In the past few months, Illinois-Indiana Sea Grant (IISG) educators rocked out with new partners to raise awareness about the threat of Asian carp. Jumpin’ Jack, IISG’s costumed silver carp sensation, was on tour at several large public venues in Milwaukee, and Education Coordinator Terri Hallesy made an appearance at Water Palooza in Chicago.
Jumpin’ Jack’s stops in Milwaukee were part of IISG’s new partnership with the Great Lakes Community Conservation Corp (Great Lakes CCC). This group is focused on training and educating disadvantaged populations in the Greater Milwaukee region, including about environmental issues. The group introduced the bedazzled Jumpin’ Jack at a tailgate party before a Brewers-Cubs game and at the Milwaukee Harbor Festival.
At both events, the Great Lakes CCC brought visitors to their booth through the costumed character as well as with cuisine, demonstrating the value of cooking these fishes. Asian carp sliders were on the menu at the tailgate party and tacos at the harbor festival.
“We ran out well before the event was over, serving 350 Asian carp tacos,” said Chris Litzau, Great Lakes CCC president. While tacos were served, Jumpin Jack posed for photos and danced for the crowd.
Visitors to the booth also learned about the threat and impact of aquatic invasive species to Great Lakes and other waters. Asian carp are prevalent in the Illinois River, with an electric barrier in the Chicago Sanitary and Ship Canal deterring them from entering Lake Michigan. Researchers and resource managers are concerned that these large fish could have devastating impact on the Great Lakes food chain.
IISG Education Coordinator Terri Hallesy helps a Manierre Elementary School student stop Asian carp in their tracks.
Like its more-crowded namesake, Water Palooza is an outdoor event geared towards young people—but in this case, elementary school children. This one-day event is organized by the Water Environment Federation’s Student and Young Professionals Committee. This year it was held on September 29 at Manierre Elementary School in Chicago.
Free pencils at Water Palooza help make it a great day.
At Water Palooza, students take part in hands‐on activities that help them learn the value of water and encourage them to care about water in their world. This year, IISG joined in the festivities with a stuffed animal Asian carp, a Stop the Carp in Their Tracks beanbag tossing game, and other aquatic invasive species-related activities.
“By engaging students in interactive activities, they develop knowledge about aquatic invasive species issues and how they pose a threat to our water resources,” said Hallesy. “Water Palooza provides students with an opportunity to develop awareness, understanding, and a stewardship ethic about an important environmental issue, and learn how we can work together as agents for change.”
Illinois-Indiana Sea Grant is a part of University of Illinois Extension and Purdue University Extension.
Much needed attention has been directed at some particularly problematic aquatic invasive species in the Great Lakes, such as Asian carps and zebra and quagga mussels. But others invaders, like crayfish, can also take their toll on the lakes.
Illinois-Indiana Sea Grant (IISG) has created a new collaborative that brings together a variety of experts and stakeholders to address the threat of invasive crayfish. The Invasive Crayfish Collaborative (ICC), includes 68 experts and other stakeholders from government agencies, universities, non-profit organizations, and private businesses to combine resources and expertise to address priority invasive crayfish research and outreach needs.
Rusty crayfish, native to the Ohio River basin, are already in all Great Lakes states. These invaders can dramatically alter food webs in aquatic environments, first reducing populations of slow moving invertebrates, like snails, and then, when that food source is gone, turning to plants. The crayfish’s consumption of aquatic vegetation can lead to a total loss of rooted plants in the water, which, in turn, can contribute to changes in fish populations.
Other non-native crayfish species also pose a threat to the region, including the red swamp crayfish—listed as one of the 100 worst invasive species in the world, the Australian red claw, and another Australian species, yabby crayfish, which have the ominous scientific name of Cherax destructor.
“Techniques for managing invasive crayfish are largely lacking. Because of this, current efforts to prevent their introduction and spread are mostly aimed at anglers and pet owners—encouraging them to refrain from releasing crayfish into new bodies of water,” said Pat Charlebois, IISG aquatic invasive outreach coordinator.
Funding for research on invasive crayfish management is also limited, so ICC is identifying priority invasive crayfish research needs. U.S. EPA has funded IISG through the Great Lakes Restoration Initiative to establish the new collaborative for the Great Lakes region.
“We know that preventing the arrival of new invasive species, and controlling the spread and impacts of those already here, requires everything from basic research to policy and outreach,” said Reuben Keller of the Institute of Environmental Sustainability at Loyola University Chicago, who is funded through this project to identify species of concern for the Great Lakes. “This collaborative will bring together experts and stakeholders so that the risk of invasive crayfish in the Great Lakes can be better understood and managed, and we encourage all stakeholders to get involved.”
