Predicting and Preventing the Spread of Hydrilla

By Kevin Bunch, IJC

hydrilla mat
A mat of invasive hydrilla found in West Creek in the Cleveland Metroparks system in August 2011. Credit: Jennifer Hillmer

A virulent, hardy, and aggressive aquatic invasive plant has been working its way north, approaching the Great Lakes in a few spots. The plant, called hydrilla, is the target of a binational effort to understand its spread and how it can be dealt with before it gets established. In states like Ohio, its encroachment on the Great Lakes has prompted lengthy eradication efforts as close to the shoreline as Cleveland, and research to better predict its movement in coming years. In Ontario, officials are working to keep the province hydrilla-free.

Hydrilla will root itself into sandy and rich, mucky beds of whatever water body it has settled in and can grow stems up to 30 feet (9 meters) in length, forming dense mats near the surface. Each stem has whorls of small, serrated leaves visible to the naked eye. The plant outcompetes native species for nutrients and can survive a variety of conditions, said Mark Warman, hydrilla project coordinator for Cleveland Metroparks.

It can tolerate less sunlight than native plants, low carbon dioxide environments, and could take advantage of the phosphorus and nitrogen runoff into Lake Erie to expand. It can settle into water up to 49 feet (15 meters) deep and is capable of overwintering in cooler environments like those around the Great Lakes.

Additionally, hydrilla has several reproductive and survival strategies. Warman said in addition to seeds, hydrilla can grow from fragmentation – if a piece of the plant is broken off, both parts may continue to grow, with the free-floating piece attempting to root itself again. Waterfowl can be a vector for transportation, and studies have shown that hydrilla tubers can survive and grow after being regurgitated. Finally, it overwinters with the help of tubers and leaf buds called turions that can be moved in a sediment washout or flood event.

“The biggest risk is fragmentation on fishing equipment and on boats and trailers,” Warman said. “We advocate for proper training in boat inspections and providing infrastructure to properly clean boats, and we let the community know to clean, drain and dry their boats.”

Hydrilla could readily spread at a boat ramp or marina, rendering it difficult to move a boat through without some plant management, he added. The US National Oceanic and Atmospheric Administration notes that hydrilla has caused millions of dollars in damages to irrigation and hydroelectric power projects in the southeastern United States, with the local fishing and tourism industries also taking a hit.

The dense hydrilla mats along the water surface can cause problems not only for boaters and anglers, but also for irrigation and water intake systems, said Francine MacDonald, senior invasive species biologist with the Ontario Ministry of Natural Resources and Forestry (MNRF). The mats also can hurt fish abundance and distribution in the areas they’re found as they change the habitat around them and crowd out native plants, MacDonald said.

Besides watercraft, the water garden trade is another major avenue for hydrilla’s spread, Macdonald said. Hydrilla can be mistaken for other species or mixed in with the roots of other pond plants. The species is prohibited under the 2016 Ontario Invasive Species Act, which makes it illegal to import, possess, deposit, release, transport, grow, buy, sell, lease or trade in the province. The act also includes measures to help control and eradication responses in case it’s found in Ontario, though so far it hasn’t been detected north of the United States.

Completely eradicating the plant in a specific area isn’t easy. Warman said hydrilla was first detected in 2011 at the Cleveland Metropark system in the Cuyahoga River watershed in six locations (all artificial wetlands), and a rapid response plan went into effect to begin hitting it with herbicide. Those treatments, using fluridone-based herbicides, can take seven to 10 years to complete. This year they’ve only found a single tuber; 2016 was the last year his staff found any vegetative hydrilla at the initial discovery site.Other than herbicide, hydrilla control methods are a mixed bag, according to information from New York Sea Grant and Cornell State University.

Mechanical cutters are expensive to run (around US$1,000 per acre) and there’s a risk that fragments could be carried elsewhere; the same is true of suctioning out the plants using vacuums. Biological control using other nonnative species is risky and has seen mixed results in Florida; while grass carp has been successful in small lakes it is a nuisance otherwise in the Great Lakes. Drawing down water levels, where possible, can dry out hydrilla, but the tubers can survive to grow once water levels increase again, and other native plants could suffer in the meantime.

Additional searches outside of the metroparks in the Cuyahoga River watershed haven’t turned up any additional plants, but Warman is vigilant. While the species is federally prohibited for trade and sale without a permit in the US, he believes it initially turned up in the metroparks when it was illegally dumped with other aquarium plants.

hydrilla tuber
A hydrilla plant with its tuber, removed from West Creek in the Cleveland Metropark system in May 2012. Credit: Jennifer Hillmer

Even if hydrilla isn’t around the Ohio metropark now, it has continued to creep its way north from the southern United States. Kristen Hebebrand, a master’s student at University of Toledo, has been studying and modeling how hydrilla has spread north, alongside other researchers working on a risk assessment for the US Army Corps of Engineers (USACE) Buffalo District, the USACE’s Engineering Research and Development Center, Texas Technical University, North Carolina State University, and Ecology and Environment Inc.

The assessment is being prepared to identify locations most vulnerable to invasion by hydrilla within the Great Lakes, based on likelihood of introduction and environmental suitability. The assessment and related research work is being done under the USACE’s Aquatic Plant Control Research Program and is funded by the US Great Lakes Restoration Initiative.

