Bottom dwellers—aquatic insects, the tiny spineless organisms in silt on the bottoms of streams – have a lot to tell us. These indicator species, known by researchers as benthic macro invertebrates, pick up all the bad stuff in the water. Their presence, absence, and what they’ve absorbed can tell everything about the general health of a stream.
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| A young citizen scientist identifies aquatic insects. Photo: Lori Fox Rossi |
Now, residents of Thunder Bay will be collecting some of that information themselves, so they can join in helping protect local streams and tributaries that flow into Lake Superior, and the lake itself. Citizens will learn how to take field samples and use microscopes to identify benthic macro invertebrates. The project is part of a Ministry of Natural Resources biomonitoring program in which researchers with Eco Superior gather baseline data about the benthic macro invertebrates in select Superior tributaries between Thunder Bay and Sault Ste. Marie.
Next, researchers will compare data from “healthy” aquatic ecosystems with information from water bodies believed to be impaired. The streams that have the best rehabilitation potential will then become demonstration sites. As improvements are made, biologists will study the trends and changes in the biological health of the water by once again examining the bottom dwellers—the local aquatic invertebrate communities.
Click here to view a map of the project area
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About Benthic Macro Invertebrates:
• Benthic macro invertebrates (“benthos”) are aquatic insects – aquatic worms and the immature forms of aquatic insects, such as stonefly and mayfly nymphs.
• Benthos are indicator species, like the canaries coal miners once used to detect dangerous gases.
• Almost immobile, benthos can’t escape the effects of sediments and other pollutants. Thus, they respond to changes in stream ecosystems faster than aquatic creatures. In fact, the presence or absence of certain species of benthic macro invertebrates in stream sediments indicates the presence or absence of certain pollutants.
• Benthos are, in effect, tiny recorders of recent and past pollution and the providers of reliable information about the health of a water body.
Project Partners:
- City of Thunder Bay
- Deacon's BioConsulting
- Department of Fisheries and Oceans Canada
- Eco Superior Environmental Programs
- Lake Superior Binational Forum
- North Shore Steelhead Association
- Ontario Benthos Biomonitoring Network
- Thunder Bay Field Naturalists
For more information, contact:
- Marilee Chase, COA Lake Superior Basin Coordinator, Upper Great Lakes Management Unit, Ministry of Natural Resources, Thunder Bay (807) 475-1371