The work of the collaborative will include prioritizing research and outreach needs, identifying crayfish of particular concern, developing a framework for evaluating management techniques, and creating communication tools for ICC members, including a website.
The Lake Michigan food web is in transition—not just in the question of who’s eating whom, but where fish and other organisms are finding food. In recent years, the nearshore has become the go-to location.
Ben Turschak and Harvey Bootsma, biologists at the University of Wisconsin-Milwaukee, set out to characterize the food web in Lake Michigan by capturing the dynamics of what’s happening in the waters near Milwaukee. They use carbon and nitrogen stable isotopes from fish tissue to learn what they are eating, and to understand where each species fits in the food web.
“Carbon stable isotope ratios tell us what a species eats or its primary energy source,” said Turschak. “Predators have a similar carbon isotope ratio to their prey. For instance, a fish that eats zooplankton might have a very different carbon isotope ratio than one that eats bottom-dwelling insects. By contrast, nitrogen stable isotopes become heavier as they go from a prey source to a predator, so they can reveal where a species is positioned in the food chain.”
The Milwaukee shoreline is characterized by a mixed sand and boulder bottom, with frequent cool water upwellings caused by wind pushing warm surface water towards Michigan. The researchers found the food web there could generally be separated into species that eat phytoplankton or those that dine on algae on the lake bottom in shallower nearshore areas. Generally, however, most fish species have begun to rely more heavily on nearshore energy sources.
The likely culprits in shifting the balance of productivity to the nearshore waters are invasive species. In particular, quagga mussels filter large quantities of water to feed on phytoplankton, this process clears the water and, in shallower nearshore areas, allows more light to reach the bottom. The mussels also excrete nutrient-rich waste that fertilizes the lake bottom. With more light and nutrients, bottom-growing algae can proliferate and support more bottom-dwelling invertebrates and the fish that feed on them.
“On the other hand, in offshore waters, mussels also filter phytoplankton and make the water clearer, but the increased water depth prevents enough light from reaching the bottom to support much algae. As a result, quagga mussels are leaving the deep offshore waters depleted relative to nearshore waters,” said Turschak.
“Decreases in offshore energy sources and increases in nearshore energy sources likely account for the fact that fish appear to be feeding more on nearshore energy sources,” explained Turschak.
The researchers also observed that typical patterns of diet change that occur as fish get larger have also shifted for some species. “This indicates that some fish species may have greater reliance on nearshore energy at particular stages of their life because of these food web changes,” said Turschak.
Illinois-Indiana Sea Grant is a part of University of Illinois Extension and Purdue University Extension.
Round gobies have become big players in the Lake Michigan food web. A small but invasive fish, their success may be due to being masters of survival. More specifically, they make themselves at home in a variety of conditions with a variety of food options, settle in for the long haul, and protect their territory.
IISG Assistant Research Coordinator Carolyn Foley took part in a study to learn more about the round goby’s place in the food web. The research team sampled three sizes of gobies from many locations and in multiple seasons. They analyzed the goby diets using three techniques—stomach contents to learn what the fish are eating when caught, fatty acid signatures, which reveal what they have been consuming over several weeks, and stable isotopes, providing a picture of an even longer time frame.
They found location was the driving factor in terms of what the gobies ate and the fish tended to stay put over time. “It’s striking how they tend to stay in the same spot,” said Foley. “This makes sense for them because they are very territorial—they aggressively defend their home turf.”
University of Illinois graduate student Austin Happel and Carolyn Foley, Illinois-Indiana Sea Grant assistant research coodinator, head out to collect fish and invertebrate samples in the waters near Manistee County. Photo by Sarah Stein
Gobies are known to prefer hard, rocky areas and to eat zebra mussels, but the reality may be more complicated. “We caught more gobies over hard substrate, which makes sense, but we found them over soft substrate too,” said Foley. “And since the diet analysis—stomach contents, fatty acids, and isotopes—are conveying the same information no matter what the timescale, we think it means they are taking advantage of whatever food sources are nearby.”
That gobies have become major players in Lake Michigan and that they are survivors may have the potential of providing some stability to the food web. “Their adaptability suggests that they will likely persist for a long time,” said Foley. “And as part of the food web, they too are being eaten—smallmouth bass and birds are eating gobies and are growing.”
But this brings up a concern. As bottom dwellers, round gobies hang out where the contaminants are. As these fish become entrenched in the food web, scientists wonder whether contaminants are more likely to move up through the food web to birds, top predator fish, and eventually, people.
Illinois-Indiana Sea Grant is a part of University of Illinois Extension and Purdue University Extension.
Weatherfish, known in scientific circles as Misgurnus anguillicaudatus, were spotted in the recently restored Indiana wetland, Roxana Marsh, by researchers from the University of Notre Dame.
