Fish Consumption Advisories Mean Watching What You Eat

By Kevin Bunch, IJC

Cisco – a pan fish – is a nutritious forage fish found in Lakes Superior and Huron that is generally considered safe to eat once a week. Credit: US Fish and Wildlife Service

The Great Lakes have long been a source of nutritious food for people who live along its shores, with an abundance of aquatic life like walleye, yellow perch, catfish, and bass. This is still the case, though pollutants in the waterways mean anglers need to pay attention to what they eat and how often.

Harmful substances like mercury, dioxins and polychlorinated biphenyls (PCBs) have been entering the lakes for decades, where they make their way into the food web. New and emerging chemicals such as pharmaceuticals and the flame-retardant polybrominated diphenyl ethers (PBDEs) also may be entering the food web. These can accumulate in fish and work their way up from preyfish to predators, posing a risk to human health. The province of Ontario and the eight Great Lakes states – Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio, Pennsylvania and New York – issue fish consumption advisories to help residents know how much of any given species is safe to eat in a given timeframe. Eating more contaminated fish doesn’t mean health problems will develop in a person, just that it’s more likely.

Developing these advisory guidelines takes work in the field and the lab. Fish are collected by state or provincial agencies and tested for chemicals of concern in the meat, fat and other tissues, according to Jennifer Gray, a toxicologist with the Michigan Department of Health and Human Services. The fish are prepared as if they were being eaten, such as if a particular species typically has the skin removed or the fat cut off.

Based on what substances are left, governments issue consumption guidelines. These can be different depending on where the fish was caught, as different locations have different amounts of contaminants. Since fish move throughout the water system without regard to political boundaries, however, an advisory in one area doesn’t mean fish from elsewhere, with different guidelines, aren’t also there.

“It really depends on where you are and the inputs (of pollutants) and what industries may have impacted the rivers, and all rivers flow to the Great Lakes,” said Michelle Bruneau, project manager and health educator with the Michigan Department of Health and Human Services.

Each state and province has its own methodology for consumption guidelines, she added, and while there are efforts underway to harmonize these practices Bruneau doesn’t believe all entities will adopt identical standards. Raw data is shared between governments, however – Ontario shares contaminant data collected by its scientists in the Great Lakes with the US states, who all share experiences on best ways of communicating advisories, said Satyendra Bhavsar, a research scientist with the Ontario Ministry of Environment and Climate Change’s (OMECC) fish contaminant monitoring program.

“We try to capitalize on advancements from both sides of the border,” Bhavsar said.

IJC’s Health Professionals Advisory Board noted in a 2014 report that risks and benefits should be considered when deciding to consume Great Lakes fish. Fish supply healthy unsaturated fats and high-quality protein, but may contain contaminants at high enough levels to impact human health. Common alternative foods to fish may provide health promoting nutritional value, but also saturated fats or sugars and contaminants of their own. These chemicals aren’t a reason to avoid the health benefits of eating fish from the Great Lakes, as long as consumers are aware of and use the guidelines available to help them choose and eat fish that are lower in contaminants.

Some chemicals like mercury, Gray said, collect more heavily in the meat of the fish, leaving few options to reduce the amount an angler would be eating. Dioxins and PCBs tend to collect more in the fat of a fish and can be reduced by cleaning away the fat, removing flesh around the belly area, and cooking the meat over a rack or grill so the remaining fat can drip away. The US National Cancer Institute warns not to let the flesh char while grilling, as that can cause compounds linked to cancer to form. And since contaminants tend to collect at the bottom of a waterway, Bruneau said people should check the consumption guidelines before eating bottom-feeding fish like catfish or drum.

Smaller walleye, although not a pan fish, still contain far fewer contaminants than larger ones, as they are younger and have had less time to accumulate substances like dioxins. Credit: Wisconsin Department of Natural Resources

One of the most helpful choices an angler can make is to choose smaller fish of a species. Bhavsar said a smaller fish is likely going to have significantly fewer contaminants than a larger one of the same species, as it’ll probably be younger and thus have less of an opportunity for these contaminants to accumulate in its tissues. Fish eggs can contain higher concentrations because of their higher fat content, he added, and should be avoided. Additionally, the province of Ontario recommends leaner fish from the Great Lakes, such as pike or walleye, and choosing panfish – fish that don’t grow larger than a standard frying pan.

In some places, guidelines are different for “sensitive populations,” such as children, pregnant women or women who could become pregnant, Bhavsar said. Excessive contaminants can impact a child’s development, or get passed along in the womb from a pregnant woman. In other areas, such as Michigan, guidelines take these populations into account when recommending serving sizes.

Having guidelines is one thing, but making sure people are aware of them is another. Thanks to Great Lakes Restoration Initiative funds, US states have been working to inform communities, recreational and subsistence anglers and vulnerable populations about the recommended limits on fish consumption. Bruneau said that this has included contacting community organizations that can spread the word, including working with tribal governments, Women, Infants and Children departments and sportsmen clubs to assist in their own areas.

In Ontario, Bhavsar said the ministry works with local health agencies – such as Toronto Public Health – and other stakeholders, and with First Nations communities to get the word out about the consumption advisories. Fact sheets are available in 17 languages, including English, French, Cree and Ojibwe, and written copies of the advisories are available for free through Service Ontario.