The modeling is built on a watershed-by-watershed basis within the United States, focusing on accidental overland transportation by recreational boats. Overall, Hebebrand said, hydrilla is expected to continue to spread in areas with current infestations, and the watersheds surrounding those will be at a higher risk of infestation. While her study isn’t complete, initial results discussed at the International Association of Great Lakes Research (IAGLR) conference in June suggests its biggest gains by 2025 will be in watersheds just south and on the western end of Lake Erie, the St. Clair-Detroit River watershed, and in watersheds around southeastern and southwestern Lake Ontario, which are already infested. Hydrilla also is expected to increase around the Ohio River and the Susquehanna watersheds south of Lake Erie, according to the ongoing study.

Once the risk assessment project is complete, Hebebrand hopes managers and officials can use it to make more informed decisions about early detection and where to prioritize monitoring efforts for hydrilla. Hebebrand said her portion of it should be finished within a few months, but the work is ongoing.

MacDonald said MNRF is working with a binational invasive species program to document the spread and help find hydrilla and other invasive pests, called the Early Detection and Distribution Mapping System. Alongside an Invading Species Hotline, MacDonald said it’s an important tool to enable citizens and conservation groups to report potential hydrilla sightings and other invasive plants. The MNRF also is studying using environmental DNA to help support early detection before plants themselves have been spotted.

The US Army Corps of Engineers Buffalo District is working with Ecology and Environment Inc. to develop a basin-wide collaborative initiative to fight hydrilla. It’s in the early stages, but Ecology and Environment hopes to have a website up to provide a place for managers to share lessons learned and technical information in coming months.

Finally, there are formal commitments from Great Lakes governors and premiers to prevent and respond to aquatic invasive species together, including hydrilla. MacDonald said this includes a mutual aid agreement to combat shared threats within the basin – though so far Ontario has not been asked to assist with any hydrilla eradication efforts. Information on control efforts is shared regularly through organizations like the Great Lakes Panel on Aquatic Nuisance Species and the Conference of Great Lakes St. Lawrence Governors and Premiers’ Aquatic Invasive Species Task Force.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

University of Windsor Research Studies Beach Testing, Enlists Citizen Scientists

By Daniel Heath, GLIER

The Great Lakes Institute for Environmental Research (GLIER) at the University of Windsor is a multidisciplinary research facility located on the Canadian side of the Detroit River. Researchers at GLIER address complex environmental problems such as the effects of multiple environmental stressors on large lakes and their watersheds. One of the major concerns for public health around the Great Lakes basin is microbial (bacterial and algal) contamination in recreational and drinking water. The greatest health concern associated with recreational water use is gastrointestinal illness resulting from exposure to bacteria, viruses or protozoa from human or animal fecal sources.

Aside from the direct public health risks, microbial contamination has enormous economic impacts, including beach closures, commercial and recreational fisheries losses, increased water treatment costs and loss of productivity due to illness and imposed protective measures. Water for recreation is a top tourist attraction in North America, which contributes billions annually to the Canadian and US economies. In Canada, Great Lakes recreational water use injected $12.3 billion into the Ontario economy in 2010, while the US National Oceanic and Atmospheric Administration (NOAA) estimates that a third of all US recreational boaters are based in the Great Lakes

Limitations in current monitoring

Public health agencies in Canada and US have used fecal indicator bacteria (FIB) cultures, especially Escherichia coli (EC) for freshwater and enterococci (ENT) for salt water, as indicators of fecal contamination and associated risks to human health. However, there is growing evidence that these cultures may not necessarily correlate well with actual pathogen presence or abundance.

There is also evidence that EC and ENT can survive, grow and establish populations in natural environments such as freshwater lakes and streams, soils and sediments. Culture-based measurements of EC and ENT don’t indicate their potential sources and therefore are of limited value for identifying significant pollution sources and determining most cost-effective mitigation measures.

Further, the approved standard culture methods for measurements of EC and ENT require a minimum of 18 hours for the results to become available, although the state of Michigan recently initiated a rapid genetic test for E. coli.

Studies have shown FIB numbers to be quite dynamic with no correlations observed from one day to the next, which is also true in the Windsor/Essex region of Ontario. These types of fluctuations can result in false positive and false negative errors in beach warnings and closures; false negative errors pose a health risk to beach users.

A example of beach water quality monitoring by the Windsor-Essex County Health Unit.
A example of beach water quality monitoring by the Windsor-Essex County Health Unit.

Role of Citizen Scientists

Given the limitations in culture-based water testing, GLIER researchers are developing rapid, culture free, genomic-based tools (by amplifying the DNA) to provide fast and accurate identification of the microbial community and the probable source of contamination (human, animal or sediment).

To maximize the geographic coverage of the testing, GLIER researchers organized a water quality testing event on Aug. 19. Water samples were collected at 450 locations along Lake Erie, Lake St. Clair and the Detroit River, as well as other small river and stream tributaries with the help of citizen scientists.

Without this involvement, such broad-scale water sampling is close to impossible. Beach testing results using the developed methods in a commercial lab or test facility will take less than six hours. As a research facility, GLIER is developing these techniques and hopes to have the process optimized for use by health departments and other agencies before the end of the year.

volunteer filters water sample lasalle
A volunteer filters a water sample in LaSalle, Ontario.

Future monitoring

In addition to pathogen identification, the GLIER research team is working on models to allow managers and public health officials to identify probable sources of microbial outbreaks and make decisions based on accurate predictions, ahead of time. The developed tools and methodology in this project can be applied seamlessly in other jurisdictions around the Great Lakes, across Canada and around the world.

Dr. Daniel Heath is an evolutionary and conservation genomics professor at the Great Lakes Institute for Environmental Research at the University of Windsor in Windsor, Ontario.

