Tracking invaders: hunting for non-native species

Katie Grzesiak currently has one thing on her mind: garlic mustard. The invasive terrestrial plant might look cute with its small white flower petals but it’s wreacking havoc across the state. It grows quickly and returns in the early spring, which is why it’s at the front of the minds of people like Grzesiak, who is the Invasive Species Network Coordinator for the Northwest Michigan Invasive Species Network (NMISN). With the thousands of seeds it can produce – up to 3,000 for one plant – it can quickly spread to the point of domination, outcompeting native plants with zero benefit to native wildlife. “Right now, garlic mustard is all we’re thinking about,” Grzesiak said. It's only one of the many terrestrial and aquatic invasive species currently having a major effect on the Great Lakes and Michigan. An invasive species is basically any type of plant, animal, or any other organism that isn’t native to a specific location and has a tendency to cause damage. Michigan and the Great Lakes are well familiar with them. Garlic mustard isn’t only an issue in the northwest part of the lower peninsula, it can also be found much closer to home. “If you drive around Bloomfield Township, you’ll see it,” said Charles Markus, project coordinator, Engineering and Environmental Services, Charter Township of Bloomfield. The county fights garlic mustard with a Rouge River clean-up every year and officials educate people on how to pull garlic mustard, one of the more common and easy ways to dispose of the invasive plant. Not surprisingly, there’s a list of other invasive species of concern in Bloomfield Township, like purple loosestrife, a clustered flower that can grow as large as 10 feet tall and persist throughout the summer, as well as an ongoing issue with buckthorn. But the concerns aren’t only those that have been here for years. There are two new invasive species for Oakland County to worry about, European frog-bit and red swamp crayfish. “It (European frog-bit) was discovered in Oakland County in 2018, and we’re not really sure how it got there,” said Erica Clites, Oakland County Cooperative Invasive Species Management Area (CISMA) Director. Clites said since it’s a relatively common aquarium plant that is prohibited in Michigan, the most likely reason for the spread is that its was released accidentally or on purpose from a water garden. The Oakland CISMA recently received a $205,200 grant from the Michigan Invasive Species Grant Program (MISGP) to do more standardized surveys of European frog-bit in the Rouge, Huron, and Clinton River watersheds. These surveys of both public and private lands will help determine how far it has currently spread so they can create response plans accordingly. Their main goal is to try to prevent it from entering boating lakes in the county. “One of the reasons that it would be a bad one to get into our boating lakes is that it’s a plant that just fills the whole top of the water,” said Clites of the rapidly spreading invasive species. “It makes it hard for fish and ducks to swim around and also for people to swim.” “It also causes a big die-off, because if there’s that many plants on there they all die, which draws a lot of oxygen out of the water and that can impact a lot of things that live there,” she said. The Oakland CISMA is working with three regional partners, the Friends of the Rouge, Huron River Watershed Council and the Clinton River Watershed Council, to conduct surveys in southern Oakland County. There’s also work being done at Central Michigan University to learn more about the plant, especially turions, which are European frog-bits overwintering buds, to help identify management methods. Another species the Oakland CISMA, and many others in the state, are keeping a close eye on is the red swamp crayfish. “There’s always something knocking on the door coming in,” said Mike Bryan, a plant industry specialist for the Pesticide and Plant Pest Management Division at the Michigan Department of Agriculture & Rural Development (MDARD). The red swamp crayfish didn’t knock, – they barged into Oakland County. Discovered in Michigan in 2017, the crayfish, which are native to the Gulf Coast region, have primarily been found in small retention ponds in developed areas and golf courses, and are believed to have made their way north through releases from classrooms, laboratories and food stores. Lucas Nathan, an aquatic invasive species coordinator for the Michigan Department of Natural Resources (MDNR) Fisheries Division, said this new invasive species, to put it simply, is really concerning. They’ve been found in the thousands among 29 water bodies so far. Nathan said they tend to cluster, so it’s common they will find two neighboring, artificial ponds across the street from each other infested – the crayfish can walk up to a mile on land in-between ponds – or an entire golf course. Not only are they mobile, but the crayfish can be a host for different diseases, a major issue considering how quickly they reproduce. One smaller female can produce around 100 eggs, while the larger ones can produce closer to 500. And they