukee County Parks, the Park People, the Wisconsin Department of Natural Resources, and Wisconsin Sea Grant, is now working to revitalize Lincoln Park in a way that brings together the surrounding community.
“Most members have grown up enjoying the parks,” said David Thomas, secretary for the Friends of Lincoln Park. “We all think of the parks as a valuable community resource.”
The group hopes to instill a similar sense of stewardship in other community members. Along with plans to clear out areas overgrown with invasive plants, some members have expressed an interest in creating youth groups to provide opportunities to learn how to fish or canoe and to get to know the park’s natural surroundings in general.
“There’s a ton of work to do, but we want to build organically,” Thomas added. “We want to build it slowly, and we want it to be strong and sustainable.”
Swimmers, boaters, and anglers visiting Indiana’s coastline can once again learn about conditions in southern Lake Michigan with real-time data collected by the Michigan City buoy. The buoy, launched for the first time in 2012, returned to its post four miles from shore today to collect data on wave height and direction, wind speed, and air and surface water temperatures.
The only one of its kind in the Indiana waters of the lake, the Michigan City buoy and its temperature chain helps anglers and boaters find fishing hot spots and identify the safest times to be out on the lake.
Scientists at the National Weather Service in northern Indiana will also use wave height and frequency data collected throughout the season to better anticipate the locations of strong waves and currents that cause dangerous swimming conditions. Real-time data on nearshore temperatures and wave characteristics is also vital for research on fisheries and nearshore hydrodynamics.
Data will be available on IISG’s websiteuntil the buoy is pulled out for the winter in mid-October. The site shows snapshots of lake conditions—updated every 10 minutes—as well as trends over 24-hour and 5-day periods. Buoy-watchers can also download raw historical data at NOAA’s National Data Buoy Center.
And starting later this season, our website will also relay data collected by a new environmental sensing buoy placed north of Chicago. In addition to allowing people to track waves and temperatures, the data collected by this buoy could also help officials warn beachgoers when contamination levels may make swimming unsafe.
The Wonder Lake Master Property Owners Association is reminding boaters, anglers, and water skiers to remove, drain, and dry after a day on the water to prevent the spread of invasive species. These Be a Hero—Transport Zero™ steps can now be found at 14 boat ramps around the Illinois private lake.
The signs were installed during the annual spring cleanup, one of many events hosted by the Wonder Lake Sportsman’s Club. And it’s just the latest effort designed to raise awareness of aquatic invasive species and how they spread.
The recent surge of outreach at Wonder Lake is largely driven by concern over invasive plants like Phragmites, a species that’s spreading quickly across the Great Lakes region. Plant life along the lakeshore is limited now, but an ongoing dredging project is expected to change that. Randy Stowe, the lake manager, wants to make sure that the species that move in don’t pose a threat to habitats and recreation.
“We’ll be reaching out to those who own the land along the lake to educate them about invasive plants—how to recognize them, and what to do if you find one,” said Stowe. “We’re really trying to stay ahead of things.”
Learn more about how you can fight the spread of invasive species at TransportZero.org. ***Photo credit: Wonder Lake Sportsman’s Club
A closer look at web tools and sites that boost research and empower Great Lakes communities to secure a healthy environment and economy.
Residents living near sediment remediation projects can now stay up-to-date on cleanup goals and milestones with GreatLakesMud.org. Developed by IISG, this comprehensive site provides information on waterways selected for cleanup and restoration through the Great Lakes Legacy Act.
At the heart of Great Lakes Mud are site-specific pages that identify contaminants of concern and outline plans for cleanup and habitat restoration. Here, visitors will find the latest on dredging schedules, truck routes, opportunities for community involvement, and more.
The website also provides insight into how Legacy Act projects are chosen and designed and explains how cleanup strategies like dredging and capping are able to remove the dangers of contaminated sediment while improving aquatic habitats.
Illustrative photos and videos bring these processes to life and help viewers understand how project components that often span several years fit together.
The Great Lakes Legacy Act was passed in 2002 to accelerate sediment cleanup in Areas of Concern, waterways blighted by decades of industrial discharges and poor municipal sewage practices. Since then, the program has cleaned up nearly 3 million cubic yards of contaminated sediment and restored acres of habitat.
For additional information or to request that your waterbody be added to the website, contact Caitie McCoy.