Get Involved: Asian Carp and Excess Algae

By Jeff Kart, IJC

You can make noise about Asian carp and excess algae this month.

A live Asian carp was caught earlier this year, nine miles from Lake Michigan and beyond a system of underwater electric barriers. The US Army Corps of Engineers is seeking public comment on a draft report related to preventing the spread of these invasive fish. Comments are being taken until Sept. 21 on proposed measures at the Brandon Road Lock & Dam in Illinois. The tentatively selected plan is called the “Technology Alternative – Complex Noise with Electric Barrier.”

Click the links above to learn more, and see other highlights below on ways to “get involved” in helping protect the Great Lakes.

map army corps plan
A map showing key features of the tentatively selected plan. Credit: USACE

More Asian Carp: The state of Michigan is offering up to $700,000 in cash awards for a Great Lakes Invasive Carp Challenge. Written proposals are being accepted through Oct. 31 “for innovative methods to prevent invasive (or Asian) carp from entering the Great Lakes.” Michigan officials note that they’re working with other states and Canadian provinces to keep silver and bighead carp – two species of Asian carp – from entering the Great Lakes.

Asian Carp Canada, by the way, is encouraging people to report sightings of Asian carp and other invasive species to EDD MapS (Early Detection & Distribution Mapping System), a binational program that includes Ontario.

Lake Erie: Until Sept. 29, the US Environmental Protection Agency is taking comment on a Draft Domestic Action Plan for Lake Erie. In 2016, as part of the Great Lakes Water Quality Agreement, Canada and the US adopted phosphorus reduction targets for the lake, to address excess algae fed by nutrients. Each country is developing domestic action plans which outline strategies to meet the targets.

Canada received comments on its Draft Action Plan earlier this year. Plans for both countries are to be in place by 2018.

More: This is only a small sample of opportunities for public comment in the basin. See our Twitter and Facebook feeds for daily updates on Great Lakes news, and feel free to send “get involved” tips to Jeff Kart at

Jeff Kart is executive editor of the IJC’s monthly Great Lakes Connection and quarterly Water Matters newsletters.

Forecasting ‘Dead Zones’ to Help Protect Drinking Water

By Kevin Bunch, IJC

Cleveland, Ohio, depends on water from Lake Erie for its drinking supply, which can be affected by a hypoxic zone
Cleveland, Ohio, depends on water from Lake Erie for its drinking supply, which can be affected by a hypoxic zone. Credit: Rick Harris

A new tool in development should help water treatment plants in communities along Lake Erie prepare for when dead zones reach their shores.

Lake Erie is periodically affected by oxygen-poor hypoxic zones, also known as “dead zones” for how few things can survive in them. These zones form at the bottom layers of water in Erie’s central basin. Aside from being bad for aquatic life, hypoxic zones present a special challenge to water treatment facilities. The hypoxic zones can spread toward shorelines and temporarily impede operations for hours as treatment systems are set up to deal with the specific impacts of those conditions. The US National Oceanic and Atmospheric Administration, working with the Cooperative Institute for Great Lakes Research, hopes to lend a hand to water treatment plants with an experimental early warning system that would provide advance notice of potential hypoxic events.

Oxygen-deficient water often has a lower pH balance and may have higher concentrations of metals like manganese and iron, which can cause discoloration of treated water, according to Craig Stow, aquatic ecosystems modeling researcher at NOAA’s Great Lakes Environmental Research Laboratory. Water treatment plants can account for these water conditions, but operators need to know about those conditions to make the necessary treatment adjustments, and it takes time to retool their systems. Right now, they get alerted only when the hypoxic water has reached the intake.

“Hypoxic water can be treated, but it requires knowing hypoxic water is present to put those treatment adjustments in place,” Stow said. “Since these adjustments are more expensive to do or counter to normal treatment goals, you don’t want to be treating water all the time as if it were hypoxic.”

Hypoxic conditions typically occur in late summer, caused by long periods of high temperatures and stormwater events that wash fertilizer and manure off farms, and sewage from combined stormwater overflows into the lake. The nutrient input stimulates algal growth, and as that algae decomposes the aerobic bacteria feeding off it consumes oxygen, reducing the levels of dissolved oxygen in the water.

Lake Erie isn’t a static body – water is constantly being churned around, and occasionally this brings the hypoxic water from the bottom layers of the central basin near the shore and to the water intake pipes located near cities. By adapting an existing Lake Erie computer modeling framework used for other types of forecasts (like meteorology), Stow believes an effective early warning system can be developed to alert water managers that a hypoxic zone could be heading toward their intakes so that managers can adjust their treatment methods accordingly, possibly up to a few days in advance.

The project got underway in 2016. In the initial stages the warning system involved taking existing models focused on water temperature and other conditions and adding hypoxia to it, but chemical and biological components – like phytoplankton growth and phosphorus inputs – will be included later.

An additional goal of the project is to determine whether adding nutrient and biological components to the model will improve the accuracy of the hypoxia simulations over a purely physical model, according to Stow. A model that includes chemical and biological components may have additional applications, such as forecasting algal blooms, which would be helpful for water managers, anglers and boaters.

Seasonal changes through 2005 show how Lake Erie’s hypoxic (low-oxygen) zone develops in the central basin in July through September
Seasonal changes through 2005 show how Lake Erie’s hypoxic (low-oxygen) zone develops in the central basin in July through September. Credit: NOAA

NOAA researchers also are reaching out to groups with a stake in such a warning system. Water treatment and management agencies, Ohio Sea Grant and the Ohio Environmental Protection Agency are just some of those who could use the early warning system.