PhD candidate Katherine O’Reilly, who led the team that confirmed the weatherfish finding, was at the marsh in 2015 for an IISG-funded project evaluating how coastal wetlands around Lake Michigan support the nearshore lake food webs.
“The main goal of the project is to figure out how fish moving between these habitats might be moving energy,” O’Reilly said.
“You might have fish moving out to the nearshore and becoming prey for larger sport fish. That moves food, energy, and nutrients from these highly productive coastal wetland systems to the less productive lake habitat.”
When the researchers returned to their nets left out overnight as part of routine sampling, what they saw was baffling. After some “on-the-spot Googling,” they figured out what they had.
“I wasn’t familiar with the weatherfish. I saw these little eel-like things, something I wasn’t used to seeing in the Great Lakes,” O’Reilly said. “We must have just hit the weatherfish jackpot.”
The weatherfish, originally from Eastern Asia, has been in the United States since the early twentieth century. It was brought over through the aquarium trade. Anglers also have used them as bait because of their wriggly disposition. They are greenish-grey-brown and are typically less than eight inches.
But what’s particularly unique about this species is its breathing anatomy. The weatherfish can use their intestine to supplement their gills when oxygen conditions in the water are low. They’re tolerant in what are considered rough, degraded habitats.
In fact, that lung structure is what gave the weatherfish its name. Because they have an intestine that can take in air, they’re very sensitive to changes in barometric pressure. There are reports of when there are drops in pressure, they start to get increasingly active in anticipation of an impending storm.
Some of the Roxana Marsh weatherfish were brought back to the lab at University of Notre Dame for further analysis.
Many of the fish O’Reilly and (then) undergraduate Amelia McReynolds pulled up in their nets that day were females filled with eggs, which made O’Reilly think that they may have been spawning in the marsh. Through further investigation, they found that the weatherfish diet of small benthic invertebrates and insects was similar to that of some native fish. She posits that could potentially have an impact down the road if they out-compete the native fish for resources.
Gary Lamberti, O’Reilly’s adviser, was impressed by his students’ findings.
“It really is the most exciting thing in science when you’re doing some routine work and you’re expecting the usual and then you find something that’s very different,” Lamberti said.
“Having serendipitous discoveries really makes science and ecology very interesting and rewarding.”
*This story was updated on April 28, 2017.
To learn more about how to prevent the spread of aquatic invasive species, visitBe A Hero—Transport Zero™
Illinois-Indiana Sea Grant is a part of University of Illinois Extension and Purdue University Extension.
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.
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.
Descend 55 meters to the floor of Lake Michigan and you’ll find the bottom carpeted with tens of thousands of one of the most prolific invasive species in the Great Lakes: the quagga mussel.
Researchers have long known that these voracious filter feeders impact water quality in the lake, but their influence on water movement had remained largely a mystery.
From 2012 to 2013, Purdue University PhD candidate David Cannon, working under hydrodynamicist Cary Troy, used water velocity sensors to measure dynamics in the deep waters of Lake Michigan near Milwaukee, Wisconsin and determine the filtration effects of the invasive mussels. The project was supported by a grant from the Illinois-Indiana and Wisconsin Sea Grant programs.
Quagga mussels, which arrived in Lake Michigan in the 1990s via ballast water discharged from ships, have colonized vast expanses of the Lake Michigan bottom, reaching densities as high as roughly 35,000 quagga mussels per square meter. The invasive species that can have major economic impacts filters up to 4 liters of water per day, and so far seems unaffected by any means of population control. It is also a constant threat to other systems, as it is readily transported between water bodies.
“Quagga mussels filter by ‘sucking in’ the water around them and then ‘spitting out’ what (nutrients and particles) they don’t want,” said Cannon. “While they’re doing this, they’re able to directly move a very small amount of water around them—only about 10 cm above the lake bed.”
Quagga mussels harvested from Lake Michigan.
Although this filtering has a dramatic effect on water quality, the measurements taken near Milwaukee suggest that quaggas do not strongly influence movement throughout the entire water column.
But the movement they cause in the thin layer immediately above the lake bed—a phenomenon consistent throughout the year thanks to stable temperatures at the bottom of Lake Michigan—is an element missing from most mussel filtration models.
Cannon and Troy hope that will now change. Their results could lead to the development of better models to study the effects of these organisms on lakes and reservoirs around the world.
“Although Lake Michigan is already infested with these mussels, an accurate filtration model would be imperative for determining the fate of substances like nutrients and plankton in the water,” Cannon said. “In other quagga mussel-threatened systems, like Lake Mead, this could be used to determine the potential impact of mussels on the lake, which could in turn be used to develop policy and push for funding to keep mussels out of the lakes.”