Where we take a moment to explore some of the unique and impressive species that call the Great Lakes home. Sun-gazer. Squirrel of the marshes. Smallest heron in the Americas. Measuring about a foot in length and weighing in at less than 4 oz., the least bittern is widely spread but rarely seen.
Least bitterns make their homes among the reeds of dense wetlands. Even with a migratory range from southern Canada to northern Argentina, the bittern remains elusive, making it hard for wetland managers to get an idea of their numbers.
Migrating to the Great Lakes each summer to breed, least bitterns fly only at night. And as if that didn’t make visual identification difficult enough, they also prefer to flee from predators and approach their nests on foot. On top of it all, least bitterns are well camouflaged. When threatened, the bird will freeze and point its head upward, exposing vertical striping on its throat that allows it to blend in with its surroundings—thus the nickname “sun grazer.” They will even sway in the breeze to match the motion of the reeds.
Elusive as they are, least bitterns are more often heard than seen—a low cooing from the males and a ticking from the females is the best way to “spot” them. Nests are made by constructing platforms of reeds above the water. Even these are camouflaged. A canopy of surrounding marsh plants is crimped in place above the nest. But the 4-5 eggs laid every season won’t be in the nest for long. Over the span of roughly 50 days, the chicks will hatch, fledge, and leave the nest to start hunting on their own.
Like squirrels leap from branch to branch, least bitterns walk among the reeds 2-3 feet above the water, allowing them to hunt in areas well outside the wading range of larger birds. Balancing on a reed, they strike down with their long bills to catch their prey. Their diet consists of fish like minnows and perch, insects, frogs and other small amphibians, invertebrates, crayfish, and even mammals like shrews and mice.
We’ll have more species spotlights in the coming weeks. In the meantime, check out our spotlight on lake sturgeon.
Last weekend, high school anglers from across the state gathered at central Illinois’ Clinton Lake to battle for one of the top honors in competitive bass fishing—the Big Bass award. But the teams participating in the Illinois Bass Fishing Club High School Open walked away with a lot more than awards and prize bags. The 150-plus competitors and coaches also left with “how-to” tips for stopping aquatic invasive species (AIS) in their tracks.
AIS prevention has become a fixture at this annual tournament, one of few in the state that allow students to hone their skills and learn about ways to carry their love of bass fishing into college. During the tournament’s four-year history, IISG specialists have joined teams at the Mascoutin Recreation Area to talk about the threat of invasive species and what anglers can do to halt their spread. Frequent announcements from Illini Bass Fishing Club members each year also remind students and parents alike of the importance of “leaving the lakes better than we found them.”
“No one cares more about Illinois’ fisheries than fishermen,” said Luke Stoner, former Illini Bass Fishing Club president and tournament director. “It’s our job to keep them as healthy as we can, and that includes fighting the spread of invasive species.”
This is not the only event where conservation has taken center stage. In fact, in the last decade, groups like the Shawnee MuskieHunters and Illinois Bass Federation have expanded their interest in casting technique, water safety, and fishing etiquette to become leaders in invasive species prevention.
Tournaments and club events give young anglers a chance to practice easy steps that prevent AIS from hitchhiking to new habitats and wreaking havoc on food webs and recreation. For example, removing plants, animals, and mud from all equipment, draining all water from your boat and gear, and drying everything thoroughly with a towel after a day on the water will help keep waterways clean and healthy. Throwing any removed plants and unused bait in the trash is also a simple way to join the fight against aquatic invaders.
“To be really effective, these practices have to become routine—the first thing you do after leaving the water,” said Sarah Zack, IISG’s aquatic invasive species outreach specialist. “That’s why it is so encouraging that Illinois anglers and boaters are learning these practices early and are being encouraged to share them with their friends and family.”
Learn more about IISG’s invasive species prevention program, Be a Hero – Transport ZeroTM, at TransportZero.org.
In the Great Lakes region, the word “eDNA” is never far from “Asian carp.” And for good reason. The technology was originally applied by Notre Dame scientists in response to the federal government’s need to discover—and ultimately control—the spread of this voracious invader.
But in the six years since, environmental DNA has become a commonly used tool for detecting fish and other aquatic organisms. Biologists in the UK use it to locate crested newts, Kentucky scientists use eDNA to monitor salamanders, and a city in Washington state even plans to use the technology to track an invasive snail threatening salmon habitats. And scientists see even greater potential on the horizon.