“The drinking water plant managers not only benefit from sharing operational information and research, but also by establishing lines of communication between water utilities and researchers that help identify common areas of interest,” Scott Moegling, water quality manager at Cleveland’s Division of Water, wrote in a NOAA blog post. “The end result, researchers providing products that can be immediately used by water utilities, is of obvious interest to the water treatment industry on Lake Erie.”

The current effort is focused on the US side of the lake. Stow said Canadian information isn’t available right now, but there have been discussions with Canadian agencies on collaboration efforts.

Ontario has been working along similar lines on its Lake Erie coastline, however.

Communities along the north shore of Lake Erie contend with the upwelling of hypoxic water, according to Todd Howell, Great Lakes ecologist with Ontario Ministry of the Environment and Climate Change. Fish kills have been reported that were linked to hypoxic water reaching the shoreline, and the ministry has conducted water quality monitoring that has confirmed that hypoxic water is reaching the coastline. Upwelling also can push nutrients like phosphorus from the lake bottom to the surface, giving algal blooms an additional food source in the summer.

Howell said the province has acquired and deployed a real-time sensor system offshore of Port Glasgow, located off the central basin of Lake Erie. The system is designed to detect low-oxygen water and upwelling, and was first deployed in late summer 2016.

“Our intent is to deploy the system annually over the May-to-November period,” Howell said.

The Ontario Great Lakes Intake Program has routinely monitored nutrient, chemical and chlorophyll characteristics and concentrations at water intakes along the north shore since 1976. While this has not been specifically developed to detect hypoxic water, the data it has collected suggests indirectly, through phosphorus detections, that there has been upwelling occurring around some central basin water intakes. A 2015 report prepared by Freshwater Research for the ministry recommends collecting more evidence of hypoxic events along the north shore.

Since receiving funding a year ago from the NOAA Center for Sponsored Coastal Ocean Research – which is studying hypoxic zones in the Gulf of Mexico and other waters – Stow said his team has an early version of their dissolved oxygen model online right now. The researchers are working on predicting hypoxic zones and watching to see how reality matches the model, by using profilers and sensor strings in the lake that measure oxygen and water temperature. Those will be retrieved in the fall to refine the model. Part of the project also includes studying how these hypoxic zones form in the first place.

Stow said the early warning system could be operational within the next few years, at which point it would be run by NOAA’s forecasting unit.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

New Tool for the Tackle Box: An Algal Bloom Tracker

By Kevin Bunch, IJC

An angler casts his line out into Lake Erie near an algal bloom. Credit: Jeff Reutter
An angler casts his line out into Lake Erie near an algal bloom. Credit: Jeff Reutter

Water condition forecasts developed by the US National Oceanic and Atmospheric Administration’s (NOAA) Great Lakes Environmental Research Laboratory (GLERL) and University of Michigan’s Cooperative Institute for Great Lakes Research (CIGLR) could help recreational anglers, charter boat businesses and other folks around Lake Erie prepare in advance for algal blooms.

Since 2014, GLERL and CIGLR have tested an experimental harmful algal bloom (HAB) tracker program on the GLERL website, designed primarily around the needs of drinking water managers. NOAA’s Lake Erie HAB forecasting bulletin, which also launched experimentally in 2014, was bumped up to a full-fledged operational project in June.

Recent research by Devin Gill, stakeholder engagement specialist with CIGLR, says that the tracker tool could be made more helpful for the recreational fishing industry. Gill held focus group sessions and met with charter boat captains and recreational anglers from Wyandotte, Michigan, to Erie, Pennsylvania to gather input.

“Everyone agreed that HABs are gross, stinky, and that they don’t enjoy fishing in them,” Gill said. “That was the primary reason they prefer to not fish in them and to try and find clear water.”

Going into HABs means getting algae slime on a boat and having to go slower in the water. Fish also can accumulate microcystins, a toxin associated with harmful algal blooms.

The HAB tracker uses color coding on maps to indicate where blooms are, how severe they are and where they are likely to move in the coming days. Gill said most anglers responded positively to the tool, but the information was somewhat abstract for her focus groups, and additional information is needed to help anglers interpret what the color coding means. One idea being considered is adding a photo reference guide to show what each color means on the ground, though nothing has been decided yet. She also found that more work was needed to get the word out about the tracker: of 41 participants, only 11 had heard of the tracker, and only four had tried to use it.

Using the HAB tracker program, a forecast image from Aug. 18, 2016, was taken that shows a harmful algal bloom on western Lake Erie with arrows indicating the expected surface water movement in coming days, which would influence where the bloom moves and spreads. Credit: National Oceanic and Atmospheric Administration
Using the HAB tracker program, a forecast image from Aug. 18, 2016, was taken that shows a harmful algal bloom on western Lake Erie with arrows indicating the expected surface water movement in coming days, which would influence where the bloom moves and spreads. Credit: National Oceanic and Atmospheric Administration

Gill said researchers are exploring additional information to include, like a photo library of the blooms at varying concentrations, to help anglers and boaters interpret conditions and whether they want to go on the water. Beyond that, more outreach is necessary to build trust with managers and researchers. She said several participants weren’t aware of efforts to try and deal with the causes of the blooms, and getting a better idea of the wants and needs of users can make for a stronger forecast program. Since the recreational fishing industry is worth US$2 billion a year in Ohio alone, it’s important to local economies that the forecast be helpful to anglers.