are very aggressive. “They can eat plants and gunk off the bottom but they like flesh. They prefer it,” said Michigan State University researcher Brian Roth, who is currently working with the MDNR on red swamp crayfish. They also burrow during their mating season. “These burrows can be really extensive – often times you can put your entire arm down them and not find the back of it,” Nathan said. Since they are burrowing so close to the shoreline, Nathan said it’s very possible that could lead to concerns from shoreline erosion to infrastructure problems if they burrow close enough to sidewalks or dams. Currently, Nathan, along with partners at MSU, are working to test out sound and heat-based attractants, with the goal of increasing the effectiveness of their removal efforts. They have also been approved to try a chemical in infested ponds but hasn’t used it yet. Right now, the bulk of their work has been focused on trappings, and while that can be effective it has limitations to eradicate an entire population. “Another challenge with invasive species work is finding that silver bullets of sorts to try to eradicate them,” Nathan said. “Now, that silver bullet doesn’t exist for crayfish.” Nathan said with what they know about the red swamp crayfish, the Great Lakes proper doesn’t seem to be an ideal habitat for them. But there is some potential that they could succeed in coastal habitats, like the Sandusky Bay region of Ohio, where they have been found. If the red swamp crayfish do find their way to the Great Lakes, they won’t be lonely. Invasive species have been entering the Great Lakes for centuries, according to the U.S. Environmental Protection Agency (EPA), including the 25 invasive fish species that have shown up since the 1800s. There are some that remain an issue, almost 200 years later, like the sea lamprey, whose first recorded observation in the Great Lakes, Lake Ontario, was in 1835. Throughout the 1920s until the end of the 1930s, the fish went on to spread to the other four Great Lakes. “They’re one of the first ones in, they decimated our large fish population,” said Donna Kashian, professor and director, Environmental Sciences at Wayne State, who has researched aquatic and invasion ecology for years. Not only does the Great Lakes spend a fortune on control of the invasive fish, as they have for decades now, but Kashian said that there are entire field stations with the U.S. Geological Survey dedicated to them. With their eel-like body and mouth with sharp, curved teeth, they look like something out of a horror film. A more familiar name on that list is Asian carp, which are competition with other fish for food. There are four different types of the species that are a threat to the Great Lakes: bighead carp, silver carp, black carp, and grass carp, the latter which has already been found in western Lake Erie and occasionally Lake Huron. Aquatic Invasive Species Biologist Christina Haska Baugher, who works for the Michigan Department of Natural Resources (MDNR), said while grass carp can move outside where they’re found, they aren’t seeing many leave the Lake Erie area, which the carp prefer. “Why venture out of the place where you’re comfortable?” Baugher laughed. Since 2014, the MDNR has made efforts to remove them from Lake Erie, such as the telemetry work they’ve done, which is where grass carp are caught, tagged, and released back into the water, allowing researchers to more easily track where they’re going and see where they’re congregating. Work has also been done in testing their fertility. Baugher said that some carp in Lake Erie are infertile, making those ones less of a concern. Researchers aren’t only concerned about grass carp, though. Bighead carp and silver carp, which would consume large amounts of plankton and other material through filter feeding, has the potential to make them compete with native species, among other negative impacts, and they could be making an appearance in the Great Lakes soon. Nathan said the MDNR is currently working with partners around the Great Lakes basin to prevent that from happening. How would they get here though? Multiple waters pathways, like the Chicago Area Waterway System that connects Lake Michigan with the Mississippi River via the Lower Des Plaines and Illinois rivers – an area which is too close for comfort for many. “We don’t have an actual, physical barrier between Asian carp and the Great Lakes. We’ve known about this now for at least 10 years as a major looming threat and we still haven’t had the political will as a country to deal with that problem,” said Nicholas Schroeck, associate dean of experiential education, associate professor of law and director of the Environmental Law Clinic, University of Detroit Mercy School of Law. “In my opinion, there’s no doubt they’re going to make it,” said Kashian, the professor at Oakland University. “The minute they get into our tributaries… they are going to wreak havoc on the rivers and lakes. We’re going to see catastrophic changes because of them.” Since Michigan has no jurisdictional authority in Illinois, the situation is a tricky one. The MDNR is currently working with