Skip to main content

The big picture of Great Lakes mercury pollution

Jan 24, 2018 06:43AM ● Published by Editor

Fishing on Keweenaw Bay is an all-seasons endeavor and is an important source for food the local indigenous community. However, because of the landscape's sensitivity, mercury levels remain higher than the tribe considers safe in key species like lake trout and whitefish. Credit: Sarah Bird/Michigan Tech

From Michigan Technological University - January 23, 2018

Mercury is a widespread environmental toxicant and pollutant that travels up the food chain onto people's dinner plates. Although a global issue, mercury regulations vary worldwide. Depending on where one lives in relation to mercury emissions, regional remediation makes minimal impacts for local fish consumption advisories. This is particularly true in a sensitive landscape like Michigan's Upper Peninsula, where nearly 80 percent of inland lakes are impaired.

For the Keweenaw Bay Indian Community (KBIC), the problem culminates in the question, when can we eat the fish? A simple answer is elusive, but a study led by Michigan Technological University did provide insights as to what must be done to make the fish safe to eat.

The KBIC's question helped guide biogeochemical modelers, environmental engineers and social scientists to bridge global-chemical transport models and the local impacts on the KBIC and Michigan's Upper Peninsula. The study will be published next week in the Royal Society of Chemistry's peer-reviewed journal Environmental Science: Processes & Impacts, and the work is part of a National Science Foundation program looking at the dynamics of coupled natural and human systems.

Sensitive Communities

Mercury is an atmosphere-surface exchangeable pollutant (ASEP) along with polychlorinated biphenyl (PCB) compounds, polycyclic aromatic hydrocarbon (PAH) compounds and other  (POPs). ASEP molecules are invisible, tasteless world-hoppers that can travel great distances.

Eventually, they make their way to the Great Lakes where they move through the air, landscape, water and animals. Researchers can describe ASEP movement and impacts through policy, socioeconomic pressures, ecosystem services, stressors like climate change and land use as well as biogeochemical cycling. The study's lead researcher is Judith Perlinger, professor of environmental engineering at Michigan Tech. She says the project is an example of using state-of-the-art science to answer a community-relevant question.

The big picture of Great Lakes mercury pollution
The Keweenaw Bay Indian Community's Natural Resources Department runs a fishery where they raise whitefish fry. The staff tag the fins and release the young fish into the bay. Credit: Sarah Bird/Michigan Tech

"We're taking phenomena that act on a global scale and predicting what they will do," Perlinger says, adding that working with the KBIC is a key piece of the project. "Clearly the issue matters to them, so how can we make the science relevant to them?"

To do so, take a big team: Six institutions, 36 researchers and 11 partnering organizations. Perlinger's team uses GEOS-Chem, a global three-dimensional Eulerian chemical transport model. It has been widely used to better understand tropospheric chemistry and composition. For ASEPs, GEOS-Chem sorts through the emission sources, migration, exchange rates and resting places of the pollutants and is coupled with mass balance modeling to understand the aquatic dynamics of the system.

Sensitive Landscapes

In the Environmental Science: Processes & Impacts paper, Perlinger and her team focus on mercury and three different policy scenarios through 2050.

In the first, they analyzed aspirational targets where all mercury emissions from anthropogenic sources are eliminated; in the second, they examined a moderate reduction based on policy-in-action; and in the third, they assessed a minimal-regulation scenario with no policy action.

They found little would change within the lifetimes of the KBIC community. Noel Urban, professor of  and a project researcher who focuses on the biogeochemistry of the pollutants, says the process would likely take generations to reach levels that the community considers safe.

The big picture of Great Lakes mercury pollution
The winter waters of Lake Superior make geometric art around the Keweenaw Bay where local Ojibwe families have fished for generations. Credit: Sarah Bird/Michigan Tech

"People assume that what is deposited in a forest is also deposited the same in a lake, which isn't true, so models have been miscalculating," Urban says, adding that the feedback between land and aquatic systems also takes longer than researchers previously thought. "This is apparent in the Great Lakes, and the Upper Peninsula is a particularly sensitive landscape to mercury."