“I think the HAB tracker has the potential to show people that even though there’s a bloom occurring on Lake Erie, there are pockets of clear water,” Gill said. “The bloom isn’t everywhere – it’s not blanketing the lake unless it’s a bad season.”

Gill added that while CIGLR is working to develop a formal way for the public to give feedback and thoughts on the HAB tracker, in the meantime they can contact her at

As of June 2, NOAA has noted that since May was a wet month in the region, the amount of phosphorus washing into western Lake Erie from the Maumee River has exceeded the amounts seen in mild bloom years. There is uncertainty regarding the final amount of phosphorus that will end up in Lake Erie, which in turn feeds the algal blooms in the late summer. NOAA releases regular bulletins updating HAB conditions and forecasts on the lake.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Sea Lamprey: The Greatest Invasive Control Success Story

By Kevin Bunch, IJC

sea lamprey
Sea lampreys are among the oldest invaders of the Great Lakes. Credit: C. Krueger, GLFC

An invader in a massive freshwater basin. An uncountable number of spawning grounds. A fishery on the brink. A desperate search for a solution that ended up becoming the most successful aquatic invasive species control team effort in American and Canadian history. It’s not a movie, but rather the true tale of the sea lamprey’s invasion of the Great Lakes.

The sea lamprey is parasitic fish native to the Atlantic Ocean. As an adult, it latches onto other fish with its suction cup-like mouth, using a rasping tongue to cut into its victim to suck out bodily fluids and blood. In the Atlantic it doesn’t typically kill its hosts, but the fish in the Great Lakes have no such luck. It’s estimated that a single lamprey can destroy an average of 18 kilograms (39 pounds) of fish in its parasitic lifetime, with only about one in seven fish surviving a lamprey attack. It’s not to be confused with native lamprey, which are smaller and have different coloration, and don’t usually kill the host fish.

Sea lampreys were first detected in Lake Ontario in 1835. While there has been discussion on whether it is native to Lake Ontario, it most likely is an invasive species that entered through the Erie Canal, according to Marc Gaden, communications director for the Great Lakes Fishery Commission (GLFC), a binational organization funded by the Canadian and US governments. The 1919 reconstruction of the Welland Canal, which bypasses Niagara Falls to connect Lake Ontario to Lake Erie, likely allowed the sea lamprey to enter Lake Erie and on to the rest of the basin. They were discovered in Lake Erie in 1921, Lake Michigan in 1936, Lake Huron in 1937 and Lake Superior in 1939. The sea lamprey found an immense number of tributaries featuring the combination of rocky nesting grounds to lay eggs and silt for larval lampreys to grow in, making the Great Lakes a lamprey Eden. In its native habitat, the sea lamprey spends most of its life in saltwater, making it the rare species that has adapted to living entirely in freshwater systems like the Great Lakes, similar to the Pacific salmon species introduced to control invasive alewives.

lake trout lamprey
A Lake Trout caught in Lake Huron with a sea lamprey attached. Credit: Marc Gaden, GLFC

The impact on the Great Lakes fishery was devastating. Prior to the invasion, about 20 million pounds or about 9 million kilograms of fish were harvested commercially each year in the upper Great Lakes – Superior, Huron and Michigan. By the 1960s that amount was reduced to about 300,000 pounds (136,077 kg) per year, while sea lamprey were killing close to 100 million pounds (45.4 million kg) of fish each year, and 85 percent of the remaining fish were scarred with lamprey attack wounds.

“Commercial fishermen and fishery managers first realized they had a problem around 1940, when it became clear what was happening to the Huron-Michigan fisheries from lamprey,” Gaden said. “That’s when the managers and scientists went into high gear and started seeking control measures.”

With little experience with aquatic invasive species, a wide variety of control methods were attempted. These methods included physical barriers to keep lamprey from entering the streams they use to spawn, crude electrical barriers to block their advances and sieves to stop larvae from eventually entering the Great Lakes from those inland streams. Entrepreneurs tried to make sea lamprey a commercially fished species for human consumption, but none of these attempts worked in stopping the sea lamprey.

The breakthrough came after years of searching for a chemical compound that would kill sea lamprey and not harm other organisms. A compound called TFM was discovered and field-tested in 1957, and entered management usage in 1958 through the binational GLFC. It has been used to great success.

The lampricide targets larval sea lampreys living in streams. After hatching from eggs found upstream in rocky areas, larvae make their way to silty areas and burrow into the substrate until they emerge as adults. The lampricide kills them in that weak, larval state by disrupting their metabolism before they can ever grow up to become the top predator in the Great Lakes. After decades of use, Gaden said the sea lamprey population in the Great Lakes has been reduced by about 90-95 percent from their peak in the late 1950s, and dropped the amount of fish killed by the lamprey to about 10 million pounds (4.5 million kg) a year. While it also affects native lamprey species, sea lamprey larvae tend to live and spawn in different areas from the native species; fishery managers focus on those stream areas where sea lamprey larvae burrow to minimize the impact on native species.

Dead sea lamprey larvae washed up on the shore of the Manistee River after a successful lampricide treatment. Credit: R. McDaniels, GLFC

Lampricide isn’t the only tool used to control lamprey numbers, Gaden said, as good pest control takes multiple tacks. Physical barriers are still in use to deny lampreys a path to their preferred spawning grounds. And if those lampreys can’t reach a place to spawn, there’s no need use lampricide treatments, which is expensive and time-consuming. The GLFC also deploys traps to catch lamprey entering or leaving the streams to remove them from the system, and has tested sterilizing male lamprey in the St. Marys River to try and overwhelm the number of fertile males. Most recently, Gaden said the GLFC “is on the cusp” of using isolated lamprey pheromones to affect their behavior – drawing lamprey away from ideal spawning locations and toward traps.