“It’s generally accepted that the ecosystems of smaller, shallower lakes—Lake Erie, for example—are at the greatest risk of quagga mussel invasion,” he 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.”
Illinois-Indiana Sea Grant is a part of University of Illinois Extension and Purdue University Extension.
Not all non-native plants and animals turn out to be invasive in a new environment. How can we predict whether a species poses a threat to local waters? If we could predict that, how can we make the best use of that information?
IISG and University of Notre Dame researchers set out to answer the first question by analyzing which traits help a species thrive in a new environment. They brought this data to an Indiana working group looking to proactively prevent the introduction of invasive plant species through water garden and aquarium retailing. The group of researchers, resource managers, retailers, and hobbyists created a risk assessment tool and their work led to 28 aquatic plants being banned in the state.
As a result of this work, Notre Dame’s David Lodge, and Reuben Keller, now with Loyola University Chicago, were funded through the Great Lakes Restoration Initiative to create risk assessment tools for all taxa in the Great Lakes, including crayfish, fish, mollusks, plants, and turtles. These tools can help decision makers establish consistent and comprehensive regulations focused on species that pose the biggest threat.
Meanwhile, IISG’s aquatic invasive species (AIS) team has been pulling out all the stops to distribute information that can help prevent the spread of AIS in trade—in other words, species that are bought and sold for water gardens, aquariums, and to a lesser extent, classrooms. Leading the effort as part of the Great Lakes Sea Grant Network, and informed by social science research from North Carolina State University, the specialists are targeting all levels of this AIS pathway—from retailers to hobbyists—and sharing information across the region through a variety of media.
The suite of tools contains publications for retailers and their customers that include lists of non-invaders as well as known or potential invaders. “Many of these resources are informed directly from the risk assessment findings,” said Pat Charlebois, AIS outreach coordinator.
Great Lakes Sea Grant programs and the Sea Grant Law Center are contributing their expertise. For example, Wisconsin Sea Grant created a training video for water garden retailers, and Ohio Sea Grant hosted a webinar for aquarium hobbyists. In addition to writing news articles, other programs helped craft non-technical versions of relevant state regulations to give retailers easy access to the information.
All of this work is raising awareness and potentially changing behavior. “Most of the retailers that have received materials about the risk of AIS have reported that they will distribute publications and talk with their customers about invasive species, and a majority will avoid selling them,” said Greg Hitzroth, IISG AIS outreach specialist.
You can find these resources and many more on the new website Aquatic Invaders in the Marketplace (AIM) or TakeAIM.org. AIM are aquatic plants and animals available for sale that can negatively impact ecosystems, economies, or public health. These organisms are commonly found in the live food, aquarium, pet, biological supply, live bait, water garden, and aquaculture industries.
This comprehensive resource provides a wealth of information for resource managers, retailers, hobbyists, aquatic farmers, and more on how to prevent the spread of AIS that can happen with plants and animals that come to new environments through the marketplace. The website includes links to regulations, lists of contacts and invasive species, and species prediction tools for the Great Lakes and beyond.
Illinois-Indiana Sea Grant is a part of University of Illinois Extension.
Despite all the good that natural resource biologists strive to do in monitoring the spread of Asian carp in Illinois waterways, their very presence could have unintended, perhaps even harmful consequences.
All waters are filled with environmental DNA, (eDNA) bits of cells and genetic material left behind like fingerprints at the scene of a crime. Biologists are concerned that while monitoring the movement of Asian carp they may be inadvertently spreading eDNA and clouding their monitoring efforts as well as introducing invasive species into other waterways.
“eDNA is not an invasive species, but we recognize it can be spread by boats or by our gear in the water. In our work we definitely see it can happen very quickly,” said Kevin Irons of Illinois Department of Natural Resources and coordinator of the monitoring and response plan.
“These best management practices work to prevent our day to day activities as natural resource professionals from moving this eDNA around and further exacerbating invasive species spread.”
It’s been noted that some of the most invaded waters are where not only lots of people go, but also where lots of biologists do their work. Irons looked to Pat Charlebois, IISG AIS outreach coordinator, to help with the guidelines aimed at biologists.
“Some of the personnel involved in the agencies doing fieldwork don’t have a protocol in place to deal with this kind of thing,” Charlebois said. “They might not be familiar with the steps they can take or if they’re not from Illinois, they might not be aware of laws that are in place.”
IDNR is promoting prevention and trying to be proactive by encouraging the same recommendations aimed at the average angler, remove, drain and dry, but with more detailed decontamination guidelines.
“In Illinois we have our Be A Hero—Transport Zero™ campaign, so as biologists we need to be a hero and not transport things around,” Irons said.
“Sometimes we get so caught up in looking for the fish that we forget another tenet of good science—prevention.”
“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.”
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