The Merrimack Dragonfly Mercury Project

Take two things people generally don't like: bugs and chemistry, and mix in something they can't see: air pollution, and you have a recipe for some pretty boring science, right? Wrong. The Dragonfly Mercury Project has been responsible for over 5,000 exclamations of "Wow!" in over 180 parks, local greenspaces, and other protected lands from Alaska to Hawaii to Florida to Maine. And now the project is digging deep in the Merrimack River Watershed in New Hampshire and Massachusetts.

The Merrimack River starts in the White Mountains of New Hampshire. Small streams and mountain ponds in the headwaters combine into the Pemigewasset River and Lake Winnipesaukee. From there it travels over 115 miles south, into Massachusetts, gathering water from other tributary streams and rivers as it makes its way to the Atlantic Ocean in Newburyport, MA. The  Merrimack River Watershed  is the fourth largest watershed in New England; it covers 5,010 square miles and includes ~200 communities, including Lowell and Lawrence, Massachusetts.

Partners at the  Tsongas Industrial History Center  created a remote learning module that includes information about the history of the Merrimack Valley, environmental contaminants, laws that address pollution, and other activities. Read more about the industrial history of the Merrimack Valley and access this educational resource  here. 

In marginalized communities such as those classified as “ environmental justice ” communities by US EPA, the potential risks of legacy and ongoing pollution lead to disproportionate risk for vulnerable populations. Lowell and Lawrence, MA, are two such communities. The US Census counts more than two dozen languages spoken by residents of Lowell; the local high school estimates that twice that number are spoken by families at home. An immigrant city, Lawrence is a textbook environmental justice community; the majority of residents (82%) are people of color, with over 40% foreign born. English is a second language in 76% of Lawrence households. Median per-capita income in Lowell and Lawrence is lower than and economic poverty is higher than regional and national averages.

In the Lowell and Lawrence Today interactive map, below, we show three different ways of defining aspects of EJ communities. The  NE EJ Focus Areas  combine demographics and areas with limited land protection. The  Nature Gap Hot Spots  combine demographics and areas of nature deprivation. Lastly, the  MA 2020 Environmental Justice Blockgroups  are only based on demographics. By clicking on a map feature below a pop-up window will appear containing information on that feature.

The map below shows proximity of communities including Lowell and Lawrence to US EPA Superfund sites. For more information and to explore the map, check out the  EPA EJScreen Mapping Tool . In addition to industrial sources, continued burning of fossil fuels across the country and the world has contributed to “ atmospheric deposition " of mercury and other substances. These particles are carried in the air and fall to the ground in rain, snow, and dust where they collect in watersheds, flowing into rivers, streams, lakes, ponds, and wetlands.

Mercury is a toxic pollutant that bio-accumulates (builds up) in animals, including dragonflies and fish – and people. Mercury exposure can cause effects on the immune and endocrine systems, reproduction, and the central nervous system. Decades of atmospheric pollution in the northeastern US, combined with the legacy of point-source pollution in industrialized watersheds in the region, has led to widespread fish consumption advisories due to elevated mercury in fish. The Merrimack is no exception.

 OARS , the watershed organization for the Sudbury, Assabet, and Concord Rivers, published a river  report card  that shows moderate to very poor condition in these tributaries of the Merrimack for fish edibility, due to mercury. Urban rivers are often important food sources for lower income urban populations; thus urban anglers are at higher risk of exposure to contaminants via fish consumption. Effects of mercury act as threat multipliers and put urban, under-resourced populations at risk for other health and environmental impacts, including exposure to other toxins.

Data from fish sampling by the  Commonwealth of Massachusetts  have documented concentrations of mercury in biota in this watershed that are high or severe enough to warrant fish consumption advisories for humans and of concern for wildlife.

Community scientists around the country are working with national parks and other land managers to collect dragonfly larvae, juvenile dragonflies that live in the water before they molt and fly away. Dragonfly larvae are effective indicators of the risk of mercury contamination in rivers, streams, lakes, ponds, and wetlands. ¹  Fish eat dragonfly larvae and people eat fish, which is how mercury can go from water pollution into the food chain.