“We’re working on unlocking their genome,” Gaden said. “There are things within the lamprey genome we can exploit, like create conditions so they only produce males, but that’s further into the future.”

Mark Burrows, physical scientist and project manager in the IJC’s Great Lakes Regional Office, said the GFLC has sponsored important research devoted to controlling and eradicating sea lampreys while protecting native species, much of which was highlighted at the recent International Association for Great Lakes Research conference in Detroit.

“They deserve a lot of praise for the progress they have made in combatting this destructive invasive species, and I look forward to the GLFC forging another 10-fold decrease in lamprey numbers at some point in the future,” Burrows said.

While a focused and targeted approach to invasive species can work in smaller inland lakes, the size of the Great Lakes makes controlling aquatic invaders difficult. That they invaded a waterway that also serves as a border between Canada and the United States added an additional wrinkle. It meant both countries needed to work together, even though fishery management is primarily the domain of state, province, tribal and First Nation governments. This team effort has kept sea lamprey from completely dominating the ecosystem of the Great Lakes for decades.

lamprey traps
Sea lamprey traps are being tested in the field, set up in the Ocqueoc River in Michigan. Credit: T. Lawrence, GLFC

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.


Hacking Away at Lake Erie Problems

By Paul Riser, TechTown Detroit

Not all hacking is bad. One of several Great Lakes regional efforts to find solutions to Lake Erie’s biggest problems took home two top awards at an Erie Hack Innovation Summit.

Erie Hack, “Innovate Around the Lake,” was a data and engineering competition uniting coders, developers, engineers, and water experts from Ontario and five US cities to generate enduring solutions to Lake Erie challenges, including harmful algal blooms.

Erie Hack included teams ranging from high-school students to seasoned professionals. The teams were charged with creating innovative digital tools, hardware innovations, and engineering solutions that build “the Blue Economy”: the emergent economic sector dedicated to the sustainable stewardship of bodies of freshwater around the globe.

In Michigan, Erie Hack Detroit began in the fall of 2016 by hosting a session of experts led by the US National Aeronautics and Space Administration (NASA) and a web-based public portal that allowed the community to prioritize focus issue areas concerning the health of the Lake Erie basin. ­

From November through February, TechTown Detroit (and stakeholders in Buffalo, New York; Cleveland, Ohio; Erie, Pennsylvania; Toledo, Ohio; and Windsor, Ontario) engaged communities of software experts, hardware developers, designers, and entrepreneurs in their respective geographies. TechTown Detroit worked closely with Wayne State leadership who led efforts to leverage the energy of students, researchers, other Michigan academic institutions, and concerned citizens.

erie hack map
A map of teams in participating cities. Credit: Erie Hack

In the first week of March, the target groups initiated the Detroit Water Innovation Hackathon, hosted by the Detroit partnership and coordinated by the Cleveland Water Alliance. After local quarter-final rounds were held in each city, the Detroit-based partnership hosted another event as the winners of regional 2017 Water Innovation Hackathons came to Detroit in April to compete in an Erie Hack 2017 Semi-Final.  A panel of experts selected eight teams to advance to Cleveland for a May 2-3 Erie Hack Innovation Summit.

Four winning teams took home $100,000 in cash and prizes for their concepts.

The $40,000 cash grand-prize winner was Micro Buoy, a team from Wayne State University in Detroit. Its creation is a nano-sensor, contained in a buoy, that can detect environmental contaminants and help find pathogens in water. In addition, the team will receive more than $10,000 in support services to help commercialize its sensor.

Other winners were:

  • Second place: ExtremeComms Lab at the University of Buffalo, for an underwater wifi network to help detect toxic algae blooms and tsunamis.
  • Third place: Water Warriors at the University of Akron, for water testing kits that use light-filtering spectrometers to detect phosphorus and nitrogen in a lake.
  • Fourth place: Purily at the University of Michigan, which developed a system for people to track water usage in their homes and win prizes, such as restaurant coupons, for meeting conservation goals.
erie hack first fourth teams
Members of the first- and fourth-place teams. Credit: TechTown Detroit

The four top teams presented innovative solutions to Challenge Statements derived from the Cleveland Water Alliance (a network of corporations, academic institutions, and public agencies in Northeast Ohio) and partners in each of the six participating cities. Over the course of multiple months and ultimately at the May 2-3 Erie Hack finals, teams worked to solve problems such as nutrient loading and its environmental impacts, reducing urban pollution and managing aging water infrastructure systems.

In the future, Erie Hack Detroit hopes to play a critical role in a regional strategy to transform the quality of Lake Erie while building the base of a stable, water-centered economy for its inhabitants.

For more information on Erie Hack, see

Paul Riser is managing director of technology-based entrepreneurship at the nonprofit TechTown Detroit, Detroit’s longest-standing business accelerator and incubator.

Invasive Mussels Turning Central Lakes into a Food Desert

By Kevin Bunch, IJC

invasive mussels nutrients
Invasive mussels have caused nutrients such as phosphorus in the Great Lakes to clump closer to the shorelines. Coupled with mussels’ tendency to clarify water, this has led to an expansion of the algae Cladophora. Credit: USGS

Invasive zebra and quagga mussels are taking nutrients that would otherwise be in deeper waters and shunting them closer to the shore, which could make it more difficult to halt harmful algal blooms.