Think of eDNA as forensic detective work. When a silver carp, salamander, or other aquatic animal shed skin cells, they leave behind traces of their DNA. Using the method developed at Notre Dame, scientists can run water samples through a fine-meshed filter, separate DNA from any other microscopic particles, and determine whether any of the genetic material matches the species they are looking for.
“The importance of the method lies in its ability to detect the presence of recluse species or ones with population levels that make catching them difficult,” said David Lodge, a Notre Dame biologist and director of the team that developed this forensic method.
Most of the testing done so far has focused on finding the genetic material of a single species. But Lodge, Notre Dame professor Michael Pfrender, and their team are working on an approach that would allow scientists to map the aquatic life of an entire habitat by sequencing all the genes in a water sample. Although it wouldn’t replace the more time-intensive field studies, this strategy could help natural resource managers know where to target conservation efforts. Lodge received funding to develop a metagenetics approach from the Department of Defense and the National Science Foundation after early results of IISG-funded research revealed ways to strengthen eDNA sampling.
Despite its growing use, eDNA testing is not without controversy, especially when it comes to Asian carp. And the approach does have its limits. eDNA doesn’t tell scientists how many fish there are or whether they are alive or dead. The genetic material found in the water could also come from other sources. There could be feces from birds that fed on Asian carp elsewhere. And boaters and anglers could unknowingly be transporting DNA from one waterway to another.
These possibilities cast some doubt on eDNA results. In fact, the Illinois Department of Natural Resources has said they no longer react to these results alone and are instead looking for entire fish.
Still, supporters say the technology has huge potential.
“Nothing is as sure as holding the fish in your hand,” Lodge said, “but the repeated findings and patterns of Asian carp eDNA make the alternative explanations for how the material got there less plausible.”
🌊 Save the Date! 🌊 Shipboard Science Immersion 2026 Join the Center for Great Lakes Literacy aboard the R/V Lake Guardian on Lake Superior, July 7–14, 2026!
✅ Open to formal & nonformal educators (grades 5–12) across the Great Lakes region. 📅 Applications open January 2026
Learn more: https://cgll.org/signature-program/r-v-lake-guardian-shipboard-science-immersion/ or the link in bio.
Join the Invasive Crayfish Collaborative for an exciting webinar featuring Dr. Chris Taylor from the Illinois Natural History Survey who will provide an overview of midwestern crayfish habitat requirements, feeding, reproductive biology, and life-history.
Crayfishes in the Midwest occupy almost every type of aquatic and semi-aquatic habitat in the region. They function as critically important components of those ecosystems and in many cases represent a majority of invertebrate biomass. As “keystone” species, understanding their biology and roles in ecosystems is critically important.
Register for the webinar at InvasiveCrayfish.org/events1 Or the link in bio.
This season, let’s teach eco-friendly habits while spreading cheer! NOAA’s Greener Holiday Gift Guide is full of ideas to reduce waste and protect our precious water resources.
The gales of November may come early, but, as usual, the nominations for the Lakies are right on time along with our official call for nominations!
Brought to you by the Teach Me About the Great Lakes podcast, The Lakies (aka "quite possibly not the least prestigious Great Lakes-focused awards ceremony there is”) are back.
Our goal isn`t to be the Official Arbiters of Quality, but to host a fun celebration of amazing Great Lakes-related research, outreach, and communication in the inimitable Teach Me style.
Nomination categories are: -Great Lakes Science Communication of the Year -Great Lakes Outreach Program of the Year -Great Lakes News Event of the Year -Great Lakes Research Finding of the Year -Coolest Thing You Learned Listening to TMATGL in 2025 -Science Podcast of the Year (Non-TMATGL edition) -Great Lakes Animal of the Year -Great Lakes Non-Animal of the Year -Great Lakes Sandwich of the Year -Great Lakes Donut of the Year
The Details: -Deadline: Nominations close on December 4th. Process: It`s easy (just enter the name/title and a link). -Self-Nominations: Highly encouraged. Don`t be shy.
We’d love to get a broad swath of work across both the serious and less-serious categories to celebrate. Feel free to pass the link on to interested people: https://bit.ly/Lakies25