partners in the Great Lakes and the federal government, partnerships that Baugher believes are strong ones. The state of Michigan has pledged money to put towards continued containment of these coming up the Mississippi River. Only time will tell if the electric barriers and dams in place hold. Asian carp may have gotten a lot of attention over the years, but another invasive species that has really made people take notice over the last 30 years are zebra and quagga mussels, which showed up in the late 1980s from ballast water via a transatlantic freighter. Quickly, they spread to all five of the Great Lakes. “Zebra mussels are a really effective kind of poster child for invasive species awareness,” said Jo Latimore, an aquatic ecologist and outreach specialist in the Department of Fisheries and Wildlife at MSU. “It really raised awareness about the challenges of invasive species.” Zebra mussels spread so quickly and rapidly since they can attach to hard surfaces, like boats and other recreational equipment used in water, even in the early stages of their life, making it easy for them to move from the Great Lakes to more inland waters. Intake pipes on the lakes that suck in water for drinking water have to have them chiseled off, they’ve filtered a lot of natural organism out of the lake as well, and most importantly, they dramatically changed the Great Lakes in terms of the food web and the way they look. Now, 30 years later, it isn’t so much about completely eradicating them, but managing them. “Unlike the sea lamprey, we don’t have an effective, feasible, large scale method to control zebra and quagga mussels right now,” said Erika Jensen, program manager, Great Lakes Commission (GLC). “There are control methods available that can be effective on a small, localized scale but we don’t have anything right now that would allow us to treat say, all of Lake Michigan.” The GLC is currently leading the Invasive Mussel Collaborative, a program established to advance potential control methods for the two types of mussels. Sarah LeSage, Aquatic Invasive Species Program Coordinator for the Water Resources Division at the Michigan Department of Environment, Great Lakes, and Energy (EGLE) said there is currently research on zequanox, a bacterial product, as a potential way to manage zebra and quagga mussels with fewer impact on other organisms. They are currently looking at how to use a product like that in a targeted way. There has been some slow in the spread of zebra mussels though, thanks to preventions and regulations put in place. Now, ships have to flush their ballast tanks with salt water into the open ocean. Ships are required to install treatment technology to treat their ballast water. There are national campaigns like Clean, Drain, Dry, that encourages recreational users to do just that – and dispose of anything they find – before putting their equipment into another body of water. Its terrestrial counterpart, Play, Clean, Go, wants people to clean their gear before entering and leaving a reaction site. At the federal level, the Vessel Incidental Discharge Act was recently passed. LeSage said it aims to streamline the regulatory landscape for shipping industry by preempting state authority and giving the U.S. Environmental Protection Agency (EPA) the mandate to develop new standards for living organisms in ballast water discharges and the U.S. Coast Guard will be required to enforce those regulations. The EPA is currently developing those standards. While the Great Lakes themselves are filled with invasive species, so are the areas surrounding them, on the coastal wetlands nearby. Aquatic invasive species like Eurasian watermilfoil which costs Michigan millions of dollars each year in management. Then there’s one that came up again and again – phragmites. “Phragmites...that’s probably one of the worst of the worst, and one of the most noticeable along the shores of the Great Lakes,” said Clair Ryan, coordinator for the Midwest Invasive Plant Network. Non-native phragmites – which grows from six to 13 feet tall – can be found everywhere from along lakes to highway ditches. The restricted species, at least under Michigan law, forms dense strands that are impossible to pass through, making it able to displace native plants, cut off road drainage when found in a roadside ditch, and can even become a fire hazard due to its dry thatch. It’s also costly to get rid of – but if you don’t fully eradicate it all, it’s coming back. Some successful proven methods include herbicide, cutting, burning, and there’s research towards a pilot program that would use a biocontrol on the invasive plant. The spread of phragmites is a major concern for the Great Lakes and across Michigan’s entire lower peninsula. It's seeds and aggressive rhizome system, which lives for three to six years and is aggressive with both horizontal and vertical rhizome, have played critical roles in its quick spread. GLC has even formed a group for this problem as well, the Great Lakes Phragmites Collaborative, and is working with the USGS on the Phragmites Adaptive Management Framework (PAMF). “We established that collaborative in