In terms of tracking mercury, Urban takes fish mercury concentration data from lakes and estimates mercury in fish from similar water bodies along with the Great Lakes Indian Fish and Wildlife Commission (GLIFWC)—one of the project's research partner organizations. They found that mercury persists differently depending on the size of the .

"Which poison do you want?" Urban asks. "Go to the big lakes and get PCBs, go to the small lakes and get mercury."

Simply put, there is no simple answer to the KBIC's question.

To further clarify the answer, Urban, Perlinger and their team plan to continue sampling in local Upper Peninsula lakes, assessing the regional impacts in the Great Lakes and vetting their findings through global models. Their transdisciplinary work deepens the understanding of  cycling and the accuracy of modeling, evaluates multi-scale policy, and offers insight into the best practices for engaging local indigenous communities in global research.

Environmental Science: Processes & Impacts publishes high quality papers in all areas of the environmental chemical sciences, including chemistry of the air, water, soil and sediment. We welcome studies on the environmental fate and effects of anthropogenic and naturally occurring contaminants, both chemical and microbiological, as well as related natural element cycling processes.


Read more at: https://phys.org/news/2018-01-big-picture-great-lakes-mercury.html#jCp
News
  • The 100DayProject

    02/22/2018
    12:00AM — 12:00AM

    January 21 - April 30, 2018 The 100DayProject is an effort to motivate participants to commit ...


  • Terra Bella Floral hours

    02/22/2018
    12:00AM

    Monday and Tuesday Noon to 5 Wednesday through Friday 10 to 4 Saturday 10 to 2 Sunday Closed


  • Join us at Harbor House Grille, featuring Chef prepared handcrafted meals. Today's specials inclu...


  • MOVE IT!

    02/22/2018
    12:00AM

    MOVE IT is about moving towards good health in lots of ways, including being physically active. ...


  • Free tax help for low to moderate income folks in Cook County! Bring your tax information with ...


  • Lunch at the Senior Center

    02/22/2018
    12:00PM — 12:30PM

    Open Face Roast Beef/Mash Potato/Beets/Fruit/Milk


  • Snowmobilers! Ride Lutsen Trails With Us

    02/22/2018
    06:00PM — 10:00PM

    Join us to ride the trails with us. We meet at the snowmobile parking lot at 466 Caribou Trail [...


  • Alcoholics Anonymous

    02/22/2018
    06:30PM

    Alcoholics Anonymous is a fellowship of men and women who share their experience, strength and ho...


  • Film Night at North House

    02/22/2018
    07:00PM — 09:00PM

    Winter Series returns every Thursday in February at North House with film nights. We’ll revisit f...


  • Terra Bella Floral hours

    02/23/2018
    12:00AM

    Monday and Tuesday Noon to 5 Wednesday through Friday 10 to 4 Saturday 10 to 2 Sunday Closed


  • The 100DayProject

    02/23/2018
    12:00AM — 12:00AM

    January 21 - April 30, 2018 The 100DayProject is an effort to motivate participants to commit ...


  • Come join us at Harbor House Grille, featuring chef prepared, handcrafted food. Today's specials ...


  • MOVE IT!

    02/23/2018
    12:00AM

    MOVE IT is about moving towards good health in lots of ways, including being physically active. ...


  • Lunch at the Senior Center

    02/23/2018
    12:00PM — 12:30PM

    Chicken Chowmein/Rice/Mixed Vegetable/Dessert/Milk


  • Taste of Winter Potluck and Seed Discussion

    02/23/2018
    05:30PM — 07:30PM

    There will be a ‘Taste of Winter’ Potluck and seed discussion on Friday, February 23 at 5:30 p.m....


  • Friday Night Reels

    02/23/2018
    06:00PM — 08:00PM

    Friday nights from January 5 to March 9, the library is transformed into a Free-Admission movie t...


  • Annual Beer Lover's Dinner

    02/23/2018
    06:30PM — 09:30PM

    We are now taking reservations for our annual Beer Lover’s Dinner, which will take place on Frida...


Lake Superior Ice Coverage Map. Click on map to enlarge. [GLERL Ice Concentration for Lake Superior]

Weather Alerts Provided by Willy Weather