Another tricky area is fish purchased in a store, a farmers market or served in a restaurant. It’s often difficult to pinpoint where a particular fish was caught on the Great Lakes, and since each part of the lakes is unique in its degree and makeup of contaminants, it’s also difficult to say what specific guidelines would apply. In the US, the Food and Drug Administration is responsible for food labeling, and doesn’t have regulations in place for adding safety recommendations to labels, though it did release general advisories for children and pregnant women. Bruneau suggested following basic consumption guidelines is the best way to go in these cases. Bhavsar said local health agencies take the lead on purchased fish, like Toronto’s, but generally the province recommends people cut back one meal of wild-caught Ontario fish for every two meals of store-bought fish.

The concentrations of some of these chemicals are shrinking, but others remain problems. Bruneau said PCBs and dioxins have been regulated for years and are slowly dropping in concentrations throughout much of the Great Lakes, particularly thanks to work cleaning up Areas of Concern. Mercury – which is transported through the air into the water system via sources such as coal-fired power plants – and newly emerging chemicals such as PBDEs will most likely drive guidelines into the future, however. The costs for chemical testing can quickly add up when all the potential contaminants, locations and fish species are being accounted for, becoming prohibitively expensive.

Fish consumption guidelines for provinces and states in the region are linked below:

fatty fish
As a fatty fish, lake trout should be cleaned with as much of the fat removed as possible before eating to remove dioxins and PCBs. Credit: US Fish and Wildlife Service

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

The IJC at International Association of Great Lakes Research Conference

By IJC staff

lake guardian
The Lake Guardian research vessel was anchored on the Detroit River during the International Association of Great Lakes Research conference, which took place in downtown Detroit from May 15-19. Credit: IJC

More than 1,000 scientists, educators, policymakers, academics, engineers and others descended upon Detroit, Michigan, from May 15-19 for the 60th annual International Association of Great Lakes Research (IAGLR) conference to discuss their latest findings and discoveries.

Attendees gave 20-minute presentations ranging from discussions on Lake Erie algal blooms and invasive species to updates on habitat restoration efforts and new technologies for management and research. IJC staff members were among those who participated.

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IJC Physical Scientist Matthew Child. Credit: IJC

Dr. Glenn Benoy, senior water quality and ecosystem adviser, spoke on the implications of Red-Assiniboine River basin nutrient models – created using a US Geological Survey modeling program – on Lake Winnipeg in Alberta. Physical Scientist Matthew Child presented an evaluation of the status of cleanup efforts in binational Areas of Concern.

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Michigan Sea Grant Fellow Allison Voglesong. Credit: IJC

Allison Voglesong, who has spent the last year at the IJC as a Michigan Sea Grant Fellow, gave a presentation on how to effectively connect with and identify audiences for science communications on social media.

Two keynote speakers presented before wide audiences in plenary sessions. Dr. Joan Rose, a member of the IJC’s Health Professionals Advisory Board and chair of Michigan State University’s water research program, talked about the science of water quality and how it relates to public health through contaminants, bacteria and viruses. Cameron Davis, vice president of GEI Consultants and former US Environmental Protection Agency (EPA) adviser on the Great Lakes, talked about the “ecosystem” connections to the economy, politics, institutions and technology that all play a part in the health of the Great Lakes.

“We need to be a strong voice here for what we do with water,” Rose said in her remarks. “The water quality compact (between Canada and the United States) is among the strongest in the world – other places deal with water quantity but not quality, and we have a tremendous problem with waterborne diseases in the rest of the world.”

Tad Slawecki, a senior engineer with Limnotech, demonstrates the concept of an ecological “point of no return” using a ball and a two-section bowl during a talk on Great Lakes early warning systems. Credit: IJC

IJC staff members from its Windsor, Ottawa and Washington offices attended sessions throughout the week, and will provide highlights in coming issues of Great Lakes Connection.

The meeting took place at Cobo Hall next to the Detroit River, so attendees also had the chance to tour the EPA’s Lake Guardian, one of the largest research vessels dedicated to the Great Lakes. The ship travels across all five lakes for eight months each year, collecting water and plankton samples, and helping scientists with their research. The crew focuses on a different lake each year for the bulk of the ship’s time in the water, and Lake Huron is in the spotlight this year. (See also: “Lake Guardian Research Vessel Completes Summer Survey”)

IAGLR’s 61st annual conference will be held in Toronto, Ontario, in 2018.

tank invasives
A tank of invasive sea lampreys found at one of the booths in a common area, where companies, government agencies and academic programs set up shop for attendees. Credit: IJC

Watermarks: Swimming Surprise, Fishing Legacy

Jeff Kart, IJC

In our travels to assess progress under the Great Lakes Water Quality Agreement, we’ve met many interesting people. They have stories to tell about personal connections to the lakes … and its rivers, too.

Patty Troy starts out this month’s series of Watermarks. Troy tells of growing up along the St. Clair River, and memories of jumping off a pipe into the water. She didn’t find out until later that it was an outfall for combined sewer overflows.

The IJC is collecting video (and written) Watermarks as part of a project with Lake Ontario Waterkeeper.

In other Watermarks this month, Bob Dunn offers thoughts on Lake Huron and paints a grim picture of deteriorating conditions.

More upbeat is Candace Day Neveau, whose family has fished Lake Superior for generations. She looks forward to the day her son Maquinna takes over the family business.

You can find these and other Watermarks in our Great Lakes Connection archive, and submit yours here.


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


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.

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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.
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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.