the beginning because the species was widespread throughout the basin but everybody was employing different approaches to manage the species, and efforts weren’t coordinated very well, and lessons learned about what approaches work better than others, and less so, weren’t being effectively communicated,” Jenson said. Oakland County isn’t safe from non-native phragmites either. “Once you learn to recognize it, you start seeing it everywhere,” said Scott Tiegs, biology and ecology professor at Oakland University. Since 2015, the Road Commission for Oakland County (RCOC) has worked with the Oakland County CISMA to help eliminate phragmites from road rights-of-way. CISMAs are groups that cover every region across the state and consist of volunteers, businesses, non-profits and government agency partners, all with the goal to better prevent, educate, and manage invasive species. Markus, who works in the Environment and Engineering Services Department of Bloomfield Township, said that last year they allocated $70,000 for the program, an increase from previous years. With its ability to really take over a space, phragmites can decrease property value if it becomes too invasive and can prevent access to recreation. “No one wants to go bushwhacking through these 12-foot tall fields of phragmites,” Ryan said. Other statewide invasive species of concern are of the terrestrial kind. Turns out, Grzesiak, from NMISN, isn’t the only one worried about garlic mustard and other invasive plants. “The bigger thing you hear about is the murder hornets, which are all sensationalized, but really, what I think are most risky are plants that can take over, like the garlic mustard,” Schroeck said. People like Susie Iott, an invasive species program and terrestrial plant specialist with MDARD, is equally concerned about the invasive plants in Michigan. Listed immediately as high concern were giant hogweed and Japanese knotweed. Giant hogweed isn’t only an invasive species but also comes with a public health concern due to its sap which contains toxic chemicals, photosensitizing furanocoumarins. If a human’s skin comes into contact with them, it can cause a skin reaction that is highly sensitive to light. It also looks a lot like cow parsnip, a well-established plant in Michigan. The latter, from Japan, where it grew in lava beds, has exceptionally strong roots that can go right up through people’s concrete and even through a home's foundation. All of which equals property damage and reduced property values. Like so many other invasive species, it’s easily spread through vegetation and its seeds. And manual removal doesn’t work, making it difficult to kill. “It’s a very resilient species and sometimes to get a full kill you have to get the chemical to translate all the way down in to the root system and their root system is very tough,” Iott said. “If you break off a piece, like a fragment of a stem and it gets moved to another area, that fragment can root and grow and sprout.” That type of accidental spread is frequent with both aquatic and terrestrial plants. All it takes is one seed or fragment to get attached to something like a boat or hiking boots for it to spread. Even wildlife rubbing against each other can land an invasive species somewhere they aren’t meant to be. There are a few ways invasive species spread happens is a little less accidental, though, such as when people dump the entire contents of their aquariums into lakes and ponds after buying them through the aquarium trade. For those worried about spreading invasive species, check Part 413 of the Natural Resources and Environmental Protection Act, which defines all prohibited and restricted species in the state. That lists limits the possession, import, or sale of those specific species. A first offense usually ends in a warning letter, while a second could result in a fine. Some invasive species are legal to sell and buy, though, such as water lettuce and water hyacinth. Grzesiak listed Japanese barberry, a common shrub that can harbor ticks that spread lyme disease, and blue lyme grass as two more to look out for. Humans may quicken the spread, but they can also be the best weapon against invasive species. “The general public is a freely available… now fully invested, citizen science army,” said Amos Ziegler, coordinator for the Midwest Invasive Species Information Network. One of the most vital, and cheapest, ways to fight the spread of invasive species is early detection and response. “The most cost-effective way to deal with aquatic invasive species is to prevent them in the first place so you don’t have those long-term damages in terms of economic losses or direct control costs,” LeSage said. And with so much land in the state to cover and small invasive species departments that surge in public interest over the last 30 years is essential. “We cover four million acres of land in our service area. We have one full-time person on invasive species and some seasonal staff, and that’s mostly grant-funded,” said Steve Woods, Conservation Stewardship Director at Huron Pines, a conservation non-profit that serves the northeast part of Michigan’s lower