With partners at Dartmouth College and coordination with the Dragonfly Mercury Project (DMP), a  national-scale mercury biosentinel program , AMC engaged youth and community members through schools and partners. They actively participated in sampling of mercury biosentinels (dragonfly larvae) in 2021.

 ¹   _{Eagles-Smith, C.A., J.J. Willacker, S.J. Nelson, C.M. Flanagan Pritz, D.P. Krabbenhoft, C.Y.   Chen, J.T. Ackerman, E.H. Campbell Grant, D.S. Pilliod, 2020. A national-scale assessment of mercury bioaccumulation in us national parks using dragonfly larvae as biosentinels through a citizen science framework.   Environmental Science and Technology; 54, 14, 8779–8790.}   

In our first year of sampling around the Merrimack in Lowell and Lawrence, 107 public participants – mostly youth – collected 120 dragonfly larvae for mercury analysis. Three of the five sites sampled indicated potential for moderate impairment of foodwebs, and one site indicated potential high impairment. This means the concentrations of mercury we found could be of concern for fish, birds, other wildlife, and humans that consume fish in these waterbodies.

In addition, sampling of tributaries of the Merrimack, the Concord, Sudbury, and Assabet Rivers, by the DMP team in coordination with OARS and national park staff, indicated similar impairment indices. We have included data for these sites in our overview map, but readers should consult the official  US Geological Survey Data Dashboard  for site-specific information.

The hands-on, minds-on engagement reveals biodiversity in local greenspaces and immerses youth in the scientific process of data collection and analysis. The DMP shows how community or  citizen scientists  contribute to our knowledge of ecosystems, and learn more about greenspaces and protected places. Working with primarily youth, our goal is to empower them to be messengers to their families and communities, sharing what they’ve learned about relative mercury risk around their cities and watersheds, and spreading awareness of issues with mercury fish consumption in their communities.

• Learn which fish to avoid and which are safer to eat. Massachusetts provides fish safety guides in multiple languages  here .
• Want to learn more about mercury in fish? Check out this  video  by Merrimack-DMP scientist Dr. Celia Chen.
• Take steps to keep mercury out of the environment!
  • Avoid buying products that contain mercury.
  •  Most products now have a mercury-free alternative . Some common household products that can be replaced with mercury-free options are fluorescent light bulbs, thermometers, thermostats for household heating systems, and dental fillings.
• If you have the products above or others such as those on this  list  from US EPA
  • “Please recycle mercury-containing products rather than disposing of them in regular household trash. Recycling mercury-containing products is one of the best ways to help prevent mercury releases to the environment by keeping these products out of landfills and incinerators. Once landfilled, mercury from the products may end up in groundwater, and potentially in sources of drinking water. Once incinerated, mercury may end up in the air.”
•  Lowell  and  Lawrence  each have household hazardous waste collection days – check with your city and dispose of mercury-containing products responsibly!

One of the big things we can do globally to reduce mercury pollution is to reduce energy use that comes from burning coal. Countries around the world, including the US, have signed on to the  Minamata Treaty  to reduce global mercury pollution. The DMP has added dragonfly sampling to the list of ways countries can monitor for changing mercury as part of this global treaty.

Protect your family and future generations! Make your voice heard and tell your circle about mercury pollution. Speak up about air and water pollution in your city, state, and country.

• Abbott and Dorothy H. Stevens Foundation
• The Dorr Foundation
• Theodore Edson Parker Foundation
• Dartmouth College matching funds
• US Environmental Protection Agency - Healthy Communities Grant Program
• AMC Worcester Chapter
• Cell Signaling Technology, Inc.
• National Forest Foundation
• Edward S. and Winifred G. Moseley Foundation
• Horne Family Foundation
• Merrimack Conservation Partnership (Society for the Protection of New Hampshire Forests)

 ^{The information in this document has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement (HC-00A01090-0) to the Appalachian Mountain Club. It has been subjected to the Agency's publications review process and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute recommendation or endorsement of use.}