Known as the “nearshore nutrient shunt,” this migration of phosphorus and other nutrients used as food by plankton has led to some severe negative impacts in the existing Great Lakes food web. Algae, particularly Cladophora which grows on the hard surfaces near the mussels and feeds on the nutrients the mussels excrete, are thriving in those nearshore regions where nutrients are stockpiling.

The shift in nutrient locations also has benefitted other species that prefer nearshore and benthic – or lake floor – environments, according to Dr. Harvey Bootsma, associate professor in the School of Freshwater Sciences at the University of Wisconsin-Milwaukee.

Historically, a greater chunk of phosphorus entering the lakes has found its way offshore, where it serves as food to phytoplankton. Those in turn are eaten by zooplankton, and fish can feed on both types of plankton, as well as other aquatic species that eat them. Some phosphorus ends up finding its way into the benthic level, periodically getting kicked back up dissolved into the water, where it can continue to serve as fertilizer for phytoplankton.

With invasive mussels, more phosphorus is staying in the nearshore environment, cycling through and never making it into deeper waters. Nearshore currents also tend to keep dissolved phosphorus in the water column, where Cladophora gets the first crack at this food supply. Coupled with the mussels’ voracious appetites clarifying the water column, this can lead to greater harmful algal growth, resulting in the blooms seen on Lake Erie and in bays throughout the Great Lakes. The mussels also are capable of scavenging offshore plankton as it drifts into the nearshore zone, ultimately retaining the nutrients from the plankton in the mussels’ nearshore home.

zebra quagga mussels
The zebra mussel, left, and quagga mussel, right, are a pair of invasive species originally from Europe that have dramatically altered the Great Lakes food web. Credit: NOAA

The impact this has had on the food web is significant. Some species of fish that historically have lived offshore or in the water column are willing to enter nearshore or benthic regions for food. Round goby, an invasive fish that feeds on the mussels and other invertebrates, has a ready food source in the nearshore region. This has led to some native predatory fish, like the brown trout, steelhead trout and Atlantic salmon, venturing into the nearshore areas to feed on the gobies. Other species, such as Chinook salmon and coho salmon, don’t feed on round gobies and aren’t making that move into the nearshore. Instead, their food supply is declining as the offshore plankton production is limited by the mussels, and their populations are suffering.

The expanded Cladophora mats could be causing other problems too. Bootsma said studies have shown Cladophora can harbor higher concentrations of bacteria as it decomposes on beaches. In northern Lake Michigan there have been an increasing number of birds killed by avian botulism. Bootsma said there is evidence suggesting the Cladophora could be promoting growth of the bacteria that cause botulism. When round gobies end up eating the toxic bacteria and in turn get eaten by birds, the birds get sick and die.

This nutrient shunt has led researchers to conclude that more stringent controls on the amount of phosphorus and other nutrients making it into the Great Lakes are needed to improve water quality. While mussels are the primary culprit behind the resurgence of Cladophora, on Lake Erie it’s believed this is why harmful algal blooms and other water quality issues associated with excessive nutrients rebounded in the 1990s, despite existing regulations of phosphorus and other nutrients, and have continued to plague the lake in the decades since.

The United States and Canada have agreed to reduce phosphorus entering Lake Erie by 40 percent of 2008 runoff amounts, though neither government has unveiled its plan yet. Bootsma said based on historical data and numerical models, that reduction amount should be enough to reduce the problems of toxic algae and deep-water hypoxia – the formation of oxygen-deprived zones in the water – to acceptable levels. The IJC recommended similar reduction amounts in a 2014 report released as part of the Lake Erie Ecosystem Priority.

While reduced phosphorus loading may help to address phytoplankton blooms in Lake Erie, Bootsma said there’s still uncertainty as to how nearshore Cladophora growth will respond to a reduction in phosphorus entering the water. Lake Michigan, with its lower phosphorus concentration compared to Lake Erie, still has problems with the nearshore algae. This is leading scientists to question whether localized phosphorus reductions will impede Cladophora growth or if phosphorus concentrations in the entire lake need to come down first. Lower phosphorus concentrations in the offshore areas could further reduce the amount of plankton in those areas, hurting the food web in those areas even more than the mussels already have.

“What we need now is models, based on solid research, that tell us how both the offshore and the nearshore zones will respond to changes in phosphorus loading,” Bootsma said.

Great Lakes Water Levels Expected to Stay Above Long-Term Average

(See also: “Extreme Conditions and Challenges During High Water Levels on Lake Ontario and the St. Lawrence River“)

By Kevin Bunch, IJC

chicago coastline lake michigan
Extremely high water levels can cause erosion and increase flood risks in coastal areas, such as along the Chicago coastline off Lake Michigan. Levels are not expected to be high enough to significantly increase those risks in the coming months, however. Credit: L.S. Gerstner

Water levels on the Great Lakes are likely to remain above the long-term average through the spring and summer, according to forecasts assembled by the US National Oceanic and Atmospheric Administration, Fisheries and Oceans Canada, Environment and Climate Change Canada and the US Army Corps of Engineers. But none of the Great Lakes are expected to reach record high water levels set mostly in the 1980s or 1950s.

While each lake is unique, they all tend to follow a similar cycle based on seasonal changes. Water levels typically reach their seasonal low during the winter months before increasing in the spring due to snowmelt and precipitation. Water levels tend to peak during the summer months, before beginning to drop in the fall and early winter.