peninsula. “So we really need more people to be aware to build the army of addressing invasive species as a part of what every landowner does.” It’s easy for people to participate in, too. For those looking for more hands-on programs, many CISMAs have trainings and classes to learn how to identify invasive species. The Exotic Aquatic Plant Watch also does trainings for what to look for and how to survey a lake for invasive plant species. Grzesiak at NMISN said they do an all-day and half-day identification training and conduct workshops about Japanese knotweed and autumn olive. NMISIN produces a top 12 list of prioritized species to be on the lookout for. Then, there are apps, like EDDMapS, which allows users to report invasive species on a national level. MISIN’s app and website has more of a Midwestern focus, but essentially does the same thing. People can search and report findings on both the app and website. According to Claire Peterson, data manager for MISIN, of their almost 300,000 records currently in the MISIN database, about 24,000 of them are from the general public. The rest come from CISMAs and other groups and organizations around Michigan and the Midwest. With MISIN, once the data is submitted it goes to their observation table, where the public can see all the data complied on the website. Peterson said users can set up species alerts so any time an observation is added to the database they are notified. Many departments in the state have alerts set-up for notifications if something comes in from the Michigan Invasive Species watchlist so they can verify and deal with it. Those species are ones with little to no confirmation of distribution in the state but have been identified as ones with an immediate or potential threat to Michigan, which all goes back to the crucial step of early detection and response to slow and stop the spread. Currently on the watchlist are European frog-bit, hydrilla, Japanese stillgrass, kudzu, marbled crayfish, New Zealand Mud Snail, and the Red Swamp Crayfish, among others. As far as on-the-ground treatment goes, people can remove invasive species themselves, but it’s emphasized that they should be 100 percent sure of what it is before removal because each species is different. Or they could report to their local CISMA, MDNR, or MDARD. “The real heroes in all this stuff are these local cooperatives, the CISMAs,” said Ryan Wheeler, invasive species biologist with the Forest Resources and Wildlife Divisions at the MDNR. “Those are the rock stars, the local partners working together across county lines on the things that are really important to the folks who live in those areas.” Much like public awareness, information sharing, like what’s done with MISIN and across the EGLE, MDNR, and MDARD, is another key element to slowing down invasive species. “As we all know invasive species don’t respect those state boundaries,” laughed Jensen with the GLC. “So, if we’re all working together and coordinating our policies and activities we have a much better chance of mitigating the potential negative impact of invasive species.” Especially because once they are here that spread is often quick, and then it becomes less about early prevention and response, and simply about management, as emphasized on the Invasion Curve. But when they do find them early, it really can make all the difference. Take for instance, yellow-floating hearts and parrotfeather, two watchlist species that LeSage said they’ve been able to eradicate from some smaller, private ponds and constructed waters. And sometimes, after successful treatment and removal of invasive species, native plants come back. “We’ve seen plants that are normally rare native plant species for wetlands have come back in areas they haven’t been seen for many years because they were overcrowded by the invasive plants,” said Chris May, director, Protect Land and Water for The Nature Conservancy, and Detroit River and Western Lake Erie Cooperative Weed Management Area coordinator. They’ve been able to remove invasive species from close to 3,000 acres since their inception in 2011, and have seen the resurgence of lizard’s tail, Virginia spiderwort, common boneset, river bulrush, and giant arrowhead, a state threatened species. The CWMA has covered so much land thanks in part to the Marsh Master amphibious vehicle, which can move on the ground and float in land to do surveys to look for invasive species. It’s used to support prescribed fire and has a system with an herbicide tank and boom sprayers for treatment. As for the future of managing invasive species, there’s hope for more bio-control treatments and gene silencing techniques that would get plants to close down and shut certain genes to keep them from reproducing or growing. In spite of new technology and more awareness, will we ever reach a point where invasive species are no longer an issue in Michigan and the Great Lakes? “That would be a dream, right?” Baugher said. “This is something we will continue to have to prepare for, plan for, and manage for, forever I would think. As long as people are moving around the globe, invasive species are going to be a concern.”