There are three main factors that impact lake water levels, said Drew Gronewold, physical scientist with NOAA’s Great Lakes Environmental Research Laboratory: the precipitation over the lakes, evaporation of water on the lakes into vapor, and the runoff that comes into the lakes.

These variables, in turn, are affected by changes in air and water temperatures. For example, Gronewold said the timing of big runoff pulses is dependent on the amount of snow building up in the winter months and when it melts in the spring.

A water level decline in the fall is generally driven by evaporation, as air temperatures drop while surface water temperatures are still relatively warm. While water temperatures were relatively warm during the fall and winter months of 2016-2017 – leading to a lack of ice cover – evaporation amounts have been typical for this time of year due to a relatively mild winter air temperatures, Gronewold said.

These recent conditions, coupled with historical data, lead agencies to expect the water level rise to remain fairly typical this spring and into the summer. As water levels are already above their long-term average for this time of year, researchers expect that they’ll remain above average in the coming months, Gronewold explained.

There is still plenty of uncertainty, he added, as the amount of snow on the ground is less than it has been in some recent winters. It’s also difficult to predict continental-wide meteorological and climate patterns that impact Great Lakes weather patterns and temperatures. These can range from an El Niño effect like the one seen in the winter of 2015-2016 or a “polar vortex” that hit the region in the winters of 2013-2014 and 2014-2015. This uncertainty is expressed as a range of possible water levels in the forecasts released by the US Army Corps and Fisheries and Oceans Canada.

Great Lakes water levels also can be influenced by human management. Hydropower plants and a gated dam on the St. Marys River are used to manage outflows from Lake Superior into Lake Michigan-Huron, while a hydropower plant on the St. Lawrence River is used to manage outflows from Lake Ontario. Outflows through these structures are managed binationally by boards and according to orders and criteria established by the IJC. Nonetheless, the control of water flows through these lakes is limited, and weather conditions and water supplies remain the most significant factor affecting water levels.

Water levels are measured based on the International Great Lakes Datum, defined as the height above sea level at Rimouski Quebec on the St. Lawrence River. Agencies have been measuring lake levels since the 1860s, with more reliable levels going back as far as 1918. They base the lakes’ long-term average water levels on that information.

“We expect a range of water level conditions depending on water supplies,” said Jacob Bruxer, senior water resources engineer with Environment and Climate Change Canada. “There’s a lot of variability and uncertainty in weather and water supply forecasts, particularly when looking beyond a few weeks’ time, so we don’t try to forecast any specific trends and instead consider a full range of water supply scenarios that could be expected.”

According to recent forecasts, through September 2017 Lake Superior is likely to remain at or above seasonal averages, with a small chance of falling below its long-term average in July. There is less uncertainty for the spring months; water levels were about 5.5 inches (0.14 meters) above the long-term average by the end of March, and by May that range could be between 2.7 inches to 10 inches above the average (0.07 meters to 0.27 meters). By September, water levels could be as high as 1 foot (0.3 meters) above the long-term monthly average for Superior.

low water levels grand traverse bay
Low water levels can limit boat access to the water – as seen with these docks off Grand Traverse Bay in Michigan – and cause shipping problems in the Great Lakes. Credit: Michigan Sea Grant

Lake Michigan-Huron, considered as one lake hydrologically, was about 9.4 inches (0.24 meters) above the March long-term average by the end of the month. By September, Michigan-Huron is expected to remain above the long-term average, in a range of 1-16 inches (0.02-0.4 meters). Gronewold said Michigan-Huron saw water levels fall slightly more during the fall months of 2016 than is typical, but that is unlikely to make a discernible difference during this spring and summer.

Higher-than-average water levels are anticipated on Lake Erie, which has seen water levels on the rise in recent months, reaching more than 17 inches (0.44 meters) above the long-term average by the end of March. Water levels are expected to continue to remain above average this spring, before starting to fall around June to a range of 3.9-16 inches above average (0.10-0.41 meters).

Lake Ontario has a slight chance of being just barely below its long-term average going into summer, but will more likely be above it by up to 15 inches (0.38 meters). The forecasted peak is in May, when water levels could be 3.9-21 inches above average (0.10-0.55 meters). Water levels are then expected to fall at about the same degree as they usually do, according to the long-term average.

The US Army Corps publishes 12-month forecasts for Lakes Erie, Huron-Michigan and Superior, as well as Lake St. Clair, based on current conditions and similar historical weather data. Uncertainty grows substantially more than six months out, but most outcomes for Lakes Erie and Michigan-Huron suggest a greater likelihood of continued higher-than-average water levels through the year. Lake Superior also has a better chance of higher-than-average water levels, but faces a substantial possibility of being below that long-term average, too.

(See also: “Extreme Conditions and Challenges During High Water Levels on Lake Ontario and the St. Lawrence River“)

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Finding Inspiration on ‘Big Water’

By IJC staff

Great Lakes Watermarks are about inspiration. The two latest examples come from Katherine O’Reilly and John Kennedy.

O’Reilly, a graduate student at Notre Dame, talks about growing up near Lake Erie, “pea green water” and how she was moved to study coastal wetlands and their role in improving water quality.

Kennedy, of Green Bay, Wisconsin, says his interest in “big water” started as a child, on Lake Michigan. He’s spent decades working to solve water quality problems in Green Bay.

The IJC’s Great Lakes Watermark Project includes these and other watermarks in partnership with Lake Ontario Waterkeeper. We’ve been gathering and sharing stories about the freshwater seas since last year.

See a special Watermark Project website for more, including how to submit your own.